static WebPMuxError MuxGetFrameFragmentInternal(const WebPMuxImage* const wpi,
WebPMuxFrameInfo* const frame) {
const int is_frame = (wpi->header_->tag_ == kChunks[IDX_ANMF].tag);
const CHUNK_INDEX idx = is_frame ? IDX_ANMF : IDX_FRGM;
const WebPData* frame_frgm_data;
if (!is_frame) return WEBP_MUX_INVALID_ARGUMENT;
assert(wpi->header_ != NULL); // Already checked by WebPMuxGetFrame().
// Get frame/fragment chunk.
frame_frgm_data = &wpi->header_->data_;
if (frame_frgm_data->size < kChunks[idx].size) return WEBP_MUX_BAD_DATA;
// Extract info.
frame->x_offset = 2 * GetLE24(frame_frgm_data->bytes + 0);
frame->y_offset = 2 * GetLE24(frame_frgm_data->bytes + 3);
if (is_frame) {
const uint8_t bits = frame_frgm_data->bytes[15];
frame->duration = GetLE24(frame_frgm_data->bytes + 12);
frame->dispose_method =
(bits & 1) ? WEBP_MUX_DISPOSE_BACKGROUND : WEBP_MUX_DISPOSE_NONE;
frame->blend_method = (bits & 2) ? WEBP_MUX_NO_BLEND : WEBP_MUX_BLEND;
} else { // Defaults for unused values.
frame->duration = 1;
frame->dispose_method = WEBP_MUX_DISPOSE_NONE;
frame->blend_method = WEBP_MUX_BLEND;
}
frame->id = ChunkGetIdFromTag(wpi->header_->tag_);
return SynthesizeBitstream(wpi, &frame->bitstream);
}
// Get the canvas width, height and flags after validating that VP8X/VP8/VP8L
// chunk and canvas size are valid.
static WebPMuxError MuxGetCanvasInfo(const WebPMux* const mux,
int* width, int* height, uint32_t* flags) {
int w, h;
uint32_t f = 0;
WebPData data;
assert(mux != NULL);
// Check if VP8X chunk is present.
if (MuxGet(mux, IDX_VP8X, 1, &data) == WEBP_MUX_OK) {
if (data.size < VP8X_CHUNK_SIZE) return WEBP_MUX_BAD_DATA;
f = GetLE32(data.bytes + 0);
w = GetLE24(data.bytes + 4) + 1;
h = GetLE24(data.bytes + 7) + 1;
} else {
const WebPMuxImage* const wpi = mux->images_;
// Grab user-forced canvas size as default.
w = mux->canvas_width_;
h = mux->canvas_height_;
if (w == 0 && h == 0 && ValidateForSingleImage(mux) == WEBP_MUX_OK) {
// single image and not forced canvas size => use dimension of first frame
assert(wpi != NULL);
w = wpi->width_;
h = wpi->height_;
}
if (wpi != NULL) {
if (wpi->has_alpha_) f |= ALPHA_FLAG;
}
}
if (w * (uint64_t)h >= MAX_IMAGE_AREA) return WEBP_MUX_BAD_DATA;
if (width != NULL) *width = w;
if (height != NULL) *height = h;
if (flags != NULL) *flags = f;
return WEBP_MUX_OK;
}
// Get the canvas width, height and flags after validating that VP8X/VP8/VP8L
// chunk and canvas size are valid.
static WebPMuxError MuxGetCanvasInfo(const WebPMux* const mux,
int* width, int* height, uint32_t* flags) {
int w, h;
uint32_t f = 0;
WebPData data;
assert(mux != NULL);
// Check if VP8X chunk is present.
if (MuxGet(mux, IDX_VP8X, 1, &data) == WEBP_MUX_OK) {
if (data.size < VP8X_CHUNK_SIZE) return WEBP_MUX_BAD_DATA;
f = GetLE32(data.bytes + 0);
w = GetLE24(data.bytes + 4) + 1;
h = GetLE24(data.bytes + 7) + 1;
} else { // Single image case.
