diff --git a/src/demux/demux.c b/src/demux/demux.c index e8e5418e..4ce242ed 100644 --- a/src/demux/demux.c +++ b/src/demux/demux.c @@ -193,6 +193,19 @@ static int AddFrame(WebPDemuxer* const dmux, Frame* const frame) { return 1; } +static void SetFrameInfo(size_t start_offset, size_t size, + int frame_num, int complete, + const WebPBitstreamFeatures* const features, + Frame* const frame) { + frame->img_components_[0].offset_ = start_offset; + frame->img_components_[0].size_ = size; + frame->width_ = features->width; + frame->height_ = features->height; + frame->has_alpha_ |= features->has_alpha; + frame->frame_num_ = frame_num; + frame->complete_ = complete; +} + // Store image bearing chunks to 'frame'. static ParseStatus StoreFrame(int frame_num, uint32_t min_size, MemBuffer* const mem, Frame* const frame) { @@ -248,13 +261,8 @@ static ParseStatus StoreFrame(int frame_num, uint32_t min_size, return PARSE_ERROR; } ++image_chunks; - frame->img_components_[0].offset_ = chunk_start_offset; - frame->img_components_[0].size_ = chunk_size; - frame->width_ = features.width; - frame->height_ = features.height; - frame->has_alpha_ |= features.has_alpha; - frame->frame_num_ = frame_num; - frame->complete_ = (status == PARSE_OK); + SetFrameInfo(chunk_start_offset, chunk_size, frame_num, + status == PARSE_OK, &features, frame); Skip(mem, payload_available); } else { goto Done; @@ -659,6 +667,41 @@ static void InitDemux(WebPDemuxer* const dmux, const MemBuffer* const mem) { dmux->mem_ = *mem; } +static ParseStatus CreateRawImageDemuxer(MemBuffer* const mem, + WebPDemuxer** demuxer) { + WebPBitstreamFeatures features; + const VP8StatusCode status = + WebPGetFeatures(mem->buf_, mem->buf_size_, &features); + *demuxer = NULL; + if (status != VP8_STATUS_OK) { + return (status == VP8_STATUS_NOT_ENOUGH_DATA) ? PARSE_NEED_MORE_DATA + : PARSE_ERROR; + } + + { + WebPDemuxer* const dmux = (WebPDemuxer*)WebPSafeCalloc(1ULL, sizeof(*dmux)); + Frame* const frame = (Frame*)WebPSafeCalloc(1ULL, sizeof(*frame)); + if (dmux == NULL || frame == NULL) goto Error; + InitDemux(dmux, mem); + SetFrameInfo(0, mem->buf_size_, 1 /*frame_num*/, 1 /*complete*/, &features, + frame); + if (!AddFrame(dmux, frame)) goto Error; + dmux->state_ = WEBP_DEMUX_DONE; + dmux->canvas_width_ = frame->width_; + dmux->canvas_height_ = frame->height_; + dmux->feature_flags_ |= frame->has_alpha_ ? ALPHA_FLAG : 0; + dmux->num_frames_ = 1; + assert(IsValidSimpleFormat(dmux)); + *demuxer = dmux; + return PARSE_OK; + + Error: + WebPSafeFree(dmux); + WebPSafeFree(frame); + return PARSE_ERROR; + } +} + WebPDemuxer* WebPDemuxInternal(const WebPData* data, int allow_partial, WebPDemuxState* state, int version) { const ChunkParser* parser; @@ -675,6 +718,15 @@ WebPDemuxer* WebPDemuxInternal(const WebPData* data, int allow_partial, if (!InitMemBuffer(&mem, data->bytes, data->size)) return NULL; status = ReadHeader(&mem); if (status != PARSE_OK) { + // If parsing of the webp file header fails attempt to handle a raw + // VP8/VP8L frame. Note 'allow_partial' is ignored in this case. + if (status == PARSE_ERROR) { + status = CreateRawImageDemuxer(&mem, &dmux); + if (status == PARSE_OK) { + if (state != NULL) *state = WEBP_DEMUX_DONE; + return dmux; + } + } if (state != NULL) { *state = (status == PARSE_NEED_MORE_DATA) ? WEBP_DEMUX_PARSING_HEADER : WEBP_DEMUX_PARSE_ERROR; diff --git a/src/webp/demux.h b/src/webp/demux.h index 6fbe7758..4ed1ce73 100644 --- a/src/webp/demux.h +++ b/src/webp/demux.h @@ -88,7 +88,8 @@ typedef enum WebPDemuxState { WEBP_EXTERN(WebPDemuxer*) WebPDemuxInternal( const WebPData*, int, WebPDemuxState*, int); -// Parses the full WebP file given by 'data'. +// Parses the full WebP file given by 'data'. For single images the WebP file +// header alone or the file header and the chunk header may be absent. // Returns a WebPDemuxer object on successful parse, NULL otherwise. static WEBP_INLINE WebPDemuxer* WebPDemux(const WebPData* data) { return WebPDemuxInternal(data, 0, NULL, WEBP_DEMUX_ABI_VERSION);