Question

14

Normalizing Video Volume using avconv

rated 0 times [ 14] [ 0] / answers: 1 / hits: 11504 / 2 Years ago, thu, april 28, 2022, 7:31:10

I have a collection of videos, in the .mkv and .mp4 (AAC+H.264) formats. The .mkv files are ok, but all the .mp4 files have such a low volume that I can hardly hear it on my phone, even when volume is maxed.

I convert them using avconv so they're smaller for my phone. It works fine, but I have not yet found out how I can normalize the volume on all the .mp4 files so they match the .mkv files.

Just raising the volume alone would be a great achievement.

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errettas

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4 Years ago

answered 2 Years ago imberst · Accepted Answer

I've just been searching for a similar problem and used this solution from SuperUser

Basically, just extract the audio from the file as wav, run normalize-audio on it and then re-encode it as aac and remux.

I just wrote this quick script to do it:

VIDEO_FILE=$1

VIDEO_FILE_FIXED=${VIDEO_FILE%.*}-fixed.${VIDEO_FILE##*.}

avconv -i $VIDEO_FILE -c:a pcm_s16le -vn audio.wav

normalize-audio audio.wav

avconv -i $VIDEO_FILE -i audio.wav -map 0:0 -map 1:0 -c:v copy -c:a libvo_aacenc 

   $VIDEO_FILE_FIXED

Put it in a file like normalize.sh, then run bash normalize.sh file_to_convert.mp4. You'll get a file out file_to_convert-fixed.mp4.

You might want to tweak the normalize-audio command to just raise the volume by some dB with the -g siwtch, or use another command entirely. I saw aacgain and wavegain mentioned elsewhere. normalize-audio is in the package normalize-audio, funnily enough.

Hope this helps you.