// Copyright 2011 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
// -----------------------------------------------------------------------------
//
// Set and delete APIs for mux.
//
// Authors: Urvang (urvang@google.com)
// Vikas (vikasa@google.com)
#include <assert.h>
#include "src/mux/muxi.h"
#include "src/utils/utils.h"
//------------------------------------------------------------------------------
// Life of a mux object.
static void MuxInit(WebPMux* const mux) {
assert(mux != NULL);
memset(mux, 0, sizeof(*mux));
mux->canvas_width_ = 0; // just to be explicit
mux->canvas_height_ = 0;
}
WebPMux* WebPNewInternal(int version) {
if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_MUX_ABI_VERSION)) {
return NULL;
} else {
WebPMux* const mux = (WebPMux*)WebPSafeMalloc(1ULL, sizeof(WebPMux));
if (mux != NULL) MuxInit(mux);
return mux;
}
}
// Delete all images in 'wpi_list'.
static void DeleteAllImages(WebPMuxImage** const wpi_list) {
while (*wpi_list != NULL) {
*wpi_list = MuxImageDelete(*wpi_list);
}
}
static void MuxRelease(WebPMux* const mux) {
assert(mux != NULL);
DeleteAllImages(&mux->images_);
ChunkListDelete(&mux->vp8x_);
ChunkListDelete(&mux->iccp_);
ChunkListDelete(&mux->anim_);
ChunkListDelete(&mux->exif_);
ChunkListDelete(&mux->xmp_);
ChunkListDelete(&mux->unknown_);
}
void WebPMuxDelete(WebPMux* mux) {
if (mux != NULL) {
MuxRelease(mux);
WebPSafeFree(mux);
}
}
//------------------------------------------------------------------------------
// Helper method(s).
// Handy MACRO, makes MuxSet() very symmetric to MuxGet().
#define SWITCH_ID_LIST(INDEX, LIST) \
if (idx == (INDEX)) { \
err = ChunkAssignData(&chunk, data, copy_data, tag); \
if (err == WEBP_MUX_OK) { \
err = ChunkSetNth(&chunk, (LIST), nth); \
} \
return err; \
}
static WebPMuxError MuxSet(WebPMux* const mux, uint32_t tag, uint32_t nth,
const WebPData* const data, int copy_data) {
WebPChunk chunk;
WebPMuxError err = WEBP_MUX_NOT_FOUND;
const CHUNK_INDEX idx = ChunkGetIndexFromTag(tag);
assert(mux != NULL);
assert(!IsWPI(kChunks[idx].id));
ChunkInit(&chunk);
SWITCH_ID_LIST(IDX_VP8X, &mux->vp8x_);
SWITCH_ID_LIST(IDX_ICCP, &mux->iccp_);
SWITCH_ID_LIST(IDX_ANIM, &mux->anim_);
SWITCH_ID_LIST(IDX_EXIF, &mux->exif_);
SWITCH_ID_LIST(IDX_XMP, &mux->xmp_);
SWITCH_ID_LIST(IDX_UNKNOWN, &mux->unknown_);
return err;
}
#undef SWITCH_ID_LIST
// Create data for frame given image data, offsets and duration.
static WebPMuxError CreateFrameData(
int width, int height, const WebPMuxFrameInfo* const info,
WebPData* const frame) {
uint8_t* frame_bytes;
const size_t frame_size = kChunks[IDX_ANMF].size;
assert(width > 0 && height > 0 && info->duration >= 0);
assert(info->dispose_method == (info->dispose_method & 1));
// Note: assertion on upper bounds is done in PutLE24().
frame_bytes = (uint8_t*)WebPSafeMalloc(1ULL, frame_size);
if (frame_bytes == NULL) return WEBP_MUX_MEMORY_ERROR;
PutLE24(frame_bytes + 0, info->x_offset / 2);
PutLE24(frame_bytes + 3, info->y_offset / 2);
PutLE24(frame_bytes + 6, width - 1);
PutLE24(frame_bytes + 9, height - 1);
PutLE24(frame_bytes + 12, info->duration);
frame_bytes[15] =
(info->blend_method == WEBP_MUX_NO_BLEND ? 2 : 0) |
(info->dispose_method == WEBP_MUX_DISPOSE_BACKGROUND ? 1 : 0);
frame->bytes = frame_bytes;
frame->size = frame_size;
return WEBP_MUX_OK;
}
// Outputs image data given a bitstream. The bitstream can either be a
// single-image WebP file or raw VP8/VP8L data.
