WebPMuxError WebPMuxSetImage(WebPMux* mux,
const WebPData* bitstream, int copy_data) {
WebPMuxError err;
WebPChunk chunk;
WebPMuxImage wpi;
WebPData image;
WebPData alpha;
int is_lossless;
int image_tag;
if (mux == NULL || bitstream == NULL || bitstream->bytes_ == NULL ||
bitstream->size_ > MAX_CHUNK_PAYLOAD) {
return WEBP_MUX_INVALID_ARGUMENT;
}
// If given data is for a whole webp file,
// extract only the VP8/VP8L data from it.
err = GetImageData(bitstream, &image, &alpha, &is_lossless);
if (err != WEBP_MUX_OK) return err;
image_tag = is_lossless ? kChunks[IDX_VP8L].tag : kChunks[IDX_VP8].tag;
// Delete the existing images.
MuxImageDeleteAll(&mux->images_);
MuxImageInit(&wpi);
if (alpha.bytes_ != NULL) { // Add alpha chunk.
ChunkInit(&chunk);
err = ChunkAssignData(&chunk, &alpha, copy_data, kChunks[IDX_ALPHA].tag);
if (err != WEBP_MUX_OK) goto Err;
err = ChunkSetNth(&chunk, &wpi.alpha_, 1);
if (err != WEBP_MUX_OK) goto Err;
}
// Add image chunk.
ChunkInit(&chunk);
err = ChunkAssignData(&chunk, &image, copy_data, image_tag);
if (err != WEBP_MUX_OK) goto Err;
err = ChunkSetNth(&chunk, &wpi.img_, 1);
if (err != WEBP_MUX_OK) goto Err;
// Add this image to mux.
err = MuxImagePush(&wpi, &mux->images_);
if (err != WEBP_MUX_OK) goto Err;
// All OK.
return WEBP_MUX_OK;
Err:
// Something bad happened.
ChunkRelease(&chunk);
MuxImageRelease(&wpi);
return err;
}
// 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;
}
// Fill the chunk with the given data (includes chunk header bytes), after some
// verifications.
static WebPMuxError ChunkVerifyAndAssign(WebPChunk* chunk,
const uint8_t* data, size_t data_size,
size_t riff_size, int copy_data) {
uint32_t chunk_size;
WebPData chunk_data;
// Sanity checks.
if (data_size < CHUNK_HEADER_SIZE) return WEBP_MUX_NOT_ENOUGH_DATA;
chunk_size = GetLE32(data + TAG_SIZE);
{
const size_t chunk_disk_size = SizeWithPadding(chunk_size);
if (chunk_disk_size > riff_size) return WEBP_MUX_BAD_DATA;
if (chunk_disk_size > data_size) return WEBP_MUX_NOT_ENOUGH_DATA;
}
// Data assignment.
chunk_data.bytes = data + CHUNK_HEADER_SIZE;
chunk_data.size = chunk_size;
return ChunkAssignData(chunk, &chunk_data, copy_data, GetLE32(data + 0));
}
static WebPMuxError MuxSet(WebPMux* const mux, CHUNK_INDEX idx, uint32_t nth,
const WebPData* const data, int copy_data) {
WebPChunk chunk;
WebPMuxError err = WEBP_MUX_NOT_FOUND;
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_LOOP, &mux->loop_);
SWITCH_ID_LIST(IDX_META, &mux->meta_);
if (idx == IDX_UNKNOWN && data->size_ > TAG_SIZE) {
// For raw-data unknown chunk, the first four bytes should be the tag to be
// used for the chunk.
const WebPData tmp = { data->bytes_ + TAG_SIZE, data->size_ - TAG_SIZE };
err = ChunkAssignData(&chunk, &tmp, copy_data, GetLE32(data->bytes_ + 0));
if (err == WEBP_MUX_OK)
err = ChunkSetNth(&chunk, &mux->unknown_, nth);
}
return err;
}
static int MuxImageParse(const WebPChunk* const chunk, int copy_data,
WebPMuxImage* const wpi) {
const uint8_t* bytes = chunk->data_.bytes;
size_t size = chunk->data_.size;
const uint8_t* const last = bytes + size;
WebPChunk subchunk;
size_t subchunk_size;
ChunkInit(&subchunk);
assert(chunk->tag_ == kChunks[IDX_ANMF].tag ||
chunk->tag_ == kChunks[IDX_FRGM].tag);
assert(!wpi->is_partial_);
// ANMF/FRGM.
{
const size_t hdr_size = (chunk->tag_ == kChunks[IDX_ANMF].tag) ?
ANMF_CHUNK_SIZE : FRGM_CHUNK_SIZE;
const WebPData temp = { bytes, hdr_size };
// Each of ANMF and FRGM chunk contain a header at the beginning. So, its
// size should at least be 'hdr_size'.
if (size < hdr_size) goto Fail;
ChunkAssignData(&subchunk, &temp, copy_data, chunk->tag_);
}
ChunkSetNth(&subchunk, &wpi->header_, 1);
wpi->is_partial_ = 1; // Waiting for ALPH and/or VP8/VP8L chunks.
