[FFmpeg-user] audio and video sync problem

[Patrick Fischer]

Hello Carl,

did you save the stream as raw mpegts to disk?
a player (like VLC) can handle mpegts files much better then an mp4 
file. due to PTS/DTS values.

t think the problem is that the ffmpeg cli failed handle missing 
audio/video frames.

in summary:
mpegts file -> play with VLC -> sync
mpegts file -> create mp4 with ffmpeg -> play mp4 file with VLC -> async

Is that your problem?
If so, i have the same problem.

I have made some test to duplicate some frames to fill the missing 
frames and send to decoder.
It seems to work but sometimes i have detected that 1-100 frames are 
missing.

best regards
Patrick



Am 07.07.2014 07:57, schrieb Murat Maman:
> Hi Carl,
>
> Yesterday out of syn problem again occurred and i saved file where to my
> disk, i saw that there is no out of sync problem. What does it mean, what
> is the source of problem, am i have internet problem, why frame drop during
> the broadcasting, is it rtmp problem.
>
> regards,
>
> Murat
>
>
> On Fri, Jul 4, 2014 at 3:32 PM, Eugene Gekhter <egekhter at pixcel.com> wrote:
>
>> Carl,
>>
>> Can you explain why sudo ffmpeg is a bad idea?
>>
>> Thx.
>>
>> Sent from my iPhone
>>
>>> On Jul 4, 2014, at 4:07 AM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
>>>
>>>> On Thursday 03 July 2014 10:10:39 am Murat Maman wrote:
>>>>
>>>> sudo ffmpeg -y -f mpegts -i 'udp://@
>>> Unrelated: I believe that everybody on this list agrees
>>> that "sudo ffmpeg" is a very bad idea.
>>>
>>>> 00.00.00.00:1111?fifo_size=1000000&overrun_nonfatal=1 \
>>>> -maxrate 2M -bufsize 2M \
>>>> -af volume=1.1 \
>>>> -strict experimental \
>>>> -c:a libfaac -ar 22050 -ac 2 -b:a 64k \
>>>> -vsync 1 -c:v libx264 -r 25 -vf yadif,scale=640:480 -aspect:v 16:9 -b:v
>>>> 900k \
>>>> -preset superfast -tune zerolatency -threads 8 -crf 25 \
>>>> -map 0:0 -map 0:1 \
>>>> -f flv 'rtmp://testt:testt@00.00.00.00:0000/live/1111'
>>> (Complete, uncut console output missing.)
>>>
>>> Why are you using -vsync 1?
>>> Did you try -async 1?
>>>
>>> Am I correct that the problem is reproducible with file output
>>> instead of network output?
>>>
>>> Is the problem reproducible if you save the udp stream to a file
>>> (including the reception problems) and transcode the file with
>>> FFmpeg?
>>>
>>> Carl Eugen
>>> _______________________________________________
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>>> ffmpeg-user at ffmpeg.org
>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
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-- 
*Patrick Fischer*
Software Developer
VITEC

T. +49-(0)4307-8358-0
E. patrick.fischer at vitec.com <mailto:patrick.fischer at vitec.com>
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