I've been struggling for the past few hours with ffmpeg trying to create an video file that Gem will accept that contains an alpha channel from a series of tiff images. While searching for answers I found some messages that mention that new versions of Gem are using gmerlin as an a/v decoder which should open it to many more formats.

I'm currently on Ubuntu 9.10 with pd-extended version 0.42.5-extended-20091114. I probably installed it from a .deb package somewhere. Gem info: GEM: Graphics Environment for Multimedia GEM: ver: 0.93.CVS GEM: compiled: Nov 14 2009

Is gmerlin support included in that Gem version? Is it a simple matter of enabling it? Are the Gem .debs with it built in? Will I have to compile from source to get what I want?

Also, I'm fully open to any suggestions on how to make alpha-channel enabled videos that Gem can read. My ffmpeg line for jpeg sequences is: ffmpeg -f image2 -vcodec copy -i sample%04d.jpg sample.avi

If I try the same with alpha enabled .png files, Gem throws errors about MPNG: <AVI reader> : Stream 0 vids : MPNG (0x474e504d) 117 chunks (0.46KB) <reader> : Initialized video stream (chunk tblsz: 117, fmtsz: 40) <codec keeper> : Found 5 plugins (/usr/lib/avifile-0.7,A:22,V:32) <codec keeper> : CreateVideoDecoder(): Unknown codec 0x474e504d = "MPNG"

Thanks,

-martin