Microsoft MP4 source?

[cablemonkey]

This is probably an obvious question, but is DirectShowSource()
the only way to open a Microsoft MP4 AVI (mp42 fourcc code) in
AviSynth? Is it possible to use AVISource somehow (with the right
codec loaded)? searching on mp42 and mpeg4 in the AVIsynth forum
didn't seem to turn up any obvious answers.

I know there is Mpeg2dec and such, will these work with MS MP4?
I've not d/l'ed and installed this yet as im not looking at ripping
DVDs but more backing up my LD collection and burning some MP4/DivX
stuff to CVD. I'm new to this (been experimenting and lurking for
about a month now), and this is my first post, so please forgive me
if this is a stupid question :). Thanks in advance!

- jeremy

[Xenoproctologist]

MP42 AVIs should open just fine with AVISource(). It's ASF and WMV files which need DirectShowSource().

[Richard Berg]

Even MP43 AVIs should be read correctly by AviFile (it's compression that was tricky enough to inspire the creation of "Divx").

[ErMaC]

You probably only have DirectShow filters for playback of the MP42 files, and no VFW codec for encoding and decoding. Like VirtualDub, AVISynth needs a VFW codec to be present to open the file.
Does VirtualDub open your MP42 file correctly? If not, then your problem is you need to go find MPEG4C32.dll and put FOURCC pointers in your registry to it.

[cablemonkey]

@all

Thanks for the assistance! I managed to find the actual Microsoft codec (no longer offered by MS apparently) and it works like a charm. I guess M$ only supports Mpeg4v3 (not v1 or 2) in their current codec offerings. No more remuxing audio or "out of sync" errors from DirectShowSource :D . Thanks again all!