| Current File : //usr/local/src/libavif-0.11.1/src/read.c |
// Copyright 2019 Joe Drago. All rights reserved.
// SPDX-License-Identifier: BSD-2-Clause
#include "avif/internal.h"
#include <assert.h>
#include <inttypes.h>
#include <limits.h>
#include <string.h>
#define AUXTYPE_SIZE 64
#define CONTENTTYPE_SIZE 64
// class VisualSampleEntry(codingname) extends SampleEntry(codingname) {
// unsigned int(16) pre_defined = 0;
// const unsigned int(16) reserved = 0;
// unsigned int(32)[3] pre_defined = 0;
// unsigned int(16) width;
// unsigned int(16) height;
// template unsigned int(32) horizresolution = 0x00480000; // 72 dpi
// template unsigned int(32) vertresolution = 0x00480000; // 72 dpi
// const unsigned int(32) reserved = 0;
// template unsigned int(16) frame_count = 1;
// string[32] compressorname;
// template unsigned int(16) depth = 0x0018;
// int(16) pre_defined = -1;
// // other boxes from derived specifications
// CleanApertureBox clap; // optional
// PixelAspectRatioBox pasp; // optional
// }
static const size_t VISUALSAMPLEENTRY_SIZE = 78;
static const char xmpContentType[] = AVIF_CONTENT_TYPE_XMP;
static const size_t xmpContentTypeSize = sizeof(xmpContentType);
// The only supported ipma box values for both version and flags are [0,1], so there technically
// can't be more than 4 unique tuples right now.
#define MAX_IPMA_VERSION_AND_FLAGS_SEEN 4
#define MAX_AV1_LAYER_COUNT 4
// ---------------------------------------------------------------------------
// Box data structures
// ftyp
typedef struct avifFileType
{
uint8_t majorBrand[4];
uint32_t minorVersion;
// If not null, points to a memory block of 4 * compatibleBrandsCount bytes.
const uint8_t * compatibleBrands;
int compatibleBrandsCount;
} avifFileType;
// ispe
typedef struct avifImageSpatialExtents
{
uint32_t width;
uint32_t height;
} avifImageSpatialExtents;
// auxC
typedef struct avifAuxiliaryType
{
char auxType[AUXTYPE_SIZE];
} avifAuxiliaryType;
// infe mime content_type
typedef struct avifContentType
{
char contentType[CONTENTTYPE_SIZE];
} avifContentType;
// colr
typedef struct avifColourInformationBox
{
avifBool hasICC;
uint64_t iccOffset;
size_t iccSize;
avifBool hasNCLX;
avifColorPrimaries colorPrimaries;
avifTransferCharacteristics transferCharacteristics;
avifMatrixCoefficients matrixCoefficients;
avifRange range;
} avifColourInformationBox;
#define MAX_PIXI_PLANE_DEPTHS 4
typedef struct avifPixelInformationProperty
{
uint8_t planeDepths[MAX_PIXI_PLANE_DEPTHS];
uint8_t planeCount;
} avifPixelInformationProperty;
typedef struct avifOperatingPointSelectorProperty
{
uint8_t opIndex;
} avifOperatingPointSelectorProperty;
typedef struct avifLayerSelectorProperty
{
uint16_t layerID;
} avifLayerSelectorProperty;
typedef struct avifAV1LayeredImageIndexingProperty
{
uint32_t layerSize[3];
} avifAV1LayeredImageIndexingProperty;
// ---------------------------------------------------------------------------
// Top-level structures
struct avifMeta;
// Temporary storage for ipco/stsd contents until they can be associated and memcpy'd to an avifDecoderItem
typedef struct avifProperty
{
uint8_t type[4];
union
{
avifImageSpatialExtents ispe;
avifAuxiliaryType auxC;
avifColourInformationBox colr;
avifCodecConfigurationBox av1C;
avifPixelAspectRatioBox pasp;
avifCleanApertureBox clap;
avifImageRotation irot;
avifImageMirror imir;
avifPixelInformationProperty pixi;
avifOperatingPointSelectorProperty a1op;
avifLayerSelectorProperty lsel;
avifAV1LayeredImageIndexingProperty a1lx;
} u;
} avifProperty;
AVIF_ARRAY_DECLARE(avifPropertyArray, avifProperty, prop);
static const avifProperty * avifPropertyArrayFind(const avifPropertyArray * properties, const char * type)
{
for (uint32_t propertyIndex = 0; propertyIndex < properties->count; ++propertyIndex) {
avifProperty * prop = &properties->prop[propertyIndex];
if (!memcmp(prop->type, type, 4)) {
return prop;
}
}
return NULL;
}
AVIF_ARRAY_DECLARE(avifExtentArray, avifExtent, extent);
// one "item" worth for decoding (all iref, iloc, iprp, etc refer to one of these)
typedef struct avifDecoderItem
{
uint32_t id;
struct avifMeta * meta; // Unowned; A back-pointer for convenience
uint8_t type[4];
size_t size;
avifBool idatStored; // If true, offset is relative to the associated meta box's idat box (iloc construction_method==1)
uint32_t width; // Set from this item's ispe property, if present
uint32_t height; // Set from this item's ispe property, if present
avifContentType contentType;
avifPropertyArray properties;
avifExtentArray extents; // All extent offsets/sizes
avifRWData mergedExtents; // if set, is a single contiguous block of this item's extents (unused when extents.count == 1)
avifBool ownsMergedExtents; // if true, mergedExtents must be freed when this item is destroyed
avifBool partialMergedExtents; // If true, mergedExtents doesn't have all of the item data yet
uint32_t thumbnailForID; // if non-zero, this item is a thumbnail for Item #{thumbnailForID}
uint32_t auxForID; // if non-zero, this item is an auxC plane for Item #{auxForID}
uint32_t descForID; // if non-zero, this item is a content description for Item #{descForID}
uint32_t dimgForID; // if non-zero, this item is a derived image for Item #{dimgForID}
uint32_t premByID; // if non-zero, this item is premultiplied by Item #{premByID}
avifBool hasUnsupportedEssentialProperty; // If true, this item cites a property flagged as 'essential' that libavif doesn't support (yet). Ignore the item, if so.
avifBool ipmaSeen; // if true, this item already received a property association
avifBool progressive; // if true, this item has progressive layers (a1lx), but does not select a specific layer (the layer_id value in lsel is set to 0xFFFF)
} avifDecoderItem;
AVIF_ARRAY_DECLARE(avifDecoderItemArray, avifDecoderItem, item);
// grid storage
typedef struct avifImageGrid
{
uint32_t rows; // Legal range: [1-256]
uint32_t columns; // Legal range: [1-256]
uint32_t outputWidth;
uint32_t outputHeight;
} avifImageGrid;
// ---------------------------------------------------------------------------
// avifTrack
typedef struct avifSampleTableChunk
{
uint64_t offset;
} avifSampleTableChunk;
AVIF_ARRAY_DECLARE(avifSampleTableChunkArray, avifSampleTableChunk, chunk);
typedef struct avifSampleTableSampleToChunk
{
uint32_t firstChunk;
uint32_t samplesPerChunk;
uint32_t sampleDescriptionIndex;
} avifSampleTableSampleToChunk;
AVIF_ARRAY_DECLARE(avifSampleTableSampleToChunkArray, avifSampleTableSampleToChunk, sampleToChunk);
typedef struct avifSampleTableSampleSize
{
uint32_t size;
} avifSampleTableSampleSize;
AVIF_ARRAY_DECLARE(avifSampleTableSampleSizeArray, avifSampleTableSampleSize, sampleSize);
typedef struct avifSampleTableTimeToSample
{
uint32_t sampleCount;
uint32_t sampleDelta;
} avifSampleTableTimeToSample;
AVIF_ARRAY_DECLARE(avifSampleTableTimeToSampleArray, avifSampleTableTimeToSample, timeToSample);
typedef struct avifSyncSample
{
uint32_t sampleNumber;
} avifSyncSample;
AVIF_ARRAY_DECLARE(avifSyncSampleArray, avifSyncSample, syncSample);
typedef struct avifSampleDescription
{
uint8_t format[4];
avifPropertyArray properties;
} avifSampleDescription;
AVIF_ARRAY_DECLARE(avifSampleDescriptionArray, avifSampleDescription, description);
typedef struct avifSampleTable
{
avifSampleTableChunkArray chunks;
avifSampleDescriptionArray sampleDescriptions;
avifSampleTableSampleToChunkArray sampleToChunks;
avifSampleTableSampleSizeArray sampleSizes;
avifSampleTableTimeToSampleArray timeToSamples;
avifSyncSampleArray syncSamples;
uint32_t allSamplesSize; // If this is non-zero, sampleSizes will be empty and all samples will be this size
} avifSampleTable;
static void avifSampleTableDestroy(avifSampleTable * sampleTable);
static avifSampleTable * avifSampleTableCreate()
{
avifSampleTable * sampleTable = (avifSampleTable *)avifAlloc(sizeof(avifSampleTable));
memset(sampleTable, 0, sizeof(avifSampleTable));
if (!avifArrayCreate(&sampleTable->chunks, sizeof(avifSampleTableChunk), 16)) {
goto error;
}
if (!avifArrayCreate(&sampleTable->sampleDescriptions, sizeof(avifSampleDescription), 2)) {
goto error;
}
if (!avifArrayCreate(&sampleTable->sampleToChunks, sizeof(avifSampleTableSampleToChunk), 16)) {
goto error;
}
if (!avifArrayCreate(&sampleTable->sampleSizes, sizeof(avifSampleTableSampleSize), 16)) {
goto error;
}
if (!avifArrayCreate(&sampleTable->timeToSamples, sizeof(avifSampleTableTimeToSample), 16)) {
goto error;
}
if (!avifArrayCreate(&sampleTable->syncSamples, sizeof(avifSyncSample), 16)) {
goto error;
}
return sampleTable;
error:
avifSampleTableDestroy(sampleTable);
return NULL;
}
static void avifSampleTableDestroy(avifSampleTable * sampleTable)
{
avifArrayDestroy(&sampleTable->chunks);
for (uint32_t i = 0; i < sampleTable->sampleDescriptions.count; ++i) {
avifSampleDescription * description = &sampleTable->sampleDescriptions.description[i];
avifArrayDestroy(&description->properties);
}
avifArrayDestroy(&sampleTable->sampleDescriptions);
avifArrayDestroy(&sampleTable->sampleToChunks);
avifArrayDestroy(&sampleTable->sampleSizes);
avifArrayDestroy(&sampleTable->timeToSamples);
avifArrayDestroy(&sampleTable->syncSamples);
avifFree(sampleTable);
}
static uint32_t avifSampleTableGetImageDelta(const avifSampleTable * sampleTable, int imageIndex)
{
int maxSampleIndex = 0;
for (uint32_t i = 0; i < sampleTable->timeToSamples.count; ++i) {
const avifSampleTableTimeToSample * timeToSample = &sampleTable->timeToSamples.timeToSample[i];
maxSampleIndex += timeToSample->sampleCount;
if ((imageIndex < maxSampleIndex) || (i == (sampleTable->timeToSamples.count - 1))) {
return timeToSample->sampleDelta;
}
}
// TODO: fail here?
return 1;
}
static avifBool avifSampleTableHasFormat(const avifSampleTable * sampleTable, const char * format)
{
for (uint32_t i = 0; i < sampleTable->sampleDescriptions.count; ++i) {
if (!memcmp(sampleTable->sampleDescriptions.description[i].format, format, 4)) {
return AVIF_TRUE;
}
}
return AVIF_FALSE;
}
static uint32_t avifCodecConfigurationBoxGetDepth(const avifCodecConfigurationBox * av1C)
{
if (av1C->twelveBit) {
return 12;
} else if (av1C->highBitdepth) {
return 10;
}
return 8;
}
// This is used as a hint to validating the clap box in avifDecoderItemValidateAV1.
static avifPixelFormat avifCodecConfigurationBoxGetFormat(const avifCodecConfigurationBox * av1C)
{
if (av1C->monochrome) {
return AVIF_PIXEL_FORMAT_YUV400;
} else if (av1C->chromaSubsamplingY == 1) {
return AVIF_PIXEL_FORMAT_YUV420;
} else if (av1C->chromaSubsamplingX == 1) {
return AVIF_PIXEL_FORMAT_YUV422;
}
return AVIF_PIXEL_FORMAT_YUV444;
}
static const avifPropertyArray * avifSampleTableGetProperties(const avifSampleTable * sampleTable)
{
for (uint32_t i = 0; i < sampleTable->sampleDescriptions.count; ++i) {
const avifSampleDescription * description = &sampleTable->sampleDescriptions.description[i];
if (!memcmp(description->format, "av01", 4)) {
return &description->properties;
}
}
return NULL;
}
// one video track ("trak" contents)
typedef struct avifTrack
{
uint32_t id;
uint32_t auxForID; // if non-zero, this track is an auxC plane for Track #{auxForID}
uint32_t premByID; // if non-zero, this track is premultiplied by Track #{premByID}
uint32_t mediaTimescale;
uint64_t mediaDuration;
uint32_t width;
uint32_t height;
avifSampleTable * sampleTable;
struct avifMeta * meta;
} avifTrack;
AVIF_ARRAY_DECLARE(avifTrackArray, avifTrack, track);
// ---------------------------------------------------------------------------
// avifCodecDecodeInput
avifCodecDecodeInput * avifCodecDecodeInputCreate(void)
{
avifCodecDecodeInput * decodeInput = (avifCodecDecodeInput *)avifAlloc(sizeof(avifCodecDecodeInput));
memset(decodeInput, 0, sizeof(avifCodecDecodeInput));
if (!avifArrayCreate(&decodeInput->samples, sizeof(avifDecodeSample), 1)) {
goto error;
}
return decodeInput;
error:
avifFree(decodeInput);
return NULL;
}
void avifCodecDecodeInputDestroy(avifCodecDecodeInput * decodeInput)
{
for (uint32_t sampleIndex = 0; sampleIndex < decodeInput->samples.count; ++sampleIndex) {
avifDecodeSample * sample = &decodeInput->samples.sample[sampleIndex];
if (sample->ownsData) {
avifRWDataFree((avifRWData *)&sample->data);
}
}
avifArrayDestroy(&decodeInput->samples);
avifFree(decodeInput);
}
// Returns how many samples are in the chunk.
static uint32_t avifGetSampleCountOfChunk(const avifSampleTableSampleToChunkArray * sampleToChunks, uint32_t chunkIndex)
{
uint32_t sampleCount = 0;
for (int sampleToChunkIndex = sampleToChunks->count - 1; sampleToChunkIndex >= 0; --sampleToChunkIndex) {
const avifSampleTableSampleToChunk * sampleToChunk = &sampleToChunks->sampleToChunk[sampleToChunkIndex];
if (sampleToChunk->firstChunk <= (chunkIndex + 1)) {
sampleCount = sampleToChunk->samplesPerChunk;
break;
}
}
return sampleCount;
}
static avifBool avifCodecDecodeInputFillFromSampleTable(avifCodecDecodeInput * decodeInput,
avifSampleTable * sampleTable,
const uint32_t imageCountLimit,
const uint64_t sizeHint,
avifDiagnostics * diag)
{
if (imageCountLimit) {
// Verify that the we're not about to exceed the frame count limit.
uint32_t imageCountLeft = imageCountLimit;
for (uint32_t chunkIndex = 0; chunkIndex < sampleTable->chunks.count; ++chunkIndex) {
// First, figure out how many samples are in this chunk
uint32_t sampleCount = avifGetSampleCountOfChunk(&sampleTable->sampleToChunks, chunkIndex);
if (sampleCount == 0) {
// chunks with 0 samples are invalid
avifDiagnosticsPrintf(diag, "Sample table contains a chunk with 0 samples");
return AVIF_FALSE;
}
if (sampleCount > imageCountLeft) {
// This file exceeds the imageCountLimit, bail out
avifDiagnosticsPrintf(diag, "Exceeded avifDecoder's imageCountLimit");
return AVIF_FALSE;
}
imageCountLeft -= sampleCount;
}
}
uint32_t sampleSizeIndex = 0;
for (uint32_t chunkIndex = 0; chunkIndex < sampleTable->chunks.count; ++chunkIndex) {
avifSampleTableChunk * chunk = &sampleTable->chunks.chunk[chunkIndex];
// First, figure out how many samples are in this chunk
uint32_t sampleCount = avifGetSampleCountOfChunk(&sampleTable->sampleToChunks, chunkIndex);
if (sampleCount == 0) {
// chunks with 0 samples are invalid
avifDiagnosticsPrintf(diag, "Sample table contains a chunk with 0 samples");
return AVIF_FALSE;
}
uint64_t sampleOffset = chunk->offset;
for (uint32_t sampleIndex = 0; sampleIndex < sampleCount; ++sampleIndex) {
uint32_t sampleSize = sampleTable->allSamplesSize;
if (sampleSize == 0) {
if (sampleSizeIndex >= sampleTable->sampleSizes.count) {
// We've run out of samples to sum
avifDiagnosticsPrintf(diag, "Truncated sample table");
return AVIF_FALSE;
}
avifSampleTableSampleSize * sampleSizePtr = &sampleTable->sampleSizes.sampleSize[sampleSizeIndex];
sampleSize = sampleSizePtr->size;
}
avifDecodeSample * sample = (avifDecodeSample *)avifArrayPushPtr(&decodeInput->samples);
sample->offset = sampleOffset;
sample->size = sampleSize;
sample->spatialID = AVIF_SPATIAL_ID_UNSET; // Not filtering by spatial_id
sample->sync = AVIF_FALSE; // to potentially be set to true following the outer loop
if (sampleSize > UINT64_MAX - sampleOffset) {
avifDiagnosticsPrintf(diag,
"Sample table contains an offset/size pair which overflows: [%" PRIu64 " / %u]",
sampleOffset,
sampleSize);
return AVIF_FALSE;
}
if (sizeHint && ((sampleOffset + sampleSize) > sizeHint)) {
avifDiagnosticsPrintf(diag, "Exceeded avifIO's sizeHint, possibly truncated data");
return AVIF_FALSE;
}
sampleOffset += sampleSize;
++sampleSizeIndex;
}
}
// Mark appropriate samples as sync
for (uint32_t syncSampleIndex = 0; syncSampleIndex < sampleTable->syncSamples.count; ++syncSampleIndex) {
uint32_t frameIndex = sampleTable->syncSamples.syncSample[syncSampleIndex].sampleNumber - 1; // sampleNumber is 1-based
if (frameIndex < decodeInput->samples.count) {
decodeInput->samples.sample[frameIndex].sync = AVIF_TRUE;
}
}
// Assume frame 0 is sync, just in case the stss box is absent in the BMFF. (Unnecessary?)
if (decodeInput->samples.count > 0) {
decodeInput->samples.sample[0].sync = AVIF_TRUE;
}
return AVIF_TRUE;
}
static avifBool avifCodecDecodeInputFillFromDecoderItem(avifCodecDecodeInput * decodeInput,
avifDecoderItem * item,
avifBool allowProgressive,
const uint32_t imageCountLimit,
const uint64_t sizeHint,
avifDiagnostics * diag)
{
if (sizeHint && (item->size > sizeHint)) {
avifDiagnosticsPrintf(diag, "Exceeded avifIO's sizeHint, possibly truncated data");
return AVIF_FALSE;
}
uint8_t layerCount = 0;
size_t layerSizes[4] = { 0 };
const avifProperty * a1lxProp = avifPropertyArrayFind(&item->properties, "a1lx");
if (a1lxProp) {
// Calculate layer count and all layer sizes from the a1lx box, and then validate
size_t remainingSize = item->size;
for (int i = 0; i < 3; ++i) {
++layerCount;
const size_t layerSize = (size_t)a1lxProp->u.a1lx.layerSize[i];
if (layerSize) {
if (layerSize >= remainingSize) { // >= instead of > because there must be room for the last layer
avifDiagnosticsPrintf(diag, "a1lx layer index [%d] does not fit in item size", i);
return AVIF_FALSE;
}
layerSizes[i] = layerSize;
remainingSize -= layerSize;
} else {
layerSizes[i] = remainingSize;
remainingSize = 0;
break;
}
}
if (remainingSize > 0) {
assert(layerCount == 3);
++layerCount;
layerSizes[3] = remainingSize;
}
}
const avifProperty * lselProp = avifPropertyArrayFind(&item->properties, "lsel");
// Progressive images offer layers via the a1lxProp, but don't specify a layer selection with lsel.