const WebPMuxImage* const wpi = mux->images_;
WebPMuxError err = ValidateForSingleImage(mux);
if (err != WEBP_MUX_OK) return err;
assert(wpi != NULL);
w = wpi->width_;
h = wpi->height_;
if (wpi->has_alpha_) f |= ALPHA_FLAG;
}
if (w * (uint64_t)h >= MAX_IMAGE_AREA) return WEBP_MUX_BAD_DATA;
if (width != NULL) *width = w;
if (height != NULL) *height = h;
if (flags != NULL) *flags = f;
return WEBP_MUX_OK;
}
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 GetFrameFragmentInfo(
const WebPChunk* const frame_frgm_chunk,
int* const x_offset, int* const y_offset, int* const duration) {
const uint32_t tag = frame_frgm_chunk->tag_;
const int is_frame = (tag == kChunks[IDX_ANMF].tag);
const WebPData* const data = &frame_frgm_chunk->data_;
const size_t expected_data_size =
is_frame ? ANMF_CHUNK_SIZE : FRGM_CHUNK_SIZE;
assert(frame_frgm_chunk != NULL);
assert(tag == kChunks[IDX_ANMF].tag || tag == kChunks[IDX_FRGM].tag);
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);
if (is_frame) *duration = GetLE24(data->bytes + 12);
return WEBP_MUX_OK;
}
static WebPMuxError GetFrameTileInfo(const WebPChunk* const frame_tile_chunk,
int* const x_offset, int* const y_offset,
int* const duration) {
const uint32_t tag = frame_tile_chunk->tag_;
const int is_frame = (tag == kChunks[IDX_FRAME].tag);
const WebPData* const data = &frame_tile_chunk->data_;
const size_t expected_data_size =
is_frame ? FRAME_CHUNK_SIZE : TILE_CHUNK_SIZE;
assert(frame_tile_chunk != NULL);
assert(tag == kChunks[IDX_FRAME].tag || tag == kChunks[IDX_TILE].tag);
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);
if (is_frame) *duration = 1 + GetLE24(data->bytes_ + 12);
return WEBP_MUX_OK;
}
// Validates the VP8X header and skips over it.
// Returns VP8_STATUS_BITSTREAM_ERROR for invalid VP8X header,
// VP8_STATUS_NOT_ENOUGH_DATA in case of insufficient data, and
// VP8_STATUS_OK otherwise.
// If a VP8X chunk is found, found_vp8x is set to true and *width_ptr,
// *height_ptr and *flags_ptr are set to the corresponding values extracted
// from the VP8X chunk.
static VP8StatusCode ParseVP8X(const uint8_t** const data,
size_t* const data_size,
int* const found_vp8x,
int* const width_ptr, int* const height_ptr,
uint32_t* const flags_ptr) {
const uint32_t vp8x_size = CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE;
assert(data != NULL);
assert(data_size != NULL);
assert(found_vp8x != NULL);
*found_vp8x = 0;
if (*data_size < CHUNK_HEADER_SIZE) {
return VP8_STATUS_NOT_ENOUGH_DATA; // Insufficient data.
}
if (!memcmp(*data, "VP8X", TAG_SIZE)) {
int width, height;
uint32_t flags;
const uint32_t chunk_size = GetLE32(*data + TAG_SIZE);
if (chunk_size != VP8X_CHUNK_SIZE) {
return VP8_STATUS_BITSTREAM_ERROR; // Wrong chunk size.
}
// Verify if enough data is available to validate the VP8X chunk.
if (*data_size < vp8x_size) {
return VP8_STATUS_NOT_ENOUGH_DATA; // Insufficient data.
}
flags = GetLE32(*data + 8);
width = 1 + GetLE24(*data + 12);
height = 1 + GetLE24(*data + 15);
if (width * (uint64_t)height >= MAX_IMAGE_AREA) {
return VP8_STATUS_BITSTREAM_ERROR; // image is too large
}
if (flags_ptr != NULL) *flags_ptr = flags;
if (width_ptr != NULL) *width_ptr = width;
if (height_ptr != NULL) *height_ptr = height;
// Skip over VP8X header bytes.
