[FFmpeg-devel] [RFC][PATCH] ticks_per_frame / timebase

[Michael Niedermayer]

On Thu, Feb 26, 2009 at 03:30:22PM -0800, Baptiste Coudurier wrote:
> Baptiste Coudurier wrote:
> > Michael Niedermayer wrote:
> >> On Thu, Feb 26, 2009 at 02:46:36PM -0800, Baptiste Coudurier wrote:
> >>> Michael Niedermayer wrote:
> >>>> On Thu, Feb 26, 2009 at 02:18:41PM -0800, Baptiste Coudurier wrote:
> >>>>> Hi guys,
> >>>>>
> >>>>> Michael Niedermayer wrote:
> >>>>>> On Thu, Feb 26, 2009 at 10:05:28PM +0100, Ivan Schreter wrote:
> >>>>>>> Michael Niedermayer wrote:
> >>>>>>>> [...]
> >>>>>>>> also i think the reset of the sei vars should be in
> >>>>>>>> decode_nal_units()
> >>>>>>>> ...
> >>>>>>>>     if(!(s->flags2 & CODEC_FLAG2_CHUNKS)){
> >>>>>>>>         h->current_slice = 0;
> >>>>>>>>         if (!s->first_field)
> >>>>>>>>             s->current_picture_ptr= NULL;
> >>>>>>>>         <-----------------------here
> >>>>>>>>     }
> >>>>>>>>
> >>>>>>>> the reason is that just reseting at the end of a pic is "risky" if that 
> >>>>>>>> end
> >>>>>>>> isnt reached
> >>>>>>>>
> >>>>>>>>   
> >>>>>>> Like in the attached patch?
> >>>>>> yes, patch ok
> >>>>>>
> >>>>>> btw, if you want a svn write account, (and agree to the devel/svn policy
> >>>>>> and split patches a little more, this one should be
> >>>>>> factorizing the code and then seperately adding the new call)
> >>>>>> then send diego b. some username & password gpg encrypted
> >>>>>>
> >>>>> Applied both patches:
> >>>>>
> >>>>> ffmpeg -i h264.mp4 -vcodec copy test.mov
> >>>>>
> >>>>> Seems stream 1 codec frame rate differs from container frame rate: 12.50
> >>>>> (25/2) -> 25.00 (25/1)
> >>>>> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'H264.mp4':
> >>>>>   Duration: 00:00:02.18, start: 0.000000, bitrate: 2245 kb/s
> >>>>>     Stream #0.0(eng): Audio: aac, 44100 Hz, stereo, s16
> >>>>>     Stream #0.1(eng): Video: h264, yuv420p, 720x576, 25 tbr, 25 tbn, 25 tbc
> >>>>> File 'test.mov' already exists. Overwrite ? [y/N] y
> >>>>> Output #0, mov, to 'test.mov':
> >>>>>     Stream #0.0(eng): Video: libx264, yuv420p, 720x576, q=2-31, 90k tbn,
> >>>>> 25 tbc
> >>>>>     Stream #0.1(eng): Audio: libfaac, 44100 Hz, stereo, s16, 64 kb/s
> >>>>>
> >>>>> Is this supposed to report 12.50 ?
> >>>> no, ive droped the hunk that messed with the printing in ffmpeg.c locally
> >>>> is the nonsense it prints the only problem? or are there other problems?
> >>>>
> >>> It seems ok, however it does not do the same for MPEG-2 when I stream copy:
> >>>
> >>> Seems stream 0 codec frame rate differs from container frame rate: 25.00
> >>> (50/2) -> 25.00 (25/1)
> >>> Input #0, mpeg, from 'PubMatrix.mpg':
> >>>   Duration: 00:00:24.26, start: 0.220000, bitrate: 11888 kb/s
> >>>     Stream #0.0[0x1e0]: Video: mpeg2video, yuv422p, 720x608 [PAR 1:1 DAR
> >>> 45:38], 11386 kb/s, 25 tbr, 90k tbn, 50 tbc
> >>>     Stream #0.1[0x1c0]: Audio: mp2, 48000 Hz, stereo, s16, 384 kb/s
> >>> File 'test.mov' already exists. Overwrite ? [y/N] y
> >>> Output #0, mov, to 'test.mov':
> >>>     Stream #0.0: Video: mpeg2video, yuv422p, 720x608 [PAR 1:1 DAR
> >>> 45:38], q=2-31, 11386 kb/s, 90k tbn, 50 tbc
> >>>     Stream #0.1: Audio: libfaac, 48000 Hz, stereo, s16, 64 kb/s
> >>> Stream mapping:
> >>>   Stream #0.0 -> #0.0
> >>>   Stream #0.1 -> #0.1
> >>>
> >>> In this case pkt->duration is 2 and timebase.den is 50, with H.264
> >>> pkt->duration is 1 and timebase.den is 25, is this normal ? Can't we get
> >>> 1 and 1/25 with MPEG-2 too ?
> >> yes, the following hunk does that:
> >> @@ -1750,9 +1751,10 @@
> >>              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:
> >>
> >>
> >> more issues left before i can commit it?
> > 
> > Nice.
> > 
> > Please gimme 5 mins, I'm testing TS with H.264 and MPEG-2.
> > 
> 
> I don't see any regression for now.

good, ive applied it, if you find more regressions please tell me

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

No snowflake in an avalanche ever feels responsible. -- Voltaire
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