error compressing AC3 in virtualdubmod

[dudubitn]

Hello

im trying to make a compression to AC3 stream and leave the video in direct stream copy.
the original ac3 info: 48000Hz 448 kb/s tot , 6 chnls (3/2 .1)

when i choose a smaller compression to AC3 codec like: 192,224 or any .. in same frequency and channels i get the error:
Error initializing audio stream compression: The requested conversion is not possible.

i have the AC3 codec installed.

what im doing wrong?

tnx
david.

[midders]

I don't think that the AC3 "codec" shown in Virtualdub includes the compressor part of the the codec. I suggest that you:
1. save the audio stream to a file from the Vdub audio stream dialog
2. resample the audio using eac3to ("eac3to input.ac3 output.ac3 -384", add -down2 to downmix to stereo)
3. disable the original audio stream in Vdub
4. add the new audio stream in Vdub

Note that 384 is a minimum bitrate for AC3 6 channel audio and I would recommend using 448. If you downmix to 2 channels, then 192 should give reasonable results.

Slainte

midders