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

Baptiste Coudurier baptiste.coudurier
Fri Feb 27 04:01:15 CET 2009


Michael Niedermayer wrote:
> 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
> 

I believe something may be wrong with the last frame:

ffmpeg -y -i H264.mp4 test.mov


FFmpeg version SVN-r17630, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  configuration: --enable-gpl --enable-libmp3lame --enable-libfaac
--enable-libgsm --enable-nonfree --enable-libamr-nb --enable-libtheora
--enable-libx264 --enable-libspeex --enable-pthreads --enable-swscale
--enable-libopenjpeg
  libavutil     49.15. 0 / 49.15. 0
  libavcodec    52.20. 0 / 52.20. 0
  libavformat   52.30. 1 / 52.30. 1
  libavdevice   52. 1. 0 / 52. 1. 0
  libswscale     0. 7. 1 /  0. 7. 1
  built on Feb 26 2009 16:03:06, gcc: 4.3.3
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
Output #0, mov, to 'test.mov':
    Stream #0.0(eng): Video: mpeg4, yuv420p, 720x576, q=2-31, 200 kb/s,
25 tbn, 25 tbc
    Stream #0.1(eng): Audio: libfaac, 44100 Hz, stereo, s16, 64 kb/s
Stream mapping:
  Stream #0.1 -> #0.0
  Stream #0.0 -> #0.1
Press [q] to stop encoding
[mpeg4 @ 0x980e260]Error, Invalid timestamp=52,
last=52trate=1975.1kbits/s
Video encoding failed

This did not appear before.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
Key fingerprint                 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
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FFmpeg maintainer                                  http://www.ffmpeg.org




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