How to increase the volume for an avi file
I have one or two .avi files for which the sound is simply too low. I like to play them in vlc, and enabling the graphic equalizer helps somewhat, but is there any other (easy and quick!) way of increasing the volume? Thanks!
You could use VirtualDub for this. This guide has a short and straight-forward explanation.
Brief:
-
- Start VirtualDub and load in your converted DivX file.
- From the "Video" menu, select "Direct Stream Copy".
- From the "Audio" menu, select "Full Processing Mode".
- From the "Audio" menu, select "Volume", check the "Adjust volume of audio channels" option, and you can use the slider to change the level of audio.
- Press the "Preview Output" button and listen to the audio - if it isn't loud enough, go back to the previous step and increase the amplification level.
- From the "Audio" menu, select "Compression" and select "MPEG Layer-3" and the same or lower bitrate/attributes (eg. 128 kBit/s, 48000 Hz, Stereo) you used earlier to make the DivX movie.
- From the "File" menu, select "Save AVI" to save the AVI to include the normalized audio. This shouldn't take too long as only the audio is re-encoded/compressed - the video will be left alone.
Very easy to do using ffmpeg:
For older versions of ffmpeg:
ffmpeg -i myvideo.avi -vcodec copy -acodec libmp3lame -ab 128k -vol 5000 myvideo_louder.avi
Adjust the "-vol" parameter until you're satisfied with the volume.
While you're looking for the appropriate "-vol" value, I suggest you add a "-t 30" to your commandline, so it'll only process the first 30s of video. It's much faster and should be enough for you to evaluate the results.
The new versions of ffmpeg support audio filters (-af), so you may alter volume using the volume filter which accepts volume gain specified in dB:
ffmpeg -i inputfile -vcodec copy -af "volume=-20dB" outputfile
VLC enables you to increase the volume up to 400% by holding down CTRL + UP ARROW.