johann scholz wrote:

hi,

got a prob again...i'm trying to overlay a live camera feed with pix_video with footage from a pix_film object. the overlay is working fine with pix_mix..put all i got is 2 semi transparent videos, now my question:

if you only want to overlay to pixes (no matter whether it is films or still images)without alpha-masking, i suggest to just use [color] and change the transparency for the entire Geo rather than using pix_mix. it should be way more efficient.

i'd like to overlay them using an alpha channel/color for the footage in the pix_film patch...is this possible or does pd can only handle still pics with alpha????

any pix can have alpha; there is no difference between still images, pre-recorded movies and live videos. (well, of course depending on the colorspace of the pix; any pix can be either grayscale (luminance only; now alpha), YUV (color, but no alpha) and RGBA (color with alpha); so obviously only rgba-pixes can manipulate their alpha-channel on a pixel basis; luckily you can convert between all colorspaces with objects like [pix_rgba], [pix_yuv] and [pix_grey]; the natural colorspace used to be RGBA; on OSX (for moving images) it is YUV)

so, this means, that you can use alpha blending with pixes for all footage.

the only remaining thing to consider is, that Gem probably does not read alpha-channels from stored movies (video-cameras usually don't have any alpha-channel); there has been a featurerequest for reading alpha-channels in movie-files for ages and i already started to fix it, but was unable to find/generate a movie containing an alpha-channel so ii stopped....

mfdgasdr IOhannes