//
// For backward compatibility with earlier drafts of AVIF spec v1.1.0, treat an absent lsel as
// equivalent to layer_id == 0xFFFF during the transitional period. Remove !lselProp when the test
// images have been updated to the v1.1.0 spec.
item->progressive = (a1lxProp && (!lselProp || (lselProp->u.lsel.layerID == 0xFFFF)));
if (lselProp && (lselProp->u.lsel.layerID != 0xFFFF)) {
// Layer selection. This requires that the underlying AV1 codec decodes all layers,
// and then only returns the requested layer as a single frame. To the user of libavif,
// this appears to be a single frame.
decodeInput->allLayers = AVIF_TRUE;
size_t sampleSize = 0;
if (layerCount > 0) {
// Optimization: If we're selecting a layer that doesn't require the entire image's payload (hinted via the a1lx box)
if (lselProp->u.lsel.layerID >= layerCount) {
avifDiagnosticsPrintf(diag,
"lsel property requests layer index [%u] which isn't present in a1lx property ([%u] layers)",
lselProp->u.lsel.layerID,
layerCount);
return AVIF_FALSE;
}
for (uint8_t i = 0; i <= lselProp->u.lsel.layerID; ++i) {
sampleSize += layerSizes[i];
}
} else {
// This layer's payload subsection is unknown, just use the whole payload
sampleSize = item->size;
}
avifDecodeSample * sample = (avifDecodeSample *)avifArrayPushPtr(&decodeInput->samples);
sample->itemID = item->id;
sample->offset = 0;
sample->size = sampleSize;
assert(lselProp->u.lsel.layerID < MAX_AV1_LAYER_COUNT);
sample->spatialID = (uint8_t)lselProp->u.lsel.layerID;
sample->sync = AVIF_TRUE;
} else if (allowProgressive && item->progressive) {
// Progressive image. Decode all layers and expose them all to the user.
if (imageCountLimit && (layerCount > imageCountLimit)) {
avifDiagnosticsPrintf(diag, "Exceeded avifDecoder's imageCountLimit (progressive)");
return AVIF_FALSE;
}
decodeInput->allLayers = AVIF_TRUE;
size_t offset = 0;
for (int i = 0; i < layerCount; ++i) {
avifDecodeSample * sample = (avifDecodeSample *)avifArrayPushPtr(&decodeInput->samples);
sample->itemID = item->id;
sample->offset = offset;
sample->size = layerSizes[i];
sample->spatialID = AVIF_SPATIAL_ID_UNSET;
sample->sync = (i == 0); // Assume all layers depend on the first layer
offset += layerSizes[i];
}
} else {
// Typical case: Use the entire item's payload for a single frame output
avifDecodeSample * sample = (avifDecodeSample *)avifArrayPushPtr(&decodeInput->samples);
sample->itemID = item->id;
sample->offset = 0;
sample->size = item->size;
sample->spatialID = AVIF_SPATIAL_ID_UNSET;
sample->sync = AVIF_TRUE;
}
return AVIF_TRUE;
}
// ---------------------------------------------------------------------------
// Helper macros / functions
#define BEGIN_STREAM(VARNAME, PTR, SIZE, DIAG, CONTEXT) \
avifROStream VARNAME; \
avifROData VARNAME##_roData; \
VARNAME##_roData.data = PTR; \
VARNAME##_roData.size = SIZE; \
avifROStreamStart(&VARNAME, &VARNAME##_roData, DIAG, CONTEXT)
// Use this to keep track of whether or not a child box that must be unique (0 or 1 present) has
// been seen yet, when parsing a parent box. If the "seen" bit is already set for a given box when
// it is encountered during parse, an error is thrown. Which bit corresponds to which box is
// dictated entirely by the calling function.
static avifBool uniqueBoxSeen(uint32_t * uniqueBoxFlags, uint32_t whichFlag, const char * parentBoxType, const char * boxType, avifDiagnostics * diagnostics)
{
const uint32_t flag = 1 << whichFlag;
if (*uniqueBoxFlags & flag) {
// This box has already been seen. Error!
avifDiagnosticsPrintf(diagnostics, "Box[%s] contains a duplicate unique box of type '%s'", parentBoxType, boxType);
return AVIF_FALSE;
}
// Mark this box as seen.
*uniqueBoxFlags |= flag;
return AVIF_TRUE;
}
// ---------------------------------------------------------------------------
// avifDecoderData
typedef struct avifTile
{
avifCodecDecodeInput * input;
struct avifCodec * codec;
avifImage * image;
uint32_t width; // Either avifTrack.width or avifDecoderItem.width
uint32_t height; // Either avifTrack.height or avifDecoderItem.height
uint8_t operatingPoint;
} avifTile;
AVIF_ARRAY_DECLARE(avifTileArray, avifTile, tile);
// This holds one "meta" box (from the BMFF and HEIF standards) worth of relevant-to-AVIF information.
// * If a meta box is parsed from the root level of the BMFF, it can contain the information about
// "items" which might be color planes, alpha planes, or EXIF or XMP metadata.
// * If a meta box is parsed from inside of a track ("trak") box, any metadata (EXIF/XMP) items inside
// of that box are implicitly associated with that track.
typedef struct avifMeta
{
// Items (from HEIF) are the generic storage for any data that does not require timed processing
// (single image color planes, alpha planes, EXIF, XMP, etc). Each item has a unique integer ID >1,
// and is defined by a series of child boxes in a meta box:
// * iloc - location: byte offset to item data, item size in bytes
// * iinf - information: type of item (color planes, alpha plane, EXIF, XMP)
// * ipco - properties: dimensions, aspect ratio, image transformations, references to other items
// * ipma - associations: Attaches an item in the properties list to a given item
//
// Items are lazily created in this array when any of the above boxes refer to one by a new (unseen) ID,
// and are then further modified/updated as new information for an item's ID is parsed.
avifDecoderItemArray items;
// Any ipco boxes explained above are populated into this array as a staging area, which are
// then duplicated into the appropriate items upon encountering an item property association
// (ipma) box.
avifPropertyArray properties;
// Filled with the contents of this meta box's "idat" box, which is raw data that an item can
// directly refer to in its item location box (iloc) instead of just giving an offset into the
// overall file. If all items' iloc boxes simply point at an offset/length in the file itself,
// this buffer will likely be empty.
avifRWData idat;
// Ever-incrementing ID for uniquely identifying which 'meta' box contains an idat (when
// multiple meta boxes exist as BMFF siblings). Each time avifParseMetaBox() is called on an
// avifMeta struct, this value is incremented. Any time an additional meta box is detected at
// the same "level" (root level, trak level, etc), this ID helps distinguish which meta box's
// "idat" is which, as items implicitly reference idat boxes that exist in the same meta
// box.
uint32_t idatID;
// Contents of a pitm box, which signal which of the items in this file is the main image. For
// AVIF, this should point at an av01 type item containing color planes, and all other items
// are ignored unless they refer to this item in some way (alpha plane, EXIF/XMP metadata).
uint32_t primaryItemID;
} avifMeta;
static void avifMetaDestroy(avifMeta * meta);
static avifMeta * avifMetaCreate()
{
avifMeta * meta = (avifMeta *)avifAlloc(sizeof(avifMeta));
memset(meta, 0, sizeof(avifMeta));
if (!avifArrayCreate(&meta->items, sizeof(avifDecoderItem), 8)) {
goto error;
}
if (!avifArrayCreate(&meta->properties, sizeof(avifProperty), 16)) {
goto error;
}
return meta;
error:
avifMetaDestroy(meta);
return NULL;
}
static void avifMetaDestroy(avifMeta * meta)
{
for (uint32_t i = 0; i < meta->items.count; ++i) {
avifDecoderItem * item = &meta->items.item[i];
avifArrayDestroy(&item->properties);
avifArrayDestroy(&item->extents);
if (item->ownsMergedExtents) {
avifRWDataFree(&item->mergedExtents);
}
}
avifArrayDestroy(&meta->items);
avifArrayDestroy(&meta->properties);
avifRWDataFree(&meta->idat);
avifFree(meta);
}
static avifDecoderItem * avifMetaFindItem(avifMeta * meta, uint32_t itemID)
{
if (itemID == 0) {
return NULL;
}
for (uint32_t i = 0; i < meta->items.count; ++i) {
if (meta->items.item[i].id == itemID) {
return &meta->items.item[i];
}
}
avifDecoderItem * item = (avifDecoderItem *)avifArrayPushPtr(&meta->items);
if (!avifArrayCreate(&item->properties, sizeof(avifProperty), 16)) {
goto error;
}
if (!avifArrayCreate(&item->extents, sizeof(avifExtent), 1)) {
goto error;
}
item->id = itemID;
item->meta = meta;
return item;
error:
avifArrayDestroy(&item->extents);
avifArrayDestroy(&item->properties);
avifArrayPop(&meta->items);
return NULL;
}
typedef struct avifDecoderData
{
avifMeta * meta; // The root-level meta box
avifTrackArray tracks;
avifTileArray tiles;
unsigned int colorTileCount;
unsigned int alphaTileCount;
unsigned int decodedColorTileCount;
unsigned int decodedAlphaTileCount;
avifImageGrid colorGrid;
avifImageGrid alphaGrid;
avifDecoderSource source;
uint8_t majorBrand[4]; // From the file's ftyp, used by AVIF_DECODER_SOURCE_AUTO
avifDiagnostics * diag; // Shallow copy; owned by avifDecoder
const avifSampleTable * sourceSampleTable; // NULL unless (source == AVIF_DECODER_SOURCE_TRACKS), owned by an avifTrack
avifBool cicpSet; // True if avifDecoder's image has had its CICP set correctly yet.
// This allows nclx colr boxes to override AV1 CICP, as specified in the MIAF
// standard (ISO/IEC 23000-22:2019), section 7.3.6.4:
//
// "The colour information property takes precedence over any colour information in the image
// bitstream, i.e. if the property is present, colour information in the bitstream shall be ignored."
} avifDecoderData;
static void avifDecoderDataDestroy(avifDecoderData * data);
static avifDecoderData * avifDecoderDataCreate()
{
avifDecoderData * data = (avifDecoderData *)avifAlloc(sizeof(avifDecoderData));
memset(data, 0, sizeof(avifDecoderData));
data->meta = avifMetaCreate();
if (!avifArrayCreate(&data->tracks, sizeof(avifTrack), 2)) {
goto error;
}
if (!avifArrayCreate(&data->tiles, sizeof(avifTile), 8)) {
goto error;
}
return data;
error:
avifDecoderDataDestroy(data);
return NULL;
}
static void avifDecoderDataResetCodec(avifDecoderData * data)
{
for (unsigned int i = 0; i < data->tiles.count; ++i) {
avifTile * tile = &data->tiles.tile[i];
if (tile->image) {
avifImageFreePlanes(tile->image, AVIF_PLANES_ALL); // forget any pointers into codec image buffers
}
if (tile->codec) {
avifCodecDestroy(tile->codec);
tile->codec = NULL;
}
}
data->decodedColorTileCount = 0;
data->decodedAlphaTileCount = 0;
}
static avifTile * avifDecoderDataCreateTile(avifDecoderData * data, uint32_t width, uint32_t height, uint8_t operatingPoint)
{
avifTile * tile = (avifTile *)avifArrayPushPtr(&data->tiles);
tile->image = avifImageCreateEmpty();
if (!tile->image) {
goto error;
}
tile->input = avifCodecDecodeInputCreate();
if (!tile->input) {
goto error;
}
tile->width = width;
tile->height = height;
tile->operatingPoint = operatingPoint;
return tile;
error:
if (tile->input) {
avifCodecDecodeInputDestroy(tile->input);
}
if (tile->image) {
avifImageDestroy(tile->image);
}
avifArrayPop(&data->tiles);
return NULL;
}
static avifTrack * avifDecoderDataCreateTrack(avifDecoderData * data)
{
avifTrack * track = (avifTrack *)avifArrayPushPtr(&data->tracks);
track->meta = avifMetaCreate();
return track;
}
static void avifDecoderDataClearTiles(avifDecoderData * data)
{
for (unsigned int i = 0; i < data->tiles.count; ++i) {
avifTile * tile = &data->tiles.tile[i];
if (tile->input) {
avifCodecDecodeInputDestroy(tile->input);
tile->input = NULL;
}
if (tile->codec) {
avifCodecDestroy(tile->codec);
tile->codec = NULL;
}
if (tile->image) {
avifImageDestroy(tile->image);
tile->image = NULL;
}
}
data->tiles.count = 0;
data->colorTileCount = 0;
data->alphaTileCount = 0;
data->decodedColorTileCount = 0;
data->decodedAlphaTileCount = 0;
}
static void avifDecoderDataDestroy(avifDecoderData * data)
{
avifMetaDestroy(data->meta);
for (uint32_t i = 0; i < data->tracks.count; ++i) {
avifTrack * track = &data->tracks.track[i];
if (track->sampleTable) {
avifSampleTableDestroy(track->sampleTable);
}
if (track->meta) {
avifMetaDestroy(track->meta);
}
}
avifArrayDestroy(&data->tracks);
avifDecoderDataClearTiles(data);
avifArrayDestroy(&data->tiles);
avifFree(data);
}
// This returns the max extent that has to be read in order to decode this item. If
// the item is stored in an idat, the data has already been read during Parse() and
// this function will return AVIF_RESULT_OK with a 0-byte extent.
static avifResult avifDecoderItemMaxExtent(const avifDecoderItem * item, const avifDecodeSample * sample, avifExtent * outExtent)
{
if (item->extents.count == 0) {
return AVIF_RESULT_TRUNCATED_DATA;
}
if (item->idatStored) {
// construction_method: idat(1)
if (item->meta->idat.size > 0) {
// Already read from a meta box during Parse()
memset(outExtent, 0, sizeof(avifExtent));
return AVIF_RESULT_OK;
}
// no associated idat box was found in the meta box, bail out
return AVIF_RESULT_NO_CONTENT;
}
// construction_method: file(0)
if (sample->size == 0) {
return AVIF_RESULT_TRUNCATED_DATA;
}
uint64_t remainingOffset = sample->offset;
size_t remainingBytes = sample->size; // This may be smaller than item->size if the item is progressive
// Assert that the for loop below will execute at least one iteration.
assert(item->extents.count != 0);
uint64_t minOffset = UINT64_MAX;
uint64_t maxOffset = 0;
for (uint32_t extentIter = 0; extentIter < item->extents.count; ++extentIter) {
avifExtent * extent = &item->extents.extent[extentIter];
// Make local copies of extent->offset and extent->size as they might need to be adjusted
// due to the sample's offset.
uint64_t startOffset = extent->offset;
size_t extentSize = extent->size;
if (remainingOffset) {
if (remainingOffset >= extentSize) {
remainingOffset -= extentSize;
continue;
} else {
if (remainingOffset > UINT64_MAX - startOffset) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
startOffset += remainingOffset;
extentSize -= remainingOffset;
remainingOffset = 0;
}
}
const size_t usedExtentSize = (extentSize < remainingBytes) ? extentSize : remainingBytes;
if (usedExtentSize > UINT64_MAX - startOffset) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
const uint64_t endOffset = startOffset + usedExtentSize;
if (minOffset > startOffset) {
minOffset = startOffset;
}
if (maxOffset < endOffset) {
maxOffset = endOffset;
}
remainingBytes -= usedExtentSize;
if (remainingBytes == 0) {
// We've got enough bytes for this sample.
break;
}
}
if (remainingBytes != 0) {
return AVIF_RESULT_TRUNCATED_DATA;
}
outExtent->offset = minOffset;
const uint64_t extentLength = maxOffset - minOffset;
if (extentLength > SIZE_MAX) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
outExtent->size = (size_t)extentLength;
return AVIF_RESULT_OK;
}
static uint8_t avifDecoderItemOperatingPoint(const avifDecoderItem * item)
{
const avifProperty * a1opProp = avifPropertyArrayFind(&item->properties, "a1op");
if (a1opProp) {
return a1opProp->u.a1op.opIndex;
}
return 0; // default
}
static avifResult avifDecoderItemValidateAV1(const avifDecoderItem * item, avifDiagnostics * diag, const avifStrictFlags strictFlags)
{
const avifProperty * av1CProp = avifPropertyArrayFind(&item->properties, "av1C");
if (!av1CProp) {
// An av1C box is mandatory in all valid AVIF configurations. Bail out.
avifDiagnosticsPrintf(diag, "Item ID %u of type '%.4s' is missing mandatory av1C property", item->id, (const char *)item->type);
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
const avifProperty * pixiProp = avifPropertyArrayFind(&item->properties, "pixi");
if (!pixiProp && (strictFlags & AVIF_STRICT_PIXI_REQUIRED)) {
// A pixi box is mandatory in all valid AVIF configurations. Bail out.
avifDiagnosticsPrintf(diag,
"[Strict] Item ID %u of type '%.4s' is missing mandatory pixi property",
item->id,
(const char *)item->type);
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
if (pixiProp) {
const uint32_t av1CDepth = avifCodecConfigurationBoxGetDepth(&av1CProp->u.av1C);
for (uint8_t i = 0; i < pixiProp->u.pixi.planeCount; ++i) {
if (pixiProp->u.pixi.planeDepths[i] != av1CDepth) {
// pixi depth must match av1C depth
avifDiagnosticsPrintf(diag,
"Item ID %u depth specified by pixi property [%u] does not match av1C property depth [%u]",
item->id,
pixiProp->u.pixi.planeDepths[i],
av1CDepth);
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
}
}
if (strictFlags & AVIF_STRICT_CLAP_VALID) {
const avifProperty * clapProp = avifPropertyArrayFind(&item->properties, "clap");
if (clapProp) {
const avifProperty * ispeProp = avifPropertyArrayFind(&item->properties, "ispe");
if (!ispeProp) {
avifDiagnosticsPrintf(diag,
"[Strict] Item ID %u is missing an ispe property, so its clap property cannot be validated",
item->id);
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
avifCropRect cropRect;
const uint32_t imageW = ispeProp->u.ispe.width;
const uint32_t imageH = ispeProp->u.ispe.height;
const avifPixelFormat av1CFormat = avifCodecConfigurationBoxGetFormat(&av1CProp->u.av1C);
avifBool validClap = avifCropRectConvertCleanApertureBox(&cropRect, &clapProp->u.clap, imageW, imageH, av1CFormat, diag);
if (!validClap) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
}
}
return AVIF_RESULT_OK;
}
static avifResult avifDecoderItemRead(avifDecoderItem * item,
avifIO * io,
avifROData * outData,
size_t offset,
size_t partialByteCount,
avifDiagnostics * diag)
{
if (item->mergedExtents.data && !item->partialMergedExtents) {
// Multiple extents have already been concatenated for this item, just return it
if (offset >= item->mergedExtents.size) {
avifDiagnosticsPrintf(diag, "Item ID %u read has overflowing offset", item->id);
return AVIF_RESULT_TRUNCATED_DATA;
}
outData->data = item->mergedExtents.data + offset;
outData->size = item->mergedExtents.size - offset;
return AVIF_RESULT_OK;
}
if (item->extents.count == 0) {
avifDiagnosticsPrintf(diag, "Item ID %u has zero extents", item->id);
return AVIF_RESULT_TRUNCATED_DATA;
}
// Find this item's source of all extents' data, based on the construction method
const avifRWData * idatBuffer = NULL;
if (item->idatStored) {
// construction_method: idat(1)
if (item->meta->idat.size > 0) {
idatBuffer = &item->meta->idat;
} else {
// no associated idat box was found in the meta box, bail out
avifDiagnosticsPrintf(diag, "Item ID %u is stored in an idat, but no associated idat box was found", item->id);
return AVIF_RESULT_NO_CONTENT;
}
}
// Merge extents into a single contiguous buffer
if ((io->sizeHint > 0) && (item->size > io->sizeHint)) {
// Sanity check: somehow the sum of extents exceeds the entire file or idat size!
avifDiagnosticsPrintf(diag, "Item ID %u reported size failed size hint sanity check. Truncated data?", item->id);
return AVIF_RESULT_TRUNCATED_DATA;
}
if (offset >= item->size) {
avifDiagnosticsPrintf(diag, "Item ID %u read has overflowing offset", item->id);
return AVIF_RESULT_TRUNCATED_DATA;
}
const size_t maxOutputSize = item->size - offset;
const size_t readOutputSize = (partialByteCount && (partialByteCount < maxOutputSize)) ? partialByteCount : maxOutputSize;
const size_t totalBytesToRead = offset + readOutputSize;
// If there is a single extent for this item and the source of the read buffer is going to be
// persistent for the lifetime of the avifDecoder (whether it comes from its own internal
// idatBuffer or from a known-persistent IO), we can avoid buffer duplication and just use the
// preexisting buffer.
avifBool singlePersistentBuffer = ((item->extents.count == 1) && (idatBuffer || io->persistent));
if (!singlePersistentBuffer) {
// Always allocate the item's full size here, as progressive image decodes will do partial
// reads into this buffer and begin feeding the buffer to the underlying AV1 decoder, but
// will then write more into this buffer without flushing the AV1 decoder (which is still
// holding the address of the previous allocation of this buffer). This strategy avoids
// use-after-free issues in the AV1 decoder and unnecessary reallocs as a typical
// progressive decode use case will eventually decode the final layer anyway.
avifRWDataRealloc(&item->mergedExtents, item->size);
item->ownsMergedExtents = AVIF_TRUE;
}
// Set this until we manage to fill the entire mergedExtents buffer
item->partialMergedExtents = AVIF_TRUE;
uint8_t * front = item->mergedExtents.data;
size_t remainingBytes = totalBytesToRead;
for (uint32_t extentIter = 0; extentIter < item->extents.count; ++extentIter) {
avifExtent * extent = &item->extents.extent[extentIter];
size_t bytesToRead = extent->size;
if (bytesToRead > remainingBytes) {
bytesToRead = remainingBytes;
}
avifROData offsetBuffer;
if (idatBuffer) {
if (extent->offset > idatBuffer->size) {
avifDiagnosticsPrintf(diag, "Item ID %u has impossible extent offset in idat buffer", item->id);
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
// Since extent->offset (a uint64_t) is not bigger than idatBuffer->size (a size_t),
// it is safe to cast extent->offset to size_t.
