VirtualDubMod - No audio decompressor

[MrFriendly]

When trying to convert a video in VirtualDubMod, I get the following error:

VirtualDub Error
No audio decompressor could be found to decompress the source audio format.

Media Player Classic says the audio is WAVE_FORMAT_EXTENSIBLE. When I play the video, the sound is handled by ffdshow, so I'd say I do have the right decompressor?

I want to turn the audio stream into MP3, or maybe a similarly-compressed format that can be played back by ffdshow. It would be nice if it were still multichannel, but that's not a must-have.

[jagabo]

What codec does the audio use? Use MediaInfo or GSpot to find out. My guess is AC3. In which case you need AC3ACM.

[MrFriendly]

GSpot says

Codec: 0xfffe (Extensible wave format)
Info: 48000Hz 4608 kb/s tot (6 chnls)
Stat: Codec NOT Installed

[Placio74]

Use FFmpeg - re-mux A/V (it change audio codec id).

FFmpeg -i name_file.avi -vcodec copy -acodec copy new_name_file.avi

Or demux audio and use Audacity (when export, downmix to stereo).

[MrFriendly]

FFmpeg did change the codec ID, but then VirtualDubMod created a file with no audio even though I had the stream set to Full Processing, Compression - Lame MP3.

I had to demux it, which I was hoping to avoid, but oh well.

Thank you.

[Placio74]

FFmpeg did change the codec ID, but then VirtualDubMod created a file with no audio even though I had the stream set to Full Processing, Compression - Lame MP3.
...

With or without Conversion... (change channels to stereo)...?

If want multichannel audio, use AC3 codec.