From 297b5a3f99d7da6307f164973d0d6d375ea3fbb7 Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefano.sabatini-lala@poste.it>
Date: Wed, 22 Apr 2009 00:04:17 +0000
Subject: [PATCH] Make read_line() do not depend on put_bits.h and speed up it.
Originally committed as revision 18653 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
libavcodec/pixdesc.h | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/libavcodec/pixdesc.h b/libavcodec/pixdesc.h
index a8ca48454cb..6660ea1710f 100644
--- a/libavcodec/pixdesc.h
+++ b/libavcodec/pixdesc.h
@@ -25,7 +25,6 @@
#include <inttypes.h>
#include "libavutil/intreadwrite.h"
-#include "get_bits.h"
typedef struct AVComponentDescriptor{
uint16_t plane :2; ///< which of the 4 planes contains the component
@@ -114,15 +113,17 @@ static inline void read_line(uint16_t *dst, const uint8_t *data[4], const int li
int flags= desc->flags;
if (flags & PIX_FMT_BITSTREAM){
- GetBitContext gb;
- init_get_bits(&gb, data[plane] + y*linesize[plane], linesize[plane]*8);
- skip_bits_long(&gb, x*step + comp.offset_plus1-1);
+ int skip = x*step + comp.offset_plus1-1;
+ const uint8_t *p = data[plane] + y*linesize[plane] + (skip>>3);
+ int shift = 8 - depth - (skip&7);
while(w--){
- int val = show_bits(&gb, depth);
+ int val = (*p >> shift) & mask;
if(read_pal_component)
val= data[1][4*val + c];
- skip_bits(&gb, step);
+ shift -= step;
+ p -= shift>>3;
+ shift &= 7;
*dst++= val;
}
} else {
--
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