dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-13 14:34:33 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

multi-thread decoding: ~25-30% faster

Browse Source 
To be enabled with the flag WEBP_USE_THREAD.
For now it's only available on unix (pthread), when using Makefile.unix
Will be switched on more generally later.

In-loop filtering and output (=rescaling/yuv->rgb conversion)
is done in parallel to bitstream decoding, lagging 1 row behind.

Example:
examples/dwebp bryce.webp -v
Time to decode picture: 0.680s

examples/dwebp bryce.webp -v -mt
Time to decode picture: 0.515s

Change-Id: Ic30a897423137a3bdace9c4e30465ef758fe53f2
This commit is contained in:
Pascal Massimino
2011-07-22 13:09:10 -07:00
parent acd8ba4229
commit fc7815d692
16 changed files with 519 additions and 120 deletions
Download Patch File Download Diff File Expand all files Collapse all files

40
src/dec/idec.c
View File

@ -324,28 +324,28 @@ static VP8StatusCode DecodePartition0(WebPIDecoder* const idec) {
return IDecError(idec, dec->status_);
}
// Allocate memory and prepare everything.
if (!VP8InitFrame(dec, io)) {
return IDecError(idec, dec->status_);
}
if (!CopyParts0Data(idec)) {
return IDecError(idec, VP8_STATUS_OUT_OF_MEMORY);
}
// Finish setting up the decoding parameters.
if (VP8FinishFrameSetup(dec, io) != VP8_STATUS_OK) {
// Finish setting up the decoding parameters. Will call io->setup().
if (VP8EnterCritical(dec, io) != VP8_STATUS_OK) {
return IDecError(idec, dec->status_);
}
// Note: past this point, teardown() must always be called
// in case of error.
idec->state_ = STATE_DATA;
// Allocate memory and prepare everything.
if (!VP8InitFrame(dec, io)) {
return IDecError(idec, dec->status_);
}
return VP8_STATUS_OK;
}
// Remaining partitions
static VP8StatusCode DecodeRemaining(WebPIDecoder* const idec) {
VP8BitReader* br;
VP8BitReader* br;
VP8Decoder* const dec = idec->dec_;
VP8Io* const io = &idec->io_;
@ -355,12 +355,8 @@ static VP8StatusCode DecodeRemaining(WebPIDecoder* const idec) {
for (; dec->mb_y_ < dec->mb_h_; ++dec->mb_y_) {
VP8BitReader* token_br = &dec->parts_[dec->mb_y_ & (dec->num_parts_ - 1)];
if (dec->mb_x_ == 0) {
VP8MB* const left = dec->mb_info_ - 1;
left->nz_ = 0;
left->dc_nz_ = 0;
memset(dec->intra_l_, B_DC_PRED, sizeof(dec->intra_l_));
VP8InitScanline(dec);
}
for (; dec->mb_x_ < dec->mb_w_; dec->mb_x_++) {
MBContext context;
SaveContext(dec, token_br, &context);
@ -383,17 +379,14 @@ static VP8StatusCode DecodeRemaining(WebPIDecoder* const idec) {
assert(idec->mem_.start_ <= idec->mem_.end_);
}
}
if (dec->filter_type_ > 0) {
VP8FilterRow(dec);
}
if (!VP8FinishRow(dec, io)) {
if (!VP8ProcessRow(dec, io)) {
return IDecError(idec, VP8_STATUS_USER_ABORT);
}
dec->mb_x_ = 0;
}
if (io->teardown) {
io->teardown(io);
// Synchronize the thread and check for errors.
if (!VP8ExitCritical(dec, io)) {
return IDecError(idec, VP8_STATUS_USER_ABORT);
}
dec->ready_ = 0;
idec->state_ = STATE_DONE;
@ -443,6 +436,13 @@ WebPIDecoder* WebPINewDecoder(WebPDecBuffer* const output_buffer) {
idec->params_.output = output_buffer ? output_buffer : &idec->output_;
WebPInitCustomIo(&idec->params_, &idec->io_); // Plug the I/O functions.
#ifdef WEBP_USE_THREAD
idec->dec_->use_threads_ = idec->params_.options &&
(idec->params_.options->use_threads > 0);
#else
idec->dec_->use_threads_ = 0;
#endif
return idec;
}