How to increase audio volume of AVI WITHOUT re-encoding?

[pstein]

Occasionally I got AVI videos with a rather low audio volume. The audio is stored in a MP3 track.

Ok, I could re-ecnode the whole AVI vieo with a (much) higher volumen but I want to avoid re-encoding.

Is there a way to just change a header field or volume level indicator but leave the audio track (almost) untouched?

Does this work in Avidemux?

Peter

[zakk]

mp3gain

[styrol]

Is there a way to just change a header field or volume level indicator but leave the audio track (almost) untouched?

Use FFmpeg and the following parameter to gain e.g. 10dB:

Code Select Expand

ffmpeg -i inputfile.avi -c copy -af "volume=10dB" -y outputfile.avi

[pstein]

Use FFmpeg and the following parameter to gain e.g. 10dB:

Code Select Expand

ffmpeg -i inputfile.avi -c copy -af "volume=10dB" -y outputfile.avi

Interesting. Thank you. However I tried it out with big values but found NO difference in results.
I tried e.g.

ffmpeg -i inputfile.avi -c copy -af "volume=30dB" -y outputfile.avi
and
ffmpeg -i inputfile.avi -c copy -af "volume=3" -y outputfile.avi

On tutorial site I found a slightliy different syntax:

ffmpeg -i inputfile.avi -vcodec copy -af "volume=10dB" -y outputfile.avi

Whats the difference?

Is "-c copy" equal to "-vcodec copy  -acodec copy"?

[styrol]

Is "-c copy" equal to "-vcodec copy  -acodec copy"?

Yep, "-c copy" means "copy codecs (both audio and video)"