mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
1381 lines
37 KiB
1381 lines
37 KiB
/* |
|
* MSMPEG4 backend for ffmpeg encoder and decoder |
|
* Copyright (c) 2001 Gerard Lantau. |
|
* |
|
* This program is free software; you can redistribute it and/or modify |
|
* it under the terms of the GNU General Public License as published by |
|
* the Free Software Foundation; either version 2 of the License, or |
|
* (at your option) any later version. |
|
* |
|
* This program is distributed in the hope that it will be useful, |
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
|
* GNU General Public License for more details. |
|
* |
|
* You should have received a copy of the GNU General Public License |
|
* along with this program; if not, write to the Free Software |
|
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
|
*/ |
|
#include <stdlib.h> |
|
#include <stdio.h> |
|
#include "common.h" |
|
#include "dsputil.h" |
|
#include "mpegvideo.h" |
|
#include "avcodec.h" |
|
|
|
/* |
|
* You can also call this codec : MPEG4 with a twist ! |
|
* |
|
* TODO: |
|
* - (encoding) select best mv table (two choices) |
|
* - (encoding) select best vlc/dc table |
|
*/ |
|
//#define DEBUG |
|
|
|
/* motion vector table */ |
|
typedef struct MVTable { |
|
int n; |
|
const UINT16 *table_mv_code; |
|
const UINT8 *table_mv_bits; |
|
const UINT8 *table_mvx; |
|
const UINT8 *table_mvy; |
|
UINT16 *table_mv_index; /* encoding: convert mv to index in table_mv */ |
|
VLC vlc; /* decoding: vlc */ |
|
} MVTable; |
|
|
|
static UINT32 v2_dc_lum_table[512][2]; |
|
static UINT32 v2_dc_chroma_table[512][2]; |
|
|
|
static void msmpeg4_encode_block(MpegEncContext * s, DCTELEM * block, int n); |
|
static int msmpeg4_decode_block(MpegEncContext * s, DCTELEM * block, |
|
int n, int coded); |
|
static int msmpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr); |
|
static int msmpeg4_decode_motion(MpegEncContext * s, |
|
int *mx_ptr, int *my_ptr); |
|
static void msmpeg4v2_encode_motion(MpegEncContext * s, int val); |
|
static void init_h263_dc_for_msmpeg4(); |
|
|
|
|
|
extern UINT32 inverse[256]; |
|
|
|
#ifdef DEBUG |
|
int intra_count = 0; |
|
int frame_count = 0; |
|
#endif |
|
/* XXX: move it to mpegvideo.h */ |
|
|
|
static int init_done = 0; |
|
|
|
#include "msmpeg4data.h" |
|
|
|
#ifdef STATS |
|
|
|
const char *st_names[ST_NB] = { |
|
"unknown", |
|
"dc", |
|
"intra_ac", |
|
"inter_ac", |
|
"intra_mb", |
|
"inter_mb", |
|
"mv", |
|
}; |
|
|
|
int st_current_index = 0; |
|
unsigned int st_bit_counts[ST_NB]; |
|
unsigned int st_out_bit_counts[ST_NB]; |
|
|
|
#define set_stat(var) st_current_index = var; |
|
|
|
void print_stats(void) |
|
{ |
|
unsigned int total; |
|
int i; |
|
|
|
printf("Input:\n"); |
|
total = 0; |
|
for(i=0;i<ST_NB;i++) |
|
total += st_bit_counts[i]; |
|
if (total == 0) |
|
total = 1; |
|
for(i=0;i<ST_NB;i++) { |
|
printf("%-10s : %10.1f %5.1f%%\n", |
|
st_names[i], |
|
(double)st_bit_counts[i] / 8.0, |
|
(double)st_bit_counts[i] * 100.0 / total); |
|
} |
|
printf("%-10s : %10.1f %5.1f%%\n", |
|
"total", |
|
(double)total / 8.0, |
|
100.0); |
|
|
|
printf("Output:\n"); |
|
total = 0; |
|
for(i=0;i<ST_NB;i++) |
|
total += st_out_bit_counts[i]; |
|
if (total == 0) |
|
total = 1; |
|
for(i=0;i<ST_NB;i++) { |
|
printf("%-10s : %10.1f %5.1f%%\n", |
|
st_names[i], |
|
(double)st_out_bit_counts[i] / 8.0, |
|
(double)st_out_bit_counts[i] * 100.0 / total); |
|
} |
|
printf("%-10s : %10.1f %5.1f%%\n", |
|
"total", |
|
(double)total / 8.0, |
|
100.0); |
|
} |
|
|
|
#else |
|
|
|
#define set_stat(var) |
|
|
|
#endif |
|
|
|
/* build the table which associate a (x,y) motion vector to a vlc */ |
|
static void init_mv_table(MVTable *tab) |
|
{ |
|
int i, x, y; |
|
|
|
tab->table_mv_index = malloc(sizeof(UINT16) * 4096); |
|
/* mark all entries as not used */ |
|
for(i=0;i<4096;i++) |
|
tab->table_mv_index[i] = tab->n; |
|
|
|
for(i=0;i<tab->n;i++) { |
|
x = tab->table_mvx[i]; |
|
y = tab->table_mvy[i]; |
|
tab->table_mv_index[(x << 6) | y] = i; |
|
} |
|
} |
|
|
|
static void code012(PutBitContext *pb, int n) |
|
{ |
|
if (n == 0) { |
|
put_bits(pb, 1, 0); |
|
} else { |
|
