On Mar 16, 2005, at 5:05 PM, B. Bogart wrote:
After seeing tom's nice work online I realized I've been missing something in Gem. He is using alpha channels in video using Gem on winXP!!
...yeh, nice fish...
So after this success I went to video. I tried three cases (it seems aftereffects only exports videos with alpha channels compressed with TIFF, TARGA, and PNG. So for fun I exported alpha channel videos and tried to load them in Gem. Every single one loads fine according to the pix_film and pix_movie output, BUT only shows a green square in the render. Looking further I realized that my Gem 090 does not load any quicktime movies compressed with TARGA, TIFF or PNG.
...um, I think you're overlooking the obvious: green screens == yuv processing! So obviously there are no alpha channels (unless you use the gpu alpha blending, like [blend< )...remember, yuv is gem's "native" colorspace on osx, but not on the other platforms...in other words, you should be in alpha heaven with the above films if you send [colorspace RGBA< to [pix_film] or [pix_movie] before loading the film...
hth, james
ps: otoh, you could always add [pix_rgba] after [pix_film], but this will be sloooow...but not for too much longer, as I've been altivec'ing the color conversions :-)