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demux: split chunk parsing from ParseVP8X

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makes the header and chunk parsing portions slightly more digestible

Change-Id: I48968468b2529506b830e96a2f13e8d29976179b
This commit is contained in:
James Zern 2013-11-16 11:06:43 -08:00
parent d2e3f4e6b5
commit 6198715e89
1 changed files with 37 additions and 31 deletions
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68
src/demux/demux.c
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@ -466,36 +466,12 @@ static ParseStatus ParseSingleImage(WebPDemuxer* const dmux) {
return status;
}
static ParseStatus ParseVP8X(WebPDemuxer* const dmux) {
static ParseStatus ParseVP8XChunks(WebPDemuxer* const dmux) {
const int is_animation = !!(dmux->feature_flags_ & ANIMATION_FLAG);
MemBuffer* const mem = &dmux->mem_;
int anim_chunks = 0;
uint32_t vp8x_size;
ParseStatus status = PARSE_OK;
if (MemDataSize(mem) < CHUNK_HEADER_SIZE) return PARSE_NEED_MORE_DATA;
dmux->is_ext_format_ = 1;
Skip(mem, TAG_SIZE); // VP8X
vp8x_size = ReadLE32(mem);
if (vp8x_size > MAX_CHUNK_PAYLOAD) return PARSE_ERROR;
if (vp8x_size < VP8X_CHUNK_SIZE) return PARSE_ERROR;
vp8x_size += vp8x_size & 1;
if (SizeIsInvalid(mem, vp8x_size)) return PARSE_ERROR;
if (MemDataSize(mem) < vp8x_size) return PARSE_NEED_MORE_DATA;
dmux->feature_flags_ = ReadByte(mem);
Skip(mem, 3); // Reserved.
dmux->canvas_width_ = 1 + ReadLE24s(mem);
dmux->canvas_height_ = 1 + ReadLE24s(mem);
if (dmux->canvas_width_ * (uint64_t)dmux->canvas_height_ >= MAX_IMAGE_AREA) {
return PARSE_ERROR; // image final dimension is too large
}
Skip(mem, vp8x_size - VP8X_CHUNK_SIZE); // skip any trailing data.
dmux->state_ = WEBP_DEMUX_PARSED_HEADER;
if (SizeIsInvalid(mem, CHUNK_HEADER_SIZE)) return PARSE_ERROR;
if (MemDataSize(mem) < CHUNK_HEADER_SIZE) return PARSE_NEED_MORE_DATA;
do {
int store_chunk = 1;
const size_t chunk_start_offset = mem->start_;
@ -513,7 +489,6 @@ static ParseStatus ParseVP8X(WebPDemuxer* const dmux) {
case MKFOURCC('A', 'L', 'P', 'H'):
case MKFOURCC('V', 'P', '8', ' '):
case MKFOURCC('V', 'P', '8', 'L'): {
const int is_animation = !!(dmux->feature_flags_ & ANIMATION_FLAG);
// check that this isn't an animation (all frames should be in an ANMF).
if (anim_chunks > 0 || is_animation) return PARSE_ERROR;
@ -552,14 +527,14 @@ static ParseStatus ParseVP8X(WebPDemuxer* const dmux) {
store_chunk = !!(dmux->feature_flags_ & ICCP_FLAG);
goto Skip;
}
case MKFOURCC('X', 'M', 'P', ' '): {
store_chunk = !!(dmux->feature_flags_ & XMP_FLAG);
goto Skip;
}
case MKFOURCC('E', 'X', 'I', 'F'): {
store_chunk = !!(dmux->feature_flags_ & EXIF_FLAG);
goto Skip;
}
case MKFOURCC('X', 'M', 'P', ' '): {
store_chunk = !!(dmux->feature_flags_ & XMP_FLAG);
goto Skip;
}
Skip:
default: {
if (chunk_size_padded <= MemDataSize(mem)) {
@ -588,6 +563,37 @@ static ParseStatus ParseVP8X(WebPDemuxer* const dmux) {
return status;
}
static ParseStatus ParseVP8X(WebPDemuxer* const dmux) {
MemBuffer* const mem = &dmux->mem_;
uint32_t vp8x_size;
if (MemDataSize(mem) < CHUNK_HEADER_SIZE) return PARSE_NEED_MORE_DATA;
dmux->is_ext_format_ = 1;
Skip(mem, TAG_SIZE); // VP8X
vp8x_size = ReadLE32(mem);
if (vp8x_size > MAX_CHUNK_PAYLOAD) return PARSE_ERROR;
if (vp8x_size < VP8X_CHUNK_SIZE) return PARSE_ERROR;
vp8x_size += vp8x_size & 1;
if (SizeIsInvalid(mem, vp8x_size)) return PARSE_ERROR;
if (MemDataSize(mem) < vp8x_size) return PARSE_NEED_MORE_DATA;
dmux->feature_flags_ = ReadByte(mem);
Skip(mem, 3); // Reserved.
dmux->canvas_width_ = 1 + ReadLE24s(mem);
dmux->canvas_height_ = 1 + ReadLE24s(mem);
if (dmux->canvas_width_ * (uint64_t)dmux->canvas_height_ >= MAX_IMAGE_AREA) {
return PARSE_ERROR; // image final dimension is too large
}
Skip(mem, vp8x_size - VP8X_CHUNK_SIZE); // skip any trailing data.
dmux->state_ = WEBP_DEMUX_PARSED_HEADER;
if (SizeIsInvalid(mem, CHUNK_HEADER_SIZE)) return PARSE_ERROR;
if (MemDataSize(mem) < CHUNK_HEADER_SIZE) return PARSE_NEED_MORE_DATA;
return ParseVP8XChunks(dmux);
}
// -----------------------------------------------------------------------------
// Format validation