const size_t extentOffset = (size_t)extent->offset;
if (extent->size > idatBuffer->size - extentOffset) {
avifDiagnosticsPrintf(diag, "Item ID %u has impossible extent size in idat buffer", item->id);
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
offsetBuffer.data = idatBuffer->data + extentOffset;
offsetBuffer.size = idatBuffer->size - extentOffset;
} else {
// construction_method: file(0)
if ((io->sizeHint > 0) && (extent->offset > io->sizeHint)) {
avifDiagnosticsPrintf(diag, "Item ID %u extent offset failed size hint sanity check. Truncated data?", item->id);
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
avifResult readResult = io->read(io, 0, extent->offset, bytesToRead, &offsetBuffer);
if (readResult != AVIF_RESULT_OK) {
return readResult;
}
if (bytesToRead != offsetBuffer.size) {
avifDiagnosticsPrintf(diag,
"Item ID %u tried to read %zu bytes, but only received %zu bytes",
item->id,
bytesToRead,
offsetBuffer.size);
return AVIF_RESULT_TRUNCATED_DATA;
}
}
if (singlePersistentBuffer) {
memcpy(&item->mergedExtents, &offsetBuffer, sizeof(avifRWData));
item->mergedExtents.size = bytesToRead;
} else {
assert(item->ownsMergedExtents);
assert(front);
memcpy(front, offsetBuffer.data, bytesToRead);
front += bytesToRead;
}
remainingBytes -= bytesToRead;
if (remainingBytes == 0) {
// This happens when partialByteCount is set
break;
}
}
if (remainingBytes != 0) {
// This should be impossible?
avifDiagnosticsPrintf(diag, "Item ID %u has %zu unexpected trailing bytes", item->id, remainingBytes);
return AVIF_RESULT_TRUNCATED_DATA;
}
outData->data = item->mergedExtents.data + offset;
outData->size = readOutputSize;
item->partialMergedExtents = (item->size != totalBytesToRead);
return AVIF_RESULT_OK;
}
static avifBool avifDecoderGenerateImageGridTiles(avifDecoder * decoder, avifImageGrid * grid, avifDecoderItem * gridItem, avifBool alpha)
{
unsigned int tilesRequested = grid->rows * grid->columns;
// Count number of dimg for this item, bail out if it doesn't match perfectly
unsigned int tilesAvailable = 0;
for (uint32_t i = 0; i < gridItem->meta->items.count; ++i) {
avifDecoderItem * item = &gridItem->meta->items.item[i];
if (item->dimgForID == gridItem->id) {
if (memcmp(item->type, "av01", 4)) {
continue;
}
if (item->hasUnsupportedEssentialProperty) {
// An essential property isn't supported by libavif; can't
// decode a grid image if any tile in the grid isn't supported.
avifDiagnosticsPrintf(&decoder->diag, "Grid image contains tile with an unsupported property marked as essential");
return AVIF_FALSE;
}
++tilesAvailable;
}
}
if (tilesRequested != tilesAvailable) {
avifDiagnosticsPrintf(&decoder->diag,
"Grid image of dimensions %ux%u requires %u tiles, and only %u were found",
grid->columns,
grid->rows,
tilesRequested,
tilesAvailable);
return AVIF_FALSE;
}
avifBool firstTile = AVIF_TRUE;
for (uint32_t i = 0; i < gridItem->meta->items.count; ++i) {
avifDecoderItem * item = &gridItem->meta->items.item[i];
if (item->dimgForID == gridItem->id) {
if (memcmp(item->type, "av01", 4)) {
continue;
}
avifTile * tile = avifDecoderDataCreateTile(decoder->data, item->width, item->height, avifDecoderItemOperatingPoint(item));
if (!tile) {
return AVIF_FALSE;
}
if (!avifCodecDecodeInputFillFromDecoderItem(tile->input,
item,
decoder->allowProgressive,
decoder->imageCountLimit,
decoder->io->sizeHint,
&decoder->diag)) {
return AVIF_FALSE;
}
tile->input->alpha = alpha;
if (firstTile) {
firstTile = AVIF_FALSE;
// Adopt the av1C property of the first av01 tile, so that it can be queried from
// the top-level color/alpha item during avifDecoderReset().
const avifProperty * srcProp = avifPropertyArrayFind(&item->properties, "av1C");
if (!srcProp) {
avifDiagnosticsPrintf(&decoder->diag, "Grid image's first tile is missing an av1C property");
return AVIF_FALSE;
}
avifProperty * dstProp = (avifProperty *)avifArrayPushPtr(&gridItem->properties);
*dstProp = *srcProp;
if (!alpha && item->progressive) {
decoder->progressiveState = AVIF_PROGRESSIVE_STATE_AVAILABLE;
if (tile->input->samples.count > 1) {
decoder->progressiveState = AVIF_PROGRESSIVE_STATE_ACTIVE;
decoder->imageCount = tile->input->samples.count;
}
}
}
}
}
return AVIF_TRUE;
}
// Checks the grid consistency and copies the pixels from the tiles to the
// dstImage. Only the freshly decoded tiles are considered, skipping the already
// copied or not-yet-decoded tiles.
static avifBool avifDecoderDataFillImageGrid(avifDecoderData * data,
avifImageGrid * grid,
avifImage * dstImage,
unsigned int firstTileIndex,
unsigned int oldDecodedTileCount,
unsigned int decodedTileCount,
avifBool alpha)
{
assert(decodedTileCount > oldDecodedTileCount);
avifTile * firstTile = &data->tiles.tile[firstTileIndex];
avifBool firstTileUVPresent = (firstTile->image->yuvPlanes[AVIF_CHAN_U] && firstTile->image->yuvPlanes[AVIF_CHAN_V]);
// Check for tile consistency: All tiles in a grid image should match in the properties checked below.
for (unsigned int i = AVIF_MAX(1, oldDecodedTileCount); i < decodedTileCount; ++i) {
avifTile * tile = &data->tiles.tile[firstTileIndex + i];
avifBool uvPresent = (tile->image->yuvPlanes[AVIF_CHAN_U] && tile->image->yuvPlanes[AVIF_CHAN_V]);
if ((tile->image->width != firstTile->image->width) || (tile->image->height != firstTile->image->height) ||
(tile->image->depth != firstTile->image->depth) || (tile->image->yuvFormat != firstTile->image->yuvFormat) ||
(tile->image->yuvRange != firstTile->image->yuvRange) || (uvPresent != firstTileUVPresent) ||
(tile->image->colorPrimaries != firstTile->image->colorPrimaries) ||
(tile->image->transferCharacteristics != firstTile->image->transferCharacteristics) ||
(tile->image->matrixCoefficients != firstTile->image->matrixCoefficients)) {
avifDiagnosticsPrintf(data->diag, "Grid image contains mismatched tiles");
return AVIF_FALSE;
}
}
// Validate grid image size and tile size.
//
// HEIF (ISO/IEC 23008-12:2017), Section 6.6.2.3.1:
// The tiled input images shall completely "cover" the reconstructed image grid canvas, ...
if (((firstTile->image->width * grid->columns) < grid->outputWidth) ||
((firstTile->image->height * grid->rows) < grid->outputHeight)) {
avifDiagnosticsPrintf(data->diag,
"Grid image tiles do not completely cover the image (HEIF (ISO/IEC 23008-12:2017), Section 6.6.2.3.1)");
return AVIF_FALSE;
}
// Tiles in the rightmost column and bottommost row must overlap the reconstructed image grid canvas. See MIAF (ISO/IEC 23000-22:2019), Section 7.3.11.4.2, Figure 2.
if (((firstTile->image->width * (grid->columns - 1)) >= grid->outputWidth) ||
((firstTile->image->height * (grid->rows - 1)) >= grid->outputHeight)) {
avifDiagnosticsPrintf(data->diag,
"Grid image tiles in the rightmost column and bottommost row do not overlap the reconstructed image grid canvas. See MIAF (ISO/IEC 23000-22:2019), Section 7.3.11.4.2, Figure 2");
return AVIF_FALSE;
}
if (alpha) {
// An alpha tile does not contain any YUV pixels.
assert(firstTile->image->yuvFormat == AVIF_PIXEL_FORMAT_NONE);
}
if (!avifAreGridDimensionsValid(firstTile->image->yuvFormat,
grid->outputWidth,
grid->outputHeight,
firstTile->image->width,
firstTile->image->height,
data->diag)) {
return AVIF_FALSE;
}
// Lazily populate dstImage with the new frame's properties. If we're decoding alpha,
// these values must already match.
if ((dstImage->width != grid->outputWidth) || (dstImage->height != grid->outputHeight) ||
(dstImage->depth != firstTile->image->depth) || (!alpha && (dstImage->yuvFormat != firstTile->image->yuvFormat))) {
if (alpha) {
// Alpha doesn't match size, just bail out
avifDiagnosticsPrintf(data->diag, "Alpha plane dimensions do not match color plane dimensions");
return AVIF_FALSE;
}
avifImageFreePlanes(dstImage, AVIF_PLANES_ALL);
dstImage->width = grid->outputWidth;
dstImage->height = grid->outputHeight;
dstImage->depth = firstTile->image->depth;
dstImage->yuvFormat = firstTile->image->yuvFormat;
dstImage->yuvRange = firstTile->image->yuvRange;
if (!data->cicpSet) {
data->cicpSet = AVIF_TRUE;
dstImage->colorPrimaries = firstTile->image->colorPrimaries;
dstImage->transferCharacteristics = firstTile->image->transferCharacteristics;
dstImage->matrixCoefficients = firstTile->image->matrixCoefficients;
}
}
if (avifImageAllocatePlanes(dstImage, alpha ? AVIF_PLANES_A : AVIF_PLANES_YUV) != AVIF_RESULT_OK) {
avifDiagnosticsPrintf(data->diag, "Image allocation failure");
return AVIF_FALSE;
}
avifPixelFormatInfo formatInfo;
avifGetPixelFormatInfo(firstTile->image->yuvFormat, &formatInfo);
unsigned int tileIndex = oldDecodedTileCount;
size_t pixelBytes = avifImageUsesU16(dstImage) ? 2 : 1;
unsigned int rowIndex = oldDecodedTileCount / grid->columns;
unsigned int colIndex = oldDecodedTileCount % grid->columns;
// Only the first iteration of the outer for loop uses this initial value of colIndex.
// Subsequent iterations of the outer for loop initializes colIndex to 0.
for (; rowIndex < grid->rows; ++rowIndex, colIndex = 0) {
for (; colIndex < grid->columns; ++colIndex, ++tileIndex) {
if (tileIndex >= decodedTileCount) {
// Tile is not ready yet.
return AVIF_TRUE;
}
avifTile * tile = &data->tiles.tile[firstTileIndex + tileIndex];
unsigned int widthToCopy = firstTile->image->width;
unsigned int maxX = firstTile->image->width * (colIndex + 1);
if (maxX > grid->outputWidth) {
widthToCopy -= maxX - grid->outputWidth;
}
unsigned int heightToCopy = firstTile->image->height;
unsigned int maxY = firstTile->image->height * (rowIndex + 1);
if (maxY > grid->outputHeight) {
heightToCopy -= maxY - grid->outputHeight;
}
// Y and A channels
size_t yaColOffset = (size_t)colIndex * firstTile->image->width;
size_t yaRowOffset = (size_t)rowIndex * firstTile->image->height;
size_t yaRowBytes = widthToCopy * pixelBytes;
if (alpha) {
// A
for (unsigned int j = 0; j < heightToCopy; ++j) {
uint8_t * src = &tile->image->alphaPlane[j * tile->image->alphaRowBytes];
uint8_t * dst = &dstImage->alphaPlane[(yaColOffset * pixelBytes) + ((yaRowOffset + j) * dstImage->alphaRowBytes)];
memcpy(dst, src, yaRowBytes);
}
} else {
// Y
for (unsigned int j = 0; j < heightToCopy; ++j) {
uint8_t * src = &tile->image->yuvPlanes[AVIF_CHAN_Y][j * tile->image->yuvRowBytes[AVIF_CHAN_Y]];
uint8_t * dst =
&dstImage->yuvPlanes[AVIF_CHAN_Y][(yaColOffset * pixelBytes) + ((yaRowOffset + j) * dstImage->yuvRowBytes[AVIF_CHAN_Y])];
memcpy(dst, src, yaRowBytes);
}
if (!firstTileUVPresent) {
continue;
}
// UV
heightToCopy >>= formatInfo.chromaShiftY;
size_t uvColOffset = yaColOffset >> formatInfo.chromaShiftX;
size_t uvRowOffset = yaRowOffset >> formatInfo.chromaShiftY;
size_t uvRowBytes = yaRowBytes >> formatInfo.chromaShiftX;
for (unsigned int j = 0; j < heightToCopy; ++j) {
uint8_t * srcU = &tile->image->yuvPlanes[AVIF_CHAN_U][j * tile->image->yuvRowBytes[AVIF_CHAN_U]];
uint8_t * dstU =
&dstImage->yuvPlanes[AVIF_CHAN_U][(uvColOffset * pixelBytes) + ((uvRowOffset + j) * dstImage->yuvRowBytes[AVIF_CHAN_U])];
memcpy(dstU, srcU, uvRowBytes);
uint8_t * srcV = &tile->image->yuvPlanes[AVIF_CHAN_V][j * tile->image->yuvRowBytes[AVIF_CHAN_V]];
uint8_t * dstV =
&dstImage->yuvPlanes[AVIF_CHAN_V][(uvColOffset * pixelBytes) + ((uvRowOffset + j) * dstImage->yuvRowBytes[AVIF_CHAN_V])];
memcpy(dstV, srcV, uvRowBytes);
}
}
}
}
return AVIF_TRUE;
}
// If colorId == 0 (a sentinel value as item IDs must be nonzero), accept any found EXIF/XMP metadata. Passing in 0
// is used when finding metadata in a meta box embedded in a trak box, as any items inside of a meta box that is
// inside of a trak box are implicitly associated to the track.
static avifResult avifDecoderFindMetadata(avifDecoder * decoder, avifMeta * meta, avifImage * image, uint32_t colorId)
{
if (decoder->ignoreExif && decoder->ignoreXMP) {
// Nothing to do!
return AVIF_RESULT_OK;
}
for (uint32_t itemIndex = 0; itemIndex < meta->items.count; ++itemIndex) {
avifDecoderItem * item = &meta->items.item[itemIndex];
if (!item->size) {
continue;
}
if (item->hasUnsupportedEssentialProperty) {
// An essential property isn't supported by libavif; ignore the item.
continue;
}
if ((colorId > 0) && (item->descForID != colorId)) {
// Not a content description (metadata) for the colorOBU, skip it
continue;
}
if (!decoder->ignoreExif && !memcmp(item->type, "Exif", 4)) {
avifROData exifContents;
avifResult readResult = avifDecoderItemRead(item, decoder->io, &exifContents, 0, 0, &decoder->diag);
if (readResult != AVIF_RESULT_OK) {
return readResult;
}
// Advance past Annex A.2.1's header
BEGIN_STREAM(exifBoxStream, exifContents.data, exifContents.size, &decoder->diag, "Exif header");
uint32_t exifTiffHeaderOffset;
AVIF_CHECKERR(avifROStreamReadU32(&exifBoxStream, &exifTiffHeaderOffset),
AVIF_RESULT_BMFF_PARSE_FAILED); // unsigned int(32) exif_tiff_header_offset;
avifRWDataSet(&image->exif, avifROStreamCurrent(&exifBoxStream), avifROStreamRemainingBytes(&exifBoxStream));
} else if (!decoder->ignoreXMP && !memcmp(item->type, "mime", 4) &&
!memcmp(item->contentType.contentType, xmpContentType, xmpContentTypeSize)) {
avifROData xmpContents;
avifResult readResult = avifDecoderItemRead(item, decoder->io, &xmpContents, 0, 0, &decoder->diag);
if (readResult != AVIF_RESULT_OK) {
return readResult;
}
avifImageSetMetadataXMP(image, xmpContents.data, xmpContents.size);
}
}
return AVIF_RESULT_OK;
}
// ---------------------------------------------------------------------------
// URN
static avifBool isAlphaURN(const char * urn)
{
return !strcmp(urn, AVIF_URN_ALPHA0) || !strcmp(urn, AVIF_URN_ALPHA1);
}
// ---------------------------------------------------------------------------
// BMFF Parsing
static avifBool avifParseHandlerBox(const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[hdlr]");
AVIF_CHECK(avifROStreamReadAndEnforceVersion(&s, 0));
uint32_t predefined;
AVIF_CHECK(avifROStreamReadU32(&s, &predefined)); // unsigned int(32) pre_defined = 0;
if (predefined != 0) {
avifDiagnosticsPrintf(diag, "Box[hdlr] contains a pre_defined value that is nonzero");
return AVIF_FALSE;
}
uint8_t handlerType[4];
AVIF_CHECK(avifROStreamRead(&s, handlerType, 4)); // unsigned int(32) handler_type;
if (memcmp(handlerType, "pict", 4) != 0) {
avifDiagnosticsPrintf(diag, "Box[hdlr] handler_type is not 'pict'");
return AVIF_FALSE;
}
for (int i = 0; i < 3; ++i) {
uint32_t reserved;
AVIF_CHECK(avifROStreamReadU32(&s, &reserved)); // const unsigned int(32)[3] reserved = 0;
}
// Verify that a valid string is here, but don't bother to store it
AVIF_CHECK(avifROStreamReadString(&s, NULL, 0)); // string name;
return AVIF_TRUE;
}
static avifBool avifParseItemLocationBox(avifMeta * meta, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[iloc]");
uint8_t version;
AVIF_CHECK(avifROStreamReadVersionAndFlags(&s, &version, NULL));
if (version > 2) {
avifDiagnosticsPrintf(diag, "Box[iloc] has an unsupported version [%u]", version);
return AVIF_FALSE;
}
uint8_t offsetSizeAndLengthSize;
AVIF_CHECK(avifROStreamRead(&s, &offsetSizeAndLengthSize, 1));
uint8_t offsetSize = (offsetSizeAndLengthSize >> 4) & 0xf; // unsigned int(4) offset_size;
uint8_t lengthSize = (offsetSizeAndLengthSize >> 0) & 0xf; // unsigned int(4) length_size;
uint8_t baseOffsetSizeAndIndexSize;
AVIF_CHECK(avifROStreamRead(&s, &baseOffsetSizeAndIndexSize, 1));
uint8_t baseOffsetSize = (baseOffsetSizeAndIndexSize >> 4) & 0xf; // unsigned int(4) base_offset_size;
uint8_t indexSize = 0;
if ((version == 1) || (version == 2)) {
indexSize = baseOffsetSizeAndIndexSize & 0xf; // unsigned int(4) index_size;
if (indexSize != 0) {
// extent_index unsupported
avifDiagnosticsPrintf(diag, "Box[iloc] has an unsupported extent_index");
return AVIF_FALSE;
}
}
uint16_t tmp16;
uint32_t itemCount;
if (version < 2) {
AVIF_CHECK(avifROStreamReadU16(&s, &tmp16)); // unsigned int(16) item_count;
itemCount = tmp16;
} else {
AVIF_CHECK(avifROStreamReadU32(&s, &itemCount)); // unsigned int(32) item_count;
}
for (uint32_t i = 0; i < itemCount; ++i) {
uint32_t itemID;
if (version < 2) {
AVIF_CHECK(avifROStreamReadU16(&s, &tmp16)); // unsigned int(16) item_ID;
itemID = tmp16;
} else {
AVIF_CHECK(avifROStreamReadU32(&s, &itemID)); // unsigned int(32) item_ID;
}
avifDecoderItem * item = avifMetaFindItem(meta, itemID);
if (!item) {
avifDiagnosticsPrintf(diag, "Box[iloc] has an invalid item ID [%u]", itemID);
return AVIF_FALSE;
}
if (item->extents.count > 0) {
// This item has already been given extents via this iloc box. This is invalid.
