Question / Help Problems with Mesa and Sandybridge

[djfun]

Hello,

having heard some problems with mesa were fixed in the new version, I thought I gave it a try running obs with an intel hd 3000 graphics chip under Ubuntu 14.04.

OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Sandybridge Mobile
OpenGL core profile version string: 3.1 (Core Profile) Mesa 10.2.2
OpenGL core profile shading language version string: 1.40
OpenGL core profile context flags: (none)
OpenGL core profile extensions:
OpenGL version string: 3.0 Mesa 10.2.2
OpenGL shading language version string: 1.30
OpenGL context flags: (none)
OpenGL extensions:

I downloaded the newest code from the Github git repository.
When just running the compiled version with ./obs the program gives an error after starting:

error: Failed to create OpenGL context.
error: device_create (GL) failed
error: Failed to initialize video:  Unspecified error

I found out that I could avoid this error by using MESA_GL_VERSION_OVERRIDE=3.2 ./obs but with that I ran into a bunch of those messages

error: device_vertexshader_create (GL) failed
error: device_pixelshader_create (GL) failed

With debugging enabled I saw then that the interface blocks, that the shaderparser writes, are not compatible with the shading language version 1.4 which my graphics chip provides, but that they would need 1.5

With commenting out the line that writes those interface blocks I could get obs to run and it is possible to create scenes, sources and record. I have not tested streaming yet, though.

While the program runs now I get the following error message all the time:

error: glClear failed, glGetError returned 0x502
error: device_clear (GL) failed

As I have not a lot of opengl knowledge my questions are now if the interface blocks, I commented out, are necessary (because the program runs without them) and if that error message I get now is related to that or if that is another problem with my graphics chip or if that is a bug.

Even if the program does not run perfectly here, I want to thank you for making this great program and for making it now available on linux!

 

[Lain]

First of all, make sure mesa is up to date. The latest versions should work fine with what we're doing.

However, if that doesn't help, then it may just be that your device is quite dated or does not have the capabilities of the things we want to do. You should specify what video adapter you're using. If your actual adapter itself does not support the specific features the program requires, then you might not be able to run it. I'm not entirely sure.

 

[djfun]

The mesa version I was using before (10.2.2) was the latest, I could get from the Intel graphics drivers installer. Ubuntu 14.04 itself only has updates to mesa 10.1.3.

I could find however the latest development version of mesa here https://launchpad.net/~oibaf/+archive/ubuntu/graphics-drivers which lets me run obs without problems (I haven't noticed any so far at least) \o/

To summarize: you need at least OpenGL 3.2 and GLSL 1.5 to start obs (maybe obs could give the user a more helpful error message?)

 

[Lain]

Ah, good to see you got it working. That is correct, we are using some later features as well as GLSL 1.5 (just for reference, GLSL is up to version 4.5 right now, so we're not particularly asking for much)