📄 msmpeg4.c
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if (!s->mb_intra) {
int mx, my;
//printf("P at %d %d\n", s->mb_x, s->mb_y);
if(s->per_mb_rl_table && cbp){
s->rl_table_index = decode012(&s->gb);
s->rl_chroma_table_index = s->rl_table_index;
}
h263_pred_motion(s, 0, 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;
*mb_type_ptr = MB_TYPE_L0 | MB_TYPE_16x16;
} else {
//printf("I at %d %d %d %06X\n", s->mb_x, s->mb_y, ((cbp&3)? 1 : 0) +((cbp&0x3C)? 2 : 0), show_bits(&s->gb, 24));
s->ac_pred = get_bits1(&s->gb);
*mb_type_ptr = MB_TYPE_INTRA;
if(s->inter_intra_pred){
s->h263_aic_dir= get_vlc2(&s->gb, inter_intra_vlc.table, INTER_INTRA_VLC_BITS, 1);
// printf("%d%d %d %d/", s->ac_pred, s->h263_aic_dir, s->mb_x, s->mb_y);
}
if(s->per_mb_rl_table && cbp){
s->rl_table_index = decode012(&s->gb);
s->rl_chroma_table_index = s->rl_table_index;
}
}
s->dsp.clear_blocks(s->block[0]);
for (i = 0; i < 6; i++) {
if (msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1, NULL) < 0)
{
av_log(s->avctx, AV_LOG_ERROR, "\nerror while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i);
return -1;
}
}
return 0;
}
//#define ERROR_DETAILS
static inline int msmpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
int n, int coded, const uint8_t *scan_table)
{
int level, i, last, run, run_diff;
int dc_pred_dir;
RLTable *rl;
RL_VLC_ELEM *rl_vlc;
int qmul, qadd;
if (s->mb_intra) {
qmul=1;
qadd=0;
/* DC coef */
level = msmpeg4_decode_dc(s, n, &dc_pred_dir);
if (level < 0){
av_log(s->avctx, AV_LOG_ERROR, "dc overflow- block: %d qscale: %d//\n", n, s->qscale);
if(s->inter_intra_pred) level=0;
else return -1;
}
if (n < 4) {
rl = &rl_table[s->rl_table_index];
if(level > 256*s->y_dc_scale){
av_log(s->avctx, AV_LOG_ERROR, "dc overflow+ L qscale: %d//\n", s->qscale);
if(!s->inter_intra_pred) return -1;
}
} else {
rl = &rl_table[3 + s->rl_chroma_table_index];
if(level > 256*s->c_dc_scale){
av_log(s->avctx, AV_LOG_ERROR, "dc overflow+ C qscale: %d//\n", s->qscale);
if(!s->inter_intra_pred) return -1;
}
}
block[0] = level;
run_diff = s->msmpeg4_version >= 4;
i = 0;
if (!coded) {
goto not_coded;
}
if (s->ac_pred) {
if (dc_pred_dir == 0)
scan_table = s->intra_v_scantable.permutated; /* left */
else
scan_table = s->intra_h_scantable.permutated; /* top */
} else {
scan_table = s->intra_scantable.permutated;
}
rl_vlc= rl->rl_vlc[0];
} else {
qmul = s->qscale << 1;
qadd = (s->qscale - 1) | 1;
i = -1;
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;
return 0;
}
if(!scan_table)
scan_table = s->inter_scantable.permutated;
rl_vlc= rl->rl_vlc[s->qscale];
}
{
OPEN_READER(re, &s->gb);
for(;;) {
UPDATE_CACHE(re, &s->gb);
GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
if (level==0) {
int cache;
cache= GET_CACHE(re, &s->gb);
/* escape */
if (s->msmpeg4_version==1 || (cache&0x80000000)==0) {
if (s->msmpeg4_version==1 || (cache&0x40000000)==0) {
/* third escape */
if(s->msmpeg4_version!=1) LAST_SKIP_BITS(re, &s->gb, 2);
UPDATE_CACHE(re, &s->gb);
if(s->msmpeg4_version<=3){
last= SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
run= SHOW_UBITS(re, &s->gb, 6); SKIP_CACHE(re, &s->gb, 6);
level= SHOW_SBITS(re, &s->gb, 8); LAST_SKIP_CACHE(re, &s->gb, 8);
SKIP_COUNTER(re, &s->gb, 1+6+8);
}else{
int sign;
last= SHOW_UBITS(re, &s->gb, 1); SKIP_BITS(re, &s->gb, 1);
if(!s->esc3_level_length){
int ll;
//printf("ESC-3 %X at %d %d\n", show_bits(&s->gb, 24), s->mb_x, s->mb_y);
if(s->qscale<8){
ll= SHOW_UBITS(re, &s->gb, 3); SKIP_BITS(re, &s->gb, 3);
if(ll==0){
if(SHOW_UBITS(re, &s->gb, 1)) av_log(s->avctx, AV_LOG_ERROR, "cool a new vlc code ,contact the ffmpeg developers and upload the file\n");
SKIP_BITS(re, &s->gb, 1);
ll=8;
}
}else{
ll=2;
while(ll<8 && SHOW_UBITS(re, &s->gb, 1)==0){
ll++;
SKIP_BITS(re, &s->gb, 1);
}
if(ll<8) SKIP_BITS(re, &s->gb, 1);
}
s->esc3_level_length= ll;
s->esc3_run_length= SHOW_UBITS(re, &s->gb, 2) + 3; SKIP_BITS(re, &s->gb, 2);
//printf("level length:%d, run length: %d\n", ll, s->esc3_run_length);
UPDATE_CACHE(re, &s->gb);
}
run= SHOW_UBITS(re, &s->gb, s->esc3_run_length);
SKIP_BITS(re, &s->gb, s->esc3_run_length);
sign= SHOW_UBITS(re, &s->gb, 1);
SKIP_BITS(re, &s->gb, 1);
level= SHOW_UBITS(re, &s->gb, s->esc3_level_length);
SKIP_BITS(re, &s->gb, s->esc3_level_length);
if(sign) level= -level;
}
//printf("level: %d, run: %d at %d %d\n", level, run, s->mb_x, s->mb_y);
#if 0 // waste of time / this will detect very few errors
{
const int abs_level= FFABS(level);
const int run1= run - rl->max_run[last][abs_level] - run_diff;
if(abs_level<=MAX_LEVEL && run<=MAX_RUN){
if(abs_level <= rl->max_level[last][run]){
av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
return DECODING_AC_LOST;
}
if(abs_level <= rl->max_level[last][run]*2){
av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
return DECODING_AC_LOST;
}
if(run1>=0 && abs_level <= rl->max_level[last][run1]){
av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
return DECODING_AC_LOST;
}
}
}
#endif
//level = level * qmul + (level>0) * qadd - (level<=0) * qadd ;
if (level>0) level= level * qmul + qadd;
else level= level * qmul - qadd;
#if 0 // waste of time too :(
if(level>2048 || level<-2048){
av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc\n");
return DECODING_AC_LOST;
}
#endif
i+= run + 1;
if(last) i+=192;
#ifdef ERROR_DETAILS
if(run==66)
av_log(s->avctx, AV_LOG_ERROR, "illegal vlc code in ESC3 level=%d\n", level);
else if((i>62 && i<192) || i>192+63)
av_log(s->avctx, AV_LOG_ERROR, "run overflow in ESC3 i=%d run=%d level=%d\n", i, run, level);
#endif
} else {
/* second escape */
#if MIN_CACHE_BITS < 23
LAST_SKIP_BITS(re, &s->gb, 2);
UPDATE_CACHE(re, &s->gb);
#else
SKIP_BITS(re, &s->gb, 2);
#endif
GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
i+= run + rl->max_run[run>>7][level/qmul] + run_diff; //FIXME opt indexing
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
#ifdef ERROR_DETAILS
if(run==66)
av_log(s->avctx, AV_LOG_ERROR, "illegal vlc code in ESC2 level=%d\n", level);
else if((i>62 && i<192) || i>192+63)
