AC3 in VirtualDub... is it possible??

[stormy1777]

I've tried all the virtualdub versions that I could find, but NONE of them could play the audio in an AVI file with AC3 sound.

A regular avi player plays the file just fine, but not virtualdub, I get and error message:
"The requested audio compression is not compatible with the input format. Check that the sampling rate and channel count of the input match those of the requested format."

both direct copy stream and full processing returns same error.

on following versions:
1.4.13 mpeg2+ac3
1.4.10
1.4.12
1.4.13
vdub-mod
vdub-asf


Can virtualdub play the ac3 stream?? as it plays mp3...

Thanks,

Stormy...

[ivan_alias]

There is another MPEG2 version of vdub that might.. Have a search around the forum, thread was only a couple of days ago.

[stormy1777]

I tried the Vdub MOD 1.4.13.1 and it too can not play an AVI with AC3 audio...

I suspect the problem is not with virtualdub, maybe I need a special codec installed to be able to play the AC3 sound.. This is strange since regular avi plays on this win2k box play avi's with ac3 sound with no problems..

any other ideas are welcome..

[Belgabor]

I suspect the problem is with the diffrent multimedia architectures present on windows, vfw and direct show. Vdub (and VDubMod) is entirely vfw, so to play back videos it needs the correct video vfw codec and the correct vfw/acm sound codec. All ac3 playback thingys are, afaik, direct show filters, so it won't work with vdub, only in directshow players like WiMP.

[stormy1777]

Thanks for the input.. I'm not familiar with the codes you refer to.. Just wondering if I'm doing something wrong or what.. seems to me that this would be a basic need and a nice feature to have in virtualdub... the ability to play ac3 sound...

If anyone knows how to make that work... please drop me a line or update this thread...

[pulco-citron]

I prefer the idea of an ACM wrapper for the AC3 DirectShow filter

[stormy1777]

Can VirtualDub on other platforms (Mac or Linux) play embeded ac3 track in an avi file?

these days looks like most people use ac3 sound instead of mp3 so virtualdub can't handle it on playback.. worse of course is that they use VBR mp3... just use CBR mp3...

[Asmodian]

I do not think there is a way to play AC3 in virtual dub (but why do you need sound in virtual dub?) You can, however, use an avs with the ac3source filter to feed audio to virtualdub(mod) but it will be uncompressed so a direct stream copy would not put the ac3 in the final avi/ogm.
I also like vbr audio more then cbr but I usually use vorbis in an ogm. I haven’t had problems with vbr mp3s in avis except when the avis were corrupted. Of course this is a matter of preference (compatibility vs quality, and I admit the quality difference is not too significant unless the target size is very small)

[stormy1777]

why ac3 sound in virtual dub??
the quickest simplest way to synchronize lips to sound is using virtualdub.. you can also use synchronizer 0.08b but it's sometimes buggy.. Actually I don't use/recommend using vbrmp3 in avi's, it's pretty bad on playback in most of the times the lips just shift in synch.. sometimes it's ok, sometimes it's off.. I use an 800Mhz cpu which is enough in my opinion..

I always convert the vbr mp3 to cbr mp3 and let me tell you one thing.. the size difference is VERY small, even when I remux to original AVI and save.. Of course when I do this vbr mp3 to cbr mp3 conversion the final AVI plays just fine without any synchronization problems, even on a lowerend PC let alone the 800Mhz..

all these people who use vbr mp3 for AVIs are wasting their time thinking they are saving alot of space and thus gaining better quality... go ahead try it on any movie you like and you will see for yourself... the difference in size is very very small... and you don't notice any change in quality.. I always convert 128vbr to 128cbr, (not 128vbr to 64k cbr in which case surely there's a noticeable quality drop..)

vbr is good for CD music collection..

[Asmodian]

So you could use an avs with the ac3source filter to test sync right? That is Slightly more annoying then just opening it in vdub but still easy.

Well, Ok I have never actually made my own vbr mp3 in an avi but I have watched a few and always assumed the slight audio desync was just from errors in the avi (some of the bad ones were, when I re-encoded the audio it was still out of sync). I use the ogg container so vbr hasn't been a problem. My music collection is in mixed vbr/cbr and the difference in quality is defiantly noticeable in the ~160Kbps range (oddly this is not true with classical music, last time I tried classical with vbr was worse than with cbr, but a lot smaller – I couldn't make it bigger!).

[stormy1777]

Thanks for the response..

I've used avs filters one or twice, but I read the manual about 8 months ago, almost completely... so I know the concept, etc... do you mind posting the syntax of such a filter since the ac3 track is part of the avi file...

create file called: test_ac3.avs inside put:
<cmdname>("c:\...file.avi")

I'm sure other will appreciate too...

thanks.