put_bits(pb, 1, 1); |
|
put_bits(pb, 1, (n >= 2)); |
|
} |
|
} |
|
|
|
/* write MSMPEG4 V3 compatible frame header */ |
|
void msmpeg4_encode_picture_header(MpegEncContext * s, int picture_number) |
|
{ |
|
int i; |
|
|
|
align_put_bits(&s->pb); |
|
|
|
put_bits(&s->pb, 2, s->pict_type - 1); |
|
|
|
put_bits(&s->pb, 5, s->qscale); |
|
|
|
s->rl_table_index = 2; |
|
if(s->msmpeg4_version==2) |
|
s->rl_chroma_table_index = 2; /* only for I frame */ |
|
else |
|
s->rl_chroma_table_index = 1; /* only for I frame */ |
|
|
|
s->dc_table_index = 1; |
|
s->mv_table_index = 1; /* only if P frame */ |
|
s->use_skip_mb_code = 1; /* only if P frame */ |
|
|
|
if (s->pict_type == I_TYPE) { |
|
put_bits(&s->pb, 5, 0x17); /* indicate only one "slice" */ |
|
|
|
if(s->msmpeg4_version!=2){ |
|
code012(&s->pb, s->rl_chroma_table_index); |
|
code012(&s->pb, s->rl_table_index); |
|
|
|
put_bits(&s->pb, 1, s->dc_table_index); |
|
} |
|
s->no_rounding = 1; |
|
} else { |
|
put_bits(&s->pb, 1, s->use_skip_mb_code); |
|
|
|
s->rl_chroma_table_index = s->rl_table_index; |
|
if(s->msmpeg4_version!=2){ |
|
code012(&s->pb, s->rl_table_index); |
|
|
|
put_bits(&s->pb, 1, s->dc_table_index); |
|
|
|
put_bits(&s->pb, 1, s->mv_table_index); |
|
} |
|
|
|
if(s->flipflop_rounding){ |
|
s->no_rounding ^= 1; |
|
}else{ |
|
s->no_rounding = 0; |
|
} |
|
} |
|
|
|
if (!init_done) { |
|
/* init various encoding tables */ |
|
init_done = 1; |
|
init_mv_table(&mv_tables[0]); |
|
init_mv_table(&mv_tables[1]); |
|
for(i=0;i<NB_RL_TABLES;i++) |
|
init_rl(&rl_table[i]); |
|
|
|
init_h263_dc_for_msmpeg4(); |
|
} |
|
|
|
#ifdef DEBUG |
|
intra_count = 0; |
|
printf("*****frame %d:\n", frame_count++); |
|
#endif |
|
} |
|
|
|
void msmpeg4_encode_ext_header(MpegEncContext * s) |
|
{ |
|
s->flipflop_rounding=1; |
|
s->bitrate= 910; // FIXME |
|
|
|
put_bits(&s->pb, 5, s->frame_rate / FRAME_RATE_BASE); //yes 29.97 -> 29 |
|
|
|
put_bits(&s->pb, 11, s->bitrate); |
|
|
|
put_bits(&s->pb, 1, s->flipflop_rounding); |
|
} |
|
|
|
/* predict coded block */ |
|
static inline int coded_block_pred(MpegEncContext * s, int n, UINT8 **coded_block_ptr) |
|
{ |
|
int xy, wrap, pred, a, b, c; |
|
|
|
xy = s->block_index[n]; |
|
wrap = s->block_wrap[0]; |
|
|
|
/* B C |
|
* A X |
|
*/ |
|
a = s->coded_block[xy - 1 ]; |
|
b = s->coded_block[xy - 1 - wrap]; |
|
c = s->coded_block[xy - wrap]; |
|
|
|
if (b == c) { |
|
pred = a; |
|
} else { |
|
pred = c; |
|
} |
|
|
|
/* store value */ |
|
*coded_block_ptr = &s->coded_block[xy]; |
|
|
|
return pred; |
|
} |
|
|
|
static void msmpeg4_encode_motion(MpegEncContext * s, |
|
int mx, int my) |
|
{ |
|
int code; |
|
MVTable *mv; |
|
|
|
/* modulo encoding */ |
|
/* WARNING : you cannot reach all the MVs even with the modulo |
|
encoding. This is a somewhat strange compromise they took !!! */ |
|
if (mx <= -64) |
|
mx += 64; |
|
else if (mx >= 64) |
|
mx -= 64; |
|
if (my <= -64) |
|
my += 64; |
|
else if (my >= 64) |
|
my -= 64; |
|
|
|
mx += 32; |
|
my += 32; |
|
#if 0 |
|
if ((unsigned)mx >= 64 || |
|
(unsigned)my >= 64) |
|
fprintf(stderr, "error mx=%d my=%d\n", mx, my); |
|
#endif |
|
mv = &mv_tables[s->mv_table_index]; |
|
|
|
code = mv->table_mv_index[(mx << 6) | my]; |
|
set_stat(ST_MV); |
|
put_bits(&s->pb, |
|
mv->table_mv_bits[code], |
|
mv->table_mv_code[code]); |
|
if (code == mv->n) { |
|
/* escape : code litterally */ |
|
put_bits(&s->pb, 6, mx); |
|
put_bits(&s->pb, 6, my); |
|
} |
|
} |
|
|
|
void msmpeg4_encode_mb(MpegEncContext * s, |
|
DCTELEM block[6][64], |
|
int motion_x, int motion_y) |
|
{ |
|
int cbp, coded_cbp, i; |
|
int pred_x, pred_y; |
|
UINT8 *coded_block; |
|
|
|
if (!s->mb_intra) { |
|
/* compute cbp */ |
|
set_stat(ST_INTER_MB); |
|
cbp = 0; |
|
for (i = 0; i < 6; i++) { |
|
if (s->block_last_index[i] >= 0) |
|
cbp |= 1 << (5 - i); |
|
} |
|
if (s->use_skip_mb_code && (cbp | motion_x | motion_y) == 0) { |
|
/* skip macroblock */ |
|
put_bits(&s->pb, 1, 1); |
|
return; |
|
} |
|
if (s->use_skip_mb_code) |
|
put_bits(&s->pb, 1, 0); /* mb coded */ |
|
|
|
if(s->msmpeg4_version==2){ |
|
put_bits(&s->pb, |
|
v2_mb_type[cbp&3][1], |
|
v2_mb_type[cbp&3][0]); |
|
if((cbp&3) != 3) coded_cbp= cbp ^ 0x3C; |
