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decode mpeg-2 closed gop first b frames, fix issue #824

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Originally committed as revision 18837 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Baptiste Coudurier 2009-05-15 05:39:44 +00:00
parent 8be080aebb
commit 9d9a623925
3 changed files with 17 additions and 5 deletions
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20
libavcodec/mpeg12.c
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@ -30,6 +30,7 @@
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"
#include "mpegvideo_common.h"
#include "mpeg12.h"
#include "mpeg12data.h"
@ -2139,7 +2140,7 @@ static void mpeg_decode_gop(AVCodecContext *avctx,
int drop_frame_flag;
int time_code_hours, time_code_minutes;
int time_code_seconds, time_code_pictures;
int closed_gop, broken_link;
int broken_link;
init_get_bits(&s->gb, buf, buf_size*8);
@ -2151,7 +2152,7 @@ static void mpeg_decode_gop(AVCodecContext *avctx,
time_code_seconds = get_bits(&s->gb,6);
time_code_pictures = get_bits(&s->gb,6);
closed_gop = get_bits1(&s->gb);
s->closed_gop = get_bits1(&s->gb);
/*broken_link indicate that after editing the
reference frames of the first B-Frames after GOP I-Frame
are missing (open gop)*/
@ -2160,7 +2161,7 @@ static void mpeg_decode_gop(AVCodecContext *avctx,
if(s->avctx->debug & FF_DEBUG_PICT_INFO)
av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) closed_gop=%d broken_link=%d\n",
time_code_hours, time_code_minutes, time_code_seconds,
time_code_pictures, closed_gop, broken_link);
time_code_pictures, s->closed_gop, broken_link);
}
/**
* Finds the end of the current frame in the bitstream.
@ -2354,8 +2355,17 @@ static int decode_chunks(AVCodecContext *avctx,
int mb_y= start_code - SLICE_MIN_START_CODE;
if(s2->last_picture_ptr==NULL){
/* Skip B-frames if we do not have reference frames. */
if(s2->pict_type==FF_B_TYPE) break;
/* Skip B-frames if we do not have reference frames and gop is not closed */
if(s2->pict_type==FF_B_TYPE){
int i;
if(!s2->closed_gop)
break;
/* Allocate a dummy frame */
i= ff_find_unused_picture(s2, 0);
s2->last_picture_ptr= &s2->picture[i];
if(alloc_picture(s2, s2->last_picture_ptr, 0) < 0)
return -1;
}
}
if(s2->next_picture_ptr==NULL){
/* Skip P-frames if we do not have a reference frame or we have an invalid header. */

1
libavcodec/mpegvideo.c
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@ -2107,6 +2107,7 @@ void ff_mpeg_flush(AVCodecContext *avctx){
s->current_picture_ptr = s->last_picture_ptr = s->next_picture_ptr = NULL;
s->mb_x= s->mb_y= 0;
s->closed_gop= 0;
s->parse_context.state= -1;
s->parse_context.frame_start_found= 0;

1
libavcodec/mpegvideo.h
View File

@ -312,6 +312,7 @@ typedef struct MpegEncContext {
int *lambda_table;
int adaptive_quant; ///< use adaptive quantization
int dquant; ///< qscale difference to prev qscale
int closed_gop; ///< MPEG1/2 GOP is closed
int pict_type; ///< FF_I_TYPE, FF_P_TYPE, FF_B_TYPE, ...
int last_pict_type; //FIXME removes
int last_non_b_pict_type; ///< used for mpeg4 gmc b-frames & ratecontrol