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Merge "demux: accept raw bitstreams"

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James Zern 2015-12-17 22:52:10 +00:00 committed by Gerrit Code Review
commit d48e427b1d
2 changed files with 61 additions and 8 deletions
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66
src/demux/demux.c
View File

@ -192,6 +192,19 @@ 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) {
@ -247,13 +260,8 @@ 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;
@ -650,6 +658,41 @@ 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;
@ -666,6 +709,15 @@ 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;

3
src/webp/demux.h
View File

@ -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);