[FFmpeg-user] mix 2 mp4 audio only

[Madovsky]

----- Original Message ----- 
From: "Carl Eugen Hoyos" <cehoyos at ag.or.at>
To: <ffmpeg-user at ffmpeg.org>
Sent: Monday, February 04, 2013 9:37 AM
Subject: Re: [FFmpeg-user] mix 2 mp4 audio only


> Madovsky <infos <at> madovsky.org> writes:
>
>> ffmpeg -i "stream2.mp4" -i "stream1.mp4" -vn
>> -map 0:1 -map 1:1 -y -acodec copy output.mp4
>
> So you have two input stereo files and one output
> file that contains two stereo streams.
>
> Am I correct that both ffplay ("a") and MPlayer ("#")
> allow to switch between the two stereo streams in
> the output file?
>
> (And I would assume QT allows you to choose between
> the two stereo audio streams or does that not work?)
>
> It appears that the command does not do what you
> want - please explain what it is that you want.
>
> Carl Eugen

my whole goal is to merge 2 rtmp network inputs
to one output video/mono audio file without decode encode anything

so I tried
ffmpeg -i "rtmp://server/app/live1 live=1" -i "rtmp://server/app/live2 
live=1" -i -filter_complex "[0:0]pad=682:450:21:105[left]; 
[left][1:0]overlay=341:105; [0:1][1:1]amerge" -shortest -y output.flv

but as I use filter_complex I can't use -acodec copy to avoid decode 
encoding audio/video
and also amerge above create 2.4 s latency between the first and second 
stream (if I remove amerge it's ok).
so I try to figure out how toconcat audio first without encoding and after 
use a pipe to map it with the live streams with video only

another idea ?

Thanks

Franck