[MPlayer-users] cat files

[Philippe De Neve]

I've tried a setup with 2 mplayers: one writinging yuv4mpeg to a pipe  
and one writing the raw audio (pcm)  to a pipe. And then ffmpeg takes  
both pipes as input. This works but sync is lost and is therefore not  
usefull.

I've also tried (let me mention that I always check the non pipe  
version, with files, first to make sure the syntax and parameters are  
correct):

(I've disabled audio here)
mencoder -noidx -nosound -ovc lavc -lavcopts  
vcodec=mpeg2video:vbitrate=10000 -format mpeg2  -o -   
berlitz_junior_raw.avi volver_raw.avi |  ffmpeg  -i -  -vcodec mpeg4 - 
an out.mp4

RESULT:
FFmpeg version CVS, Copyright (c) 2000-2004 Fabrice Bellard
   configuration:  --enable-mp3lame --enable-faad --enable-gpl -- 
enable-faac --enable-amr_nb --enable-amr_nb-fixed --enable-amr_wb -- 
enable-amr_if2 --enable-pthreads --enable-x264
   libavutil version: 49.0.0
   libavcodec version: 51.1.0
   libavformat version: 50.0.0
   built on Oct 12 2006 19:16:08, gcc: 3.3.5 (Debian 1:3.3.5-13)
[mpeg2video @ 0x86194a0]mpeg1_encode_end called, with s: 0x8716b40, s- 
 >pb: 0x8716b94
pipe:: Unknown format

Which I can understand: ffmpeg does not now what it will get as  
input. So I tried informing ffmpeg of the format (-f):



mencoder -nosound -ovc lavc -lavcopts  
vcodec=mpeg2video:vbitrate=10000 -format mpeg2  -o -   
berlitz_junior_raw.avi volver_raw.avi |  ffmpeg  -f mpeg -i -  - 
vcodec mpeg4 -an out.mp4

RESULT:
FFmpeg version CVS, Copyright (c) 2000-2004 Fabrice Bellard
   configuration:  --enable-mp3lame --enable-faad --enable-gpl -- 
enable-faac --enable-amr_nb --enable-amr_nb-fixed --enable-amr_wb -- 
enable-amr_if2 --enable-pthreads --enable-x264
   libavutil version: 49.0.0
   libavcodec version: 51.1.0
   libavformat version: 50.0.0
   built on Oct 12 2006 19:16:08, gcc: 3.3.5 (Debian 1:3.3.5-13)
Input #0, mpeg, from 'pipe:':
   Duration: N/A, bitrate: N/A
No audio or video streams available
[mpeg2video @ 0x86194a0]mpeg1_encode_end called, with s: 0x871b470, s- 
 >pb: 0x871b4c4



the search continues ....





On 25 Apr 2007, at 21:40, Alexander Roalter wrote:

> Saurabh Singhvi wrote:
>> On 4/25/07, Michel Bardiaux <mbardiaux at mediaxim.be> wrote:
>>> Philippe De Neve wrote:
>>>> Yes, I saw that the sampling rates were different and reencoded the
>>>> source files. Now there are the same (as far as I can check with
>>>> ffmpeg).
>>>> I tried the configuration without pipes and the file playedback
>>>> succesfull with correct audio. With pipes I cannot realize this.
>>>>
>>> You mean something like:
>>>
>>> mencoder <options> -o - 1.avi 2.avi | ffmpeg -i - ...
>>>
>>> If mencoder uses avi format in this case, it cant work: an avi  
>>> needs to
>>> be complete before it can be opened for read. You need to re-encode
>>> using something that can be streamed through the pipe, eg DVD- 
>>> equivalent
>>> (high-bitrate MPEG2 video, say MP3 audio, in an MPG container).
>>>
>>
>>
>> why not something like
>>
>> mkfifo stream.yuv|mplayer -vo yuv4mpeg filename1.avi filename2.avi
>> ffmpeg stream.yuv .....
>> _______________________________________________
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>> MPlayer-users at mplayerhq.hu
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>
> What about audio? -vo is only video out... is there a possibility to
> dump the audio to a fifo too and use it again in ffmpeg? dumping could
> be done via -ao pcm:file=pcmstream, where pcmstream was also made via
> mkfifo... How this is usable in ffmpeg I don't know. And maintaining
> sync is still something to achieve..
>
> -- 
> cheers,
> Alex
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