|
else coded_cbp= cbp; |
|
|
|
put_bits(&s->pb, |
|
cbpy_tab[coded_cbp>>2][1], |
|
cbpy_tab[coded_cbp>>2][0]); |
|
|
|
h263_pred_motion(s, 0, &pred_x, &pred_y); |
|
msmpeg4v2_encode_motion(s, motion_x - pred_x); |
|
msmpeg4v2_encode_motion(s, motion_y - pred_y); |
|
}else{ |
|
put_bits(&s->pb, |
|
table_mb_non_intra[cbp + 64][1], |
|
table_mb_non_intra[cbp + 64][0]); |
|
|
|
/* motion vector */ |
|
h263_pred_motion(s, 0, &pred_x, &pred_y); |
|
msmpeg4_encode_motion(s, motion_x - pred_x, |
|
motion_y - pred_y); |
|
} |
|
} else { |
|
/* compute cbp */ |
|
cbp = 0; |
|
coded_cbp = 0; |
|
for (i = 0; i < 6; i++) { |
|
int val, pred; |
|
val = (s->block_last_index[i] >= 1); |
|
cbp |= val << (5 - i); |
|
if (i < 4) { |
|
/* predict value for close blocks only for luma */ |
|
pred = coded_block_pred(s, i, &coded_block); |
|
*coded_block = val; |
|
val = val ^ pred; |
|
} |
|
coded_cbp |= val << (5 - i); |
|
} |
|
#if 0 |
|
if (coded_cbp) |
|
printf("cbp=%x %x\n", cbp, coded_cbp); |
|
#endif |
|
|
|
if(s->msmpeg4_version==2){ |
|
if (s->pict_type == I_TYPE) { |
|
put_bits(&s->pb, |
|
v2_intra_cbpc[cbp&3][1], v2_intra_cbpc[cbp&3][0]); |
|
} else { |
|
if (s->use_skip_mb_code) |
|
put_bits(&s->pb, 1, 0); /* mb coded */ |
|
put_bits(&s->pb, |
|
v2_mb_type[(cbp&3) + 4][1], |
|
v2_mb_type[(cbp&3) + 4][0]); |
|
} |
|
put_bits(&s->pb, 1, 0); /* no AC prediction yet */ |
|
put_bits(&s->pb, |
|
cbpy_tab[cbp>>2][1], |
|
cbpy_tab[cbp>>2][0]); |
|
}else{ |
|
if (s->pict_type == I_TYPE) { |
|
set_stat(ST_INTRA_MB); |
|
put_bits(&s->pb, |
|
table_mb_intra[coded_cbp][1], table_mb_intra[coded_cbp][0]); |
|
} else { |
|
if (s->use_skip_mb_code) |
|
put_bits(&s->pb, 1, 0); /* mb coded */ |
|
put_bits(&s->pb, |
|
table_mb_non_intra[cbp][1], |
|
table_mb_non_intra[cbp][0]); |
|
} |
|
set_stat(ST_INTRA_MB); |
|
put_bits(&s->pb, 1, 0); /* no AC prediction yet */ |
|
} |
|
} |
|
|
|
for (i = 0; i < 6; i++) { |
|
msmpeg4_encode_block(s, block[i], i); |
|
} |
|
} |
|
|
|
|
|
/* strongly inspirated from MPEG4, but not exactly the same ! */ |
|
void msmpeg4_dc_scale(MpegEncContext * s) |
|
{ |
|
if (s->qscale < 5 || s->msmpeg4_version==2){ |
|
s->y_dc_scale = 8; |
|
s->c_dc_scale = 8; |
|
}else if (s->qscale < 9){ |
|
s->y_dc_scale = 2 * s->qscale; |
|
s->c_dc_scale = (s->qscale + 13)>>1; |
|
}else{ |
|
s->y_dc_scale = s->qscale + 8; |
|
s->c_dc_scale = (s->qscale + 13)>>1; |
|
} |
|
} |
|
|
|
/* dir = 0: left, dir = 1: top prediction */ |
|
static int msmpeg4_pred_dc(MpegEncContext * s, int n, |
|
INT16 **dc_val_ptr, int *dir_ptr) |
|
{ |
|
int a, b, c, wrap, pred, scale; |
|
INT16 *dc_val; |
|
|
|
/* find prediction */ |
|
if (n < 4) { |
|
scale = s->y_dc_scale; |
|
} else { |
|
scale = s->c_dc_scale; |
|
} |
|
wrap = s->block_wrap[n]; |
|
dc_val= s->dc_val[0] + s->block_index[n]; |
|
|
|
/* B C |
|
* A X |
|
*/ |
|
a = dc_val[ - 1]; |
|
b = dc_val[ - 1 - wrap]; |
|
c = dc_val[ - wrap]; |
|
|
|
/* XXX: the following solution consumes divisions, but it does not |
|
necessitate to modify mpegvideo.c. The problem comes from the |
|
fact they decided to store the quantized DC (which would lead |
|
to problems if Q could vary !) */ |
|
#if defined ARCH_X86 && !defined PIC |
|
asm volatile( |
|
"movl %3, %%eax \n\t" |
|
"shrl $1, %%eax \n\t" |
|
"addl %%eax, %2 \n\t" |
|
"addl %%eax, %1 \n\t" |
|
"addl %0, %%eax \n\t" |
|
"mull %4 \n\t" |
|
"movl %%edx, %0 \n\t" |
|
"movl %1, %%eax \n\t" |
|
"mull %4 \n\t" |
|
"movl %%edx, %1 \n\t" |
|
"movl %2, %%eax \n\t" |
|
"mull %4 \n\t" |
|
"movl %%edx, %2 \n\t" |
|
: "+b" (a), "+c" (b), "+D" (c) |
|
: "g" (scale), "S" (inverse[scale]) |
|
: "%eax", "%edx" |
|
); |
|
#else |
|
/* #elif defined (ARCH_ALPHA) */ |
|
/* Divisions are extremely costly on Alpha; optimize the most |
|
common case. But they are costly everywhere... |
|
*/ |
|
if (scale == 8) { |
|
a = (a + (8 >> 1)) / 8; |
|
b = (b + (8 >> 1)) / 8; |
|
c = (c + (8 >> 1)) / 8; |
|
} else { |
|
a = (a + (scale >> 1)) / scale; |
|
b = (b + (scale >> 1)) / scale; |
|
c = (c + (scale >> 1)) / scale; |
|
} |
|
#endif |
|
/* XXX: WARNING: they did not choose the same test as MPEG4. This |
|
