generic-library/ffmpeg
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optimizing mpeg4_encode_dc

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Originally committed as revision 361 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2002-03-25 15:36:16 +00:00
parent 9c15096e3f
commit 2a164b253c
1 changed files with 69 additions and 1 deletions
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70
libavcodec/h263.c
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@ -57,6 +57,9 @@ static UINT16 mv_penalty[MAX_FCODE+1][MAX_MV*2+1];
static UINT8 fcode_tab[MAX_MV*2+1];
static UINT8 umv_fcode_tab[MAX_MV*2+1];
static UINT16 uni_DCtab_lum [512][2];
static UINT16 uni_DCtab_chrom[512][2];
int h263_get_picture_format(int width, int height)
{
int format;
@ -706,12 +709,67 @@ static void init_mv_penalty_and_fcode(MpegEncContext *s)
}
}
static void init_uni_dc_tab()
{
int level, uni_code, uni_len;
for(level=-255; level<256; level++){
int size, v, l;
/* find number of bits */
size = 0;
v = abs(level);
while (v) {
v >>= 1;
size++;
}
if (level < 0)
l= (-level) ^ ((1 << size) - 1);
else
l= level;
/* luminance */
uni_code= DCtab_lum[size][0];
uni_len = DCtab_lum[size][1];
if (size > 0) {
uni_code<<=size; uni_code|=l;
uni_len+=size;
if (size > 8){
uni_code<<=1; uni_code|=1;
uni_len++;
}
}
uni_DCtab_lum[level+256][0]= uni_code;
uni_DCtab_lum[level+256][1]= uni_len;
/* chrominance */
uni_code= DCtab_chrom[size][0];
uni_len = DCtab_chrom[size][1];
if (size > 0) {
uni_code<<=size; uni_code|=l;
uni_len+=size;
if (size > 8){
uni_code<<=1; uni_code|=1;
uni_len++;
}
}
uni_DCtab_chrom[level+256][0]= uni_code;
uni_DCtab_chrom[level+256][1]= uni_len;
}
}
void h263_encode_init(MpegEncContext *s)
{
static int done = 0;
if (!done) {
done = 1;
init_uni_dc_tab();
init_rl(&rl_inter);
init_rl(&rl_intra);
@ -1033,9 +1091,18 @@ static void mpeg4_inv_pred_ac(MpegEncContext * s, INT16 *block, int n,
}
}
static inline void mpeg4_encode_dc(MpegEncContext * s, int level, int n)
{
#if 1
level+=256;
if (n < 4) {
/* luminance */
put_bits(&s->pb, uni_DCtab_lum[level][1], uni_DCtab_lum[level][0]);
} else {
/* chrominance */
put_bits(&s->pb, uni_DCtab_chrom[level][1], uni_DCtab_chrom[level][0]);
}
#else
int size, v;
/* find number of bits */
size = 0;
@ -1061,6 +1128,7 @@ static inline void mpeg4_encode_dc(MpegEncContext * s, int level, int n)
if (size > 8)
put_bits(&s->pb, 1, 1);
}
#endif
}
static void mpeg4_encode_block(MpegEncContext * s, DCTELEM * block, int n, int intra_dc, UINT8 *scan_table)