*data += vp8x_size;
*data_size -= vp8x_size;
*found_vp8x = 1;
}
return VP8_STATUS_OK;
}
static WEBP_INLINE int ReadLE24s(MemBuffer* const mem) {
const uint8_t* const data = mem->buf_ + mem->start_;
const int val = GetLE24(data);
Skip(mem, 3);
return val;
}
WebPMux* WebPMuxCreateInternal(const WebPData* bitstream, int copy_data,
int version) {
size_t riff_size;
uint32_t tag;
const uint8_t* end;
WebPMux* mux = NULL;
WebPMuxImage* wpi = NULL;
const uint8_t* data;
size_t size;
WebPChunk chunk;
ChunkInit(&chunk);
// Sanity checks.
if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_MUX_ABI_VERSION)) {
return NULL; // version mismatch
}
if (bitstream == NULL) return NULL;
data = bitstream->bytes;
size = bitstream->size;
if (data == NULL) return NULL;
if (size < RIFF_HEADER_SIZE) return NULL;
if (GetLE32(data + 0) != MKFOURCC('R', 'I', 'F', 'F') ||
GetLE32(data + CHUNK_HEADER_SIZE) != MKFOURCC('W', 'E', 'B', 'P')) {
return NULL;
}
mux = WebPMuxNew();
if (mux == NULL) return NULL;
if (size < RIFF_HEADER_SIZE + TAG_SIZE) goto Err;
tag = GetLE32(data + RIFF_HEADER_SIZE);
if (tag != kChunks[IDX_VP8].tag &&
tag != kChunks[IDX_VP8L].tag &&
tag != kChunks[IDX_VP8X].tag) {
goto Err; // First chunk should be VP8, VP8L or VP8X.
}
riff_size = SizeWithPadding(GetLE32(data + TAG_SIZE));
if (riff_size > MAX_CHUNK_PAYLOAD || riff_size > size) {
goto Err;
} else {
if (riff_size < size) { // Redundant data after last chunk.
size = riff_size; // To make sure we don't read any data beyond mux_size.
}
}
end = data + size;
data += RIFF_HEADER_SIZE;
size -= RIFF_HEADER_SIZE;
wpi = (WebPMuxImage*)WebPSafeMalloc(1ULL, sizeof(*wpi));
if (wpi == NULL) goto Err;
MuxImageInit(wpi);
// Loop over chunks.
while (data != end) {
size_t data_size;
WebPChunkId id;
WebPChunk** chunk_list;
if (ChunkVerifyAndAssign(&chunk, data, size, riff_size,
copy_data) != WEBP_MUX_OK) {
goto Err;
}
data_size = ChunkDiskSize(&chunk);
id = ChunkGetIdFromTag(chunk.tag_);
switch (id) {
case WEBP_CHUNK_ALPHA:
if (wpi->alpha_ != NULL) goto Err; // Consecutive ALPH chunks.
if (ChunkSetNth(&chunk, &wpi->alpha_, 1) != WEBP_MUX_OK) goto Err;
wpi->is_partial_ = 1; // Waiting for a VP8 chunk.
break;
case WEBP_CHUNK_IMAGE:
if (ChunkSetNth(&chunk, &wpi->img_, 1) != WEBP_MUX_OK) goto Err;
if (!MuxImageFinalize(wpi)) goto Err;
wpi->is_partial_ = 0; // wpi is completely filled.
PushImage:
// Add this to mux->images_ list.
if (MuxImagePush(wpi, &mux->images_) != WEBP_MUX_OK) goto Err;
MuxImageInit(wpi); // Reset for reading next image.
break;
case WEBP_CHUNK_ANMF:
if (wpi->is_partial_) goto Err; // Previous wpi is still incomplete.
if (!MuxImageParse(&chunk, copy_data, wpi)) goto Err;
ChunkRelease(&chunk);
goto PushImage;
break;
default: // A non-image chunk.
if (wpi->is_partial_) goto Err; // Encountered a non-image chunk before
// getting all chunks of an image.
chunk_list = MuxGetChunkListFromId(mux, id); // List to add this chunk.
if (ChunkSetNth(&chunk, chunk_list, 0) != WEBP_MUX_OK) goto Err;
if (id == WEBP_CHUNK_VP8X) { // grab global specs
mux->canvas_width_ = GetLE24(data + 12) + 1;
mux->canvas_height_ = GetLE24(data + 15) + 1;
}
break;
}
data += data_size;
size -= data_size;
ChunkInit(&chunk);
}
// Validate mux if complete.
if (MuxValidate(mux) != WEBP_MUX_OK) goto Err;
MuxImageDelete(wpi);
return mux; // All OK;
Err: // Something bad happened.
ChunkRelease(&chunk);
MuxImageDelete(wpi);
WebPMuxDelete(mux);
return NULL;
}