is very important ! */ |
|
if (abs(a - b) <= abs(b - c)) { |
|
pred = c; |
|
*dir_ptr = 1; |
|
} else { |
|
pred = a; |
|
*dir_ptr = 0; |
|
} |
|
|
|
/* update predictor */ |
|
*dc_val_ptr = &dc_val[0]; |
|
return pred; |
|
} |
|
|
|
#define DC_MAX 119 |
|
|
|
static void msmpeg4_encode_dc(MpegEncContext * s, int level, int n, int *dir_ptr) |
|
{ |
|
int sign, code; |
|
int pred; |
|
INT16 *dc_val; |
|
|
|
pred = msmpeg4_pred_dc(s, n, &dc_val, dir_ptr); |
|
|
|
/* update predictor */ |
|
if (n < 4) { |
|
*dc_val = level * s->y_dc_scale; |
|
} else { |
|
*dc_val = level * s->c_dc_scale; |
|
} |
|
|
|
/* do the prediction */ |
|
level -= pred; |
|
|
|
if(s->msmpeg4_version==2){ |
|
if (n < 4) { |
|
put_bits(&s->pb, |
|
v2_dc_lum_table[level+256][1], |
|
v2_dc_lum_table[level+256][0]); |
|
}else{ |
|
put_bits(&s->pb, |
|
v2_dc_chroma_table[level+256][1], |
|
v2_dc_chroma_table[level+256][0]); |
|
} |
|
}else{ |
|
sign = 0; |
|
if (level < 0) { |
|
level = -level; |
|
sign = 1; |
|
} |
|
code = level; |
|
if (code > DC_MAX) |
|
code = DC_MAX; |
|
|
|
if (s->dc_table_index == 0) { |
|
if (n < 4) { |
|
put_bits(&s->pb, table0_dc_lum[code][1], table0_dc_lum[code][0]); |
|
} else { |
|
put_bits(&s->pb, table0_dc_chroma[code][1], table0_dc_chroma[code][0]); |
|
} |
|
} else { |
|
if (n < 4) { |
|
put_bits(&s->pb, table1_dc_lum[code][1], table1_dc_lum[code][0]); |
|
} else { |
|
put_bits(&s->pb, table1_dc_chroma[code][1], table1_dc_chroma[code][0]); |
|
} |
|
} |
|
|
|
if (code == DC_MAX) |
|
put_bits(&s->pb, 8, level); |
|
|
|
if (level != 0) { |
|
put_bits(&s->pb, 1, sign); |
|
} |
|
} |
|
} |
|
|
|
/* Encoding of a block. Very similar to MPEG4 except for a different |
|
escape coding (same as H263) and more vlc tables. |
|
*/ |
|
static void msmpeg4_encode_block(MpegEncContext * s, DCTELEM * block, int n) |
|
{ |
|
int level, run, last, i, j, last_index; |
|
int last_non_zero, sign, slevel; |
|
int code, run_diff, dc_pred_dir; |
|
const RLTable *rl; |
|
|
|
if (s->mb_intra) { |
|
set_stat(ST_DC); |
|
msmpeg4_encode_dc(s, block[0], n, &dc_pred_dir); |
|
i = 1; |
|
if (n < 4) { |
|
rl = &rl_table[s->rl_table_index]; |
|
} else { |
|
rl = &rl_table[3 + s->rl_chroma_table_index]; |
|
} |
|
run_diff = 0; |
|
set_stat(ST_INTRA_AC); |
|
} else { |
|
i = 0; |
|
rl = &rl_table[3 + s->rl_table_index]; |
|
if(s->msmpeg4_version==2) |
|
run_diff = 0; |
|
else |
|
run_diff = 1; |
|
set_stat(ST_INTER_AC); |
|
} |
|
|
|
/* AC coefs */ |
|
last_index = s->block_last_index[n]; |
|
last_non_zero = i - 1; |
|
for (; i <= last_index; i++) { |
|
j = zigzag_direct[i]; |
|
level = block[j]; |
|
if (level) { |
|
run = i - last_non_zero - 1; |
|
last = (i == last_index); |
|
sign = 0; |
|
slevel = level; |
|
if (level < 0) { |
|
sign = 1; |
|
level = -level; |
|
} |
|
code = get_rl_index(rl, last, run, level); |
|
put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]); |
|
if (code == rl->n) { |
|
int level1, run1; |
|
|
|
level1 = level - rl->max_level[last][run]; |
|
if (level1 < 1) |
|
goto esc2; |
|
code = get_rl_index(rl, last, run, level1); |
|
if (code == rl->n) { |
|
esc2: |
|
put_bits(&s->pb, 1, 0); |
|
if (level > MAX_LEVEL) |
|
goto esc3; |
|
run1 = run - rl->max_run[last][level] - run_diff; |
|
if (run1 < 0) |
|
goto esc3; |
|
code = get_rl_index(rl, last, run1, level); |
|
if (code == rl->n) { |
|
esc3: |
|
/* third escape */ |
|
put_bits(&s->pb, 1, 0); |
|
put_bits(&s->pb, 1, last); |
|
put_bits(&s->pb, 6, run); |
|
put_bits(&s->pb, 8, slevel & 0xff); |
|
} else { |
|
/* second escape */ |
|
put_bits(&s->pb, 1, 1); |
|
put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]); |
|
put_bits(&s->pb, 1, sign); |
|
} |
|
} else { |
|
/* first escape */ |
|
put_bits(&s->pb, 1, 1); |
|
put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]); |
|
put_bits(&s->pb, 1, sign); |
|
} |
|
} else { |
|
put_bits(&s->pb, 1, sign); |
|
} |
|
last_non_zero = i; |
|
} |
|
} |
|
} |
|
|
|
/****************************************/ |
|
/* decoding stuff */ |
|
|
|
static VLC mb_non_intra_vlc; |
|
static VLC mb_intra_vlc; |
|
static VLC dc_lum_vlc[2]; |
|
static VLC dc_chroma_vlc[2]; |
|
static VLC v2_dc_lum_vlc; |
|
