Compress PCM audio in existing avi/mpg?

Hi. I have a bunch of movies that were saved with VCD and SVCD in mind. They have PCM audio and are about twice as big as the same movie with compressed audio.

I don’t care about VCD or SVCD compatibility. Is there a convenient way to compress the audio portion of the file? I’ve tried TMPGEnc and various tools that require me to reprocess the video as well, burning much CPU time and creating a loss in video quality. Also, I have to match the resolutions/framerates of the files, do all kinds of pushups, and handle each file seperately.

Any suggestions are appreciated!

Hi. I have a bunch of movies that were saved with VCD and SVCD in mind

The way you express yourself is it possible that these are still in avi format but with vcd/svcd type resolutions?

If yes the virtualdub will let you open the avi, compress the audio only and save the new avi without changing the video compression.

What you need to do under the video menu is select Direct stream copy instead of full processing mode.


If they are vcd or svcd then you need to demux the 2 streams, then compress the audio and then remux the video and new audio. This will not change the video and you do not need to recompress the video .

Since you have tmpgenc you just need to change what you were doing a bit.

I use tmpgenc v2.5.13… in the file menu, select Mpeg Tools Simple demultiplex and choose the type of file you have and the inputs. This will create 2 files containing the video and the audio. Once you have the outputs, use the audio only and re-encode it with any audio processing program.

List of Audio encoders

List of audio editors

After you are done just choose Simple Multiplex and the new audio and the original video split in demultiplex step.

You will also note that tmpgenc has a simple cut and merge/join option for alike clips before or after you have corrected the audio.

Thanks for the help here!

As El Guapo would say, I have a plethora of avi and mpg files (full length movies) that are at vcd and svcd frame rates and resolutions but haven’t been burned to CD. I have no intention of burning them to CD and don’t care if my DVD player can read them because my computer is hooked to our TV. So I just want to reduce the file size on my hard disk without losing video frame rate or resolution.