av_log(s->avctx, AV_LOG_ERROR, "run overflow in ESC2 i=%d run=%d level=%d\n", i, run, level);
#endif
}
} else {
/* first escape */
#if MIN_CACHE_BITS < 22
LAST_SKIP_BITS(re, &s->gb, 1);
UPDATE_CACHE(re, &s->gb);
#else
SKIP_BITS(re, &s->gb, 1);
#endif
GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
i+= run;
level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
#ifdef ERROR_DETAILS
if(run==66)
av_log(s->avctx, AV_LOG_ERROR, "illegal vlc code in ESC1 level=%d\n", level);
else if((i>62 && i<192) || i>192+63)
av_log(s->avctx, AV_LOG_ERROR, "run overflow in ESC1 i=%d run=%d level=%d\n", i, run, level);
#endif
}
} else {
i+= run;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
#ifdef ERROR_DETAILS
if(run==66)
av_log(s->avctx, AV_LOG_ERROR, "illegal vlc code level=%d\n", level);
else if((i>62 && i<192) || i>192+63)
av_log(s->avctx, AV_LOG_ERROR, "run overflow i=%d run=%d level=%d\n", i, run, level);
#endif
}
if (i > 62){
i-= 192;
if(i&(~63)){
const int left= s->gb.size_in_bits - get_bits_count(&s->gb);
if(((i+192 == 64 && level/qmul==-1) || s->error_resilience<=1) && left>=0){
av_log(s->avctx, AV_LOG_ERROR, "ignoring overflow at %d %d\n", s->mb_x, s->mb_y);
break;
}else{
av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
return -1;
}
}
block[scan_table[i]] = level;
break;
}
block[scan_table[i]] = level;
}
CLOSE_READER(re, &s->gb);
}
not_coded:
if (s->mb_intra) {
mpeg4_pred_ac(s, block, n, dc_pred_dir);
if (s->ac_pred) {
i = 63; /* XXX: not optimal */
}
}
if(s->msmpeg4_version>=4 && i>0) i=63; //FIXME/XXX optimize
s->block_last_index[n] = i;
return 0;
}
static int msmpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
{
int level, pred;
if(s->msmpeg4_version<=2){
if (n < 4) {
level = get_vlc2(&s->gb, v2_dc_lum_vlc.table, DC_VLC_BITS, 3);
} else {
level = get_vlc2(&s->gb, v2_dc_chroma_vlc.table, DC_VLC_BITS, 3);
}
if (level < 0)
return -1;
level-=256;
}else{ //FIXME optimize use unified tables & index
if (n < 4) {
level = get_vlc2(&s->gb, ff_msmp4_dc_luma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
} else {
level = get_vlc2(&s->gb, ff_msmp4_dc_chroma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
}
if (level < 0){
av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
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;
}
}
if(s->msmpeg4_version==1){
int32_t *dc_val;
pred = msmpeg4v1_pred_dc(s, n, &dc_val);
level += pred;
/* update predictor */
*dc_val= level;
}else{
int16_t *dc_val;
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_vlc2(&s->gb, mv->vlc.table, MV_VLC_BITS, 2);
if (code < 0){
av_log(s->avctx, AV_LOG_ERROR, "illegal MV code at %d %d\n", s->mb_x, s->mb_y);
return -1;
}
if (code == mv->n) {
//printf("MV ESC %X at %d %d\n", show_bits(&s->gb, 24), s->mb_x, s->mb_y);
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;
}
/* cleanest way to support it
* there is too much shared between versions so that we cant have 1 file per version & 1 common
* as allmost everything would be in the common file
*/
#include "wmv2.c"
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