// Also outputs 'is_lossless' to be true if the given bitstream is lossless.
static WebPMuxError GetImageData(const WebPData* const bitstream,
WebPData* const image, WebPData* const alpha,
int* const is_lossless) {
WebPDataInit(alpha); // Default: no alpha.
if (bitstream->size < TAG_SIZE ||
memcmp(bitstream->bytes, "RIFF", TAG_SIZE)) {
// It is NOT webp file data. Return input data as is.
*image = *bitstream;
} else {
// It is webp file data. Extract image data from it.
const WebPMuxImage* wpi;
WebPMux* const mux = WebPMuxCreate(bitstream, 0);
if (mux == NULL) return WEBP_MUX_BAD_DATA;
wpi = mux->images_;
assert(wpi != NULL && wpi->img_ != NULL);
*image = wpi->img_->data_;
if (wpi->alpha_ != NULL) {
*alpha = wpi->alpha_->data_;
}
WebPMuxDelete(mux);
}
*is_lossless = VP8LCheckSignature(image->bytes, image->size);
return WEBP_MUX_OK;
}
static WebPMuxError DeleteChunks(WebPChunk** chunk_list, uint32_t tag) {
WebPMuxError err = WEBP_MUX_NOT_FOUND;
assert(chunk_list);
while (*chunk_list) {
WebPChunk* const chunk = *chunk_list;
if (chunk->tag_ == tag) {
*chunk_list = ChunkDelete(chunk);
err = WEBP_MUX_OK;
} else {
chunk_list = &chunk->next_;
}
}
return err;
}
static WebPMuxError MuxDeleteAllNamedData(WebPMux* const mux, uint32_t tag) {
const WebPChunkId id = ChunkGetIdFromTag(tag);
assert(mux != NULL);
if (IsWPI(id)) return WEBP_MUX_INVALID_ARGUMENT;
return DeleteChunks(MuxGetChunkListFromId(mux, id), tag);
}
//------------------------------------------------------------------------------
// Set API(s).
WebPMuxError WebPMuxSetChunk(WebPMux* mux, const char fourcc[4],
const WebPData* chunk_data, int copy_data) {
uint32_t tag;
WebPMuxError err;
if (mux == NULL || fourcc == NULL || chunk_data == NULL ||
chunk_data->bytes == NULL || chunk_data->size > MAX_CHUNK_PAYLOAD) {
return WEBP_MUX_INVALID_ARGUMENT;
}
tag = ChunkGetTagFromFourCC(fourcc);
// Delete existing chunk(s) with the same 'fourcc'.
err = MuxDeleteAllNamedData(mux, tag);
if (err != WEBP_MUX_OK && err != WEBP_MUX_NOT_FOUND) return err;
// Add the given chunk.
return MuxSet(mux, tag, 1, chunk_data, copy_data);
}
// Creates a chunk from given 'data' and sets it as 1st chunk in 'chunk_list'.
static WebPMuxError AddDataToChunkList(
const WebPData* const data, int copy_data, uint32_t tag,
WebPChunk** chunk_list) {
WebPChunk chunk;
WebPMuxError err;
ChunkInit(&chunk);
err = ChunkAssignData(&chunk, data, copy_data, tag);
if (err != WEBP_MUX_OK) goto Err;
err = ChunkSetNth(&chunk, chunk_list, 1);
if (err != WEBP_MUX_OK) goto Err;
return WEBP_MUX_OK;
Err:
ChunkRelease(&chunk);
return err;
}
// Extracts image & alpha data from the given bitstream and then sets wpi.alpha_
// and wpi.img_ appropriately.
