From 04824298a9e2fec292cc2859c6a50a5d5a6d7752 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Thu, 18 Dec 2008 16:11:19 +0000
Subject: Faster CAVLC decoding of trailing_ones. Based on a patch by dark
shikari. decode_residual is about 3.3% faster.
Originally committed as revision 16219 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
libavcodec/h264.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
(limited to 'libavcodec')
diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index d3a8e56bbc..6f68095ae2 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -4087,9 +4087,11 @@ static int decode_residual(H264Context *h, GetBitContext *gb, DCTELEM *block, in
tprintf(h->s.avctx, "trailing:%d, total:%d\n", trailing_ones, total_coeff);
assert(total_coeff<=16);
- for(i=0; i<trailing_ones; i++){
- level[i]= 1 - 2*get_bits1(gb);
- }
+ i = show_bits(gb, 3);
+ skip_bits(gb, trailing_ones);
+ level[0] = 1-((i&4)>>1);
+ level[1] = 1-((i&2) );
+ level[2] = 1-((i&1)<<1);
if(trailing_ones<total_coeff) {
int level_code, mask;
--
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