// 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;
}
WebPMuxError MuxValidate(const WebPMux* const mux) {
int num_iccp;
int num_exif;
int num_xmp;
int num_anim;
int num_frames;
int num_fragments;
int num_vp8x;
int num_images;
int num_alpha;
uint32_t flags;
WebPMuxError err;
// Verify mux is not NULL.
if (mux == NULL) return WEBP_MUX_INVALID_ARGUMENT;
// Verify mux has at least one image.
if (mux->images_ == NULL) return WEBP_MUX_INVALID_ARGUMENT;
err = WebPMuxGetFeatures(mux, &flags);
if (err != WEBP_MUX_OK) return err;
// At most one color profile chunk.
err = ValidateChunk(mux, IDX_ICCP, ICCP_FLAG, flags, 1, &num_iccp);
if (err != WEBP_MUX_OK) return err;
// At most one EXIF metadata.
err = ValidateChunk(mux, IDX_EXIF, EXIF_FLAG, flags, 1, &num_exif);
if (err != WEBP_MUX_OK) return err;
// At most one XMP metadata.
err = ValidateChunk(mux, IDX_XMP, XMP_FLAG, flags, 1, &num_xmp);
if (err != WEBP_MUX_OK) return err;
// Animation: ANIMATION_FLAG, ANIM chunk and ANMF chunk(s) are consistent.
// At most one ANIM chunk.
err = ValidateChunk(mux, IDX_ANIM, NO_FLAG, flags, 1, &num_anim);
if (err != WEBP_MUX_OK) return err;
err = ValidateChunk(mux, IDX_ANMF, NO_FLAG, flags, -1, &num_frames);
if (err != WEBP_MUX_OK) return err;
{
const int has_animation = !!(flags & ANIMATION_FLAG);
if (has_animation && (num_anim == 0 || num_frames == 0)) {
return WEBP_MUX_INVALID_ARGUMENT;
}
if (!has_animation && (num_anim == 1 || num_frames > 0)) {
return WEBP_MUX_INVALID_ARGUMENT;
}
}
// Fragmentation: FRAGMENTS_FLAG and FRGM chunk(s) are consistent.
err = ValidateChunk(mux, IDX_FRGM, FRAGMENTS_FLAG, flags, -1, &num_fragments);
if (err != WEBP_MUX_OK) return err;
// Verify either VP8X chunk is present OR there is only one elem in
// mux->images_.
err = ValidateChunk(mux, IDX_VP8X, NO_FLAG, flags, 1, &num_vp8x);
if (err != WEBP_MUX_OK) return err;
err = ValidateChunk(mux, IDX_VP8, NO_FLAG, flags, -1, &num_images);
if (err != WEBP_MUX_OK) return err;
if (num_vp8x == 0 && num_images != 1) return WEBP_MUX_INVALID_ARGUMENT;
// ALPHA_FLAG & alpha chunk(s) are consistent.
if (MuxHasLosslessImages(mux->images_)) {
if (num_vp8x > 0) {
// Special case: we have a VP8X chunk as well as some lossless images.
if (!(flags & ALPHA_FLAG)) return WEBP_MUX_INVALID_ARGUMENT;
}
} else {
err = ValidateChunk(mux, IDX_ALPHA, ALPHA_FLAG, flags, -1, &num_alpha);
if (err != WEBP_MUX_OK) return err;
}
// num_fragments & num_images are consistent.
if (num_fragments > 0 && num_images != num_fragments) {
return WEBP_MUX_INVALID_ARGUMENT;
}
return WEBP_MUX_OK;
}