static WebPMuxError SetAlphaAndImageChunks(
const WebPData* const bitstream, int copy_data, WebPMuxImage* const wpi) {
int is_lossless = 0;
WebPData image, alpha;
WebPMuxError err = GetImageData(bitstream, &image, &alpha, &is_lossless);
const int image_tag =
is_lossless ? kChunks[IDX_VP8L].tag : kChunks[IDX_VP8].tag;
if (err != WEBP_MUX_OK) return err;
if (alpha.bytes != NULL) {
err = AddDataToChunkList(&alpha, copy_data, kChunks[IDX_ALPHA].tag,
&wpi->alpha_);
if (err != WEBP_MUX_OK) return err;
}
err = AddDataToChunkList(&image, copy_data, image_tag, &wpi->img_);
if (err != WEBP_MUX_OK) return err;
return MuxImageFinalize(wpi) ? WEBP_MUX_OK : WEBP_MUX_INVALID_ARGUMENT;
}
WebPMuxError WebPMuxSetImage(WebPMux* mux, const WebPData* bitstream,
int copy_data) {
WebPMuxImage wpi;
WebPMuxError err;
// Sanity checks.
if (mux == NULL || bitstream == NULL || bitstream->bytes == NULL ||
bitstream->size > MAX_CHUNK_PAYLOAD) {
return WEBP_MUX_INVALID_ARGUMENT;
}
if (mux->images_ != NULL) {
// Only one 'simple image' can be added in mux. So, remove present images.
DeleteAllImages(&mux->images_);
}
MuxImageInit(&wpi);
err = SetAlphaAndImageChunks(bitstream, copy_data, &wpi);
if (err != WEBP_MUX_OK) goto Err;
// Add this WebPMuxImage to mux.
err = MuxImagePush(&wpi, &mux->images_);
if (err != WEBP_MUX_OK) goto Err;
// All is well.
return WEBP_MUX_OK;
Err: // Something bad happened.
MuxImageRelease(&wpi);
return err;
}
WebPMuxError WebPMuxPushFrame(WebPMux* mux, const WebPMuxFrameInfo* info,
int copy_data) {
WebPMuxImage wpi;
WebPMuxError err;
const WebPData* const bitstream = &info->bitstream;
// Sanity checks.
if (mux == NULL || info == NULL) return WEBP_MUX_INVALID_ARGUMENT;
if (info->id != WEBP_CHUNK_ANMF) return WEBP_MUX_INVALID_ARGUMENT;
if (bitstream->bytes == NULL || bitstream->size > MAX_CHUNK_PAYLOAD) {
return WEBP_MUX_INVALID_ARGUMENT;
}
if (mux->images_ != NULL) {
const WebPMuxImage* const image = mux->images_;
const uint32_t image_id = (image->header_ != NULL) ?
ChunkGetIdFromTag(image->header_->tag_) : WEBP_CHUNK_IMAGE;
if (image_id != info->id) {
return WEBP_MUX_INVALID_ARGUMENT; // Conflicting frame types.
}
}
MuxImageInit(&wpi);
err = SetAlphaAndImageChunks(bitstream, copy_data, &wpi);
if (err != WEBP_MUX_OK) goto Err;
assert(wpi.img_ != NULL); // As SetAlphaAndImageChunks() was successful.
{
WebPData frame;
const uint32_t tag = kChunks[IDX_ANMF].tag;
WebPMuxFrameInfo tmp = *info;
tmp.x_offset &= ~1; // Snap offsets to even.
tmp.y_offset &= ~1;
if (tmp.x_offset < 0 || tmp.x_offset >= MAX_POSITION_OFFSET ||
tmp.y_offset < 0 || tmp.y_offset >= MAX_POSITION_OFFSET ||
(tmp.duration < 0 || tmp.duration >= MAX_DURATION) ||
tmp.dispose_method != (tmp.dispose_method & 1)) {
err = WEBP_MUX_INVALID_ARGUMENT;
goto Err;
}
err = CreateFrameData(wpi.width_, wpi.height_, &tmp, &frame);
if (err != WEBP_MUX_OK) goto Err;
// Add frame chunk (with copy_data = 1).
err = AddDataToChunkList(&frame, 1, tag, &wpi.header_);
WebPDataClear(&frame); // frame owned by wpi.header_ now.
if (err != WEBP_MUX_OK) goto Err;
}
// Add this WebPMuxImage to mux.
err = MuxImagePush(&wpi, &mux->images_);
if (err != WEBP_MUX_OK) goto Err;
// All is well.
return WEBP_MUX_OK;
Err: // Something bad happened.
