// Validates that the given mux has a single image.
static WebPMuxError ValidateForSingleImage(const WebPMux* const mux) {
const int num_images = MuxImageCount(mux->images_, WEBP_CHUNK_IMAGE);
const int num_frames = MuxImageCount(mux->images_, WEBP_CHUNK_ANMF);
const int num_fragments = MuxImageCount(mux->images_, WEBP_CHUNK_FRGM);
if (num_images == 0) {
// No images in mux.
return WEBP_MUX_NOT_FOUND;
} else if (num_images == 1 && num_frames == 0 && num_fragments == 0) {
// Valid case (single image).
return WEBP_MUX_OK;
} else {
// Frame/Fragment case OR an invalid mux.
return WEBP_MUX_INVALID_ARGUMENT;
}
}
WebPMuxError WebPMuxNumChunks(const WebPMux* mux,
WebPChunkId id, int* num_elements) {
if (mux == NULL || num_elements == NULL) {
return WEBP_MUX_INVALID_ARGUMENT;
}
if (IsWPI(id)) {
*num_elements = MuxImageCount(mux->images_, id);
} else {
WebPChunk* const* chunk_list = MuxGetChunkListFromId(mux, id);
const CHUNK_INDEX idx = ChunkGetIndexFromId(id);
*num_elements = CountChunks(*chunk_list, kChunks[idx].tag);
}
return WEBP_MUX_OK;
}
// Outputs a pointer to 'prev_wpi->next_',
// where 'prev_wpi' is the pointer to the image at position (nth - 1).
// Returns true if nth image was found.
static int SearchImageToGetOrDelete(WebPMuxImage** wpi_list, uint32_t nth,
WebPMuxImage*** const location) {
uint32_t count = 0;
assert(wpi_list);
*location = wpi_list;
if (nth == 0) {
nth = MuxImageCount(*wpi_list, WEBP_CHUNK_NIL);
if (nth == 0) return 0; // Not found.
}
while (*wpi_list != NULL) {
WebPMuxImage* const cur_wpi = *wpi_list;
++count;
if (count == nth) return 1; // Found.
wpi_list = &cur_wpi->next_;
*location = wpi_list;
}
return 0; // Not found.
}
// 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_FRGM].tag) {
// This is a fragmented image.
flags |= FRAGMENTS_FLAG;
} else 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.
}
if (flags == 0) {
// For Simple Image, VP8X chunk should not be added.
return WEBP_MUX_OK;
}
err = GetImageCanvasWidthHeight(mux, flags, &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 (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);
}
// 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 size_t data_size = 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, IDX_VP8X);
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->meta_ != NULL && mux->meta_->data_.bytes_ != NULL) {
flags |= META_FLAG;
}
if (images->header_ != NULL) {
if (images->header_->tag_ == kChunks[IDX_TILE].tag) {
// This is a tiled image.
flags |= TILE_FLAG;
} else if (images->header_->tag_ == kChunks[IDX_FRAME].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.
}
if (flags == 0) {
// For Simple Image, VP8X chunk should not be added.
return WEBP_MUX_OK;
}
err = GetImageCanvasWidthHeight(mux, flags, &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 (MuxHasLosslessImages(images)) {
// We have a file with a VP8X chunk having some lossless images.
// As lossless images implicitly contain alpha, force ALPHA_FLAG to be true.
// 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.
err = MuxAddChunk(mux, 1, kChunks[IDX_VP8X].tag, data, data_size, 1);
return err;
}
