AVI compression with alpha channel..

Hello there.

I have a set of video files whihc are uncompressed AVI’s in the format ARGB 32bit. Does anybody know if it is possible to compress these files anyway, whilst retaining the alpha channel? I tried using HuffyUV and VirtualDub and the alpha channel is lost.

I would be willing to convert the videos to a lower bit rate if that would help me compress them, but I would have to keep the alpha channel...

Is it actaully possible to compress an AVI with an alpha channel at all?

Thanks for any help.

Mark Coleman

When you do your conversion in VirtualDub the default color depth is set to 24 bit for output (I don’t know if it’s also the default for input). See if setting it to 32 bits solves your problem. Click on video, color depth, then choose 32 bit for both input (if it has it) and output. Oddly I have some 32-bit videos, but when I open them in VirtualDub I don’t have a 32-bit option for input. Only for output.

If it doesn’t help, you might want to drop avery lee (maker of virtualdub) an e-mail on that. If anyone has the kind of expertise needed to answer your question, he would.

I had already tried that but no luck!

Thanks for the suggestion, I will email Avery and see what he thinks.

Thanks again.

Mark Coleman

Found this GNU one, it works really well.

http://neuron2.net/www.math.berkeley.edu/benrg/huffyuv.html

Rgds, Paul