VDubMod + Layer II audio question

[phro]

My general rule of thumb, is that by the time I'm ready to post my question here, I sleep on it and try again in the morning and most times a clear head finds me the answer I need. But no luck this time :/

I'm using Vdubmod 1.5.4.1 with the VirtualDubMod_CVS_20030809 update and I'm confused about getting layer two audio encoded. If I load an mpeg 1 video that has layer 2 audio and set my compression I get a nice xvid with mp3 result. However if I take that same mpeg, parse out the audio with TMPGenc to an mp2, then try to add that as a stream to the encoded xvid file I get an error about no audio decompressor being found. If I try to refer to the mpeg file itself as the audio source I get either a crash or a warning about vbr mp3 files (which this is not).

Am I missing some obvious detail here? Or worse yet, is this in an FAQ that I missed?

[Belgabor]

VDubMod is a vfw (Video for Widnows) programm, as such it firstly cannot deal with mpeg/mp2 content at all. Luckily it includes a decoder for mpeg video and mp2/ac3 audio IF IT COMES FROM A MPEGI/II STREAM, you currently cannot add a mpeg file (video or (mp2) audio only) as an audio stream.

(P.S.: Its somehow it the FAQ, but not all implications are mentioned :p)

[phro]

Ahh okay I did read the VFW bit but I didn't make the connection. I'm still sorting out all the sprawling details of the windows multimedia subsystem. Thanks for the insight.

[fccHandler]

There is no ACM decompressor for mp2, but Windows Media Player can easily playback mp2 audio muxed in AVI files through the magic of DirectShow. Suiryc and I had a discussion about this once (specifically about how the AVI headers should be written), so I'm a little surprised that VirtualDubMod doesn't allow it.

[Suiryc]

VirtualDubMod should be able to open Mpeg Audio files (audio-only), including Layer II.

VirtualDubMod uses the internal Mpeg Audio decompressor (Priss) when asked (i.e. when you checked "Priss rocks" in the preferences) to decompress Mpeg Audio streams instead of relying on ACM.

Here I have no problems adding an external .mp2 (Mpeg1 LayrII) file and either keep it untouched (Direct Stream copy) or decompressing it (Full processing mode).

btw don't try to add an mpeg1 or mpeg2 (the real containers, i.e. that can have video) as external audio source. It isn't handled.