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| author | Michael Niedermayer <michaelni@gmx.at> | 2002-09-01 20:54:38 +0000 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2002-09-01 20:54:38 +0000 |
| commit | 004c18ee9ce785c33ffedcbb3b8749f4d63a9a2a (patch) | |
| tree | f1e3c8914f51245d901ffc9212c2ff4ebd684d88 | |
| parent | 81e0d0b412e7d3d4ee8cc3a9ac940f60a7b1ae3b (diff) | |
| download | ffmpeg-004c18ee9ce785c33ffedcbb3b8749f4d63a9a2a.tar.gz | |
higher accuracy
Originally committed as revision 897 to svn://svn.ffmpeg.org/ffmpeg/trunk
| -rw-r--r-- | libavcodec/jfdctint.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/libavcodec/jfdctint.c b/libavcodec/jfdctint.c index b10419627a..6b0d4cadba 100644 --- a/libavcodec/jfdctint.c +++ b/libavcodec/jfdctint.c @@ -30,8 +30,10 @@ #define SHIFT_TEMPS #define DCTSIZE 8 +#define BITS_IN_JSAMPLE 8 #define GLOBAL(x) x #define RIGHT_SHIFT(x, n) ((x) >> (n)) +#define MULTIPLY16C16(var,const) ((var)*(const)) #if 1 //def USE_ACCURATE_ROUNDING #define DESCALE(x,n) RIGHT_SHIFT((x) + (1 << ((n) - 1)), n) @@ -85,7 +87,7 @@ #if BITS_IN_JSAMPLE == 8 #define CONST_BITS 13 -#define PASS1_BITS 2 +#define PASS1_BITS 4 /* set this to 2 if 16x16 multiplies are faster */ #else #define CONST_BITS 13 #define PASS1_BITS 1 /* lose a little precision to avoid overflow */ @@ -134,7 +136,7 @@ * For 12-bit samples, a full 32-bit multiplication will be needed. */ -#if BITS_IN_JSAMPLE == 8 +#if BITS_IN_JSAMPLE == 8 && CONST_BITS<=13 && PASS1_BITS<=2 #define MULTIPLY(var,const) MULTIPLY16C16(var,const) #else #define MULTIPLY(var,const) ((var) * (const)) |