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h264: don't touch H264Context->ref_count[] during MB decoding 

The variable is copied to subsequent threads at the same time, so this
may cause wrong ref_count[] values to be copied to subsequent threads.

This bug was found using TSAN.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
tags/n1.1
Ronald S. Bultje Luca Barbato 13 years ago
parent
a7329e5fc2
commit
f6f7d15041
2 changed files with 29 additions and 45 deletions
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  1. +16
    -25
      libavcodec/h264_cabac.c
  2. +13
    -20
      libavcodec/h264_cavlc.c

+ 16
- 25
libavcodec/h264_cabac.c View File

@@ -2005,11 +2005,6 @@ decode_intra_mb:
return 0;
}

if(MB_MBAFF){
h->ref_count[0] <<= 1;
h->ref_count[1] <<= 1;
}

fill_decode_caches(h, mb_type);

if( IS_INTRA( mb_type ) ) {
@@ -2078,10 +2073,11 @@ decode_intra_mb:
for( i = 0; i < 4; i++ ) {
if(IS_DIRECT(h->sub_mb_type[i])) continue;
if(IS_DIR(h->sub_mb_type[i], 0, list)){
if( h->ref_count[list] > 1 ){
int rc = h->ref_count[list] << MB_MBAFF;
if (rc > 1) {
ref[list][i] = decode_cabac_mb_ref( h, list, 4*i );
if(ref[list][i] >= (unsigned)h->ref_count[list]){
av_log(s->avctx, AV_LOG_ERROR, "Reference %d >= %d\n", ref[list][i], h->ref_count[list]);
if (ref[list][i] >= (unsigned) rc) {
av_log(s->avctx, AV_LOG_ERROR, "Reference %d >= %d\n", ref[list][i], rc);
return -1;
}
}else
@@ -2163,11 +2159,11 @@ decode_intra_mb:
if(IS_16X16(mb_type)){
for(list=0; list<h->list_count; list++){
if(IS_DIR(mb_type, 0, list)){
int ref;
if(h->ref_count[list] > 1){
int ref, rc = h->ref_count[list] << MB_MBAFF;
if (rc > 1) {
ref= decode_cabac_mb_ref(h, list, 0);
if(ref >= (unsigned)h->ref_count[list]){
av_log(s->avctx, AV_LOG_ERROR, "Reference %d >= %d\n", ref, h->ref_count[list]);
if (ref >= (unsigned) rc) {
av_log(s->avctx, AV_LOG_ERROR, "Reference %d >= %d\n", ref, rc);
return -1;
}
}else
@@ -2191,11 +2187,11 @@ decode_intra_mb:
for(list=0; list<h->list_count; list++){
for(i=0; i<2; i++){
if(IS_DIR(mb_type, i, list)){
int ref;
if(h->ref_count[list] > 1){
int ref, rc = h->ref_count[list] << MB_MBAFF;
if (rc > 1) {
ref= decode_cabac_mb_ref( h, list, 8*i );
if(ref >= (unsigned)h->ref_count[list]){
av_log(s->avctx, AV_LOG_ERROR, "Reference %d >= %d\n", ref, h->ref_count[list]);
if (ref >= (unsigned) rc) {
av_log(s->avctx, AV_LOG_ERROR, "Reference %d >= %d\n", ref, rc);
return -1;
}
}else
@@ -2226,11 +2222,11 @@ decode_intra_mb:
for(list=0; list<h->list_count; list++){
for(i=0; i<2; i++){
if(IS_DIR(mb_type, i, list)){ //FIXME optimize
int ref;
if(h->ref_count[list] > 1){
int ref, rc = h->ref_count[list] << MB_MBAFF;
if (rc > 1) {
ref= decode_cabac_mb_ref( h, list, 4*i );
if(ref >= (unsigned)h->ref_count[list]){
av_log(s->avctx, AV_LOG_ERROR, "Reference %d >= %d\n", ref, h->ref_count[list]);
if (ref >= (unsigned) rc) {
av_log(s->avctx, AV_LOG_ERROR, "Reference %d >= %d\n", ref, rc);
return -1;
}
}else
@@ -2403,10 +2399,5 @@ decode_intra_mb:
s->current_picture.f.qscale_table[mb_xy] = s->qscale;
write_back_non_zero_count(h);

if(MB_MBAFF){
h->ref_count[0] >>= 1;
h->ref_count[1] >>= 1;
}

return 0;
}

+ 13
- 20
libavcodec/h264_cavlc.c View File

@@ -784,11 +784,6 @@ decode_intra_mb:
return 0;
}

if(MB_MBAFF){
h->ref_count[0] <<= 1;
h->ref_count[1] <<= 1;
}

fill_decode_neighbors(h, mb_type);
fill_decode_caches(h, mb_type);

@@ -868,7 +863,7 @@ decode_intra_mb:
}

for(list=0; list<h->list_count; list++){
int ref_count= IS_REF0(mb_type) ? 1 : h->ref_count[list];
int ref_count = IS_REF0(mb_type) ? 1 : h->ref_count[list] << MB_MBAFF;
for(i=0; i<4; i++){
if(IS_DIRECT(h->sub_mb_type[i])) continue;
if(IS_DIR(h->sub_mb_type[i], 0, list)){
@@ -948,13 +943,14 @@ decode_intra_mb:
for(list=0; list<h->list_count; list++){
unsigned int val;
if(IS_DIR(mb_type, 0, list)){
if(h->ref_count[list]==1){
int rc = h->ref_count[list] << MB_MBAFF;
if (rc == 1) {
val= 0;
}else if(h->ref_count[list]==2){
} else if (rc == 2) {
val= get_bits1(&s->gb)^1;
}else{
val= get_ue_golomb_31(&s->gb);
if(val >= h->ref_count[list]){
if (val >= rc) {
av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);
return -1;
}
@@ -978,13 +974,14 @@ decode_intra_mb:
for(i=0; i<2; i++){
unsigned int val;
if(IS_DIR(mb_type, i, list)){
if(h->ref_count[list] == 1){
int rc = h->ref_count[list] << MB_MBAFF;
if (rc == 1) {
val= 0;
}else if(h->ref_count[list] == 2){
} else if (rc == 2) {
val= get_bits1(&s->gb)^1;
}else{
val= get_ue_golomb_31(&s->gb);
if(val >= h->ref_count[list]){
if (val >= rc) {
av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);
return -1;
}
@@ -1015,13 +1012,14 @@ decode_intra_mb:
for(i=0; i<2; i++){
unsigned int val;
if(IS_DIR(mb_type, i, list)){ //FIXME optimize
if(h->ref_count[list]==1){
int rc = h->ref_count[list] << MB_MBAFF;
if (rc == 1) {
val= 0;
}else if(h->ref_count[list]==2){
} else if (rc == 2) {
val= get_bits1(&s->gb)^1;
}else{
val= get_ue_golomb_31(&s->gb);
if(val >= h->ref_count[list]){
if (val >= rc) {
av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);
return -1;
}
@@ -1180,10 +1178,5 @@ decode_intra_mb:
s->current_picture.f.qscale_table[mb_xy] = s->qscale;
write_back_non_zero_count(h);

if(MB_MBAFF){
h->ref_count[0] >>= 1;
h->ref_count[1] >>= 1;
}

return 0;
}

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