avifDiagnosticsPrintf(diag, "Item ID [%u] contains duplicate sets of extents", itemID);
return AVIF_FALSE;
}
if ((version == 1) || (version == 2)) {
uint8_t ignored;
uint8_t constructionMethod;
AVIF_CHECK(avifROStreamRead(&s, &ignored, 1)); // unsigned int(12) reserved = 0;
AVIF_CHECK(avifROStreamRead(&s, &constructionMethod, 1)); // unsigned int(4) construction_method;
constructionMethod = constructionMethod & 0xf;
if ((constructionMethod != 0 /* file */) && (constructionMethod != 1 /* idat */)) {
// construction method item(2) unsupported
avifDiagnosticsPrintf(diag, "Box[iloc] has an unsupported construction method [%u]", constructionMethod);
return AVIF_FALSE;
}
if (constructionMethod == 1) {
item->idatStored = AVIF_TRUE;
}
}
uint16_t dataReferenceIndex; // unsigned int(16) data_ref rence_index;
AVIF_CHECK(avifROStreamReadU16(&s, &dataReferenceIndex)); //
uint64_t baseOffset; // unsigned int(base_offset_size*8) base_offset;
AVIF_CHECK(avifROStreamReadUX8(&s, &baseOffset, baseOffsetSize)); //
uint16_t extentCount; // unsigned int(16) extent_count;
AVIF_CHECK(avifROStreamReadU16(&s, &extentCount)); //
for (int extentIter = 0; extentIter < extentCount; ++extentIter) {
// If extent_index is ever supported, this spec must be implemented here:
// :: if (((version == 1) || (version == 2)) && (index_size > 0)) {
// :: unsigned int(index_size*8) extent_index;
// :: }
uint64_t extentOffset; // unsigned int(offset_size*8) extent_offset;
AVIF_CHECK(avifROStreamReadUX8(&s, &extentOffset, offsetSize));
uint64_t extentLength; // unsigned int(offset_size*8) extent_length;
AVIF_CHECK(avifROStreamReadUX8(&s, &extentLength, lengthSize));
avifExtent * extent = (avifExtent *)avifArrayPushPtr(&item->extents);
if (extentOffset > UINT64_MAX - baseOffset) {
avifDiagnosticsPrintf(diag,
"Item ID [%u] contains an extent offset which overflows: [base: %" PRIu64 " offset:%" PRIu64 "]",
itemID,
baseOffset,
extentOffset);
return AVIF_FALSE;
}
uint64_t offset = baseOffset + extentOffset;
extent->offset = offset;
if (extentLength > SIZE_MAX) {
avifDiagnosticsPrintf(diag, "Item ID [%u] contains an extent length which overflows: [%" PRIu64 "]", itemID, extentLength);
return AVIF_FALSE;
}
extent->size = (size_t)extentLength;
if (extent->size > SIZE_MAX - item->size) {
avifDiagnosticsPrintf(diag,
"Item ID [%u] contains an extent length which overflows the item size: [%zu, %zu]",
itemID,
extent->size,
item->size);
return AVIF_FALSE;
}
item->size += extent->size;
}
}
return AVIF_TRUE;
}
static avifBool avifParseImageGridBox(avifImageGrid * grid,
const uint8_t * raw,
size_t rawLen,
uint32_t imageSizeLimit,
uint32_t imageDimensionLimit,
avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[grid]");
uint8_t version, flags;
AVIF_CHECK(avifROStreamRead(&s, &version, 1)); // unsigned int(8) version = 0;
if (version != 0) {
avifDiagnosticsPrintf(diag, "Box[grid] has unsupported version [%u]", version);
return AVIF_FALSE;
}
uint8_t rowsMinusOne, columnsMinusOne;
AVIF_CHECK(avifROStreamRead(&s, &flags, 1)); // unsigned int(8) flags;
AVIF_CHECK(avifROStreamRead(&s, &rowsMinusOne, 1)); // unsigned int(8) rows_minus_one;
AVIF_CHECK(avifROStreamRead(&s, &columnsMinusOne, 1)); // unsigned int(8) columns_minus_one;
grid->rows = (uint32_t)rowsMinusOne + 1;
grid->columns = (uint32_t)columnsMinusOne + 1;
uint32_t fieldLength = ((flags & 1) + 1) * 16;
if (fieldLength == 16) {
uint16_t outputWidth16, outputHeight16;
AVIF_CHECK(avifROStreamReadU16(&s, &outputWidth16)); // unsigned int(FieldLength) output_width;
AVIF_CHECK(avifROStreamReadU16(&s, &outputHeight16)); // unsigned int(FieldLength) output_height;
grid->outputWidth = outputWidth16;
grid->outputHeight = outputHeight16;
} else {
if (fieldLength != 32) {
// This should be impossible
avifDiagnosticsPrintf(diag, "Grid box contains illegal field length: [%u]", fieldLength);
return AVIF_FALSE;
}
AVIF_CHECK(avifROStreamReadU32(&s, &grid->outputWidth)); // unsigned int(FieldLength) output_width;
AVIF_CHECK(avifROStreamReadU32(&s, &grid->outputHeight)); // unsigned int(FieldLength) output_height;
}
if ((grid->outputWidth == 0) || (grid->outputHeight == 0)) {
avifDiagnosticsPrintf(diag, "Grid box contains illegal dimensions: [%u x %u]", grid->outputWidth, grid->outputHeight);
return AVIF_FALSE;
}
if (avifDimensionsTooLarge(grid->outputWidth, grid->outputHeight, imageSizeLimit, imageDimensionLimit)) {
avifDiagnosticsPrintf(diag, "Grid box dimensions are too large: [%u x %u]", grid->outputWidth, grid->outputHeight);
return AVIF_FALSE;
}
return avifROStreamRemainingBytes(&s) == 0;
}
static avifBool avifParseImageSpatialExtentsProperty(avifProperty * prop, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[ispe]");
AVIF_CHECK(avifROStreamReadAndEnforceVersion(&s, 0));
avifImageSpatialExtents * ispe = &prop->u.ispe;
AVIF_CHECK(avifROStreamReadU32(&s, &ispe->width));
AVIF_CHECK(avifROStreamReadU32(&s, &ispe->height));
return AVIF_TRUE;
}
static avifBool avifParseAuxiliaryTypeProperty(avifProperty * prop, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[auxC]");
AVIF_CHECK(avifROStreamReadAndEnforceVersion(&s, 0));
AVIF_CHECK(avifROStreamReadString(&s, prop->u.auxC.auxType, AUXTYPE_SIZE));
return AVIF_TRUE;
}
static avifBool avifParseColourInformationBox(avifProperty * prop, uint64_t rawOffset, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[colr]");
avifColourInformationBox * colr = &prop->u.colr;
colr->hasICC = AVIF_FALSE;
colr->hasNCLX = AVIF_FALSE;
uint8_t colorType[4]; // unsigned int(32) colour_type;
AVIF_CHECK(avifROStreamRead(&s, colorType, 4));
if (!memcmp(colorType, "rICC", 4) || !memcmp(colorType, "prof", 4)) {
colr->hasICC = AVIF_TRUE;
// Remember the offset of the ICC payload relative to the beginning of the stream. A direct pointer cannot be stored
// because decoder->io->persistent could have been AVIF_FALSE when obtaining raw through decoder->io->read().
// The bytes could be copied now instead of remembering the offset, but it is as invasive as passing rawOffset everywhere.
colr->iccOffset = rawOffset + avifROStreamOffset(&s);
colr->iccSize = avifROStreamRemainingBytes(&s);
} else if (!memcmp(colorType, "nclx", 4)) {
AVIF_CHECK(avifROStreamReadU16(&s, &colr->colorPrimaries)); // unsigned int(16) colour_primaries;
AVIF_CHECK(avifROStreamReadU16(&s, &colr->transferCharacteristics)); // unsigned int(16) transfer_characteristics;
AVIF_CHECK(avifROStreamReadU16(&s, &colr->matrixCoefficients)); // unsigned int(16) matrix_coefficients;
// unsigned int(1) full_range_flag;
// unsigned int(7) reserved = 0;
uint8_t tmp8;
AVIF_CHECK(avifROStreamRead(&s, &tmp8, 1));
colr->range = (tmp8 & 0x80) ? AVIF_RANGE_FULL : AVIF_RANGE_LIMITED;
colr->hasNCLX = AVIF_TRUE;
}
return AVIF_TRUE;
}
static avifBool avifParseAV1CodecConfigurationBox(const uint8_t * raw, size_t rawLen, avifCodecConfigurationBox * av1C, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[av1C]");
uint8_t markerAndVersion = 0;
AVIF_CHECK(avifROStreamRead(&s, &markerAndVersion, 1));
uint8_t seqProfileAndIndex = 0;
AVIF_CHECK(avifROStreamRead(&s, &seqProfileAndIndex, 1));
uint8_t rawFlags = 0;
AVIF_CHECK(avifROStreamRead(&s, &rawFlags, 1));
if (markerAndVersion != 0x81) {
// Marker and version must both == 1
avifDiagnosticsPrintf(diag, "av1C contains illegal marker and version pair: [%u]", markerAndVersion);
return AVIF_FALSE;
}
av1C->seqProfile = (seqProfileAndIndex >> 5) & 0x7; // unsigned int (3) seq_profile;
av1C->seqLevelIdx0 = (seqProfileAndIndex >> 0) & 0x1f; // unsigned int (5) seq_level_idx_0;
av1C->seqTier0 = (rawFlags >> 7) & 0x1; // unsigned int (1) seq_tier_0;
av1C->highBitdepth = (rawFlags >> 6) & 0x1; // unsigned int (1) high_bitdepth;
av1C->twelveBit = (rawFlags >> 5) & 0x1; // unsigned int (1) twelve_bit;
av1C->monochrome = (rawFlags >> 4) & 0x1; // unsigned int (1) monochrome;
av1C->chromaSubsamplingX = (rawFlags >> 3) & 0x1; // unsigned int (1) chroma_subsampling_x;
av1C->chromaSubsamplingY = (rawFlags >> 2) & 0x1; // unsigned int (1) chroma_subsampling_y;
av1C->chromaSamplePosition = (rawFlags >> 0) & 0x3; // unsigned int (2) chroma_sample_position;
return AVIF_TRUE;
}
static avifBool avifParseAV1CodecConfigurationBoxProperty(avifProperty * prop, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
return avifParseAV1CodecConfigurationBox(raw, rawLen, &prop->u.av1C, diag);
}
static avifBool avifParsePixelAspectRatioBoxProperty(avifProperty * prop, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[pasp]");
avifPixelAspectRatioBox * pasp = &prop->u.pasp;
AVIF_CHECK(avifROStreamReadU32(&s, &pasp->hSpacing)); // unsigned int(32) hSpacing;
AVIF_CHECK(avifROStreamReadU32(&s, &pasp->vSpacing)); // unsigned int(32) vSpacing;
return AVIF_TRUE;
}
static avifBool avifParseCleanApertureBoxProperty(avifProperty * prop, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[clap]");
avifCleanApertureBox * clap = &prop->u.clap;
AVIF_CHECK(avifROStreamReadU32(&s, &clap->widthN)); // unsigned int(32) cleanApertureWidthN;
AVIF_CHECK(avifROStreamReadU32(&s, &clap->widthD)); // unsigned int(32) cleanApertureWidthD;
AVIF_CHECK(avifROStreamReadU32(&s, &clap->heightN)); // unsigned int(32) cleanApertureHeightN;
AVIF_CHECK(avifROStreamReadU32(&s, &clap->heightD)); // unsigned int(32) cleanApertureHeightD;
AVIF_CHECK(avifROStreamReadU32(&s, &clap->horizOffN)); // unsigned int(32) horizOffN;
AVIF_CHECK(avifROStreamReadU32(&s, &clap->horizOffD)); // unsigned int(32) horizOffD;
AVIF_CHECK(avifROStreamReadU32(&s, &clap->vertOffN)); // unsigned int(32) vertOffN;
AVIF_CHECK(avifROStreamReadU32(&s, &clap->vertOffD)); // unsigned int(32) vertOffD;
return AVIF_TRUE;
}
static avifBool avifParseImageRotationProperty(avifProperty * prop, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[irot]");
avifImageRotation * irot = &prop->u.irot;
AVIF_CHECK(avifROStreamRead(&s, &irot->angle, 1)); // unsigned int (6) reserved = 0; unsigned int (2) angle;
if ((irot->angle & 0xfc) != 0) {
// reserved bits must be 0
avifDiagnosticsPrintf(diag, "Box[irot] contains nonzero reserved bits [%u]", irot->angle);
return AVIF_FALSE;
}
return AVIF_TRUE;
}
static avifBool avifParseImageMirrorProperty(avifProperty * prop, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[imir]");
avifImageMirror * imir = &prop->u.imir;
AVIF_CHECK(avifROStreamRead(&s, &imir->mode, 1)); // unsigned int (7) reserved = 0; unsigned int (1) mode;
if ((imir->mode & 0xfe) != 0) {
// reserved bits must be 0
avifDiagnosticsPrintf(diag, "Box[imir] contains nonzero reserved bits [%u]", imir->mode);
return AVIF_FALSE;
}
return AVIF_TRUE;
}
static avifBool avifParsePixelInformationProperty(avifProperty * prop, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[pixi]");
AVIF_CHECK(avifROStreamReadAndEnforceVersion(&s, 0));
avifPixelInformationProperty * pixi = &prop->u.pixi;
AVIF_CHECK(avifROStreamRead(&s, &pixi->planeCount, 1)); // unsigned int (8) num_channels;
if (pixi->planeCount > MAX_PIXI_PLANE_DEPTHS) {
avifDiagnosticsPrintf(diag, "Box[pixi] contains unsupported plane count [%u]", pixi->planeCount);
return AVIF_FALSE;
}
for (uint8_t i = 0; i < pixi->planeCount; ++i) {
AVIF_CHECK(avifROStreamRead(&s, &pixi->planeDepths[i], 1)); // unsigned int (8) bits_per_channel;
}
return AVIF_TRUE;
}
static avifBool avifParseOperatingPointSelectorProperty(avifProperty * prop, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[a1op]");
avifOperatingPointSelectorProperty * a1op = &prop->u.a1op;
AVIF_CHECK(avifROStreamRead(&s, &a1op->opIndex, 1));
if (a1op->opIndex > 31) { // 31 is AV1's max operating point value
avifDiagnosticsPrintf(diag, "Box[a1op] contains an unsupported operating point [%u]", a1op->opIndex);
return AVIF_FALSE;
}
return AVIF_TRUE;
}
static avifBool avifParseLayerSelectorProperty(avifProperty * prop, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[lsel]");
avifLayerSelectorProperty * lsel = &prop->u.lsel;
AVIF_CHECK(avifROStreamReadU16(&s, &lsel->layerID));
if ((lsel->layerID != 0xFFFF) && (lsel->layerID >= MAX_AV1_LAYER_COUNT)) {
avifDiagnosticsPrintf(diag, "Box[lsel] contains an unsupported layer [%u]", lsel->layerID);
return AVIF_FALSE;
}
return AVIF_TRUE;
}
static avifBool avifParseAV1LayeredImageIndexingProperty(avifProperty * prop, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[a1lx]");
avifAV1LayeredImageIndexingProperty * a1lx = &prop->u.a1lx;
uint8_t largeSize = 0;
AVIF_CHECK(avifROStreamRead(&s, &largeSize, 1));
if (largeSize & 0xFE) {
avifDiagnosticsPrintf(diag, "Box[a1lx] has bits set in the reserved section [%u]", largeSize);
return AVIF_FALSE;
}
for (int i = 0; i < 3; ++i) {
if (largeSize) {
AVIF_CHECK(avifROStreamReadU32(&s, &a1lx->layerSize[i]));
} else {
uint16_t layerSize16;
AVIF_CHECK(avifROStreamReadU16(&s, &layerSize16));
a1lx->layerSize[i] = (uint32_t)layerSize16;
}
}
// Layer sizes will be validated layer (when the item's size is known)
return AVIF_TRUE;
}
static avifBool avifParseItemPropertyContainerBox(avifPropertyArray * properties,
uint64_t rawOffset,
const uint8_t * raw,
size_t rawLen,
avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[ipco]");
while (avifROStreamHasBytesLeft(&s, 1)) {
avifBoxHeader header;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &header));
int propertyIndex = avifArrayPushIndex(properties);
avifProperty * prop = &properties->prop[propertyIndex];
memcpy(prop->type, header.type, 4);
if (!memcmp(header.type, "ispe", 4)) {
AVIF_CHECK(avifParseImageSpatialExtentsProperty(prop, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "auxC", 4)) {
AVIF_CHECK(avifParseAuxiliaryTypeProperty(prop, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "colr", 4)) {
AVIF_CHECK(avifParseColourInformationBox(prop, rawOffset + avifROStreamOffset(&s), avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "av1C", 4)) {
AVIF_CHECK(avifParseAV1CodecConfigurationBoxProperty(prop, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "pasp", 4)) {
AVIF_CHECK(avifParsePixelAspectRatioBoxProperty(prop, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "clap", 4)) {
AVIF_CHECK(avifParseCleanApertureBoxProperty(prop, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "irot", 4)) {
AVIF_CHECK(avifParseImageRotationProperty(prop, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "imir", 4)) {
AVIF_CHECK(avifParseImageMirrorProperty(prop, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "pixi", 4)) {
AVIF_CHECK(avifParsePixelInformationProperty(prop, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "a1op", 4)) {
AVIF_CHECK(avifParseOperatingPointSelectorProperty(prop, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "lsel", 4)) {
AVIF_CHECK(avifParseLayerSelectorProperty(prop, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "a1lx", 4)) {
AVIF_CHECK(avifParseAV1LayeredImageIndexingProperty(prop, avifROStreamCurrent(&s), header.size, diag));
}
AVIF_CHECK(avifROStreamSkip(&s, header.size));
}
return AVIF_TRUE;
}
static avifBool avifParseItemPropertyAssociation(avifMeta * meta, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag, uint32_t * outVersionAndFlags)
{
// NOTE: If this function ever adds support for versions other than [0,1] or flags other than
// [0,1], please increase the value of MAX_IPMA_VERSION_AND_FLAGS_SEEN accordingly.
BEGIN_STREAM(s, raw, rawLen, diag, "Box[ipma]");
uint8_t version;
uint32_t flags;
AVIF_CHECK(avifROStreamReadVersionAndFlags(&s, &version, &flags));
avifBool propertyIndexIsU16 = ((flags & 0x1) != 0);
*outVersionAndFlags = ((uint32_t)version << 24) | flags;
uint32_t entryCount;
AVIF_CHECK(avifROStreamReadU32(&s, &entryCount));
unsigned int prevItemID = 0;
for (uint32_t entryIndex = 0; entryIndex < entryCount; ++entryIndex) {
// ISO/IEC 23008-12, First edition, 2017-12, Section 9.3.1:
// Each ItemPropertyAssociation box shall be ordered by increasing item_ID, and there shall
// be at most one association box for each item_ID, in any ItemPropertyAssociation box.
unsigned int itemID;
if (version < 1) {
uint16_t tmp;
AVIF_CHECK(avifROStreamReadU16(&s, &tmp));
itemID = tmp;
} else {
AVIF_CHECK(avifROStreamReadU32(&s, &itemID));
}
if (itemID <= prevItemID) {
avifDiagnosticsPrintf(diag, "Box[ipma] item IDs are not ordered by increasing ID");
return AVIF_FALSE;
}
prevItemID = itemID;
avifDecoderItem * item = avifMetaFindItem(meta, itemID);
if (!item) {
avifDiagnosticsPrintf(diag, "Box[ipma] has an invalid item ID [%u]", itemID);
return AVIF_FALSE;
}
if (item->ipmaSeen) {
avifDiagnosticsPrintf(diag, "Duplicate Box[ipma] for item ID [%u]", itemID);
return AVIF_FALSE;
}
item->ipmaSeen = AVIF_TRUE;
uint8_t associationCount;
AVIF_CHECK(avifROStreamRead(&s, &associationCount, 1));
for (uint8_t associationIndex = 0; associationIndex < associationCount; ++associationIndex) {
avifBool essential = AVIF_FALSE;
uint16_t propertyIndex = 0;
if (propertyIndexIsU16) {
AVIF_CHECK(avifROStreamReadU16(&s, &propertyIndex));
essential = ((propertyIndex & 0x8000) != 0);
propertyIndex &= 0x7fff;
} else {
uint8_t tmp;
AVIF_CHECK(avifROStreamRead(&s, &tmp, 1));
essential = ((tmp & 0x80) != 0);
propertyIndex = tmp & 0x7f;
}
if (propertyIndex == 0) {
// Not associated with any item
continue;
}
--propertyIndex; // 1-indexed
if (propertyIndex >= meta->properties.count) {
avifDiagnosticsPrintf(diag,
"Box[ipma] for item ID [%u] contains an illegal property index [%u] (out of [%u] properties)",
itemID,
propertyIndex,
meta->properties.count);
return AVIF_FALSE;
}
// Copy property to item
const avifProperty * srcProp = &meta->properties.prop[propertyIndex];
static const char * supportedTypes[] = { "ispe", "auxC", "colr", "av1C", "pasp", "clap",
"irot", "imir", "pixi", "a1op", "lsel", "a1lx" };
size_t supportedTypesCount = sizeof(supportedTypes) / sizeof(supportedTypes[0]);
avifBool supportedType = AVIF_FALSE;
for (size_t i = 0; i < supportedTypesCount; ++i) {
if (!memcmp(srcProp->type, supportedTypes[i], 4)) {
supportedType = AVIF_TRUE;
break;
}
}
if (supportedType) {
if (essential) {
// Verify that it is legal for this property to be flagged as essential. Any
// types in this list are *required* in the spec to not be flagged as essential
// when associated with an item.
static const char * const nonessentialTypes[] = {
// AVIF: Section 2.3.2.3.2: "If associated, it shall not be marked as essential."
"a1lx"
};
size_t nonessentialTypesCount = sizeof(nonessentialTypes) / sizeof(nonessentialTypes[0]);
for (size_t i = 0; i < nonessentialTypesCount; ++i) {
if (!memcmp(srcProp->type, nonessentialTypes[i], 4)) {
avifDiagnosticsPrintf(diag,
"Item ID [%u] has a %s property association which must not be marked essential, but is",
itemID,
nonessentialTypes[i]);
return AVIF_FALSE;
}
}
} else {
// Verify that it is legal for this property to not be flagged as essential. Any
// types in this list are *required* in the spec to be flagged as essential when
// associated with an item.
static const char * const essentialTypes[] = {
// AVIF: Section 2.3.2.1.1: "If associated, it shall be marked as essential."
"a1op",
// HEIF: Section 6.5.11.1: "essential shall be equal to 1 for an 'lsel' item property."
"lsel"
};
size_t essentialTypesCount = sizeof(essentialTypes) / sizeof(essentialTypes[0]);
for (size_t i = 0; i < essentialTypesCount; ++i) {
if (!memcmp(srcProp->type, essentialTypes[i], 4)) {
avifDiagnosticsPrintf(diag,
"Item ID [%u] has a %s property association which must be marked essential, but is not",
itemID,
essentialTypes[i]);
return AVIF_FALSE;
}
}
}
// Supported and valid; associate it with this item.
avifProperty * dstProp = (avifProperty *)avifArrayPushPtr(&item->properties);
*dstProp = *srcProp;
} else {
if (essential) {
// Discovered an essential item property that libavif doesn't support!
