dan at f3c.com
Mon Nov 28 02:00:03 CET 2005
video/x-raw-rgb, bpp=32, depth=24 will be RGBx32. to me, it is implicit that the unused byte per pixel is the alpha channel, and i think some plugins in gstreamer also think so. OTOH, videotestsrc, eg, sets it to 0, effectively making the test image invisible for any plugin that regards the alpha channel. i dont know if x-raw-rgba would be a good idea, maybe yes, maybe with an additional alpha_mask value?
but anyway, i know no (open) codec that would retain the alpha channel in compressed form. that's kinda sad, and i'd love to be educated about such a thing. all i know is that on2's vp6 (which is used in flash player 8, ugh) can have full alpha channel video, but it's everything but open.
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