MuxImageRelease(&wpi);
return err;
}
WebPMuxError WebPMuxSetAnimationParams(WebPMux* mux,
const WebPMuxAnimParams* params) {
WebPMuxError err;
uint8_t data[ANIM_CHUNK_SIZE];
const WebPData anim = { data, ANIM_CHUNK_SIZE };
if (mux == NULL || params == NULL) return WEBP_MUX_INVALID_ARGUMENT;
if (params->loop_count < 0 || params->loop_count >= MAX_LOOP_COUNT) {
return WEBP_MUX_INVALID_ARGUMENT;
}
// Delete any existing ANIM chunk(s).
err = MuxDeleteAllNamedData(mux, kChunks[IDX_ANIM].tag);
if (err != WEBP_MUX_OK && err != WEBP_MUX_NOT_FOUND) return err;
// Set the animation parameters.
PutLE32(data, params->bgcolor);
PutLE16(data + 4, params->loop_count);
return MuxSet(mux, kChunks[IDX_ANIM].tag, 1, &anim, 1);
}
WebPMuxError WebPMuxSetCanvasSize(WebPMux* mux,
int width, int height) {
WebPMuxError err;
if (mux == NULL) {
return WEBP_MUX_INVALID_ARGUMENT;
}
if (width < 0 || height < 0 ||
width > MAX_CANVAS_SIZE || height > MAX_CANVAS_SIZE) {
return WEBP_MUX_INVALID_ARGUMENT;
}
if (width * (uint64_t)height >= MAX_IMAGE_AREA) {
return WEBP_MUX_INVALID_ARGUMENT;
}
if ((width * height) == 0 && (width | height) != 0) {
// one of width / height is zero, but not both -> invalid!
return WEBP_MUX_INVALID_ARGUMENT;
}
// If we already assembled a VP8X chunk, invalidate it.
err = MuxDeleteAllNamedData(mux, kChunks[IDX_VP8X].tag);
if (err != WEBP_MUX_OK && err != WEBP_MUX_NOT_FOUND) return err;
mux->canvas_width_ = width;
mux->canvas_height_ = height;
return WEBP_MUX_OK;
}
//------------------------------------------------------------------------------
// Delete API(s).
WebPMuxError WebPMuxDeleteChunk(WebPMux* mux, const char fourcc[4]) {
if (mux == NULL || fourcc == NULL) return WEBP_MUX_INVALID_ARGUMENT;
return MuxDeleteAllNamedData(mux, ChunkGetTagFromFourCC(fourcc));
}
WebPMuxError WebPMuxDeleteFrame(WebPMux* mux, uint32_t nth) {
if (mux == NULL) return WEBP_MUX_INVALID_ARGUMENT;
return MuxImageDeleteNth(&mux->images_, nth);
}
//------------------------------------------------------------------------------
// Assembly of the WebP RIFF file.
static WebPMuxError GetFrameInfo(
const WebPChunk* const frame_chunk,
int* const x_offset, int* const y_offset, int* const duration) {
const WebPData* const data = &frame_chunk->data_;
const size_t expected_data_size = ANMF_CHUNK_SIZE;
assert(frame_chunk->tag_ == kChunks[IDX_ANMF].tag);
assert(frame_chunk != NULL);
if (data->size != expected_data_size) return WEBP_MUX_INVALID_ARGUMENT;
*x_offset = 2 * GetLE24(data->bytes + 0);
*y_offset = 2 * GetLE24(data->bytes + 3);
*duration = GetLE24(data->bytes + 12);
return WEBP_MUX_OK;
}
static WebPMuxError GetImageInfo(const WebPMuxImage* const wpi,
int* const x_offset, int* const y_offset,
int* const duration,
int* const width, int* const height) {
const WebPChunk* const frame_chunk = wpi->header_;
WebPMuxError err;
assert(wpi != NULL);
assert(frame_chunk != NULL);
// Get offsets and duration from ANMF chunk.
err = GetFrameInfo(frame_chunk, x_offset, y_offset, duration);
if (err != WEBP_MUX_OK) return err;
// Get width and height from VP8/VP8L chunk.
if (width != NULL) *width = wpi->width_;
if (height != NULL) *height = wpi->height_;
return WEBP_MUX_OK;
}
// Returns the tightest dimension for the canvas considering the image list.
static WebPMuxError GetAdjustedCanvasSize(const WebPMux* const mux,
int* const width, int* const height) {
WebPMuxImage* wpi = NULL;
assert(mux != NULL);
assert(width != NULL && height != NULL);
wpi = mux->images_;
assert(wpi != NULL);
assert(wpi->img_ != NULL);
if (wpi->next_ != NULL) {
int max_x = 0, max_y = 0;
// if we have a chain of wpi's, header_ is necessarily set
assert(wpi->header_ != NULL);
// Aggregate the bounding box for animation frames.