// Make a note to ignore this item later.
item->hasUnsupportedEssentialProperty = AVIF_TRUE;
}
}
}
}
return AVIF_TRUE;
}
static avifBool avifParsePrimaryItemBox(avifMeta * meta, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
if (meta->primaryItemID > 0) {
// Illegal to have multiple pitm boxes, bail out
avifDiagnosticsPrintf(diag, "Multiple boxes of unique Box[pitm] found");
return AVIF_FALSE;
}
BEGIN_STREAM(s, raw, rawLen, diag, "Box[pitm]");
uint8_t version;
AVIF_CHECK(avifROStreamReadVersionAndFlags(&s, &version, NULL));
if (version == 0) {
uint16_t tmp16;
AVIF_CHECK(avifROStreamReadU16(&s, &tmp16)); // unsigned int(16) item_ID;
meta->primaryItemID = tmp16;
} else {
AVIF_CHECK(avifROStreamReadU32(&s, &meta->primaryItemID)); // unsigned int(32) item_ID;
}
return AVIF_TRUE;
}
static avifBool avifParseItemDataBox(avifMeta * meta, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
// Check to see if we've already seen an idat box for this meta box. If so, bail out
if (meta->idat.size > 0) {
avifDiagnosticsPrintf(diag, "Meta box contains multiple idat boxes");
return AVIF_FALSE;
}
if (rawLen == 0) {
avifDiagnosticsPrintf(diag, "idat box has a length of 0");
return AVIF_FALSE;
}
avifRWDataSet(&meta->idat, raw, rawLen);
return AVIF_TRUE;
}
static avifBool avifParseItemPropertiesBox(avifMeta * meta, uint64_t rawOffset, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[iprp]");
avifBoxHeader ipcoHeader;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &ipcoHeader));
if (memcmp(ipcoHeader.type, "ipco", 4)) {
avifDiagnosticsPrintf(diag, "Failed to find Box[ipco] as the first box in Box[iprp]");
return AVIF_FALSE;
}
// Read all item properties inside of ItemPropertyContainerBox
AVIF_CHECK(avifParseItemPropertyContainerBox(&meta->properties,
rawOffset + avifROStreamOffset(&s),
avifROStreamCurrent(&s),
ipcoHeader.size,
diag));
AVIF_CHECK(avifROStreamSkip(&s, ipcoHeader.size));
uint32_t versionAndFlagsSeen[MAX_IPMA_VERSION_AND_FLAGS_SEEN];
uint32_t versionAndFlagsSeenCount = 0;
// Now read all ItemPropertyAssociation until the end of the box, and make associations
while (avifROStreamHasBytesLeft(&s, 1)) {
avifBoxHeader ipmaHeader;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &ipmaHeader));
if (!memcmp(ipmaHeader.type, "ipma", 4)) {
uint32_t versionAndFlags;
AVIF_CHECK(avifParseItemPropertyAssociation(meta, avifROStreamCurrent(&s), ipmaHeader.size, diag, &versionAndFlags));
for (uint32_t i = 0; i < versionAndFlagsSeenCount; ++i) {
if (versionAndFlagsSeen[i] == versionAndFlags) {
// HEIF (ISO 23008-12:2017) 9.3.1 - There shall be at most one
// ItemPropertyAssociation box with a given pair of values of version and
// flags.
avifDiagnosticsPrintf(diag, "Multiple Box[ipma] with a given pair of values of version and flags. See HEIF (ISO 23008-12:2017) 9.3.1");
return AVIF_FALSE;
}
}
if (versionAndFlagsSeenCount == MAX_IPMA_VERSION_AND_FLAGS_SEEN) {
avifDiagnosticsPrintf(diag, "Exceeded possible count of unique ipma version and flags tuples");
return AVIF_FALSE;
}
versionAndFlagsSeen[versionAndFlagsSeenCount] = versionAndFlags;
++versionAndFlagsSeenCount;
} else {
// These must all be type ipma
avifDiagnosticsPrintf(diag, "Box[iprp] contains a box that isn't type 'ipma'");
return AVIF_FALSE;
}
AVIF_CHECK(avifROStreamSkip(&s, ipmaHeader.size));
}
return AVIF_TRUE;
}
static avifBool avifParseItemInfoEntry(avifMeta * meta, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[infe]");
uint8_t version;
uint32_t flags;
AVIF_CHECK(avifROStreamReadVersionAndFlags(&s, &version, &flags));
// Version 2+ is required for item_type
if (version != 2 && version != 3) {
avifDiagnosticsPrintf(s.diag, "%s: Expecting box version 2 or 3, got version %u", s.diagContext, version);
return AVIF_FALSE;
}
// TODO: check flags. ISO/IEC 23008-12:2017, Section 9.2 says:
// The flags field of ItemInfoEntry with version greater than or equal to 2 is specified as
// follows:
//
// (flags & 1) equal to 1 indicates that the item is not intended to be a part of the
// presentation. For example, when (flags & 1) is equal to 1 for an image item, the image
// item should not be displayed.
// (flags & 1) equal to 0 indicates that the item is intended to be a part of the
// presentation.
//
// See also Section 6.4.2.
uint32_t itemID;
if (version == 2) {
uint16_t tmp;
AVIF_CHECK(avifROStreamReadU16(&s, &tmp)); // unsigned int(16) item_ID;
itemID = tmp;
} else {
assert(version == 3);
AVIF_CHECK(avifROStreamReadU32(&s, &itemID)); // unsigned int(32) item_ID;
}
uint16_t itemProtectionIndex; // unsigned int(16) item_protection_index;
AVIF_CHECK(avifROStreamReadU16(&s, &itemProtectionIndex)); //
uint8_t itemType[4]; // unsigned int(32) item_type;
AVIF_CHECK(avifROStreamRead(&s, itemType, 4)); //
avifContentType contentType;
if (!memcmp(itemType, "mime", 4)) {
AVIF_CHECK(avifROStreamReadString(&s, NULL, 0)); // string item_name; (skipped)
AVIF_CHECK(avifROStreamReadString(&s, contentType.contentType, CONTENTTYPE_SIZE)); // string content_type;
} else {
memset(&contentType, 0, sizeof(contentType));
}
avifDecoderItem * item = avifMetaFindItem(meta, itemID);
if (!item) {
avifDiagnosticsPrintf(diag, "Box[infe] has an invalid item ID [%u]", itemID);
return AVIF_FALSE;
}
memcpy(item->type, itemType, sizeof(itemType));
item->contentType = contentType;
return AVIF_TRUE;
}
static avifBool avifParseItemInfoBox(avifMeta * meta, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[iinf]");
uint8_t version;
AVIF_CHECK(avifROStreamReadVersionAndFlags(&s, &version, NULL));
uint32_t entryCount;
if (version == 0) {
uint16_t tmp;
AVIF_CHECK(avifROStreamReadU16(&s, &tmp)); // unsigned int(16) entry_count;
entryCount = tmp;
} else if (version == 1) {
AVIF_CHECK(avifROStreamReadU32(&s, &entryCount)); // unsigned int(32) entry_count;
} else {
avifDiagnosticsPrintf(diag, "Box[iinf] has an unsupported version %u", version);
return AVIF_FALSE;
}
for (uint32_t entryIndex = 0; entryIndex < entryCount; ++entryIndex) {
avifBoxHeader infeHeader;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &infeHeader));
if (!memcmp(infeHeader.type, "infe", 4)) {
AVIF_CHECK(avifParseItemInfoEntry(meta, avifROStreamCurrent(&s), infeHeader.size, diag));
} else {
// These must all be type infe
avifDiagnosticsPrintf(diag, "Box[iinf] contains a box that isn't type 'infe'");
return AVIF_FALSE;
}
AVIF_CHECK(avifROStreamSkip(&s, infeHeader.size));
}
return AVIF_TRUE;
}
static avifBool avifParseItemReferenceBox(avifMeta * meta, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[iref]");
uint8_t version;
AVIF_CHECK(avifROStreamReadVersionAndFlags(&s, &version, NULL));
while (avifROStreamHasBytesLeft(&s, 1)) {
avifBoxHeader irefHeader;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &irefHeader));
uint32_t fromID = 0;
if (version == 0) {
uint16_t tmp;
AVIF_CHECK(avifROStreamReadU16(&s, &tmp)); // unsigned int(16) from_item_ID;
fromID = tmp;
} else if (version == 1) {
AVIF_CHECK(avifROStreamReadU32(&s, &fromID)); // unsigned int(32) from_item_ID;
} else {
// unsupported iref version, skip it
break;
}
uint16_t referenceCount = 0;
AVIF_CHECK(avifROStreamReadU16(&s, &referenceCount)); // unsigned int(16) reference_count;
for (uint16_t refIndex = 0; refIndex < referenceCount; ++refIndex) {
uint32_t toID = 0;
if (version == 0) {
uint16_t tmp;
AVIF_CHECK(avifROStreamReadU16(&s, &tmp)); // unsigned int(16) to_item_ID;
toID = tmp;
} else if (version == 1) {
AVIF_CHECK(avifROStreamReadU32(&s, &toID)); // unsigned int(32) to_item_ID;
} else {
// unsupported iref version, skip it
break;
}
// Read this reference as "{fromID} is a {irefType} for {toID}"
if (fromID && toID) {
avifDecoderItem * item = avifMetaFindItem(meta, fromID);
if (!item) {
avifDiagnosticsPrintf(diag, "Box[iref] has an invalid item ID [%u]", fromID);
return AVIF_FALSE;
}
if (!memcmp(irefHeader.type, "thmb", 4)) {
item->thumbnailForID = toID;
} else if (!memcmp(irefHeader.type, "auxl", 4)) {
item->auxForID = toID;
} else if (!memcmp(irefHeader.type, "cdsc", 4)) {
item->descForID = toID;
} else if (!memcmp(irefHeader.type, "dimg", 4)) {
// derived images refer in the opposite direction
avifDecoderItem * dimg = avifMetaFindItem(meta, toID);
if (!dimg) {
avifDiagnosticsPrintf(diag, "Box[iref] has an invalid item ID dimg ref [%u]", toID);
return AVIF_FALSE;
}
dimg->dimgForID = fromID;
} else if (!memcmp(irefHeader.type, "prem", 4)) {
item->premByID = toID;
}
}
}
}
return AVIF_TRUE;
}
static avifBool avifParseMetaBox(avifMeta * meta, uint64_t rawOffset, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[meta]");
AVIF_CHECK(avifROStreamReadAndEnforceVersion(&s, 0));
++meta->idatID; // for tracking idat
avifBool firstBox = AVIF_TRUE;
uint32_t uniqueBoxFlags = 0;
while (avifROStreamHasBytesLeft(&s, 1)) {
avifBoxHeader header;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &header));
if (firstBox) {
if (!memcmp(header.type, "hdlr", 4)) {
AVIF_CHECK(uniqueBoxSeen(&uniqueBoxFlags, 0, "meta", "hdlr", diag));
AVIF_CHECK(avifParseHandlerBox(avifROStreamCurrent(&s), header.size, diag));
firstBox = AVIF_FALSE;
} else {
// hdlr must be the first box!
avifDiagnosticsPrintf(diag, "Box[meta] does not have a Box[hdlr] as its first child box");
return AVIF_FALSE;
}
} else if (!memcmp(header.type, "iloc", 4)) {
AVIF_CHECK(uniqueBoxSeen(&uniqueBoxFlags, 1, "meta", "iloc", diag));
AVIF_CHECK(avifParseItemLocationBox(meta, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "pitm", 4)) {
AVIF_CHECK(uniqueBoxSeen(&uniqueBoxFlags, 2, "meta", "pitm", diag));
AVIF_CHECK(avifParsePrimaryItemBox(meta, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "idat", 4)) {
AVIF_CHECK(uniqueBoxSeen(&uniqueBoxFlags, 3, "meta", "idat", diag));
AVIF_CHECK(avifParseItemDataBox(meta, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "iprp", 4)) {
AVIF_CHECK(uniqueBoxSeen(&uniqueBoxFlags, 4, "meta", "iprp", diag));
AVIF_CHECK(avifParseItemPropertiesBox(meta, rawOffset + avifROStreamOffset(&s), avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "iinf", 4)) {
AVIF_CHECK(uniqueBoxSeen(&uniqueBoxFlags, 5, "meta", "iinf", diag));
AVIF_CHECK(avifParseItemInfoBox(meta, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "iref", 4)) {
AVIF_CHECK(uniqueBoxSeen(&uniqueBoxFlags, 6, "meta", "iref", diag));
AVIF_CHECK(avifParseItemReferenceBox(meta, avifROStreamCurrent(&s), header.size, diag));
}
AVIF_CHECK(avifROStreamSkip(&s, header.size));
}
if (firstBox) {
// The meta box must not be empty (it must contain at least a hdlr box)
avifDiagnosticsPrintf(diag, "Box[meta] has no child boxes");
return AVIF_FALSE;
}
return AVIF_TRUE;
}
static avifBool avifParseTrackHeaderBox(avifTrack * track,
const uint8_t * raw,
size_t rawLen,
uint32_t imageSizeLimit,
uint32_t imageDimensionLimit,
avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[tkhd]");
uint8_t version;
AVIF_CHECK(avifROStreamReadVersionAndFlags(&s, &version, NULL));
uint32_t ignored32, trackID;
uint64_t ignored64;
if (version == 1) {
AVIF_CHECK(avifROStreamReadU64(&s, &ignored64)); // unsigned int(64) creation_time;
AVIF_CHECK(avifROStreamReadU64(&s, &ignored64)); // unsigned int(64) modification_time;
AVIF_CHECK(avifROStreamReadU32(&s, &trackID)); // unsigned int(32) track_ID;
AVIF_CHECK(avifROStreamReadU32(&s, &ignored32)); // const unsigned int(32) reserved = 0;
AVIF_CHECK(avifROStreamReadU64(&s, &ignored64)); // unsigned int(64) duration;
} else if (version == 0) {
AVIF_CHECK(avifROStreamReadU32(&s, &ignored32)); // unsigned int(32) creation_time;
AVIF_CHECK(avifROStreamReadU32(&s, &ignored32)); // unsigned int(32) modification_time;
AVIF_CHECK(avifROStreamReadU32(&s, &trackID)); // unsigned int(32) track_ID;
AVIF_CHECK(avifROStreamReadU32(&s, &ignored32)); // const unsigned int(32) reserved = 0;
AVIF_CHECK(avifROStreamReadU32(&s, &ignored32)); // unsigned int(32) duration;
} else {
// Unsupported version
avifDiagnosticsPrintf(diag, "Box[tkhd] has an unsupported version [%u]", version);
return AVIF_FALSE;
}
// Skipping the following 52 bytes here:
// ------------------------------------
// const unsigned int(32)[2] reserved = 0;
// template int(16) layer = 0;
// template int(16) alternate_group = 0;
// template int(16) volume = {if track_is_audio 0x0100 else 0};
// const unsigned int(16) reserved = 0;
// template int(32)[9] matrix= { 0x00010000,0,0,0,0x00010000,0,0,0,0x40000000 }; // unity matrix
AVIF_CHECK(avifROStreamSkip(&s, 52));
uint32_t width, height;
AVIF_CHECK(avifROStreamReadU32(&s, &width)); // unsigned int(32) width;
AVIF_CHECK(avifROStreamReadU32(&s, &height)); // unsigned int(32) height;
track->width = width >> 16;
track->height = height >> 16;
if ((track->width == 0) || (track->height == 0)) {
avifDiagnosticsPrintf(diag, "Track ID [%u] has an invalid size [%ux%u]", track->id, track->width, track->height);
return AVIF_FALSE;
}
if (avifDimensionsTooLarge(track->width, track->height, imageSizeLimit, imageDimensionLimit)) {
avifDiagnosticsPrintf(diag, "Track ID [%u] dimensions are too large [%ux%u]", track->id, track->width, track->height);
return AVIF_FALSE;
}
// TODO: support scaling based on width/height track header info?
track->id = trackID;
return AVIF_TRUE;
}
static avifBool avifParseMediaHeaderBox(avifTrack * track, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[mdhd]");
uint8_t version;
AVIF_CHECK(avifROStreamReadVersionAndFlags(&s, &version, NULL));
uint32_t ignored32, mediaTimescale, mediaDuration32;
uint64_t ignored64, mediaDuration64;
if (version == 1) {
AVIF_CHECK(avifROStreamReadU64(&s, &ignored64)); // unsigned int(64) creation_time;
AVIF_CHECK(avifROStreamReadU64(&s, &ignored64)); // unsigned int(64) modification_time;
AVIF_CHECK(avifROStreamReadU32(&s, &mediaTimescale)); // unsigned int(32) timescale;
AVIF_CHECK(avifROStreamReadU64(&s, &mediaDuration64)); // unsigned int(64) duration;
track->mediaDuration = mediaDuration64;
} else if (version == 0) {
AVIF_CHECK(avifROStreamReadU32(&s, &ignored32)); // unsigned int(32) creation_time;
AVIF_CHECK(avifROStreamReadU32(&s, &ignored32)); // unsigned int(32) modification_time;
AVIF_CHECK(avifROStreamReadU32(&s, &mediaTimescale)); // unsigned int(32) timescale;
AVIF_CHECK(avifROStreamReadU32(&s, &mediaDuration32)); // unsigned int(32) duration;
track->mediaDuration = (uint64_t)mediaDuration32;
} else {
// Unsupported version
avifDiagnosticsPrintf(diag, "Box[mdhd] has an unsupported version [%u]", version);
return AVIF_FALSE;
}
track->mediaTimescale = mediaTimescale;
return AVIF_TRUE;
}
static avifBool avifParseChunkOffsetBox(avifSampleTable * sampleTable, avifBool largeOffsets, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, largeOffsets ? "Box[co64]" : "Box[stco]");
AVIF_CHECK(avifROStreamReadAndEnforceVersion(&s, 0));
uint32_t entryCount;
AVIF_CHECK(avifROStreamReadU32(&s, &entryCount)); // unsigned int(32) entry_count;
for (uint32_t i = 0; i < entryCount; ++i) {
uint64_t offset;
if (largeOffsets) {
AVIF_CHECK(avifROStreamReadU64(&s, &offset)); // unsigned int(32) chunk_offset;
} else {
uint32_t offset32;
AVIF_CHECK(avifROStreamReadU32(&s, &offset32)); // unsigned int(32) chunk_offset;
offset = (uint64_t)offset32;
}
avifSampleTableChunk * chunk = (avifSampleTableChunk *)avifArrayPushPtr(&sampleTable->chunks);
chunk->offset = offset;
}
return AVIF_TRUE;
}
static avifBool avifParseSampleToChunkBox(avifSampleTable * sampleTable, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[stsc]");
AVIF_CHECK(avifROStreamReadAndEnforceVersion(&s, 0));
uint32_t entryCount;
AVIF_CHECK(avifROStreamReadU32(&s, &entryCount)); // unsigned int(32) entry_count;
uint32_t prevFirstChunk = 0;
for (uint32_t i = 0; i < entryCount; ++i) {
avifSampleTableSampleToChunk * sampleToChunk = (avifSampleTableSampleToChunk *)avifArrayPushPtr(&sampleTable->sampleToChunks);
AVIF_CHECK(avifROStreamReadU32(&s, &sampleToChunk->firstChunk)); // unsigned int(32) first_chunk;
AVIF_CHECK(avifROStreamReadU32(&s, &sampleToChunk->samplesPerChunk)); // unsigned int(32) samples_per_chunk;
AVIF_CHECK(avifROStreamReadU32(&s, &sampleToChunk->sampleDescriptionIndex)); // unsigned int(32) sample_description_index;
// The first_chunk fields should start with 1 and be strictly increasing.
