Application to lower audio gain of MPEG file?

[headless chicken]

I have a film on VCD (when extracted it becomes a MPEG file) that is deafeningly loud. I would like to reduce the audio gain on the file itself rather than simply lowering the volume manually. Is there a program for Mac that I can do this with?

[Case]

- Demux the VCD MPEG file (e.g. with bbDemux or MPEG Streamclip or).
- Open the MP2 (M1A) audio file in an audio editor. Lower the volume to your satisfaction (e.g. with Audacity or Amadeus).
- Use new audio and old video to Mux/Author as VCD (e.g. with Toast).

[headless chicken]

Thanks, Case. Is there any way I can remux to MPEG instead of creating a VCD with all it's various folders?

[tomlee59]

Lots of tools to do this. TMPGENC's mpeg tools will happily mux, either as VCD-compliant MPEG1, or as non standard (ie XVCD) MPEG1. If you later change your mind and wish to author a vcd, you can use VCDEasy to create a burnable image from the mpeg stream.

TMPGENC is free for mpeg1 operations, but it is a windows tool, so if you aren't running on a dual-os mac, then you'll need something else.

Ffmpegx will mux (and optionally author) elementary streams into MPEG. It's not free, but it's inexpensive. There is something about the muxing tool, however, that causes some players to stutter. TMPGENC's muxer does not have this problem.

You may also wish to look at the free muxer in MissingMpegTools, http://www.angelfire.com/mac/rnc/
I believe that it uses the same module that ffmpegx uses (or it traces back to a common source).

You can also use a Rube Goldberg two-step process: Create a VCD with Toast, and then use VCDGear to extract the mpeg file. VCD Gear is free (and a handy tool to have in any case), so this method involves no expense beyond time.

[headless chicken]

I can't seem to get the volume reduction to stick with Amadeus.

I tried encoding the MPEG to an AVI file with reduced volume settings with MPEG Streamclip but that didn't work either.

[Case]

I can't seem to get the volume reduction to stick with Amadeus.

Select all. Effects > Amplify > -3.00 dB. Test play. Undo and adjust value to something better. Repeat. Save as new file. Convert to .mp2.

[Alex_ander]

Try MP3DirectCut, it also works with mp2 (demuxed of course). There are chances to do it without re-encoding (at least it works for mp3).