// Rest of the chunks.
subchunk_size = ChunkDiskSize(&subchunk) - CHUNK_HEADER_SIZE;
bytes += subchunk_size;
size -= subchunk_size;
while (bytes != last) {
ChunkInit(&subchunk);
if (ChunkVerifyAndAssign(&subchunk, bytes, size, size,
copy_data) != WEBP_MUX_OK) {
goto Fail;
}
switch (ChunkGetIdFromTag(subchunk.tag_)) {
case WEBP_CHUNK_ALPHA:
if (wpi->alpha_ != NULL) goto Fail; // Consecutive ALPH chunks.
if (ChunkSetNth(&subchunk, &wpi->alpha_, 1) != WEBP_MUX_OK) goto Fail;
wpi->is_partial_ = 1; // Waiting for a VP8 chunk.
break;
case WEBP_CHUNK_IMAGE:
if (ChunkSetNth(&subchunk, &wpi->img_, 1) != WEBP_MUX_OK) goto Fail;
if (!MuxImageFinalize(wpi)) goto Fail;
wpi->is_partial_ = 0; // wpi is completely filled.
break;
case WEBP_CHUNK_UNKNOWN:
if (wpi->is_partial_) goto Fail; // Encountered an unknown chunk
// before some image chunks.
if (ChunkSetNth(&subchunk, &wpi->unknown_, 0) != WEBP_MUX_OK) goto Fail;
break;
default:
goto Fail;
break;
}
subchunk_size = ChunkDiskSize(&subchunk);
bytes += subchunk_size;
size -= subchunk_size;
}
if (wpi->is_partial_) goto Fail;
return 1;
Fail:
ChunkRelease(&subchunk);
return 0;
}
static WebPMuxError MuxPushFrameTileInternal(
WebPMux* const mux, const WebPData* const bitstream, int x_offset,
int y_offset, int duration, int copy_data, uint32_t tag) {
WebPChunk chunk;
WebPData image;
WebPData alpha;
WebPMuxImage wpi;
WebPMuxError err;
WebPData frame_tile;
const int is_frame = (tag == kChunks[IDX_FRAME].tag) ? 1 : 0;
int is_lossless;
int image_tag;
// Sanity checks.
if (mux == NULL || bitstream == NULL || bitstream->bytes_ == NULL ||
bitstream->size_ > MAX_CHUNK_PAYLOAD) {
return WEBP_MUX_INVALID_ARGUMENT;
}
if (x_offset < 0 || x_offset >= MAX_POSITION_OFFSET ||
y_offset < 0 || y_offset >= MAX_POSITION_OFFSET ||
duration <= 0 || duration > MAX_DURATION) {
return WEBP_MUX_INVALID_ARGUMENT;
}
// Snap offsets to even positions.
x_offset &= ~1;
y_offset &= ~1;
// If given data is for a whole webp file,
// extract only the VP8/VP8L data from it.
err = GetImageData(bitstream, &image, &alpha, &is_lossless);
if (err != WEBP_MUX_OK) return err;
image_tag = is_lossless ? kChunks[IDX_VP8L].tag : kChunks[IDX_VP8].tag;
WebPDataInit(&frame_tile);
ChunkInit(&chunk);
MuxImageInit(&wpi);
if (alpha.bytes_ != NULL) {
// Add alpha chunk.
err = ChunkAssignData(&chunk, &alpha, copy_data, kChunks[IDX_ALPHA].tag);
if (err != WEBP_MUX_OK) goto Err;
err = ChunkSetNth(&chunk, &wpi.alpha_, 1);
if (err != WEBP_MUX_OK) goto Err;
ChunkInit(&chunk); // chunk owned by wpi.alpha_ now.
}
// Add image chunk.
err = ChunkAssignData(&chunk, &image, copy_data, image_tag);
if (err != WEBP_MUX_OK) goto Err;
err = ChunkSetNth(&chunk, &wpi.img_, 1);
if (err != WEBP_MUX_OK) goto Err;
ChunkInit(&chunk); // chunk owned by wpi.img_ now.
// Create frame/tile data.
err = CreateFrameTileData(&image, x_offset, y_offset, duration, is_lossless,
is_frame, &frame_tile);
if (err != WEBP_MUX_OK) goto Err;
// Add frame/tile chunk (with copy_data = 1).
err = ChunkAssignData(&chunk, &frame_tile, 1, tag);
if (err != WEBP_MUX_OK) goto Err;
WebPDataClear(&frame_tile);
err = ChunkSetNth(&chunk, &wpi.header_, 1);
if (err != WEBP_MUX_OK) goto Err;
ChunkInit(&chunk); // chunk owned by wpi.header_ now.
// 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.
WebPDataClear(&frame_tile);
ChunkRelease(&chunk);
MuxImageRelease(&wpi);
return err;
}