if (i == 0) {
if (sampleToChunk->firstChunk != 1) {
avifDiagnosticsPrintf(diag, "Box[stsc] does not begin with chunk 1 [%u]", sampleToChunk->firstChunk);
return AVIF_FALSE;
}
} else {
if (sampleToChunk->firstChunk <= prevFirstChunk) {
avifDiagnosticsPrintf(diag, "Box[stsc] chunks are not strictly increasing");
return AVIF_FALSE;
}
}
prevFirstChunk = sampleToChunk->firstChunk;
}
return AVIF_TRUE;
}
static avifBool avifParseSampleSizeBox(avifSampleTable * sampleTable, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[stsz]");
AVIF_CHECK(avifROStreamReadAndEnforceVersion(&s, 0));
uint32_t allSamplesSize, sampleCount;
AVIF_CHECK(avifROStreamReadU32(&s, &allSamplesSize)); // unsigned int(32) sample_size;
AVIF_CHECK(avifROStreamReadU32(&s, &sampleCount)); // unsigned int(32) sample_count;
if (allSamplesSize > 0) {
sampleTable->allSamplesSize = allSamplesSize;
} else {
for (uint32_t i = 0; i < sampleCount; ++i) {
avifSampleTableSampleSize * sampleSize = (avifSampleTableSampleSize *)avifArrayPushPtr(&sampleTable->sampleSizes);
AVIF_CHECK(avifROStreamReadU32(&s, &sampleSize->size)); // unsigned int(32) entry_size;
}
}
return AVIF_TRUE;
}
static avifBool avifParseSyncSampleBox(avifSampleTable * sampleTable, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[stss]");
AVIF_CHECK(avifROStreamReadAndEnforceVersion(&s, 0));
uint32_t entryCount;
AVIF_CHECK(avifROStreamReadU32(&s, &entryCount)); // unsigned int(32) entry_count;
for (uint32_t i = 0; i < entryCount; ++i) {
uint32_t sampleNumber = 0;
AVIF_CHECK(avifROStreamReadU32(&s, &sampleNumber)); // unsigned int(32) sample_number;
avifSyncSample * syncSample = (avifSyncSample *)avifArrayPushPtr(&sampleTable->syncSamples);
syncSample->sampleNumber = sampleNumber;
}
return AVIF_TRUE;
}
static avifBool avifParseTimeToSampleBox(avifSampleTable * sampleTable, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[stts]");
AVIF_CHECK(avifROStreamReadAndEnforceVersion(&s, 0));
uint32_t entryCount;
AVIF_CHECK(avifROStreamReadU32(&s, &entryCount)); // unsigned int(32) entry_count;
for (uint32_t i = 0; i < entryCount; ++i) {
avifSampleTableTimeToSample * timeToSample = (avifSampleTableTimeToSample *)avifArrayPushPtr(&sampleTable->timeToSamples);
AVIF_CHECK(avifROStreamReadU32(&s, &timeToSample->sampleCount)); // unsigned int(32) sample_count;
AVIF_CHECK(avifROStreamReadU32(&s, &timeToSample->sampleDelta)); // unsigned int(32) sample_delta;
}
return AVIF_TRUE;
}
static avifBool avifParseSampleDescriptionBox(avifSampleTable * sampleTable,
uint64_t rawOffset,
const uint8_t * raw,
size_t rawLen,
avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[stsd]");
AVIF_CHECK(avifROStreamReadAndEnforceVersion(&s, 0));
uint32_t entryCount;
AVIF_CHECK(avifROStreamReadU32(&s, &entryCount)); // unsigned int(32) entry_count;
for (uint32_t i = 0; i < entryCount; ++i) {
avifBoxHeader sampleEntryHeader;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &sampleEntryHeader));
avifSampleDescription * description = (avifSampleDescription *)avifArrayPushPtr(&sampleTable->sampleDescriptions);
if (!avifArrayCreate(&description->properties, sizeof(avifProperty), 16)) {
avifArrayPop(&sampleTable->sampleDescriptions);
return AVIF_FALSE;
}
memcpy(description->format, sampleEntryHeader.type, sizeof(description->format));
size_t remainingBytes = avifROStreamRemainingBytes(&s);
if (!memcmp(description->format, "av01", 4) && (remainingBytes > VISUALSAMPLEENTRY_SIZE)) {
AVIF_CHECK(avifParseItemPropertyContainerBox(&description->properties,
rawOffset + avifROStreamOffset(&s) + VISUALSAMPLEENTRY_SIZE,
avifROStreamCurrent(&s) + VISUALSAMPLEENTRY_SIZE,
remainingBytes - VISUALSAMPLEENTRY_SIZE,
diag));
}
AVIF_CHECK(avifROStreamSkip(&s, sampleEntryHeader.size));
}
return AVIF_TRUE;
}
static avifBool avifParseSampleTableBox(avifTrack * track, uint64_t rawOffset, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
if (track->sampleTable) {
// A TrackBox may only have one SampleTable
avifDiagnosticsPrintf(diag, "Duplicate Box[stbl] for a single track detected");
return AVIF_FALSE;
}
track->sampleTable = avifSampleTableCreate();
BEGIN_STREAM(s, raw, rawLen, diag, "Box[stbl]");
while (avifROStreamHasBytesLeft(&s, 1)) {
avifBoxHeader header;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &header));
if (!memcmp(header.type, "stco", 4)) {
AVIF_CHECK(avifParseChunkOffsetBox(track->sampleTable, AVIF_FALSE, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "co64", 4)) {
AVIF_CHECK(avifParseChunkOffsetBox(track->sampleTable, AVIF_TRUE, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "stsc", 4)) {
AVIF_CHECK(avifParseSampleToChunkBox(track->sampleTable, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "stsz", 4)) {
AVIF_CHECK(avifParseSampleSizeBox(track->sampleTable, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "stss", 4)) {
AVIF_CHECK(avifParseSyncSampleBox(track->sampleTable, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "stts", 4)) {
AVIF_CHECK(avifParseTimeToSampleBox(track->sampleTable, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "stsd", 4)) {
AVIF_CHECK(avifParseSampleDescriptionBox(track->sampleTable,
rawOffset + avifROStreamOffset(&s),
avifROStreamCurrent(&s),
header.size,
diag));
}
AVIF_CHECK(avifROStreamSkip(&s, header.size));
}
return AVIF_TRUE;
}
static avifBool avifParseMediaInformationBox(avifTrack * track, uint64_t rawOffset, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[minf]");
while (avifROStreamHasBytesLeft(&s, 1)) {
avifBoxHeader header;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &header));
if (!memcmp(header.type, "stbl", 4)) {
AVIF_CHECK(avifParseSampleTableBox(track, rawOffset + avifROStreamOffset(&s), avifROStreamCurrent(&s), header.size, diag));
}
AVIF_CHECK(avifROStreamSkip(&s, header.size));
}
return AVIF_TRUE;
}
static avifBool avifParseMediaBox(avifTrack * track, uint64_t rawOffset, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[mdia]");
while (avifROStreamHasBytesLeft(&s, 1)) {
avifBoxHeader header;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &header));
if (!memcmp(header.type, "mdhd", 4)) {
AVIF_CHECK(avifParseMediaHeaderBox(track, avifROStreamCurrent(&s), header.size, diag));
} else if (!memcmp(header.type, "minf", 4)) {
AVIF_CHECK(avifParseMediaInformationBox(track, rawOffset + avifROStreamOffset(&s), avifROStreamCurrent(&s), header.size, diag));
}
AVIF_CHECK(avifROStreamSkip(&s, header.size));
}
return AVIF_TRUE;
}
static avifBool avifTrackReferenceBox(avifTrack * track, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[tref]");
while (avifROStreamHasBytesLeft(&s, 1)) {
avifBoxHeader header;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &header));
if (!memcmp(header.type, "auxl", 4)) {
uint32_t toID;
AVIF_CHECK(avifROStreamReadU32(&s, &toID)); // unsigned int(32) track_IDs[];
AVIF_CHECK(avifROStreamSkip(&s, header.size - sizeof(uint32_t))); // just take the first one
track->auxForID = toID;
} else if (!memcmp(header.type, "prem", 4)) {
uint32_t byID;
AVIF_CHECK(avifROStreamReadU32(&s, &byID)); // unsigned int(32) track_IDs[];
AVIF_CHECK(avifROStreamSkip(&s, header.size - sizeof(uint32_t))); // just take the first one
track->premByID = byID;
} else {
AVIF_CHECK(avifROStreamSkip(&s, header.size));
}
}
return AVIF_TRUE;
}
static avifBool avifParseTrackBox(avifDecoderData * data, uint64_t rawOffset, const uint8_t * raw, size_t rawLen, uint32_t imageSizeLimit, uint32_t imageDimensionLimit)
{
BEGIN_STREAM(s, raw, rawLen, data->diag, "Box[trak]");
avifTrack * track = avifDecoderDataCreateTrack(data);
while (avifROStreamHasBytesLeft(&s, 1)) {
avifBoxHeader header;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &header));
if (!memcmp(header.type, "tkhd", 4)) {
AVIF_CHECK(avifParseTrackHeaderBox(track, avifROStreamCurrent(&s), header.size, imageSizeLimit, imageDimensionLimit, data->diag));
} else if (!memcmp(header.type, "meta", 4)) {
AVIF_CHECK(avifParseMetaBox(track->meta, rawOffset + avifROStreamOffset(&s), avifROStreamCurrent(&s), header.size, data->diag));
} else if (!memcmp(header.type, "mdia", 4)) {
AVIF_CHECK(avifParseMediaBox(track, rawOffset + avifROStreamOffset(&s), avifROStreamCurrent(&s), header.size, data->diag));
} else if (!memcmp(header.type, "tref", 4)) {
AVIF_CHECK(avifTrackReferenceBox(track, avifROStreamCurrent(&s), header.size, data->diag));
}
AVIF_CHECK(avifROStreamSkip(&s, header.size));
}
return AVIF_TRUE;
}
static avifBool avifParseMovieBox(avifDecoderData * data, uint64_t rawOffset, const uint8_t * raw, size_t rawLen, uint32_t imageSizeLimit, uint32_t imageDimensionLimit)
{
BEGIN_STREAM(s, raw, rawLen, data->diag, "Box[moov]");
while (avifROStreamHasBytesLeft(&s, 1)) {
avifBoxHeader header;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &header));
if (!memcmp(header.type, "trak", 4)) {
AVIF_CHECK(
avifParseTrackBox(data, rawOffset + avifROStreamOffset(&s), avifROStreamCurrent(&s), header.size, imageSizeLimit, imageDimensionLimit));
}
AVIF_CHECK(avifROStreamSkip(&s, header.size));
}
return AVIF_TRUE;
}
static avifBool avifParseFileTypeBox(avifFileType * ftyp, const uint8_t * raw, size_t rawLen, avifDiagnostics * diag)
{
BEGIN_STREAM(s, raw, rawLen, diag, "Box[ftyp]");
AVIF_CHECK(avifROStreamRead(&s, ftyp->majorBrand, 4));
AVIF_CHECK(avifROStreamReadU32(&s, &ftyp->minorVersion));
size_t compatibleBrandsBytes = avifROStreamRemainingBytes(&s);
if ((compatibleBrandsBytes % 4) != 0) {
avifDiagnosticsPrintf(diag, "Box[ftyp] contains a compatible brands section that isn't divisible by 4 [%zu]", compatibleBrandsBytes);
return AVIF_FALSE;
}
ftyp->compatibleBrands = avifROStreamCurrent(&s);
AVIF_CHECK(avifROStreamSkip(&s, compatibleBrandsBytes));
ftyp->compatibleBrandsCount = (int)compatibleBrandsBytes / 4;
return AVIF_TRUE;
}
static avifBool avifFileTypeHasBrand(avifFileType * ftyp, const char * brand);
static avifBool avifFileTypeIsCompatible(avifFileType * ftyp);
static avifResult avifParse(avifDecoder * decoder)
{
// Note: this top-level function is the only avifParse*() function that returns avifResult instead of avifBool.
// Be sure to use AVIF_CHECKERR() in this function with an explicit error result instead of simply using AVIF_CHECK().
avifResult readResult;
uint64_t parseOffset = 0;
avifDecoderData * data = decoder->data;
avifBool ftypSeen = AVIF_FALSE;
avifBool metaSeen = AVIF_FALSE;
avifBool moovSeen = AVIF_FALSE;
avifBool needsMeta = AVIF_FALSE;
avifBool needsMoov = AVIF_FALSE;
for (;;) {
// Read just enough to get the next box header (a max of 32 bytes)
avifROData headerContents;
if ((decoder->io->sizeHint > 0) && (parseOffset > decoder->io->sizeHint)) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
readResult = decoder->io->read(decoder->io, 0, parseOffset, 32, &headerContents);
if (readResult != AVIF_RESULT_OK) {
return readResult;
}
if (!headerContents.size) {
// If we got AVIF_RESULT_OK from the reader but received 0 bytes,
// we've reached the end of the file with no errors. Hooray!
break;
}
// Parse the header, and find out how many bytes it actually was
BEGIN_STREAM(headerStream, headerContents.data, headerContents.size, &decoder->diag, "File-level box header");
avifBoxHeader header;
AVIF_CHECKERR(avifROStreamReadBoxHeaderPartial(&headerStream, &header), AVIF_RESULT_BMFF_PARSE_FAILED);
parseOffset += headerStream.offset;
assert((decoder->io->sizeHint == 0) || (parseOffset <= decoder->io->sizeHint));
// Try to get the remainder of the box, if necessary
uint64_t boxOffset = 0;
avifROData boxContents = AVIF_DATA_EMPTY;
// TODO: reorg this code to only do these memcmps once each
if (!memcmp(header.type, "ftyp", 4) || !memcmp(header.type, "meta", 4) || !memcmp(header.type, "moov", 4)) {
boxOffset = parseOffset;
readResult = decoder->io->read(decoder->io, 0, parseOffset, header.size, &boxContents);
if (readResult != AVIF_RESULT_OK) {
return readResult;
}
if (boxContents.size != header.size) {
// A truncated box, bail out
return AVIF_RESULT_TRUNCATED_DATA;
}
} else if (header.size > (UINT64_MAX - parseOffset)) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
parseOffset += header.size;
if (!memcmp(header.type, "ftyp", 4)) {
AVIF_CHECKERR(!ftypSeen, AVIF_RESULT_BMFF_PARSE_FAILED);
avifFileType ftyp;
AVIF_CHECKERR(avifParseFileTypeBox(&ftyp, boxContents.data, boxContents.size, data->diag), AVIF_RESULT_BMFF_PARSE_FAILED);
if (!avifFileTypeIsCompatible(&ftyp)) {
return AVIF_RESULT_INVALID_FTYP;
}
ftypSeen = AVIF_TRUE;
memcpy(data->majorBrand, ftyp.majorBrand, 4); // Remember the major brand for future AVIF_DECODER_SOURCE_AUTO decisions
needsMeta = avifFileTypeHasBrand(&ftyp, "avif");
needsMoov = avifFileTypeHasBrand(&ftyp, "avis");
} else if (!memcmp(header.type, "meta", 4)) {
AVIF_CHECKERR(!metaSeen, AVIF_RESULT_BMFF_PARSE_FAILED);
AVIF_CHECKERR(avifParseMetaBox(data->meta, boxOffset, boxContents.data, boxContents.size, data->diag),
AVIF_RESULT_BMFF_PARSE_FAILED);
metaSeen = AVIF_TRUE;
} else if (!memcmp(header.type, "moov", 4)) {
AVIF_CHECKERR(!moovSeen, AVIF_RESULT_BMFF_PARSE_FAILED);
AVIF_CHECKERR(avifParseMovieBox(data, boxOffset, boxContents.data, boxContents.size, decoder->imageSizeLimit, decoder->imageDimensionLimit),
AVIF_RESULT_BMFF_PARSE_FAILED);
moovSeen = AVIF_TRUE;
}
// See if there is enough information to consider Parse() a success and early-out:
// * If the brand 'avif' is present, require a meta box
// * If the brand 'avis' is present, require a moov box
if (ftypSeen && (!needsMeta || metaSeen) && (!needsMoov || moovSeen)) {
return AVIF_RESULT_OK;
}
}
if (!ftypSeen) {
return AVIF_RESULT_INVALID_FTYP;
}
if ((needsMeta && !metaSeen) || (needsMoov && !moovSeen)) {
return AVIF_RESULT_TRUNCATED_DATA;
}
return AVIF_RESULT_OK;
}
// ---------------------------------------------------------------------------
static avifBool avifFileTypeHasBrand(avifFileType * ftyp, const char * brand)
{
if (!memcmp(ftyp->majorBrand, brand, 4)) {
return AVIF_TRUE;
}
for (int compatibleBrandIndex = 0; compatibleBrandIndex < ftyp->compatibleBrandsCount; ++compatibleBrandIndex) {
const uint8_t * compatibleBrand = &ftyp->compatibleBrands[4 * compatibleBrandIndex];
if (!memcmp(compatibleBrand, brand, 4)) {
return AVIF_TRUE;
}
}
return AVIF_FALSE;
}
static avifBool avifFileTypeIsCompatible(avifFileType * ftyp)
{
return avifFileTypeHasBrand(ftyp, "avif") || avifFileTypeHasBrand(ftyp, "avis");
}
avifBool avifPeekCompatibleFileType(const avifROData * input)
{
BEGIN_STREAM(s, input->data, input->size, NULL, NULL);
avifBoxHeader header;
AVIF_CHECK(avifROStreamReadBoxHeader(&s, &header));
if (memcmp(header.type, "ftyp", 4)) {
return AVIF_FALSE;
}
avifFileType ftyp;
memset(&ftyp, 0, sizeof(avifFileType));
avifBool parsed = avifParseFileTypeBox(&ftyp, avifROStreamCurrent(&s), header.size, NULL);
if (!parsed) {
return AVIF_FALSE;
}
return avifFileTypeIsCompatible(&ftyp);
}
// ---------------------------------------------------------------------------
avifDecoder * avifDecoderCreate(void)
{
avifDecoder * decoder = (avifDecoder *)avifAlloc(sizeof(avifDecoder));
memset(decoder, 0, sizeof(avifDecoder));
decoder->maxThreads = 1;
decoder->imageSizeLimit = AVIF_DEFAULT_IMAGE_SIZE_LIMIT;
decoder->imageDimensionLimit = AVIF_DEFAULT_IMAGE_DIMENSION_LIMIT;
decoder->imageCountLimit = AVIF_DEFAULT_IMAGE_COUNT_LIMIT;
decoder->strictFlags = AVIF_STRICT_ENABLED;
return decoder;
}
static void avifDecoderCleanup(avifDecoder * decoder)
{
if (decoder->data) {
avifDecoderDataDestroy(decoder->data);
decoder->data = NULL;
}
if (decoder->image) {
avifImageDestroy(decoder->image);
decoder->image = NULL;
}
avifDiagnosticsClearError(&decoder->diag);
}
void avifDecoderDestroy(avifDecoder * decoder)
{
avifDecoderCleanup(decoder);
avifIODestroy(decoder->io);
avifFree(decoder);
}
avifResult avifDecoderSetSource(avifDecoder * decoder, avifDecoderSource source)
{
decoder->requestedSource = source;
return avifDecoderReset(decoder);
}
void avifDecoderSetIO(avifDecoder * decoder, avifIO * io)
{
avifIODestroy(decoder->io);
decoder->io = io;
}
avifResult avifDecoderSetIOMemory(avifDecoder * decoder, const uint8_t * data, size_t size)
{
avifIO * io = avifIOCreateMemoryReader(data, size);
assert(io);
avifDecoderSetIO(decoder, io);
return AVIF_RESULT_OK;
}
avifResult avifDecoderSetIOFile(avifDecoder * decoder, const char * filename)
{
avifIO * io = avifIOCreateFileReader(filename);
if (!io) {
return AVIF_RESULT_IO_ERROR;
}
avifDecoderSetIO(decoder, io);
return AVIF_RESULT_OK;
}
// 0-byte extents are ignored/overwritten during the merge, as they are the signal from helper
// functions that no extent was necessary for this given sample. If both provided extents are
// >0 bytes, this will set dst to be an extent that bounds both supplied extents.
static avifResult avifExtentMerge(avifExtent * dst, const avifExtent * src)
{
if (!dst->size) {
*dst = *src;
return AVIF_RESULT_OK;
}
if (!src->size) {
return AVIF_RESULT_OK;
}
const uint64_t minExtent1 = dst->offset;
const uint64_t maxExtent1 = dst->offset + dst->size;
const uint64_t minExtent2 = src->offset;
const uint64_t maxExtent2 = src->offset + src->size;
dst->offset = AVIF_MIN(minExtent1, minExtent2);
const uint64_t extentLength = AVIF_MAX(maxExtent1, maxExtent2) - dst->offset;
if (extentLength > SIZE_MAX) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
dst->size = (size_t)extentLength;
return AVIF_RESULT_OK;
}
avifResult avifDecoderNthImageMaxExtent(const avifDecoder * decoder, uint32_t frameIndex, avifExtent * outExtent)
{
if (!decoder->data) {
// Nothing has been parsed yet
return AVIF_RESULT_NO_CONTENT;
}
memset(outExtent, 0, sizeof(avifExtent));
uint32_t startFrameIndex = avifDecoderNearestKeyframe(decoder, frameIndex);
uint32_t endFrameIndex = frameIndex;
for (uint32_t currentFrameIndex = startFrameIndex; currentFrameIndex <= endFrameIndex; ++currentFrameIndex) {
for (unsigned int tileIndex = 0; tileIndex < decoder->data->tiles.count; ++tileIndex) {
avifTile * tile = &decoder->data->tiles.tile[tileIndex];
if (currentFrameIndex >= tile->input->samples.count) {
return AVIF_RESULT_NO_IMAGES_REMAINING;
}
avifDecodeSample * sample = &tile->input->samples.sample[currentFrameIndex];
avifExtent sampleExtent;
if (sample->itemID) {
// The data comes from an item. Let avifDecoderItemMaxExtent() do the heavy lifting.
avifDecoderItem * item = avifMetaFindItem(decoder->data->meta, sample->itemID);
avifResult maxExtentResult = avifDecoderItemMaxExtent(item, sample, &sampleExtent);
if (maxExtentResult != AVIF_RESULT_OK) {
return maxExtentResult;
}
} else {
// The data likely comes from a sample table. Use the sample position directly.
sampleExtent.offset = sample->offset;
sampleExtent.size = sample->size;
}
if (sampleExtent.size > UINT64_MAX - sampleExtent.offset) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
avifResult extentMergeResult = avifExtentMerge(outExtent, &sampleExtent);
if (extentMergeResult != AVIF_RESULT_OK) {
return extentMergeResult;
}
}
}
return AVIF_RESULT_OK;
}
static avifResult avifDecoderPrepareSample(avifDecoder * decoder, avifDecodeSample * sample, size_t partialByteCount)
{
if (!sample->data.size || sample->partialData) {
// This sample hasn't been read from IO or had its extents fully merged yet.
size_t bytesToRead = sample->size;
if (partialByteCount && (bytesToRead > partialByteCount)) {
bytesToRead = partialByteCount;
}
if (sample->itemID) {
// The data comes from an item. Let avifDecoderItemRead() do the heavy lifting.
avifDecoderItem * item = avifMetaFindItem(decoder->data->meta, sample->itemID);
avifROData itemContents;
if (sample->offset > SIZE_MAX) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
size_t offset = (size_t)sample->offset;
avifResult readResult = avifDecoderItemRead(item, decoder->io, &itemContents, offset, bytesToRead, &decoder->diag);
if (readResult != AVIF_RESULT_OK) {
return readResult;
}
// avifDecoderItemRead is guaranteed to already be persisted by either the underlying IO
// or by mergedExtents; just reuse the buffer here.
