Graphics

I decided to make a small lightweight MOVIE to Xpression AVI converter to help with our workflow. Using the Xpression Codec and DirectShow I wrote the app to batch convert ProRes 4444 movies. It works great except for 1 major thing: the alpha channel is lost! I also used Mencoder, but got the same result.

Using Xpression Video Coder I am, of course, able to convert with alpha using the RGB 32 with alpha drop-down.

Does anyone have any insight? Experience? Documentation?

DirectShow Ignoring Audio:
File --> LAV Splitter Source --> LAV Video Decoder --> Xpression Codec --> AVI MUX --> Filewriter

Have you been able to confirm the alpha channel is being decoded out of the prores correctly? i.e. do you know if your issue is on the extraction of the alpha, or on the conversion of the alpha?

The XPression codec is expecting MEDIASUBTYPE_RGB32 when dealing with a frame that has alpha, so make sure that is what you are using in your directshow code.

#XPression

I have been looking at the output of the Xpression Codec up to this point. I'll look at the output of the LAV Decoder and see what it is doing. Thanks for the help!
#XPression

it seems it's LAV decoder that don't take alpha into account : see : https://github.com/Nevcairiel/LAVFilters/issues/90

Can you upload a sample of a ProRes 4444 video file with alpha ? I'm interested to investigate on this .

Thanks
#XPression

Try this dropbox link for a sample video:

https://www.dropbox.com/sh/rp1k8w6yhewz3we/AAD1xpPGV8cpbmppHdPrmpd3a?dl=0
#XPression