diff --git a/libavcodec/h263.c b/libavcodec/h263.c index e20381da02..e654e19281 100644 --- a/libavcodec/h263.c +++ b/libavcodec/h263.c @@ -2747,7 +2747,6 @@ int mpeg4_decode_picture_header(MpegEncContext * s) { int time_incr, startcode, state, v; int time_increment; - int vol_control=-1; redo: /* search next start code */ @@ -2791,7 +2790,7 @@ int mpeg4_decode_picture_header(MpegEncContext * s) skip_bits(&s->gb, 8); // par_height } - if ((vol_control=get_bits1(&s->gb))) { /* vol control parameter */ + if ((s->vol_control_parameters=get_bits1(&s->gb))) { /* vol control parameter */ int chroma_format= get_bits(&s->gb, 2); if(chroma_format!=1){ printf("illegal chroma format\n"); @@ -3000,6 +2999,10 @@ int mpeg4_decode_picture_header(MpegEncContext * s) } s->pict_type = get_bits(&s->gb, 2) + I_TYPE; /* pict type: I = 0 , P = 1 */ + if(s->pict_type==B_TYPE && s->low_delay && s->vol_control_parameters==0){ + printf("low_delay flag set, but shouldnt, clearing it\n"); + s->low_delay=0; + } // printf("pic: %d, qpel:%d\n", s->pict_type, s->quarter_sample); time_incr=0; while (get_bits1(&s->gb) != 0) @@ -3109,9 +3112,8 @@ int mpeg4_decode_picture_header(MpegEncContext * s) } /* detect buggy encoders which dont set the low_delay flag (divx4/xvid/opendivx)*/ // note we cannot detect divx5 without b-frames easyly (allthough its buggy too) - if(s->vo_type==0 && vol_control==0 && s->divx_version==0){ - if(s->picture_number==0) - printf("looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n"); + if(s->vo_type==0 && s->vol_control_parameters==0 && s->divx_version==0 && s->picture_number==0){ + printf("looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n"); s->low_delay=1; } diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c index 75f51ffe1e..73daa0d323 100644 --- a/libavcodec/mpegvideo.c +++ b/libavcodec/mpegvideo.c @@ -159,7 +159,9 @@ int MPV_common_init(MpegEncContext *s) s->next_picture_base[i] = pict; s->next_picture[i] = pict + pict_start; - if (s->has_b_frames) { + if (s->has_b_frames || s->codec_id==CODEC_ID_MPEG4) { + /* Note the MPEG4 stuff is here cuz of buggy encoders which dont set the low_delay flag but + do low-delay encoding, so we cant allways distinguish b-frame containing streams from low_delay streams */ pict = av_mallocz(c_size); if (pict == NULL) goto fail; diff --git a/libavcodec/mpegvideo.h b/libavcodec/mpegvideo.h index 33da18ee07..4ad5009dab 100644 --- a/libavcodec/mpegvideo.h +++ b/libavcodec/mpegvideo.h @@ -313,6 +313,7 @@ typedef struct MpegEncContext { int resync_x_pos; int low_delay; /* no reordering needed / has no b-frames */ int vo_type; + int vol_control_parameters; /* does the stream contain the low_delay flag, used to workaround buggy encoders */ /* divx specific, used to workaround (many) bugs in divx5 */ int divx_version;