sample->data = itemContents;
sample->ownsData = AVIF_FALSE;
sample->partialData = item->partialMergedExtents;
} else {
// The data likely comes from a sample table. Pull the sample and make a copy if necessary.
avifROData sampleContents;
if ((decoder->io->sizeHint > 0) && (sample->offset > decoder->io->sizeHint)) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
avifResult readResult = decoder->io->read(decoder->io, 0, sample->offset, bytesToRead, &sampleContents);
if (readResult != AVIF_RESULT_OK) {
return readResult;
}
if (sampleContents.size != bytesToRead) {
return AVIF_RESULT_TRUNCATED_DATA;
}
sample->ownsData = !decoder->io->persistent;
sample->partialData = (bytesToRead != sample->size);
if (decoder->io->persistent) {
sample->data = sampleContents;
} else {
avifRWDataSet((avifRWData *)&sample->data, sampleContents.data, sampleContents.size);
}
}
}
return AVIF_RESULT_OK;
}
avifResult avifDecoderParse(avifDecoder * decoder)
{
avifDiagnosticsClearError(&decoder->diag);
// An imageSizeLimit greater than AVIF_DEFAULT_IMAGE_SIZE_LIMIT and the special value of 0 to
// disable the limit are not yet implemented.
if ((decoder->imageSizeLimit > AVIF_DEFAULT_IMAGE_SIZE_LIMIT) || (decoder->imageSizeLimit == 0)) {
return AVIF_RESULT_NOT_IMPLEMENTED;
}
if (!decoder->io || !decoder->io->read) {
return AVIF_RESULT_IO_NOT_SET;
}
// Cleanup anything lingering in the decoder
avifDecoderCleanup(decoder);
// -----------------------------------------------------------------------
// Parse BMFF boxes
decoder->data = avifDecoderDataCreate();
decoder->data->diag = &decoder->diag;
avifResult parseResult = avifParse(decoder);
if (parseResult != AVIF_RESULT_OK) {
return parseResult;
}
// Walk the decoded items (if any) and harvest ispe
avifDecoderData * data = decoder->data;
for (uint32_t itemIndex = 0; itemIndex < data->meta->items.count; ++itemIndex) {
avifDecoderItem * item = &data->meta->items.item[itemIndex];
if (!item->size) {
continue;
}
if (item->hasUnsupportedEssentialProperty) {
// An essential property isn't supported by libavif; ignore the item.
continue;
}
avifBool isGrid = (memcmp(item->type, "grid", 4) == 0);
if (memcmp(item->type, "av01", 4) && !isGrid) {
// probably exif or some other data
continue;
}
const avifProperty * ispeProp = avifPropertyArrayFind(&item->properties, "ispe");
if (ispeProp) {
item->width = ispeProp->u.ispe.width;
item->height = ispeProp->u.ispe.height;
if ((item->width == 0) || (item->height == 0)) {
avifDiagnosticsPrintf(data->diag, "Item ID [%u] has an invalid size [%ux%u]", item->id, item->width, item->height);
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
if (avifDimensionsTooLarge(item->width, item->height, decoder->imageSizeLimit, decoder->imageDimensionLimit)) {
avifDiagnosticsPrintf(data->diag, "Item ID [%u] dimensions are too large [%ux%u]", item->id, item->width, item->height);
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
} else {
const avifProperty * auxCProp = avifPropertyArrayFind(&item->properties, "auxC");
if (auxCProp && isAlphaURN(auxCProp->u.auxC.auxType)) {
if (decoder->strictFlags & AVIF_STRICT_ALPHA_ISPE_REQUIRED) {
avifDiagnosticsPrintf(data->diag,
"[Strict] Alpha auxiliary image item ID [%u] is missing a mandatory ispe property",
item->id);
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
} else {
avifDiagnosticsPrintf(data->diag, "Item ID [%u] is missing a mandatory ispe property", item->id);
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
}
}
return avifDecoderReset(decoder);
}
static avifCodec * avifCodecCreateInternal(avifCodecChoice choice)
{
return avifCodecCreate(choice, AVIF_CODEC_FLAG_CAN_DECODE);
}
static avifResult avifDecoderFlush(avifDecoder * decoder)
{
avifDecoderDataResetCodec(decoder->data);
for (unsigned int i = 0; i < decoder->data->tiles.count; ++i) {
avifTile * tile = &decoder->data->tiles.tile[i];
tile->codec = avifCodecCreateInternal(decoder->codecChoice);
if (tile->codec) {
tile->codec->diag = &decoder->diag;
tile->codec->operatingPoint = tile->operatingPoint;
tile->codec->allLayers = tile->input->allLayers;
}
}
return AVIF_RESULT_OK;
}
avifResult avifDecoderReset(avifDecoder * decoder)
{
avifDiagnosticsClearError(&decoder->diag);
avifDecoderData * data = decoder->data;
if (!data) {
// Nothing to reset.
return AVIF_RESULT_OK;
}
memset(&data->colorGrid, 0, sizeof(data->colorGrid));
memset(&data->alphaGrid, 0, sizeof(data->alphaGrid));
avifDecoderDataClearTiles(data);
// Prepare / cleanup decoded image state
if (decoder->image) {
avifImageDestroy(decoder->image);
}
decoder->image = avifImageCreateEmpty();
decoder->progressiveState = AVIF_PROGRESSIVE_STATE_UNAVAILABLE;
data->cicpSet = AVIF_FALSE;
memset(&decoder->ioStats, 0, sizeof(decoder->ioStats));
// -----------------------------------------------------------------------
// Build decode input
data->sourceSampleTable = NULL; // Reset
if (decoder->requestedSource == AVIF_DECODER_SOURCE_AUTO) {
// Honor the major brand (avif or avis) if present, otherwise prefer avis (tracks) if possible.
if (!memcmp(data->majorBrand, "avis", 4)) {
data->source = AVIF_DECODER_SOURCE_TRACKS;
} else if (!memcmp(data->majorBrand, "avif", 4)) {
data->source = AVIF_DECODER_SOURCE_PRIMARY_ITEM;
} else if (data->tracks.count > 0) {
data->source = AVIF_DECODER_SOURCE_TRACKS;
} else {
data->source = AVIF_DECODER_SOURCE_PRIMARY_ITEM;
}
} else {
data->source = decoder->requestedSource;
}
const avifPropertyArray * colorProperties = NULL;
if (data->source == AVIF_DECODER_SOURCE_TRACKS) {
avifTrack * colorTrack = NULL;
avifTrack * alphaTrack = NULL;
// Find primary track - this probably needs some better detection
uint32_t colorTrackIndex = 0;
for (; colorTrackIndex < data->tracks.count; ++colorTrackIndex) {
avifTrack * track = &data->tracks.track[colorTrackIndex];
if (!track->sampleTable) {
continue;
}
if (!track->id) { // trak box might be missing a tkhd box inside, skip it
continue;
}
if (!track->sampleTable->chunks.count) {
continue;
}
if (!avifSampleTableHasFormat(track->sampleTable, "av01")) {
continue;
}
if (track->auxForID != 0) {
continue;
}
// Found one!
break;
}
if (colorTrackIndex == data->tracks.count) {
avifDiagnosticsPrintf(&decoder->diag, "Failed to find AV1 color track");
return AVIF_RESULT_NO_CONTENT;
}
colorTrack = &data->tracks.track[colorTrackIndex];
colorProperties = avifSampleTableGetProperties(colorTrack->sampleTable);
if (!colorProperties) {
avifDiagnosticsPrintf(&decoder->diag, "Failed to find AV1 color track's color properties");
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
// Find Exif and/or XMP metadata, if any
if (colorTrack->meta) {
// See the comment above avifDecoderFindMetadata() for the explanation of using 0 here
avifResult findResult = avifDecoderFindMetadata(decoder, colorTrack->meta, decoder->image, 0);
if (findResult != AVIF_RESULT_OK) {
return findResult;
}
}
uint32_t alphaTrackIndex = 0;
for (; alphaTrackIndex < data->tracks.count; ++alphaTrackIndex) {
avifTrack * track = &data->tracks.track[alphaTrackIndex];
if (!track->sampleTable) {
continue;
}
if (!track->id) {
continue;
}
if (!track->sampleTable->chunks.count) {
continue;
}
if (!avifSampleTableHasFormat(track->sampleTable, "av01")) {
continue;
}
if (track->auxForID == colorTrack->id) {
// Found it!
break;
}
}
if (alphaTrackIndex != data->tracks.count) {
alphaTrack = &data->tracks.track[alphaTrackIndex];
}
avifTile * colorTile = avifDecoderDataCreateTile(data, colorTrack->width, colorTrack->height, 0); // No way to set operating point via tracks
if (!colorTile) {
return AVIF_RESULT_OUT_OF_MEMORY;
}
if (!avifCodecDecodeInputFillFromSampleTable(colorTile->input,
colorTrack->sampleTable,
decoder->imageCountLimit,
decoder->io->sizeHint,
data->diag)) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
data->colorTileCount = 1;
if (alphaTrack) {
avifTile * alphaTile = avifDecoderDataCreateTile(data, alphaTrack->width, alphaTrack->height, 0); // No way to set operating point via tracks
if (!alphaTile) {
return AVIF_RESULT_OUT_OF_MEMORY;
}
if (!avifCodecDecodeInputFillFromSampleTable(alphaTile->input,
alphaTrack->sampleTable,
decoder->imageCountLimit,
decoder->io->sizeHint,
data->diag)) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
alphaTile->input->alpha = AVIF_TRUE;
data->alphaTileCount = 1;
}
// Stash off sample table for future timing information
data->sourceSampleTable = colorTrack->sampleTable;
// Image sequence timing
decoder->imageIndex = -1;
decoder->imageCount = colorTile->input->samples.count;
decoder->timescale = colorTrack->mediaTimescale;
decoder->durationInTimescales = colorTrack->mediaDuration;
if (colorTrack->mediaTimescale) {
decoder->duration = (double)decoder->durationInTimescales / (double)colorTrack->mediaTimescale;
} else {
decoder->duration = 0;
}
memset(&decoder->imageTiming, 0, sizeof(decoder->imageTiming)); // to be set in avifDecoderNextImage()
decoder->image->width = colorTrack->width;
decoder->image->height = colorTrack->height;
decoder->alphaPresent = (alphaTrack != NULL);
decoder->image->alphaPremultiplied = decoder->alphaPresent && (colorTrack->premByID == alphaTrack->id);
} else {
// Create from items
avifDecoderItem * colorItem = NULL;
avifDecoderItem * alphaItem = NULL;
if (data->meta->primaryItemID == 0) {
// A primary item is required
avifDiagnosticsPrintf(&decoder->diag, "Primary item not specified");
return AVIF_RESULT_NO_AV1_ITEMS_FOUND;
}
// Find the colorOBU (primary) item
for (uint32_t itemIndex = 0; itemIndex < data->meta->items.count; ++itemIndex) {
avifDecoderItem * item = &data->meta->items.item[itemIndex];
if (!item->size) {
continue;
}
if (item->hasUnsupportedEssentialProperty) {
// An essential property isn't supported by libavif; ignore the item.
continue;
}
avifBool isGrid = (memcmp(item->type, "grid", 4) == 0);
if (memcmp(item->type, "av01", 4) && !isGrid) {
// probably exif or some other data
continue;
}
if (item->thumbnailForID != 0) {
// It's a thumbnail, skip it
continue;
}
if (item->id != data->meta->primaryItemID) {
// This is not the primary item, skip it
continue;
}
if (isGrid) {
avifROData readData;
avifResult readResult = avifDecoderItemRead(item, decoder->io, &readData, 0, 0, data->diag);
if (readResult != AVIF_RESULT_OK) {
return readResult;
}
if (!avifParseImageGridBox(&data->colorGrid,
readData.data,
readData.size,
decoder->imageSizeLimit,
decoder->imageDimensionLimit,
data->diag)) {
return AVIF_RESULT_INVALID_IMAGE_GRID;
}
}
colorItem = item;
break;
}
if (!colorItem) {
avifDiagnosticsPrintf(&decoder->diag, "Primary item not found");
return AVIF_RESULT_NO_AV1_ITEMS_FOUND;
}
colorProperties = &colorItem->properties;
// Find the alphaOBU item, if any
for (uint32_t itemIndex = 0; itemIndex < data->meta->items.count; ++itemIndex) {
avifDecoderItem * item = &data->meta->items.item[itemIndex];
if (!item->size) {
continue;
}
if (item->hasUnsupportedEssentialProperty) {
// An essential property isn't supported by libavif; ignore the item.
continue;
}
avifBool isGrid = (memcmp(item->type, "grid", 4) == 0);
if (memcmp(item->type, "av01", 4) && !isGrid) {
// probably exif or some other data
continue;
}
// Is this an alpha auxiliary item of whatever we chose for colorItem?
const avifProperty * auxCProp = avifPropertyArrayFind(&item->properties, "auxC");
if (auxCProp && isAlphaURN(auxCProp->u.auxC.auxType) && (item->auxForID == colorItem->id)) {
if (isGrid) {
avifROData readData;
avifResult readResult = avifDecoderItemRead(item, decoder->io, &readData, 0, 0, data->diag);
if (readResult != AVIF_RESULT_OK) {
return readResult;
}
if (!avifParseImageGridBox(&data->alphaGrid,
readData.data,
readData.size,
decoder->imageSizeLimit,
decoder->imageDimensionLimit,
data->diag)) {
return AVIF_RESULT_INVALID_IMAGE_GRID;
}
}
alphaItem = item;
break;
}
}
// Find Exif and/or XMP metadata, if any
avifResult findResult = avifDecoderFindMetadata(decoder, data->meta, decoder->image, colorItem->id);
if (findResult != AVIF_RESULT_OK) {
return findResult;
}
// Set all counts and timing to safe-but-uninteresting values
decoder->imageIndex = -1;
decoder->imageCount = 1;
decoder->imageTiming.timescale = 1;
decoder->imageTiming.pts = 0;
decoder->imageTiming.ptsInTimescales = 0;
decoder->imageTiming.duration = 1;
decoder->imageTiming.durationInTimescales = 1;
decoder->timescale = 1;
decoder->duration = 1;
decoder->durationInTimescales = 1;
if ((data->colorGrid.rows > 0) && (data->colorGrid.columns > 0)) {
if (!avifDecoderGenerateImageGridTiles(decoder, &data->colorGrid, colorItem, AVIF_FALSE)) {
return AVIF_RESULT_INVALID_IMAGE_GRID;
}
data->colorTileCount = data->tiles.count;
} else {
if (colorItem->size == 0) {
return AVIF_RESULT_NO_AV1_ITEMS_FOUND;
}
avifTile * colorTile =
avifDecoderDataCreateTile(data, colorItem->width, colorItem->height, avifDecoderItemOperatingPoint(colorItem));
if (!colorTile) {
return AVIF_RESULT_OUT_OF_MEMORY;
}
if (!avifCodecDecodeInputFillFromDecoderItem(colorTile->input,
colorItem,
decoder->allowProgressive,
decoder->imageCountLimit,
decoder->io->sizeHint,
&decoder->diag)) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
data->colorTileCount = 1;
if (colorItem->progressive) {
decoder->progressiveState = AVIF_PROGRESSIVE_STATE_AVAILABLE;
if (colorTile->input->samples.count > 1) {
decoder->progressiveState = AVIF_PROGRESSIVE_STATE_ACTIVE;
decoder->imageCount = colorTile->input->samples.count;
}
}
}
if (alphaItem) {
if (!alphaItem->width && !alphaItem->height) {
// NON-STANDARD: Alpha subimage does not have an ispe property; adopt width/height from color item
assert(!(decoder->strictFlags & AVIF_STRICT_ALPHA_ISPE_REQUIRED));
alphaItem->width = colorItem->width;
alphaItem->height = colorItem->height;
}
if ((data->alphaGrid.rows > 0) && (data->alphaGrid.columns > 0)) {
if (!avifDecoderGenerateImageGridTiles(decoder, &data->alphaGrid, alphaItem, AVIF_TRUE)) {
return AVIF_RESULT_INVALID_IMAGE_GRID;
}
data->alphaTileCount = data->tiles.count - data->colorTileCount;
} else {
if (alphaItem->size == 0) {
return AVIF_RESULT_NO_AV1_ITEMS_FOUND;
}
avifTile * alphaTile =
avifDecoderDataCreateTile(data, alphaItem->width, alphaItem->height, avifDecoderItemOperatingPoint(alphaItem));
if (!alphaTile) {
return AVIF_RESULT_OUT_OF_MEMORY;
}
if (!avifCodecDecodeInputFillFromDecoderItem(alphaTile->input,
alphaItem,
decoder->allowProgressive,
decoder->imageCountLimit,
decoder->io->sizeHint,
&decoder->diag)) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
alphaTile->input->alpha = AVIF_TRUE;
data->alphaTileCount = 1;
}
}
decoder->ioStats.colorOBUSize = colorItem->size;
decoder->ioStats.alphaOBUSize = alphaItem ? alphaItem->size : 0;
decoder->image->width = colorItem->width;
decoder->image->height = colorItem->height;
decoder->alphaPresent = (alphaItem != NULL);
decoder->image->alphaPremultiplied = decoder->alphaPresent && (colorItem->premByID == alphaItem->id);
avifResult colorItemValidationResult = avifDecoderItemValidateAV1(colorItem, &decoder->diag, decoder->strictFlags);
if (colorItemValidationResult != AVIF_RESULT_OK) {
return colorItemValidationResult;
}
if (alphaItem) {
avifResult alphaItemValidationResult = avifDecoderItemValidateAV1(alphaItem, &decoder->diag, decoder->strictFlags);
if (alphaItemValidationResult != AVIF_RESULT_OK) {
return alphaItemValidationResult;
}
}
}
// Sanity check tiles
for (uint32_t tileIndex = 0; tileIndex < data->tiles.count; ++tileIndex) {
avifTile * tile = &data->tiles.tile[tileIndex];
for (uint32_t sampleIndex = 0; sampleIndex < tile->input->samples.count; ++sampleIndex) {
avifDecodeSample * sample = &tile->input->samples.sample[sampleIndex];
if (!sample->size) {
// Every sample must have some data
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
}
}
// Find and adopt all colr boxes "at most one for a given value of colour type" (HEIF 6.5.5.1, from Amendment 3)
// Accept one of each type, and bail out if more than one of a given type is provided.
avifBool colrICCSeen = AVIF_FALSE;
avifBool colrNCLXSeen = AVIF_FALSE;
for (uint32_t propertyIndex = 0; propertyIndex < colorProperties->count; ++propertyIndex) {
avifProperty * prop = &colorProperties->prop[propertyIndex];
if (!memcmp(prop->type, "colr", 4)) {
if (prop->u.colr.hasICC) {
if (colrICCSeen) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
avifROData icc;
const avifResult readResult = decoder->io->read(decoder->io, 0, prop->u.colr.iccOffset, prop->u.colr.iccSize, &icc);
if (readResult != AVIF_RESULT_OK) {
return readResult;
}
colrICCSeen = AVIF_TRUE;
avifImageSetProfileICC(decoder->image, icc.data, icc.size);
}
if (prop->u.colr.hasNCLX) {
if (colrNCLXSeen) {
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
colrNCLXSeen = AVIF_TRUE;
data->cicpSet = AVIF_TRUE;
decoder->image->colorPrimaries = prop->u.colr.colorPrimaries;
decoder->image->transferCharacteristics = prop->u.colr.transferCharacteristics;
decoder->image->matrixCoefficients = prop->u.colr.matrixCoefficients;
decoder->image->yuvRange = prop->u.colr.range;
}
}
}
// Transformations
const avifProperty * paspProp = avifPropertyArrayFind(colorProperties, "pasp");
if (paspProp) {
decoder->image->transformFlags |= AVIF_TRANSFORM_PASP;
decoder->image->pasp = paspProp->u.pasp;
}
const avifProperty * clapProp = avifPropertyArrayFind(colorProperties, "clap");
if (clapProp) {
decoder->image->transformFlags |= AVIF_TRANSFORM_CLAP;
decoder->image->clap = clapProp->u.clap;
}
const avifProperty * irotProp = avifPropertyArrayFind(colorProperties, "irot");
if (irotProp) {
decoder->image->transformFlags |= AVIF_TRANSFORM_IROT;
decoder->image->irot = irotProp->u.irot;
}
const avifProperty * imirProp = avifPropertyArrayFind(colorProperties, "imir");
if (imirProp) {
decoder->image->transformFlags |= AVIF_TRANSFORM_IMIR;
decoder->image->imir = imirProp->u.imir;
}
if (!data->cicpSet && (data->tiles.count > 0)) {
avifTile * firstTile = &data->tiles.tile[0];
if (firstTile->input->samples.count > 0) {
avifDecodeSample * sample = &firstTile->input->samples.sample[0];
// Harvest CICP from the AV1's sequence header, which should be very close to the front
// of the first sample. Read in successively larger chunks until we successfully parse the sequence.