static VLC v2_dc_chroma_vlc; |
|
static VLC cbpy_vlc; |
|
static VLC v2_intra_cbpc_vlc; |
|
static VLC v2_mb_type_vlc; |
|
static VLC v2_mv_vlc; |
|
|
|
/* this table is practically identical to the one from h263 except that its inverted */ |
|
static void init_h263_dc_for_msmpeg4() |
|
{ |
|
static int inited=0; |
|
|
|
if(!inited){ |
|
int level, uni_code, uni_len; |
|
inited=1; |
|
|
|
for(level=-256; 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 h263 */ |
|
uni_code= DCtab_lum[size][0]; |
|
uni_len = DCtab_lum[size][1]; |
|
uni_code ^= (1<<uni_len)-1; //M$ doesnt like compatibility |
|
|
|
if (size > 0) { |
|
uni_code<<=size; uni_code|=l; |
|
uni_len+=size; |
|
if (size > 8){ |
|
uni_code<<=1; uni_code|=1; |
|
uni_len++; |
|
} |
|
} |
|
v2_dc_lum_table[level+256][0]= uni_code; |
|
v2_dc_lum_table[level+256][1]= uni_len; |
|
|
|
/* chrominance h263 */ |
|
uni_code= DCtab_chrom[size][0]; |
|
uni_len = DCtab_chrom[size][1]; |
|
uni_code ^= (1<<uni_len)-1; //M$ doesnt like compatibility |
|
|
|
if (size > 0) { |
|
uni_code<<=size; uni_code|=l; |
|
uni_len+=size; |
|
if (size > 8){ |
|
uni_code<<=1; uni_code|=1; |
|
uni_len++; |
|
} |
|
} |
|
v2_dc_chroma_table[level+256][0]= uni_code; |
|
v2_dc_chroma_table[level+256][1]= uni_len; |
|
|
|
} |
|
} |
|
} |
|
|
|
/* init all vlc decoding tables */ |
|
int msmpeg4_decode_init_vlc(MpegEncContext *s) |
|
{ |
|
int i; |
|
MVTable *mv; |
|
|
|
for(i=0;i<NB_RL_TABLES;i++) { |
|
init_rl(&rl_table[i]); |
|
init_vlc_rl(&rl_table[i]); |
|
} |
|
for(i=0;i<2;i++) { |
|
mv = &mv_tables[i]; |
|
init_vlc(&mv->vlc, 9, mv->n + 1, |
|
mv->table_mv_bits, 1, 1, |
|
mv->table_mv_code, 2, 2); |
|
} |
|
|
|
init_vlc(&dc_lum_vlc[0], 9, 120, |
|
&table0_dc_lum[0][1], 8, 4, |
|
&table0_dc_lum[0][0], 8, 4); |
|
init_vlc(&dc_chroma_vlc[0], 9, 120, |
|
&table0_dc_chroma[0][1], 8, 4, |
|
&table0_dc_chroma[0][0], 8, 4); |
|
init_vlc(&dc_lum_vlc[1], 9, 120, |
|
&table1_dc_lum[0][1], 8, 4, |
|
&table1_dc_lum[0][0], 8, 4); |
|
init_vlc(&dc_chroma_vlc[1], 9, 120, |
|
&table1_dc_chroma[0][1], 8, 4, |
|
&table1_dc_chroma[0][0], 8, 4); |
|
|
|
init_h263_dc_for_msmpeg4(); |
|
init_vlc(&v2_dc_lum_vlc, 9, 512, |
|
&v2_dc_lum_table[0][1], 8, 4, |
|
&v2_dc_lum_table[0][0], 8, 4); |
|
init_vlc(&v2_dc_chroma_vlc, 9, 512, |
|
&v2_dc_chroma_table[0][1], 8, 4, |
|
&v2_dc_chroma_table[0][0], 8, 4); |
|
|
|
init_vlc(&cbpy_vlc, 6, 16, |
|
&cbpy_tab[0][1], 2, 1, |
|
&cbpy_tab[0][0], 2, 1); |
|
init_vlc(&v2_intra_cbpc_vlc, 3, 4, |
|
&v2_intra_cbpc[0][1], 2, 1, |
|
&v2_intra_cbpc[0][0], 2, 1); |
|
init_vlc(&v2_mb_type_vlc, 5, 8, |
|
&v2_mb_type[0][1], 2, 1, |
|
&v2_mb_type[0][0], 2, 1); |
|
init_vlc(&v2_mv_vlc, 9, 33, |
|
&mvtab[0][1], 2, 1, |
|
&mvtab[0][0], 2, 1); |
|
|
|
init_vlc(&mb_non_intra_vlc, 9, 128, |
|
&table_mb_non_intra[0][1], 8, 4, |
|
&table_mb_non_intra[0][0], 8, 4); |
|
init_vlc(&mb_intra_vlc, 9, 64, |
|
&table_mb_intra[0][1], 4, 2, |
|
&table_mb_intra[0][0], 4, 2); |
|
return 0; |
|
} |
|
|
|
static int decode012(GetBitContext *gb) |
|
{ |
|
int n; |
|
n = get_bits1(gb); |
|
if (n == 0) |
|
return 0; |
|
else |
|
return get_bits1(gb) + 1; |
|
} |
|
|
|
int msmpeg4_decode_picture_header(MpegEncContext * s) |
|
{ |
|
int code, code2; |
|
|
|
#if 0 |
|
{ |
|
int i; |
|
for(i=0; i<s->gb.size*8; i++) |
|
printf("%d", get_bits1(&s->gb)); |
|
// get_bits1(&s->gb); |
|
printf("END\n"); |
|
return -1; |
|
} |
|
#endif |
|
s->pict_type = get_bits(&s->gb, 2) + 1; |
|
if (s->pict_type != I_TYPE && |
|
s->pict_type != P_TYPE) |
|
return -1; |
|
|
|
s->qscale = get_bits(&s->gb, 5); |
|
|
|
if (s->pict_type == I_TYPE) { |
|
code = get_bits(&s->gb, 5); |
|
/* 0x17: one slice, 0x18: two slices */ |
|
if (code < 0x17) |
|
return -1; |
|
s->slice_height = s->mb_height / (code - 0x16); |
|
|
|
switch(s->msmpeg4_version){ |
|
case 2: |
|
s->rl_chroma_table_index = 2; |
|
s->rl_table_index = 2; |
|
|
|
s->dc_table_index = 0; //not used |
|
break; |
|
case 3: |
|
s->rl_chroma_table_index = decode012(&s->gb); |
|
s->rl_table_index = decode012(&s->gb); |
|
|
|
s->dc_table_index = get_bits1(&s->gb); |
|
break; |
|
case 4: |
|
msmpeg4_decode_ext_header(s, 999 /* bufer size (useless here) */); |
