multi-thread decoding: ~25-30% faster

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

1
README
View File

@@ -217,6 +217,7 @@ Use following options to convert into alternate image formats:
-version .... print version number and exit.
-nofancy ..... don't use the fancy YUV420 upscaler.
-nofilter .... disable in-loop filtering.
-mt .......... use multi-threading
-crop <x> <y> <w> <h> ... crop output with the given rectangle
-scale <w> <h> .......... scale the output (*after* any cropping)
-h ....... this help message.