dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-14 21:09:55 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

split the VP8 and VP8L decoding properly

Browse Source 
* each with their own decoder instances.
* Refactor the incremental buffer-update code a lot.
* remove br_offset_ for VP8LDecoder along the way
* make VP8GetHeaders() be used only for VP8, not VP8L bitstream
* remove VP8LInitDecoder()
* rename VP8LBitReaderResize() to VP8LBitReaderSetBuffer()
(cherry picked from commit 5529a2e6d47212a721ca4ab003215f97bd88ebb4)

Change-Id: I58f0b8abe1ef31c8b0e1a6175d2d86b863793ead
This commit is contained in:
Pascal Massimino
2012-04-05 09:31:10 +00:00
committed by James Zern
parent f2623dbe58
commit 6f01b830e2
8 changed files with 222 additions and 243 deletions
Download Patch File Download Diff File Expand all files Collapse all files

72
src/dec/webp.c
View File

@ -298,50 +298,70 @@ void WebPResetDecParams(WebPDecParams* const params) {
// Main flow
static VP8StatusCode DecodeInto(const uint8_t* data, uint32_t data_size,
WebPDecParams* const params) {
VP8Decoder* dec = VP8New();
VP8StatusCode status = VP8_STATUS_OK;
VP8StatusCode status;
VP8Io io;
WebPHeaderStructure headers;
assert(params);
if (dec == NULL) {
return VP8_STATUS_INVALID_PARAM;
headers.data = data;
headers.data_size = data_size;
status = WebPParseHeaders(&headers); // Process Pre-VP8 chunks.
if (status != VP8_STATUS_OK) {
return status;
}
assert(params);
VP8InitIo(&io);
io.data = data;
io.data_size = data_size;
io.data = headers.data + headers.offset;
io.data_size = headers.data_size - headers.offset;
WebPInitCustomIo(params, &io); // Plug the I/O functions.
if (!headers.is_lossless) {
VP8Decoder* const dec = VP8New();
if (dec == NULL) {
return VP8_STATUS_OUT_OF_MEMORY;
}
#ifdef WEBP_USE_THREAD
dec->use_threads_ = params->options && (params->options->use_threads > 0);
dec->use_threads_ = params->options && (params->options->use_threads > 0);
#else
dec->use_threads_ = 0;
dec->use_threads_ = 0;
#endif
dec->alpha_data_ = headers.alpha_data;
dec->alpha_data_size_ = headers.alpha_data_size;
// Decode bitstream header, update io->width/io->height.
if (!VP8GetHeaders(dec, &io)) {
status = VP8_STATUS_BITSTREAM_ERROR;
} else {
// Allocate/check output buffers.
status = WebPAllocateDecBuffer(io.width, io.height, params->options,
params->output);
if (status == VP8_STATUS_OK) {
// Decode
if (!dec->is_lossless_) {
// Decode bitstream header, update io->width/io->height.
if (!VP8GetHeaders(dec, &io)) {
status = dec->status_; // An error occurred. Grab error status.
} else {
// Allocate/check output buffers.
status = WebPAllocateDecBuffer(io.width, io.height, params->options,
params->output);
if (status == VP8_STATUS_OK) { // Decode
if (!VP8Decode(dec, &io)) {
status = dec->status_;
}
} else {
VP8LDecoder* const vp8l_decoder = &dec->vp8l_decoder_;
if (!VP8LDecodeImage(vp8l_decoder)) {
status = VP8_STATUS_BITSTREAM_ERROR;
}
}
VP8Delete(dec);
} else {
VP8LDecoder* const dec = VP8LNew();
if (dec == NULL) {
return VP8_STATUS_OUT_OF_MEMORY;
}
if (!VP8LDecodeHeader(dec, &io)) {
status = dec->status_; // An error occurred. Grab error status.
} else {
// Allocate/check output buffers.
status = WebPAllocateDecBuffer(io.width, io.height, params->options,
params->output);
if (status == VP8_STATUS_OK) { // Decode
if (!VP8LDecodeImage(dec)) {
status = dec->status_;
}
}
} else if (dec->is_lossless_) { // Clear lossless decoder on error.
VP8LClear(&dec->vp8l_decoder_);
}
VP8LDelete(dec);
}
VP8Delete(dec);
if (status != VP8_STATUS_OK) {
WebPFreeDecBuffer(params->output);
}