* WinXP and LameACM

[ratboy]

Anyone have luck using the Lame ACM codec in Windows XP? It was working for me in Win 98... *grumble grumble*

I'm using XP Pro, VirtualDub 1.4.7, Lame ACM version 0.90d and a Lamecom.dll version 0.9.0.1 (check properties of the DLL file).

Whenever I try to start an encode of audio (by choosing Save AVI, ofc), I get a message dialog saying that an error was encountered in initializing the codec.

Thanks,

[LigH]

I won't stop your research, but if everything fails: Encode the audio separately with LAME.EXE (which can be set up more precisely), then mux the final MP3 audio into the silent AVI with Nandub.

[ratboy]

I'm not a big fan of nandub... Here's why:

As a test, I encoded an audio track into a silent AVI using the Radium ACM in VirtualDub and encountered no problems, except for the fact that it doesn't sound as clean as a Lame-encoded track. ;) Total file size came out as expected/calculated given the size of the original AVI, the length of the audio, and the bitrate used for the encoding (128kbps). Final file size was 697 megs.

Then I used the command line Lame 3.89beta to encode an mp3 file of the audio track, which came out to the expected/calculated size, plus a few kilobytes (the mp3's header block).

I then mixed the Lame-encoded mp3 into the same silent AVI as before, using nandub. The total file size of the finished AVI came out to 702 megs... 5 megabytes bigger than what was expected/calculated (and what I got using VirtualDub and the Radium ACM).

Nandub produced 5 megs of what would seem to be useless bloat. Like magic. Makes me wonder what exactly is contained in those 5 megs of extra space. And makes me wonder about possible compatibility issues of nandub-processed AVIs.


Which is why I'm so interested in getting the Lame ACM working with VirtualDub in Windows XP. :)

I ask that anyone running Windows XP who's interested or has a moment to spare, just try installing the Lame ACM and using it in VirtualDub under Windows XP, or if you already have it working, to simply tell us that it's working for you. I'd be interested in whatever results you happen to get.

You can download the Lame ACM at: http://www.riphelp.com/downloads/lame_codec.html

Make sure you also grab LameCom from the same page.

Thanks!

[LigH]

Creating an AVI file with a VBR audio is "per spec" unsupported. Usually, AVI players expect the audio to have a constant bitrate - even more, a constant audio block size. Avery Lee (author of VirtualDub) once wrote quite in detail why would be, as a matter of fact, impossible for strictly spec-compliant applications to do that, and why he never will support it.

The MP3 version of VirtualDub (which was taken over by Nandub) now showed that it is possible in general to include a VBR MP3 audio track (mostly because MP3 is a streaming format, and the begin of a compression block may be on each byte). But extremely varying bitrates are very complicated to keep in sync. Nandub uses months of experience and tweaking. But it cannot be successful under any possible circumstance - and if it requires some overhead to keep A/V sync, then I guess that this was found to be necessary after a long time of testing.

If you don't need VBR audio or if you are afraid of negative side effects, just don't use it. But in the experience of many users, it is possible to achieve the same quality of CBR audio with a lower average bitrate, so with careful optimising you can save more size by the VBR technology than you are losing by the synchronisation overhead.