Add ticks_per_frame, this should hopefully fix the regressions caused

by the time_base change.

Originally committed as revision 17630 to svn://svn.ffmpeg.org/ffmpeg/trunk

ffmpeg.c

@@ -1261,7 +1261,7 @@ static int output_packet(AVInputStream *ist, int ist_index,
                         goto discard_packet;
                     }
                     if (ist->st->codec->time_base.num != 0) {
-                        int ticks= ist->st->parser ? ist->st->parser->repeat_pict+1 : 1;
+                        int ticks= ist->st->parser ? ist->st->parser->repeat_pict+1 : ist->st->codec->ticks_per_frame;
                         ist->next_pts += ((int64_t)AV_TIME_BASE *
                                           ist->st->codec->time_base.num * ticks) /
                             ist->st->codec->time_base.den;
@@ -1290,7 +1290,7 @@ static int output_packet(AVInputStream *ist, int ist_index,
                 break;
             case CODEC_TYPE_VIDEO:
                 if (ist->st->codec->time_base.num != 0) {
-                    int ticks= ist->st->parser ? ist->st->parser->repeat_pict+1 : 1;
+                    int ticks= ist->st->parser ? ist->st->parser->repeat_pict+1 : ist->st->codec->ticks_per_frame;
                     ist->next_pts += ((int64_t)AV_TIME_BASE *
                                       ist->st->codec->time_base.num * ticks) /
                         ist->st->codec->time_base.den;
@@ -1750,9 +1750,10 @@ static int av_encode(AVFormatContext **output_files,
             codec->bit_rate = icodec->bit_rate;
             codec->extradata= icodec->extradata;
             codec->extradata_size= icodec->extradata_size;
-            if(av_q2d(icodec->time_base) > av_q2d(ist->st->time_base) && av_q2d(ist->st->time_base) < 1.0/1000)
+            if(av_q2d(icodec->time_base)*icodec->ticks_per_frame > av_q2d(ist->st->time_base) && av_q2d(ist->st->time_base) < 1.0/1000){
                 codec->time_base = icodec->time_base;
-            else
+                codec->time_base.num *= icodec->ticks_per_frame;
+            }else
                 codec->time_base = ist->st->time_base;
             switch(codec->codec_type) {
             case CODEC_TYPE_AUDIO:

libavcodec/avcodec.h

@@ -30,7 +30,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVCODEC_VERSION_MAJOR 52
-#define LIBAVCODEC_VERSION_MINOR 19
+#define LIBAVCODEC_VERSION_MINOR 20
 #define LIBAVCODEC_VERSION_MICRO  0
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
@@ -2323,6 +2323,15 @@ typedef struct AVCodecContext {
      * - decoding: Set by libavcodec
      */
     struct AVHWAccel *hwaccel;
+
+    /**
+     * For some codecs, the time base is closer to the field rate than the frame rate.
+     * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
+     * if no telecine is used ...
+     *
+     * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
+     */
+    int ticks_per_frame;
 } AVCodecContext;
 
 /**

libavcodec/h264.c

@@ -2201,6 +2201,7 @@ static av_cold int decode_init(AVCodecContext *avctx){
     h->sei_dpb_output_delay = 0;
     h->sei_cpb_removal_delay = -1;
     h->sei_buffering_period_present = 0;
+    avctx->ticks_per_frame = 2;
     return 0;
 }
 

libavcodec/mpeg12.c

@@ -1269,7 +1269,7 @@ static int mpeg_decode_postinit(AVCodecContext *avctx){
             //MPEG-1 aspect
             avctx->sample_aspect_ratio= av_d2q(
                     1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
-
+            avctx->ticks_per_frame=1;
         }else{//MPEG-2
         //MPEG-2 fps
             av_reduce(
@@ -1278,6 +1278,7 @@ static int mpeg_decode_postinit(AVCodecContext *avctx){
                 ff_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num*2,
                 ff_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
                 1<<30);
+            avctx->ticks_per_frame=2;
         //MPEG-2 aspect
             if(s->aspect_ratio_info > 1){
                 //we ignore the spec here as reality does not match the spec, see for example

libavcodec/options.c

@@ -393,6 +393,7 @@ static const AVOption options[]={
 {"request_channel_layout", NULL, OFFSET(request_channel_layout), FF_OPT_TYPE_INT64, DEFAULT, 0, INT64_MAX, A|D, "request_channel_layout"},
 {"rc_max_vbv_use", NULL, OFFSET(rc_max_available_vbv_use), FF_OPT_TYPE_FLOAT, 1.0/3, 0.0, FLT_MAX, V|E},
 {"rc_min_vbv_use", NULL, OFFSET(rc_min_vbv_overflow_use),  FF_OPT_TYPE_FLOAT, 3,     0.0, FLT_MAX, V|E},
+{"ticks_per_frame", NULL, OFFSET(ticks_per_frame), FF_OPT_TYPE_INT, 1, 1, INT_MAX, A|V|E|D},
 {NULL},
 };
 

libavformat/utils.c

@@ -2201,9 +2201,9 @@ int av_find_stream_info(AVFormatContext *ic)
 
             if (!st->r_frame_rate.num){
                 if(    st->codec->time_base.den * (int64_t)st->time_base.num
-                    <= st->codec->time_base.num * (int64_t)st->time_base.den){
+                    <= st->codec->time_base.num * st->codec->ticks_per_frame * (int64_t)st->time_base.den){
                     st->r_frame_rate.num = st->codec->time_base.den;
-                    st->r_frame_rate.den = st->codec->time_base.num;
+                    st->r_frame_rate.den = st->codec->time_base.num * st->codec->ticks_per_frame;
                 }else{
                     st->r_frame_rate.num = st->time_base.den;
                     st->r_frame_rate.den = st->time_base.num;
@@ -2537,7 +2537,7 @@ static int compute_pkt_fields2(AVStream *st, AVPacket *pkt){
     if (pkt->duration == 0) {
         compute_frame_duration(&num, &den, st, NULL, pkt);
         if (den && num) {
-            pkt->duration = av_rescale(1, num * (int64_t)st->time_base.den, den * (int64_t)st->time_base.num);
+            pkt->duration = av_rescale(1, num * (int64_t)st->time_base.den * st->codec->ticks_per_frame, den * (int64_t)st->time_base.num);
         }
     }