[FFmpeg-user] ffmpeg audio volume for multiple audio tracks

[Frank Häfemeier]

Am Freitag, den 02.11.2012, 22:37 +0000 schrieb Sailaja Mahendrakar:
> I have the below query with the usage of audio volume for the multiple audio tracks:
> 
> I am using the ffmpeg audio volume for the multiple audio tracks and see that only the last audio track gets the volume applied and not to all the audio tracks.
> 
> I have the ffmpeg command line as:
> 
> ./ffmpeg -i ../TestInput.ts -f mpegts -map 0:1 -codec:a:0 libfaac  -b:a:0 128000 -ar:a:0 48000 -ac:a:0 2 -af:a:0 volume=2.511886 -map 0:2 -codec:a:1 libfaac -b:a:1 96000 -ar:a:1 48000 -ac:a:1 1 -af:a:1 volume=3.981072 ../Volume.ts
IMHO the parameter syntax in your call are not correct specified. The
combination of '-af' with ':a' is properly confusing ffmpeg.

I did not test it, but you can try
./ffmpeg -i ../TestInput.ts -f mpegts -map 0:1 -codec:a:0 libfaac
-b:a:0 128000 -ar:0 48000 -ac:0 2 -af:0 volume=2.511886 -map 0:2
-codec:a:1 libfaac -b:a:1 96000 -ar:1 48000 -ac:1 1 -af:1
volume=3.981072 ../Volume.ts

or 

./ffmpeg -i ../TestInput.ts -f mpegts -map 0:1 -codec:a:0 libfaac
-b:a:0 128000 -ar:0 48000 -ac:0 2 -filter:a:0 volume=2.511886 -map 0:2
-codec:a:1 libfaac -b:a:1 96000 -ar:1 48000 -ac:1 1 -filter:a:1
volume=3.981072 ../Volume.ts

> 
> I see only the last audio filter is getting initialized. Am I missing something in connecting the 2 filters?
> 
> -Sailaja
>