static void DisposeFrame(WebPMuxAnimDispose dispose_method,
const WebPFrameRect* const gif_rect,
WebPPicture* const frame, WebPPicture* const canvas) {
if (dispose_method == WEBP_MUX_DISPOSE_BACKGROUND) {
WebPUtilClearPic(frame, NULL);
WebPUtilClearPic(canvas, gif_rect);
}
}
static void DisposeFrameRectangle(int dispose_method,
const FrameRect* const rect,
WebPPicture* const curr_canvas) {
assert(rect != NULL);
if (dispose_method == WEBP_MUX_DISPOSE_BACKGROUND) {
WebPUtilClearPic(curr_canvas, rect);
}
}
WebPAnimEncoder* WebPAnimEncoderNewInternal(
int width, int height, const WebPAnimEncoderOptions* enc_options,
int abi_version) {
WebPAnimEncoder* enc;
if (WEBP_ABI_IS_INCOMPATIBLE(abi_version, WEBP_MUX_ABI_VERSION)) {
return NULL;
}
if (width <= 0 || height <= 0 ||
(width * (uint64_t)height) >= MAX_IMAGE_AREA) {
return NULL;
}
enc = (WebPAnimEncoder*)WebPSafeCalloc(1, sizeof(*enc));
if (enc == NULL) return NULL;
// sanity inits, so we can call WebPAnimEncoderDelete():
enc->encoded_frames_ = NULL;
enc->mux_ = NULL;
// Dimensions and options.
*(int*)&enc->canvas_width_ = width;
*(int*)&enc->canvas_height_ = height;
if (enc_options != NULL) {
*(WebPAnimEncoderOptions*)&enc->options_ = *enc_options;
SanitizeEncoderOptions((WebPAnimEncoderOptions*)&enc->options_);
} else {
DefaultEncoderOptions((WebPAnimEncoderOptions*)&enc->options_);
}
// Canvas buffers.
if (!WebPPictureInit(&enc->curr_canvas_copy_) ||
!WebPPictureInit(&enc->prev_canvas_) ||
!WebPPictureInit(&enc->prev_canvas_disposed_)) {
return NULL;
}
enc->curr_canvas_copy_.width = width;
enc->curr_canvas_copy_.height = height;
enc->curr_canvas_copy_.use_argb = 1;
if (!WebPPictureAlloc(&enc->curr_canvas_copy_) ||
!WebPPictureCopy(&enc->curr_canvas_copy_, &enc->prev_canvas_) ||
!WebPPictureCopy(&enc->curr_canvas_copy_, &enc->prev_canvas_disposed_)) {
goto Err;
}
WebPUtilClearPic(&enc->prev_canvas_, NULL);
enc->curr_canvas_copy_modified_ = 1;
// Encoded frames.
ResetCounters(enc);
// Note: one extra storage is for the previous frame.
enc->size_ = enc->options_.kmax - enc->options_.kmin + 1;
// We need space for at least 2 frames. But when kmin, kmax are both zero,
// enc->size_ will be 1. So we handle that special case below.
if (enc->size_ < 2) enc->size_ = 2;
enc->encoded_frames_ =
(EncodedFrame*)WebPSafeCalloc(enc->size_, sizeof(*enc->encoded_frames_));
if (enc->encoded_frames_ == NULL) goto Err;
enc->mux_ = WebPMuxNew();
if (enc->mux_ == NULL) goto Err;
enc->count_since_key_frame_ = 0;
enc->first_timestamp_ = 0;
enc->prev_timestamp_ = 0;
enc->prev_candidate_undecided_ = 0;
enc->is_first_frame_ = 1;
enc->got_null_frame_ = 0;
return enc; // All OK.
Err:
WebPAnimEncoderDelete(enc);
return NULL;
}
