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

[Baptiste Coudurier]

On 2/27/2009 3:54 AM, Michael Niedermayer wrote:
> On Thu, Feb 26, 2009 at 07:01:15PM -0800, Baptiste Coudurier wrote:
>> 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
> 
> where can i find this file?

incoming on samples.ffmpeg.org, is it missing ?

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