static const size_t searchSampleChunkIncrement = 64;
static const size_t searchSampleSizeMax = 4096;
size_t searchSampleSize = 0;
do {
searchSampleSize += searchSampleChunkIncrement;
if (searchSampleSize > sample->size) {
searchSampleSize = sample->size;
}
avifResult prepareResult = avifDecoderPrepareSample(decoder, sample, searchSampleSize);
if (prepareResult != AVIF_RESULT_OK) {
return prepareResult;
}
avifSequenceHeader sequenceHeader;
if (avifSequenceHeaderParse(&sequenceHeader, &sample->data)) {
data->cicpSet = AVIF_TRUE;
decoder->image->colorPrimaries = sequenceHeader.colorPrimaries;
decoder->image->transferCharacteristics = sequenceHeader.transferCharacteristics;
decoder->image->matrixCoefficients = sequenceHeader.matrixCoefficients;
decoder->image->yuvRange = sequenceHeader.range;
break;
}
} while (searchSampleSize != sample->size && searchSampleSize < searchSampleSizeMax);
}
}
const avifProperty * av1CProp = avifPropertyArrayFind(colorProperties, "av1C");
if (av1CProp) {
decoder->image->depth = avifCodecConfigurationBoxGetDepth(&av1CProp->u.av1C);
if (av1CProp->u.av1C.monochrome) {
decoder->image->yuvFormat = AVIF_PIXEL_FORMAT_YUV400;
} else {
if (av1CProp->u.av1C.chromaSubsamplingX && av1CProp->u.av1C.chromaSubsamplingY) {
decoder->image->yuvFormat = AVIF_PIXEL_FORMAT_YUV420;
} else if (av1CProp->u.av1C.chromaSubsamplingX) {
decoder->image->yuvFormat = AVIF_PIXEL_FORMAT_YUV422;
} else {
decoder->image->yuvFormat = AVIF_PIXEL_FORMAT_YUV444;
}
}
decoder->image->yuvChromaSamplePosition = (avifChromaSamplePosition)av1CProp->u.av1C.chromaSamplePosition;
} else {
// An av1C box is mandatory in all valid AVIF configurations. Bail out.
return AVIF_RESULT_BMFF_PARSE_FAILED;
}
return avifDecoderFlush(decoder);
}
static avifResult avifDecoderPrepareTiles(avifDecoder * decoder,
uint32_t nextImageIndex,
unsigned int firstTileIndex,
unsigned int tileCount,
unsigned int decodedTileCount)
{
for (unsigned int tileIndex = decodedTileCount; tileIndex < tileCount; ++tileIndex) {
avifTile * tile = &decoder->data->tiles.tile[firstTileIndex + tileIndex];
// Ensure there's an AV1 codec available before doing anything else
if (!tile->codec) {
return AVIF_RESULT_NO_CODEC_AVAILABLE;
}
if (nextImageIndex >= tile->input->samples.count) {
return AVIF_RESULT_NO_IMAGES_REMAINING;
}
avifDecodeSample * sample = &tile->input->samples.sample[nextImageIndex];
avifResult prepareResult = avifDecoderPrepareSample(decoder, sample, 0);
if (prepareResult != AVIF_RESULT_OK) {
return prepareResult;
}
}
return AVIF_RESULT_OK;
}
static avifResult avifImageLimitedToFullAlpha(avifImage * image)
{
if (image->imageOwnsAlphaPlane) {
return AVIF_RESULT_NOT_IMPLEMENTED;
}
uint8_t * alphaPlane = image->alphaPlane;
const uint32_t alphaRowBytes = image->alphaRowBytes;
// We cannot do the range conversion in place since it will modify the
// codec's internal frame buffers. Allocate memory for the conversion.
image->alphaPlane = NULL;
image->alphaRowBytes = 0;
const avifResult allocationResult = avifImageAllocatePlanes(image, AVIF_PLANES_A);
if (allocationResult != AVIF_RESULT_OK) {
return allocationResult;
}
if (image->depth > 8) {
for (uint32_t j = 0; j < image->height; ++j) {
uint8_t * srcRow = &alphaPlane[j * alphaRowBytes];
uint8_t * dstRow = &image->alphaPlane[j * image->alphaRowBytes];
for (uint32_t i = 0; i < image->width; ++i) {
int srcAlpha = *((uint16_t *)&srcRow[i * 2]);
int dstAlpha = avifLimitedToFullY(image->depth, srcAlpha);
*((uint16_t *)&dstRow[i * 2]) = (uint16_t)dstAlpha;
}
}
} else {
for (uint32_t j = 0; j < image->height; ++j) {
uint8_t * srcRow = &alphaPlane[j * alphaRowBytes];
uint8_t * dstRow = &image->alphaPlane[j * image->alphaRowBytes];
for (uint32_t i = 0; i < image->width; ++i) {
int srcAlpha = srcRow[i];
int dstAlpha = avifLimitedToFullY(image->depth, srcAlpha);
dstRow[i] = (uint8_t)dstAlpha;
}
}
}
return AVIF_RESULT_OK;
}
static avifResult avifDecoderDecodeTiles(avifDecoder * decoder,
uint32_t nextImageIndex,
unsigned int firstTileIndex,
unsigned int tileCount,
unsigned int * decodedTileCount)
{
const unsigned int oldDecodedTileCount = *decodedTileCount;
for (unsigned int tileIndex = oldDecodedTileCount; tileIndex < tileCount; ++tileIndex) {
avifTile * tile = &decoder->data->tiles.tile[firstTileIndex + tileIndex];
const avifDecodeSample * sample = &tile->input->samples.sample[nextImageIndex];
if (sample->data.size < sample->size) {
assert(decoder->allowIncremental);
// Data is missing but there is no error yet. Output available pixel rows.
return AVIF_RESULT_OK;
}
avifBool isLimitedRangeAlpha = AVIF_FALSE;
if (!tile->codec->getNextImage(tile->codec, decoder, sample, tile->input->alpha, &isLimitedRangeAlpha, tile->image)) {
avifDiagnosticsPrintf(&decoder->diag, "tile->codec->getNextImage() failed");
return tile->input->alpha ? AVIF_RESULT_DECODE_ALPHA_FAILED : AVIF_RESULT_DECODE_COLOR_FAILED;
}
// Alpha plane with limited range is not allowed by the latest revision
// of the specification. However, it was allowed in version 1.0.0 of the
// specification. To allow such files, simply convert the alpha plane to
// full range.
if (tile->input->alpha && isLimitedRangeAlpha) {
avifResult result = avifImageLimitedToFullAlpha(tile->image);
if (result != AVIF_RESULT_OK) {
avifDiagnosticsPrintf(&decoder->diag, "avifImageLimitedToFullAlpha failed");
return result;
}
}
// Scale the decoded image so that it corresponds to this tile's output dimensions
if ((tile->width != tile->image->width) || (tile->height != tile->image->height)) {
if (!avifImageScale(tile->image,
tile->width,
tile->height,
decoder->imageSizeLimit,
decoder->imageDimensionLimit,
&decoder->diag)) {
avifDiagnosticsPrintf(&decoder->diag, "avifImageScale() failed");
return tile->input->alpha ? AVIF_RESULT_DECODE_ALPHA_FAILED : AVIF_RESULT_DECODE_COLOR_FAILED;
}
}
++*decodedTileCount;
}
return AVIF_RESULT_OK;
}
avifResult avifDecoderNextImage(avifDecoder * decoder)
{
avifDiagnosticsClearError(&decoder->diag);
if (!decoder->data) {
// Nothing has been parsed yet
return AVIF_RESULT_NO_CONTENT;
}
if (!decoder->io || !decoder->io->read) {
return AVIF_RESULT_IO_NOT_SET;
}
if ((decoder->data->decodedColorTileCount == decoder->data->colorTileCount) &&
(decoder->data->decodedAlphaTileCount == decoder->data->alphaTileCount)) {
// A frame was decoded during the last avifDecoderNextImage() call.
decoder->data->decodedColorTileCount = 0;
decoder->data->decodedAlphaTileCount = 0;
}
assert(decoder->data->tiles.count == (decoder->data->colorTileCount + decoder->data->alphaTileCount));
const uint32_t nextImageIndex = (uint32_t)(decoder->imageIndex + 1);
const unsigned int firstColorTileIndex = 0;
const unsigned int firstAlphaTileIndex = decoder->data->colorTileCount;
// Acquire all sample data for the current image first, allowing for any read call to bail out
// with AVIF_RESULT_WAITING_ON_IO harmlessly / idempotently, unless decoder->allowIncremental.
// Start with color tiles.
const avifResult prepareColorTileResult =
avifDecoderPrepareTiles(decoder, nextImageIndex, firstColorTileIndex, decoder->data->colorTileCount, decoder->data->decodedColorTileCount);
if ((prepareColorTileResult != AVIF_RESULT_OK) &&
(!decoder->allowIncremental || (prepareColorTileResult != AVIF_RESULT_WAITING_ON_IO))) {
return prepareColorTileResult;
}
// Do the same with alpha tiles. They are handled separately because their
// order of appearance relative to the color tiles in the bitstream is left
// to the encoder's choice, and decoding as many as possible of each
// category in parallel is beneficial for incremental decoding, as pixel
// rows need all channels to be decoded before being accessible to the user.
const avifResult prepareAlphaTileResult =
avifDecoderPrepareTiles(decoder, nextImageIndex, firstAlphaTileIndex, decoder->data->alphaTileCount, decoder->data->decodedAlphaTileCount);
if ((prepareAlphaTileResult != AVIF_RESULT_OK) &&
(!decoder->allowIncremental || (prepareAlphaTileResult != AVIF_RESULT_WAITING_ON_IO))) {
return prepareAlphaTileResult;
}
// Decode all available color tiles now, then all available alpha tiles.
const unsigned int oldDecodedColorTileCount = decoder->data->decodedColorTileCount;
const avifResult decodeColorTileResult =
avifDecoderDecodeTiles(decoder, nextImageIndex, firstColorTileIndex, decoder->data->colorTileCount, &decoder->data->decodedColorTileCount);
if (decodeColorTileResult != AVIF_RESULT_OK) {
return decodeColorTileResult;
}
const unsigned int oldDecodedAlphaTileCount = decoder->data->decodedAlphaTileCount;
const avifResult decodeAlphaTileResult =
avifDecoderDecodeTiles(decoder, nextImageIndex, firstAlphaTileIndex, decoder->data->alphaTileCount, &decoder->data->decodedAlphaTileCount);
if (decodeAlphaTileResult != AVIF_RESULT_OK) {
return decodeAlphaTileResult;
}
if (decoder->data->decodedColorTileCount > oldDecodedColorTileCount) {
// There is at least one newly decoded color tile.
if ((decoder->data->colorGrid.rows > 0) && (decoder->data->colorGrid.columns > 0)) {
assert(decoder->data->colorTileCount == (decoder->data->colorGrid.rows * decoder->data->colorGrid.columns));
if (!avifDecoderDataFillImageGrid(decoder->data,
&decoder->data->colorGrid,
decoder->image,
firstColorTileIndex,
oldDecodedColorTileCount,
decoder->data->decodedColorTileCount,
AVIF_FALSE)) {
return AVIF_RESULT_INVALID_IMAGE_GRID;
}
} else {
// Normal (most common) non-grid path. Just steal the planes from the only "tile".
assert(decoder->data->colorTileCount == 1);
avifImage * srcColor = decoder->data->tiles.tile[0].image;
if ((decoder->image->width != srcColor->width) || (decoder->image->height != srcColor->height) ||
(decoder->image->depth != srcColor->depth)) {
avifImageFreePlanes(decoder->image, AVIF_PLANES_ALL);
decoder->image->width = srcColor->width;
decoder->image->height = srcColor->height;
decoder->image->depth = srcColor->depth;
}
#if 0
// This code is currently unnecessary as the CICP is always set by the end of avifDecoderParse().
if (!decoder->data->cicpSet) {
decoder->data->cicpSet = AVIF_TRUE;
decoder->image->colorPrimaries = srcColor->colorPrimaries;
decoder->image->transferCharacteristics = srcColor->transferCharacteristics;
decoder->image->matrixCoefficients = srcColor->matrixCoefficients;
}
#endif
avifImageStealPlanes(decoder->image, srcColor, AVIF_PLANES_YUV);
}
}
if (decoder->data->decodedAlphaTileCount > oldDecodedAlphaTileCount) {
// There is at least one newly decoded alpha tile.
if ((decoder->data->alphaGrid.rows > 0) && (decoder->data->alphaGrid.columns > 0)) {
assert(decoder->data->alphaTileCount == (decoder->data->alphaGrid.rows * decoder->data->alphaGrid.columns));
if (!avifDecoderDataFillImageGrid(decoder->data,
&decoder->data->alphaGrid,
decoder->image,
firstAlphaTileIndex,
oldDecodedAlphaTileCount,
decoder->data->decodedAlphaTileCount,
AVIF_TRUE)) {
return AVIF_RESULT_INVALID_IMAGE_GRID;
}
} else {
// Normal (most common) non-grid path. Just steal the planes from the only "tile".
assert(decoder->data->alphaTileCount == 1);
avifImage * srcAlpha = decoder->data->tiles.tile[decoder->data->colorTileCount].image;
if ((decoder->image->width != srcAlpha->width) || (decoder->image->height != srcAlpha->height) ||
(decoder->image->depth != srcAlpha->depth)) {
avifDiagnosticsPrintf(&decoder->diag, "decoder->image does not match srcAlpha in width, height, or bit depth");
return AVIF_RESULT_DECODE_ALPHA_FAILED;
}
avifImageStealPlanes(decoder->image, srcAlpha, AVIF_PLANES_A);
}
}
if ((decoder->data->decodedColorTileCount != decoder->data->colorTileCount) ||
(decoder->data->decodedAlphaTileCount != decoder->data->alphaTileCount)) {
assert(decoder->allowIncremental);
// The image is not completely decoded. There should be no error unrelated to missing bytes,
// and at least some missing bytes.
assert((prepareColorTileResult == AVIF_RESULT_OK) || (prepareColorTileResult == AVIF_RESULT_WAITING_ON_IO));
assert((prepareAlphaTileResult == AVIF_RESULT_OK) || (prepareAlphaTileResult == AVIF_RESULT_WAITING_ON_IO));
assert((prepareColorTileResult != AVIF_RESULT_OK) || (prepareAlphaTileResult != AVIF_RESULT_OK));
// Return the "not enough bytes" status now instead of moving on to the next frame.
return AVIF_RESULT_WAITING_ON_IO;
}
assert((prepareColorTileResult == AVIF_RESULT_OK) && (prepareAlphaTileResult == AVIF_RESULT_OK));
// Only advance decoder->imageIndex once the image is completely decoded, so that
// avifDecoderNthImage(decoder, decoder->imageIndex + 1) is equivalent to avifDecoderNextImage(decoder)
// if the previous call to avifDecoderNextImage() returned AVIF_RESULT_WAITING_ON_IO.
decoder->imageIndex = nextImageIndex;
// The decoded tile counts will be reset to 0 the next time avifDecoderNextImage() is called,
// for avifDecoderDecodedRowCount() to work until then.
if (decoder->data->sourceSampleTable) {
// Decoding from a track! Provide timing information.
avifResult timingResult = avifDecoderNthImageTiming(decoder, decoder->imageIndex, &decoder->imageTiming);
if (timingResult != AVIF_RESULT_OK) {
return timingResult;
}
}
return AVIF_RESULT_OK;
}
avifResult avifDecoderNthImageTiming(const avifDecoder * decoder, uint32_t frameIndex, avifImageTiming * outTiming)
{
if (!decoder->data) {
// Nothing has been parsed yet
return AVIF_RESULT_NO_CONTENT;
}
if ((frameIndex > INT_MAX) || ((int)frameIndex >= decoder->imageCount)) {
// Impossible index
return AVIF_RESULT_NO_IMAGES_REMAINING;
}
if (!decoder->data->sourceSampleTable) {
// There isn't any real timing associated with this decode, so
// just hand back the defaults chosen in avifDecoderReset().
*outTiming = decoder->imageTiming;
return AVIF_RESULT_OK;
}
outTiming->timescale = decoder->timescale;
outTiming->ptsInTimescales = 0;
for (int imageIndex = 0; imageIndex < (int)frameIndex; ++imageIndex) {
outTiming->ptsInTimescales += avifSampleTableGetImageDelta(decoder->data->sourceSampleTable, imageIndex);
}
outTiming->durationInTimescales = avifSampleTableGetImageDelta(decoder->data->sourceSampleTable, frameIndex);
if (outTiming->timescale > 0) {
outTiming->pts = (double)outTiming->ptsInTimescales / (double)outTiming->timescale;
outTiming->duration = (double)outTiming->durationInTimescales / (double)outTiming->timescale;
} else {
outTiming->pts = 0.0;
outTiming->duration = 0.0;
}
return AVIF_RESULT_OK;
}
avifResult avifDecoderNthImage(avifDecoder * decoder, uint32_t frameIndex)
{
avifDiagnosticsClearError(&decoder->diag);
if (!decoder->data) {
// Nothing has been parsed yet
return AVIF_RESULT_NO_CONTENT;
}
if ((frameIndex > INT_MAX) || ((int)frameIndex >= decoder->imageCount)) {
// Impossible index
return AVIF_RESULT_NO_IMAGES_REMAINING;
}
int requestedIndex = (int)frameIndex;
if (requestedIndex == (decoder->imageIndex + 1)) {
// It's just the next image (already partially decoded or not at all), nothing special here
return avifDecoderNextImage(decoder);
}
if (requestedIndex == decoder->imageIndex) {
if ((decoder->data->decodedColorTileCount == decoder->data->colorTileCount) &&
(decoder->data->decodedAlphaTileCount == decoder->data->alphaTileCount)) {
// The current fully decoded image (decoder->imageIndex) is requested, nothing to do
return AVIF_RESULT_OK;
}
// The next image (decoder->imageIndex + 1) is partially decoded but
// the previous image (decoder->imageIndex) is requested.
// Fall through to flush and start decoding from the nearest key frame.
}
int nearestKeyFrame = (int)avifDecoderNearestKeyframe(decoder, frameIndex);
if ((nearestKeyFrame > (decoder->imageIndex + 1)) || (requestedIndex <= decoder->imageIndex)) {
// If we get here, a decoder flush is necessary
decoder->imageIndex = nearestKeyFrame - 1; // prepare to read nearest keyframe
avifDecoderFlush(decoder);
}
for (;;) {
avifResult result = avifDecoderNextImage(decoder);
if (result != AVIF_RESULT_OK) {
return result;
}
if (requestedIndex == decoder->imageIndex) {
break;
}
}
return AVIF_RESULT_OK;
}
avifBool avifDecoderIsKeyframe(const avifDecoder * decoder, uint32_t frameIndex)
{
if (!decoder->data || (decoder->data->tiles.count == 0)) {
// Nothing has been parsed yet
return AVIF_FALSE;
}
// *All* tiles for the requested frameIndex must be keyframes in order for
// avifDecoderIsKeyframe() to return true, otherwise we may seek to a frame in which the color
// planes are a keyframe but the alpha plane isn't a keyframe, which will cause an alpha plane
// decode failure.
for (unsigned int i = 0; i < decoder->data->tiles.count; ++i) {
const avifTile * tile = &decoder->data->tiles.tile[i];
if ((frameIndex >= tile->input->samples.count) || !tile->input->samples.sample[frameIndex].sync) {
return AVIF_FALSE;
}
}
return AVIF_TRUE;
}
uint32_t avifDecoderNearestKeyframe(const avifDecoder * decoder, uint32_t frameIndex)
{
if (!decoder->data) {
// Nothing has been parsed yet
return 0;
}
for (; frameIndex != 0; --frameIndex) {
if (avifDecoderIsKeyframe(decoder, frameIndex)) {
break;
}
}
return frameIndex;
}
// Returns the number of available rows in decoder->image given a color or alpha subimage.
static uint32_t avifGetDecodedRowCount(const avifDecoder * decoder,
const avifImageGrid * grid,
unsigned int firstTileIndex,
unsigned int tileCount,
unsigned int decodedTileCount)
{
if (decodedTileCount == tileCount) {
return decoder->image->height;
}
if (decodedTileCount == 0) {
return 0;
}
if ((grid->rows > 0) && (grid->columns > 0)) {
// Grid of AVIF tiles (not to be confused with AV1 tiles).
const uint32_t tileHeight = decoder->data->tiles.tile[firstTileIndex].height;
return AVIF_MIN((decodedTileCount / grid->columns) * tileHeight, decoder->image->height);
} else {
// Non-grid image.
return decoder->image->height;
}
}
uint32_t avifDecoderDecodedRowCount(const avifDecoder * decoder)
{
const uint32_t colorRowCount = avifGetDecodedRowCount(decoder,
&decoder->data->colorGrid,
/*firstTileIndex=*/0,
decoder->data->colorTileCount,
decoder->data->decodedColorTileCount);
const uint32_t alphaRowCount = avifGetDecodedRowCount(decoder,
&decoder->data->alphaGrid,
/*firstTileIndex=*/decoder->data->colorTileCount,
decoder->data->alphaTileCount,
decoder->data->decodedAlphaTileCount);
return AVIF_MIN(colorRowCount, alphaRowCount);
}
avifResult avifDecoderRead(avifDecoder * decoder, avifImage * image)
{
avifResult result = avifDecoderParse(decoder);
if (result != AVIF_RESULT_OK) {
return result;
}
result = avifDecoderNextImage(decoder);
if (result != AVIF_RESULT_OK) {
return result;
}
return avifImageCopy(image, decoder->image, AVIF_PLANES_ALL);
}
avifResult avifDecoderReadMemory(avifDecoder * decoder, avifImage * image, const uint8_t * data, size_t size)
{
avifDiagnosticsClearError(&decoder->diag);
avifResult result = avifDecoderSetIOMemory(decoder, data, size);
if (result != AVIF_RESULT_OK) {
return result;
}
return avifDecoderRead(decoder, image);
}
avifResult avifDecoderReadFile(avifDecoder * decoder, avifImage * image, const char * filename)
{
avifDiagnosticsClearError(&decoder->diag);
avifResult result = avifDecoderSetIOFile(decoder, filename);
if (result != AVIF_RESULT_OK) {
return result;
}
return avifDecoderRead(decoder, image);
}