[FFmpeg-devel] [PATCH] simplify ipmovie.c pts calculation

Michael Niedermayer michaelni
Fri Feb 27 13:45:39 CET 2009


On Fri, Feb 27, 2009 at 08:59:14AM +0100, Reimar D?ffinger wrote:
> On Fri, Feb 27, 2009 at 12:28:03AM +0100, Michael Niedermayer wrote:
> > > diff --git a/libavformat/utils.c b/libavformat/utils.c
> > > index 073e6da..9960fcd 100644
> > > --- a/libavformat/utils.c
> > > +++ b/libavformat/utils.c
> > > @@ -2006,6 +2006,7 @@ int av_find_stream_info(AVFormatContext *ic)
> > >      AVStream *st;
> > >      AVPacket pkt1, *pkt;
> > >      int64_t last_dts[MAX_STREAMS];
> > > +    int64_t duration_gcd[MAX_STREAMS]={0};
> > >      int duration_count[MAX_STREAMS]={0};
> > >      double (*duration_error)[MAX_STD_TIMEBASES];
> > >      int64_t old_offset = url_ftell(ic->pb);
> > > @@ -2127,6 +2128,7 @@ int av_find_stream_info(AVFormatContext *ic)
> > >                      double error= dur - ticks*1001*12/(double)framerate;
> > >                      duration_error[index][i] += error*error;
> > >                  }
> > > +                duration_gcd[index] = av_gcd(duration_gcd[index], duration);
> > >                  duration_count[index]++;
> > >              }
> > >              if(last == AV_NOPTS_VALUE || duration_count[index]<=1)
> > > @@ -2181,6 +2183,8 @@ int av_find_stream_info(AVFormatContext *ic)
> > >              if(st->codec->codec_id == CODEC_ID_RAWVIDEO && !st->codec->codec_tag && !st->codec->bits_per_coded_sample)
> > >                  st->codec->codec_tag= avcodec_pix_fmt_to_codec_tag(st->codec->pix_fmt);
> > >  
> > > +            if (duration_count[i] > 5 && duration_gcd[i] > 1)
> > > +                av_reduce(&st->r_frame_rate.num, &st->r_frame_rate.den, st->time_base.den, st->time_base.num * duration_gcd[i], INT_MAX);
> > 
> > maybe this should be under tb_unreliable() and the number should be higher
> > than 5 (patch ok with  <- these)
> 
> Applied with these fixed and some additional comments.
> 
> > also if you ignore the first 1-2 durations then this might fix the fps of
> > h264_acc_in_flv.flv i think
> 
> I set the code to ignore the first 4, for that file it gives a frame
> rate of 22.2222... which seems not really right either, though I don't
> actually know what the right value is.

> It does not make a difference though, since the get_std_framerate-based
> code after it overwrites it...

fix that prevents it from increasing the frame rate is welcome ...

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

When you are offended at any man's fault, turn to yourself and study your
own failings. Then you will forget your anger. -- Epictetus
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