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

View File

@ -41,6 +41,9 @@ Don't use the in-loop filtering process even if it is required by
the bitstream. This may produce visible blocks on the non-compliant output,
but will make the decoding faster.
.TP
.B \-mt
Use multi-threading for decoding, if possible.
.TP
.B \-crop x_position y_position width height
Crop the decoded picture to a rectangle with top-left corner at coordinates
(\fBx_position\fP, \fBy_position\fP) and size \fBwidth\fP x \fBheight\fP.