This bug report was migrated from our old Bugzilla tracker.

These attachments are available in the static archive:

• the culprit source file (sdl13+vlc.c, text/x-csrc, 2011-02-17 00:16:39 +0000, 4221 bytes)

Reported in version: HG 2.0
Reported for operating system, platform: Linux, x86_64

Comments on the original bug report:

On 2011-02-17 00:16:39 +0000, Vittorio Giovara wrote:

Created attachment 576
the culprit source file

I'm trying to port the sdl+vlc example
(http://wiki.videolan.org/LibVLC_SampleCode_SDL) to SDL 1.3 apis
I'm trying to use this code to decode some h264 videos and to do some
compositing operation on it live.

The attached code works fine on Windows, i can see the video and render with the
new apis; it works using the direct3d and software renderer, with the
opengl renderer i see only a black screen.
However on Linux, using the opengl renderer, it gets a segfault and
crashes at the first frame or so (works fine with software renderer).

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffe2da4700 (LWP 2995)]
0x00007ffff57e3629 in glGetError () from /usr/lib/nvidia-current/libGL.so.1
(gdb) bt

0 0x00007ffff57e3629 in glGetError () from /usr/lib/nvidia-current/libGL.so.1

1 0x00007ffff7b50533 in GL_UpdateTexture (renderer=<value optimized

out>, texture=0x88bda0, rect=0x8abfc4, pixels=0x7ffff2c29010,
pitch=7680) at src/render/opengl/SDL_render_gl.c:546

2 0x00007ffff7b4c197 in SDL_UnlockTexture (texture=0x88bda0) at

src/render/SDL_render.c:732

3 0x00000000004010d3 in unlock (data=0x7fffffffe0d0, id=0x0,

p_pixels=0x7fffe2da3bf0) at sdl13+vlc.c:26

4 0x00007fffe2aa0c66 in Unlock (picture=) at vmem.c:353

5 0x00007ffff6c48532 in vout_display_Display (vout=0xa94f50,

now=, deadline=) at
../include/vlc_vout_wrapper.h:58

6 ThreadDisplayRenderPicture (vout=0xa94f50, now=<value optimized

out>, deadline=) at
video_output/video_output.c:1040

7 ThreadDisplayPicture (vout=0xa94f50, now=,

deadline=) at video_output/video_output.c:1113

8 0x00007ffff6c48ffd in ThreadManage (object=)

at video_output/video_output.c:1125

9 Thread (object=) at video_output/video_output.c:1559

10 0x00007ffff6ed4971 in start_thread (arg=) at

pthread_create.c:304

11 0x00007ffff765792d in clone () at

../sysdeps/unix/sysv/linux/x86_64/clone.S:112

12 0x0000000000000000 in ?? ()

On 2013-05-21 02:07:10 +0000, Sam Lantinga wrote:

Is this still active in the latest snapshot?
http://www.libsdl.org/tmp/SDL-2.0.zip

On 2013-07-12 11:21:57 +0000, Ryan C. Gordon wrote:

This looks like it's trying to do OpenGL calls in a background thread. Maybe set the context current on that thread and see if it helps?

--ryan.

On 2013-07-13 06:21:04 +0000, Vittorio Giovara wrote:

Will do try again soon.
Thanks.

On 2015-02-18 03:26:37 +0000, Ryan C. Gordon wrote:

I'm assuming this turned out to be GL calls on a background thread without a current context, and the latest SDL revisions should take care of this now (grep for "GL_ActivateRenderer" in the sources).

--ryan.