Commit Graph

4 Commits

Author SHA1 Message Date
Rui Ueyama dc115882f1 go.image/vp8: use branch-free abs
This change seems to restore performance to
the level before CL 108140045.

benchmark                         old ns/op    new ns/op    delta
BenchmarkDecodeVP8SimpleFilter       796416       784394   -1.51%
BenchmarkDecodeVP8NormalFilter      4931138      4693078   -4.83%
BenchmarkDecodeVP8L                 7820030      7821796   +0.02%

LGTM=nigeltao, r
R=nigeltao, r
CC=golang-codereviews
https://golang.org/cl/107340047
2014-06-30 10:33:37 +10:00
Nigel Tao f8a86727c2 go.image/vp8: remove the filter look-up tables.
The benchmarks are a little slower, but the code is shorter.

benchmark                          old ns/op     new ns/op     delta
BenchmarkDecodeVP8SimpleFilter     621950        644184        +3.57%
BenchmarkDecodeVP8NormalFilter     4045745       4269431       +5.53%

LGTM=r
R=r, minux, ruiu
CC=golang-codereviews
https://golang.org/cl/108140045
2014-06-27 09:14:15 +10:00
Nigel Tao 0424e74a0e go.image/vp8: implement the normal filter.
The testdata was generated via:
cwebp foo.png -o foo.lossy.webp
dwebp -pgm foo.lossy.webp -o tmp.pgm
convert tmp.pgm foo.lossy.webp.ycbcr.png
rm tmp.pgm

TBR=r
R=r
CC=golang-codereviews
https://golang.org/cl/107330043
2014-06-26 13:29:30 +10:00
Nigel Tao 72be9c51b1 go.image/vp8: implement the loop filter.
The testdata files were created by:
cwebp video-001.png -o video-001.webp
dwebp -pgm video-001.webp -o tmp.pgm
convert tmp.pgm video-001.webp.ycbcr.png
rm tmp.pgm

LGTM=r
R=r
CC=chaishushan, golang-codereviews
https://golang.org/cl/91700044
2014-05-27 10:52:02 +10:00