PDA

View Full Version : video and buffers



floww
08-24-2003, 03:20 PM
has anyone an idea why screenshooting of videofiles is not possible?
are videso rendered to another buffer or how does this whole thing work?

thx, floww

Ostsol
08-24-2003, 07:40 PM
I'm not sure myself, but on a related note: FRAPS (http://www.fraps.com) works for taking screens of video. . .

AdrianD
08-25-2003, 01:42 AM
because they are displayed in a kind of overlay-window which is capable of displaying YUV directly on the screen without converting it to RGB .(this is a simple form of video "hw-acceleration").
this works a little bit like the HW-sprites on the good old C-64: you can see them on the screen, but they are actually not written into the framebuffer... just "overlayed" in video-hw.(i hope you understand this explaination)

floww
08-25-2003, 03:59 AM
ohhk thats somehow what i thought of. so is there a possibility to access this buffer that is used for the overlay window?

evanGLizr
08-25-2003, 04:40 AM
Originally posted by floww:
ohhk thats somehow what i thought of. so is there a possibility to access this buffer that is used for the overlay window?

Just disable hardware acceleration in Windows Media Player, it will stop using overlays for playing videos and you'll be able to take screenshots. I normally have to do that for the control panel gamma-setting to work when playing videos with my TNT2.

floww
08-25-2003, 04:50 AM
yiha!
thank you very much - i think u just saved us from writing our own mediaplayer =)!