for (; wpi != NULL; wpi = wpi->next_) {
int x_offset = 0, y_offset = 0, duration = 0, w = 0, h = 0;
const WebPMuxError err = GetImageInfo(wpi, &x_offset, &y_offset,
&duration, &w, &h);
const int max_x_pos = x_offset + w;
const int max_y_pos = y_offset + h;
if (err != WEBP_MUX_OK) return err;
assert(x_offset < MAX_POSITION_OFFSET);
assert(y_offset < MAX_POSITION_OFFSET);
if (max_x_pos > max_x) max_x = max_x_pos;
if (max_y_pos > max_y) max_y = max_y_pos;
}
*width = max_x;
*height = max_y;
} else {
// For a single image, canvas dimensions are same as image dimensions.
*width = wpi->width_;
*height = wpi->height_;
}
return WEBP_MUX_OK;
}
// VP8X format:
// Total Size : 10,
// Flags : 4 bytes,
// Width : 3 bytes,
// Height : 3 bytes.
static WebPMuxError CreateVP8XChunk(WebPMux* const mux) {
WebPMuxError err = WEBP_MUX_OK;
uint32_t flags = 0;
int width = 0;
int height = 0;
uint8_t data[VP8X_CHUNK_SIZE];
const WebPData vp8x = { data, VP8X_CHUNK_SIZE };
const WebPMuxImage* images = NULL;
assert(mux != NULL);
images = mux->images_; // First image.
if (images == NULL || images->img_ == NULL ||
images->img_->data_.bytes == NULL) {
return WEBP_MUX_INVALID_ARGUMENT;
}
// If VP8X chunk(s) is(are) already present, remove them (and later add new
// VP8X chunk with updated flags).
err = MuxDeleteAllNamedData(mux, kChunks[IDX_VP8X].tag);
if (err != WEBP_MUX_OK && err != WEBP_MUX_NOT_FOUND) return err;
// Set flags.
if (mux->iccp_ != NULL && mux->iccp_->data_.bytes != NULL) {
flags |= ICCP_FLAG;
}
if (mux->exif_ != NULL && mux->exif_->data_.bytes != NULL) {
flags |= EXIF_FLAG;
}
if (mux->xmp_ != NULL && mux->xmp_->data_.bytes != NULL) {
flags |= XMP_FLAG;
}
if (images->header_ != NULL) {
if (images->header_->tag_ == kChunks[IDX_ANMF].tag) {
// This is an image with animation.
flags |= ANIMATION_FLAG;
}
}
if (MuxImageCount(images, WEBP_CHUNK_ALPHA) > 0) {
flags |= ALPHA_FLAG; // Some images have an alpha channel.
}
err = GetAdjustedCanvasSize(mux, &width, &height);
if (err != WEBP_MUX_OK) return err;
if (width <= 0 || height <= 0) {
return WEBP_MUX_INVALID_ARGUMENT;
}
if (width > MAX_CANVAS_SIZE || height > MAX_CANVAS_SIZE) {
return WEBP_MUX_INVALID_ARGUMENT;
}
if (mux->canvas_width_ != 0 || mux->canvas_height_ != 0) {
if (width > mux->canvas_width_ || height > mux->canvas_height_) {
return WEBP_MUX_INVALID_ARGUMENT;
}
width = mux->canvas_width_;
height = mux->canvas_height_;
}
if (flags == 0 && mux->unknown_ == NULL) {
// For simple file format, VP8X chunk should not be added.
return WEBP_MUX_OK;
}
if (MuxHasAlpha(images)) {
// This means some frames explicitly/implicitly contain alpha.
// Note: This 'flags' update must NOT be done for a lossless image
// without a VP8X chunk!
flags |= ALPHA_FLAG;
}
PutLE32(data + 0, flags); // VP8X chunk flags.
PutLE24(data + 4, width - 1); // canvas width.