|
printf("%X\n", show_bits(&s->gb, 24)); |
|
code= get_bits(&s->gb, 2); |
|
if(code==1){ |
|
code2= get_bits(&s->gb, 3); |
|
if(code2==7) skip_bits(&s->gb, 1); |
|
} |
|
printf("%X\n", show_bits(&s->gb, 24)); |
|
s->rl_chroma_table_index = 2; |
|
s->rl_table_index = 2; |
|
|
|
s->dc_table_index = 0; |
|
break; |
|
} |
|
s->no_rounding = 1; |
|
/* printf(" %d %d %d %d \n", |
|
s->qscale, |
|
s->rl_chroma_table_index, |
|
s->rl_table_index, |
|
s->dc_table_index);*/ |
|
} else { |
|
s->use_skip_mb_code = get_bits1(&s->gb); |
|
|
|
if(s->msmpeg4_version==2){ |
|
s->rl_table_index = 2; |
|
s->rl_chroma_table_index = s->rl_table_index; |
|
|
|
s->dc_table_index = 0; //not used |
|
|
|
s->mv_table_index = 0; |
|
}else{ |
|
s->rl_table_index = decode012(&s->gb); |
|
s->rl_chroma_table_index = s->rl_table_index; |
|
|
|
s->dc_table_index = get_bits1(&s->gb); |
|
|
|
s->mv_table_index = get_bits1(&s->gb); |
|
} |
|
/* printf(" %d %d %d %d %d \n", |
|
s->use_skip_mb_code, |
|
s->rl_table_index, |
|
s->rl_chroma_table_index, |
|
s->dc_table_index, |
|
s->mv_table_index);*/ |
|
if(s->flipflop_rounding){ |
|
s->no_rounding ^= 1; |
|
}else{ |
|
s->no_rounding = 0; |
|
} |
|
// printf("%d", s->no_rounding); |
|
//return -1; |
|
} |
|
|
|
#if 0 |
|
if(s->msmpeg4_version==2) |
|
{ |
|
int i; |
|
for(i=0; i<s->gb.size*8; i++) |
|
// printf("%d", get_bits1(&s->gb)); |
|
get_bits1(&s->gb); |
|
printf("END\n"); |
|
return -1; |
|
} |
|
#endif |
|
|
|
#ifdef DEBUG |
|
printf("*****frame %d:\n", frame_count++); |
|
#endif |
|
return 0; |
|
} |
|
|
|
int msmpeg4_decode_ext_header(MpegEncContext * s, int buf_size) |
|
{ |
|
/* the alt_bitstream reader could read over the end so we need to check it */ |
|
if(get_bits_count(&s->gb) + 16 < buf_size*8) |
|
{ |
|
int fps; |
|
|
|
fps= get_bits(&s->gb, 5); |
|
s->bitrate= get_bits(&s->gb, 11); |
|
s->flipflop_rounding= get_bits1(&s->gb); |
|
|
|
// printf("fps:%2d bps:%2d roundingType:%1d\n", fps, s->bitrate, s->flipflop_rounding); |
|
} |
|
else |
|
{ |
|
s->flipflop_rounding= 0; |
|
s->bitrate= 0; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static inline void memsetw(short *tab, int val, int n) |
|
{ |
|
int i; |
|
for(i=0;i<n;i++) |
|
tab[i] = val; |
|
} |
|
|
|
static void msmpeg4v2_encode_motion(MpegEncContext * s, int val) |
|
{ |
|
int range, bit_size, sign, code, bits; |
|
|
|
if (val == 0) { |
|
/* zero vector */ |
|
code = 0; |
|
put_bits(&s->pb, mvtab[code][1], mvtab[code][0]); |
|
} else { |
|
bit_size = s->f_code - 1; |
|
range = 1 << bit_size; |
|
if (val <= -64) |
|
val += 64; |
|
else if (val >= 64) |
|
val -= 64; |
|
|
|
if (val >= 0) { |
|
sign = 0; |
|
} else { |
|
val = -val; |
|
sign = 1; |
|
} |
|
val--; |
|
code = (val >> bit_size) + 1; |
|
bits = val & (range - 1); |
|
|
|
put_bits(&s->pb, mvtab[code][1] + 1, (mvtab[code][0] << 1) | sign); |
|
if (bit_size > 0) { |
|
put_bits(&s->pb, bit_size, bits); |
|
} |
|
} |
|
} |
|
|
|
/* this is identical to h263 except that its range is multiplied by 2 */ |
|
static int msmpeg4v2_decode_motion(MpegEncContext * s, int pred, int f_code) |
|
{ |
|
int code, val, sign, shift; |
|
|
|
code = get_vlc(&s->gb, &v2_mv_vlc); |
|
if (code < 0) |
|
return 0xffff; |
|
|
|
if (code == 0) |
|
return pred; |
|
sign = get_bits1(&s->gb); |
|
shift = f_code - 1; |
|
val = (code - 1) << shift; |
|
if (shift > 0) |
|
val |= get_bits(&s->gb, shift); |
|
val++; |
|
if (sign) |
|
val = -val; |
|
val += pred; |
|
|
|
if (val <= -64) |
|
val += 64; |
|
else if (val >= 64) |
|
val -= 64; |
|
|
|
return val; |
|
} |
|
|
|
|
|
int msmpeg4v2_decode_mb(MpegEncContext *s, |
|
DCTELEM block[6][64]) |
|
{ |
|
int cbp, code, i; |
|
if (s->pict_type == P_TYPE) { |
|
if (s->use_skip_mb_code) { |
|
if (get_bits1(&s->gb)) { |
|
/* skip mb */ |
|
s->mb_intra = 0; |
|
for(i=0;i<6;i++) |
|
s->block_last_index[i] = -1; |
|
s->mv_dir = MV_DIR_FORWARD; |
|
s->mv_type = MV_TYPE_16X16; |
|
s->mv[0][0][0] = 0; |
|
s->mv[0][0][1] = 0; |
|
s->mb_skiped = 1; |
|
return 0; |
|
} |
|
} |
|
|
|
code = get_vlc(&s->gb, &v2_mb_type_vlc); |
|
s->mb_intra = code >>2; |
|
|
|
cbp = code & 0x3; |
|
} else { |
|
s->mb_intra = 1; |
|
