Green screen on video playback

[Mrfingers]

When trying to playback any type of video I get a green screen. The overlays are there and the time remaining shows that the file is playing. I'm using an older nvidia fx5200. It appears it supports opengl 2.0. Anyone have any ideas? Thanks in advance.

[slash]

Did you install the nvidia drivers using envy ?

are you able to play videos outside xbmc (using mplayer for example) ?

[Mrfingers]

Sorry I forgot to say what I've tried so far. Ubuntu 7.04 is installed. Yes I used Envy to install the Nvidia drivers. This did get rid of the flickering problem stated by others. The videos play fine in Movie Player but I get the following error when trying to open any video with mplayer: Error opening/initializing the selected video_out (-vo) device. Also, Linux is still pretty new to me.

[Mrfingers]

Just got the videos to play in Mplayer.

[slash]

did you compile xbmc with debug enabled ? (no --disable-debug).

The log in that case can help determine what is the source of the problem.

[HenrikDK]

Hi, This isnt a problem with drivers or any setup related issues, but can instead be traced back to this thread:
http://xbmc.org/forum/showthread.php?t=27366&page=2

In short: FX5200 is lying it doesnt support OpenGL 2.0 and mostly just offloads everything to the CPU. When using shadermodel 2.0 (which XBMC does) it just seems to render a green screen. D4rk fixed a simmilar problem like this one once but has since then coded a new rendering path that uses shaders to achive a number of fancy features (I think, I didnt have the time to get my head completely around the code). This can be observed by checking out svn rev 10133 which will compile and render fine (I think, cant remember if i made som modifications on my own, it may jump to 100% cpu usage).

Some notes of interest, nVidia recomends agains using the OpenGL version string to determine manufacture:
"OpenGL developers should not query and parse the GL_RENDERER string returned by glGetString to determine if a given GPU supports NV3x-based or NV4x-based functionality and performance. Instead, query the GL_EXTENSIONS string and look for the GL_NV_fragment_program2 and/or GL_NV_vertex_program3 substrings. These extensions imply the functional feature set of NV4x-based GPUs."

I have tried this and it works reliably on my machine, but the code has changed so much since then that I wouldnt know where to start on a fix for the current render path. Im also unsure if Team XBMC is interested in supporting Geforce FX and older cards, im sure it would be possible to write a video rendere based on OpenGl 1.5 specs, but not wether its worth the effort.

[Mrfingers]

Thanks for the info. I planned on getting a newer card at some point, this may speed this purchase up. I love xbmc on my xbox and am looking forward to using the linux port.