PutLE24(data + 7, height - 1); // canvas height.
return MuxSet(mux, kChunks[IDX_VP8X].tag, 1, &vp8x, 1);
}
// Cleans up 'mux' by removing any unnecessary chunks.
static WebPMuxError MuxCleanup(WebPMux* const mux) {
int num_frames;
int num_anim_chunks;
// If we have an image with a single frame, and its rectangle
// covers the whole canvas, convert it to a non-animated image
// (to avoid writing ANMF chunk unnecessarily).
WebPMuxError err = WebPMuxNumChunks(mux, kChunks[IDX_ANMF].id, &num_frames);
if (err != WEBP_MUX_OK) return err;
if (num_frames == 1) {
WebPMuxImage* frame = NULL;
err = MuxImageGetNth((const WebPMuxImage**)&mux->images_, 1, &frame);
assert(err == WEBP_MUX_OK); // We know that one frame does exist.
assert(frame != NULL);
if (frame->header_ != NULL &&
((mux->canvas_width_ == 0 && mux->canvas_height_ == 0) ||
(frame->width_ == mux->canvas_width_ &&
frame->height_ == mux->canvas_height_))) {
assert(frame->header_->tag_ == kChunks[IDX_ANMF].tag);
ChunkDelete(frame->header_); // Removes ANMF chunk.
frame->header_ = NULL;
num_frames = 0;
}
}
// Remove ANIM chunk if this is a non-animated image.
err = WebPMuxNumChunks(mux, kChunks[IDX_ANIM].id, &num_anim_chunks);
if (err != WEBP_MUX_OK) return err;
if (num_anim_chunks >= 1 && num_frames == 0) {
err = MuxDeleteAllNamedData(mux, kChunks[IDX_ANIM].tag);
if (err != WEBP_MUX_OK) return err;
}
return WEBP_MUX_OK;
}
// Total size of a list of images.
static size_t ImageListDiskSize(const WebPMuxImage* wpi_list) {
size_t size = 0;
while (wpi_list != NULL) {
size += MuxImageDiskSize(wpi_list);
wpi_list = wpi_list->next_;
}
return size;
}
// Write out the given list of images into 'dst'.
static uint8_t* ImageListEmit(const WebPMuxImage* wpi_list, uint8_t* dst) {
while (wpi_list != NULL) {
dst = MuxImageEmit(wpi_list, dst);
wpi_list = wpi_list->next_;
}
return dst;
}
WebPMuxError WebPMuxAssemble(WebPMux* mux, WebPData* assembled_data) {
size_t size = 0;
uint8_t* data = NULL;
uint8_t* dst = NULL;
WebPMuxError err;
if (assembled_data == NULL) {
return WEBP_MUX_INVALID_ARGUMENT;
}
// Clean up returned data, in case something goes wrong.
memset(assembled_data, 0, sizeof(*assembled_data));
if (mux == NULL) {
return WEBP_MUX_INVALID_ARGUMENT;
}
// Finalize mux.
err = MuxCleanup(mux);
if (err != WEBP_MUX_OK) return err;
err = CreateVP8XChunk(mux);
if (err != WEBP_MUX_OK) return err;
// Allocate data.
size = ChunkListDiskSize(mux->vp8x_) + ChunkListDiskSize(mux->iccp_)
+ ChunkListDiskSize(mux->anim_) + ImageListDiskSize(mux->images_)
+ ChunkListDiskSize(mux->exif_) + ChunkListDiskSize(mux->xmp_)
+ ChunkListDiskSize(mux->unknown_) + RIFF_HEADER_SIZE;
data = (uint8_t*)WebPSafeMalloc(1ULL, size);
if (data == NULL) return WEBP_MUX_MEMORY_ERROR;
// Emit header & chunks.
dst = MuxEmitRiffHeader(data, size);
dst = ChunkListEmit(mux->vp8x_, dst);
dst = ChunkListEmit(mux->iccp_, dst);
dst = ChunkListEmit(mux->anim_, dst);
dst = ImageListEmit(mux->images_, dst);
dst = ChunkListEmit(mux->exif_, dst);
dst = ChunkListEmit(mux->xmp_, dst);
dst = ChunkListEmit(mux->unknown_, dst);
assert(dst == data + size);
// Validate mux.
err = MuxValidate(mux);
if (err != WEBP_MUX_OK) {
WebPSafeFree(data);
data = NULL;
size = 0;
}
// Finalize data.
assembled_data->bytes = data;
assembled_data->size = size;
return err;
}
//------------------------------------------------------------------------------