cbp= get_vlc(&s->gb, &v2_intra_cbpc_vlc); |
|
} |
|
|
|
if (!s->mb_intra) { |
|
int mx, my; |
|
|
|
cbp|= get_vlc(&s->gb, &cbpy_vlc)<<2; |
|
if((cbp&3) != 3) cbp^= 0x3C; |
|
|
|
h263_pred_motion(s, 0, &mx, &my); |
|
mx= msmpeg4v2_decode_motion(s, mx, 1); |
|
my= msmpeg4v2_decode_motion(s, my, 1); |
|
|
|
s->mv_dir = MV_DIR_FORWARD; |
|
s->mv_type = MV_TYPE_16X16; |
|
s->mv[0][0][0] = mx; |
|
s->mv[0][0][1] = my; |
|
} else { |
|
s->ac_pred = get_bits1(&s->gb); |
|
cbp|= get_vlc(&s->gb, &cbpy_vlc)<<2; |
|
} |
|
|
|
for (i = 0; i < 6; i++) { |
|
if (msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1) < 0) |
|
{ |
|
fprintf(stderr,"\nIgnoring error while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i); |
|
return -1; |
|
} |
|
} |
|
return 0; |
|
} |
|
|
|
int msmpeg4_decode_mb(MpegEncContext *s, |
|
DCTELEM block[6][64]) |
|
{ |
|
int cbp, code, i; |
|
UINT8 *coded_val; |
|
|
|
/* special slice handling */ |
|
if (s->mb_x == 0) { |
|
if (s->slice_height && (s->mb_y % s->slice_height) == 0) { |
|
int wrap; |
|
/* reset DC pred (set previous line to 1024) */ |
|
wrap = 2 * s->mb_width + 2; |
|
memsetw(&s->dc_val[0][(1) + (2 * s->mb_y) * wrap], |
|
1024, 2 * s->mb_width); |
|
wrap = s->mb_width + 2; |
|
memsetw(&s->dc_val[1][(1) + (s->mb_y) * wrap], |
|
1024, s->mb_width); |
|
memsetw(&s->dc_val[2][(1) + (s->mb_y) * wrap], |
|
1024, s->mb_width); |
|
|
|
/* reset AC pred (set previous line to 0) */ |
|
wrap = s->mb_width * 2 + 2; |
|
memsetw(s->ac_val[0][0] + (1 + (2 * s->mb_y) * wrap)*16, |
|
0, 2 * s->mb_width*16); |
|
wrap = s->mb_width + 2; |
|
memsetw(s->ac_val[1][0] + (1 + (s->mb_y) * wrap)*16, |
|
0, s->mb_width*16); |
|
memsetw(s->ac_val[2][0] + (1 + (s->mb_y) * wrap)*16, |
|
0, s->mb_width*16); |
|
|
|
s->first_slice_line = 1; |
|
} else { |
|
s->first_slice_line = 0; |
|
} |
|
} |
|
|
|
if(s->msmpeg4_version==2) return msmpeg4v2_decode_mb(s, block); //FIXME merge if possible |
|
|
|
if (s->pict_type == P_TYPE) { |
|
set_stat(ST_INTER_MB); |
|
if (s->use_skip_mb_code) { |
|
if (get_bits1(&s->gb)) { |
|
/* skip mb */ |
|
s->mb_intra = 0; |
|
for(i=0;i<6;i++) |
|
s->block_last_index[i] = -1; |
|
s->mv_dir = MV_DIR_FORWARD; |
|
s->mv_type = MV_TYPE_16X16; |
|
s->mv[0][0][0] = 0; |
|
s->mv[0][0][1] = 0; |
|
s->mb_skiped = 1; |
|
return 0; |
|
} |
|
} |
|
|
|
code = get_vlc(&s->gb, &mb_non_intra_vlc); |
|
if (code < 0) |
|
return -1; |
|
//s->mb_intra = (code & 0x40) ? 0 : 1; |
|
s->mb_intra = (~code & 0x40) >> 6; |
|
|
|
cbp = code & 0x3f; |
|
} else { |
|
set_stat(ST_INTRA_MB); |
|
s->mb_intra = 1; |
|
code = get_vlc(&s->gb, &mb_intra_vlc); |
|
if (code < 0) |
|
return -1; |
|
/* predict coded block pattern */ |
|
cbp = 0; |
|
for(i=0;i<6;i++) { |
|
int val = ((code >> (5 - i)) & 1); |
|
if (i < 4) { |
|
int pred = coded_block_pred(s, i, &coded_val); |
|
val = val ^ pred; |
|
*coded_val = val; |
|
} |
|
cbp |= val << (5 - i); |
|
} |
|
} |
|
|
|
if (!s->mb_intra) { |
|
int mx, my; |
|
set_stat(ST_MV); |
|
h263_pred_motion(s, 0, &mx, &my); |
|
if (msmpeg4_decode_motion(s, &mx, &my) < 0) |
|
return -1; |
|
s->mv_dir = MV_DIR_FORWARD; |
|
s->mv_type = MV_TYPE_16X16; |
|
s->mv[0][0][0] = mx; |
|
s->mv[0][0][1] = my; |
|
} else { |
|
set_stat(ST_INTRA_MB); |
|
s->ac_pred = get_bits1(&s->gb); |
|
} |
|
|
|
for (i = 0; i < 6; i++) { |
|
if (msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1) < 0) |
|
{ |
|
fprintf(stderr,"\nIgnoring error while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i); |
|
// return -1; |
|
} |
|
} |
|
return 0; |
|
} |
|
|
|
static int msmpeg4_decode_block(MpegEncContext * s, DCTELEM * block, |
|
int n, int coded) |
|
{ |
|
int code, level, i, j, last, run, run_diff; |
|
int dc_pred_dir; |
|
RLTable *rl; |
|
const UINT8 *scan_table; |
|
int qmul, qadd; |
|
|
|
if (s->mb_intra) { |
|
qmul=1; |
|
qadd=0; |
|
|
|
/* DC coef */ |
|
set_stat(ST_DC); |
|
level = msmpeg4_decode_dc(s, n, &dc_pred_dir); |
|
if (level < 0) |
|
return -1; |
|
block[0] = level; |
|
if (n < 4) { |
|
rl = &rl_table[s->rl_table_index]; |
|
} else { |
|
rl = &rl_table[3 + s->rl_chroma_table_index]; |
|
} |
|
|
|
run_diff = 0; |
|
i = 1; |
|
if (!coded) { |
|
goto not_coded; |
|
} |
|
if (s->ac_pred) { |
|
if (dc_pred_dir == 0) |
|
scan_table = ff_alternate_vertical_scan; /* left */ |
|
else |
|
scan_table = ff_alternate_horizontal_scan; /* top */ |
|
} else { |
|
scan_table = zigzag_direct; |
|
} |
|
set_stat(ST_INTRA_AC); |
|
} else { |
|
qmul = s->qscale << 1; |
|
qadd = (s->qscale - 1) | 1; |
|
i = 0; |
|
rl = &rl_table[3 + s->rl_table_index]; |
|
|
|
if(s->msmpeg4_version==2) |
|
run_diff = 0; |
|
else |
|
run_diff = 1; |
|
|
|
if (!coded) { |
|
s->block_last_index[n] = i - 1; |
|
return 0; |
|
} |
|
scan_table = zigzag_direct; |
|
set_stat(ST_INTER_AC); |
|
} |
|
|
|
for(;;) { |
|
code = get_vlc(&s->gb, &rl->vlc); |
|
if (code < 0) |
|
return -1; |
|
if (code == rl->n) { |
|
/* escape */ |
|
if (get_bits1(&s->gb) == 0) { |
|
if (get_bits1(&s->gb) == 0) { |
|
/* third escape */ |
|
last = get_bits1(&s->gb); |
|
run = get_bits(&s->gb, 6); |
|
level = get_bits(&s->gb, 8); |
|
level = (level << 24) >> 24; /* sign extend */ |
|
//level = level * qmul + (level>0) * qadd - (level<=0) * qadd ; |
|
if (level>0) level= level * qmul + qadd; |
|
else level= level * qmul - qadd; |
|
} else { |
|
/* second escape */ |
|
code = get_vlc(&s->gb, &rl->vlc); |
|
if (code < 0 || code >= rl->n) |
|
return -1; |
|
run = rl->table_run[code]; |
|
level = rl->table_level[code]; |
|
last = code >= rl->last; |
|
run += rl->max_run[last][level] + run_diff; |
|
level= level * qmul + qadd; |
|
if (get_bits1(&s->gb)) |
|
level = -level; |
|
} |
|
} else { |
|
/* first escape */ |
|
code = get_vlc(&s->gb, &rl->vlc); |
|
if (code < 0 || code >= rl->n) |
|
return -1; |
|
run = rl->table_run[code]; |
|
level = rl->table_level[code]; |
|
last = code >= rl->last; |
|
level += rl->max_level[last][run]; |
|
level= level * qmul + qadd; |
|
if (get_bits1(&s->gb)) |
|
level = -level; |
|
} |
|
} else { |
|
run = rl->table_run[code]; |
|
level = rl->table_level[code] * qmul + qadd; |
|
last = code >= rl->last; |
|
if (get_bits1(&s->gb)) |
|
level = -level; |
|
} |
|
i += run; |
|
if (i >= 64) |
|
return -1; |
|
//printf("RL:%d %d %d ", run, level, last); |
|
j = scan_table[i]; |
|
block[j] = level; |
|
i++; |
|
if (last) |
|
break; |
|
} |
|
not_coded: |
|
if (s->mb_intra) { |
|
mpeg4_pred_ac(s, block, n, dc_pred_dir); |
|
if (s->ac_pred) { |
|
i = 64; /* XXX: not optimal */ |
|
} |
|
} |
|
s->block_last_index[n] = i - 1; |
|
|
|
return 0; |
|
} |
|
|
|
static int msmpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr) |
|
{ |
|
int level, pred; |
|
INT16 *dc_val; |
|
|
|
if(s->msmpeg4_version==2){ |
|
if (n < 4) { |
|
level = get_vlc(&s->gb, &v2_dc_lum_vlc); |
|
} else { |
|
level = get_vlc(&s->gb, &v2_dc_chroma_vlc); |
|
} |
|
if (level < 0) |
|
return -1; |
|
level-=256; |
|
}else{ //FIXME optimize use unified tables & index |
|
if (n < 4) { |
|
level = get_vlc(&s->gb, &dc_lum_vlc[s->dc_table_index]); |
|
} else { |
|
level = get_vlc(&s->gb, &dc_chroma_vlc[s->dc_table_index]); |
|
} |
|
if (level < 0) |
|
return -1; |
|
|
|
if (level == DC_MAX) { |
|
level = get_bits(&s->gb, 8); |
|
if (get_bits1(&s->gb)) |
|
level = -level; |
|
} else if (level != 0) { |
|
if (get_bits1(&s->gb)) |
|
level = -level; |
|
} |
|
} |
|
|
|
pred = msmpeg4_pred_dc(s, n, &dc_val, dir_ptr); |
|
level += pred; |
|
|
|
/* update predictor */ |
|
if (n < 4) { |
|
*dc_val = level * s->y_dc_scale; |
|
} else { |
|
*dc_val = level * s->c_dc_scale; |
|
} |
|
|
|
return level; |
|
} |
|
|
|
static int msmpeg4_decode_motion(MpegEncContext * s, |
|
int *mx_ptr, int *my_ptr) |
|
{ |
|
MVTable *mv; |
|
int code, mx, my; |
|
|
|
mv = &mv_tables[s->mv_table_index]; |
|
|
|
code = get_vlc(&s->gb, &mv->vlc); |
|
if (code < 0) |
|
return -1; |
|
if (code == mv->n) { |
|
mx = get_bits(&s->gb, 6); |
|
my = get_bits(&s->gb, 6); |
|
} else { |
|
mx = mv->table_mvx[code]; |
|
my = mv->table_mvy[code]; |
|
} |
|
|
|
mx += *mx_ptr - 32; |
|
my += *my_ptr - 32; |
|
/* WARNING : they do not do exactly modulo encoding */ |
|
if (mx <= -64) |
|
mx += 64; |
|
else if (mx >= 64) |
|
mx -= 64; |
|
|
|
if (my <= -64) |
|
my += 64; |
|
else if (my >= 64) |
|
my -= 64; |
|
*mx_ptr = mx; |
|
*my_ptr = my; |
|
return 0; |
|
}
|
|
|