fbo rendering

[hack-s]

Use projectm_opengl_render_frame_fbo() to render ProjectM to an OpenGL texture. Removes direct OpenGL buffer access and avoids copying of GPU memory to main memory if not needed.
gstaudiovisualizer is not suitable as a basis for the plugin anymore. It's hard-coded to use main memory, cpu based transition shaders, and does not expose timestamps to synchronize projectm. gstpmaudiovisualizer is added to support customized memory allocation and expose timestamps.

Rendering test video: https://www.youtube.com/watch?v=kl3nVd-iug8

[rootnotez]

I was able to test this successfully on Debian12 with Nvidia drivers in X11 with DWM window manager.

[rootnotez]

Getting this compile warning with build.sh on debian12.

[6/7] /usr/bin/cc -DPROJECTM_STATIC_DEFINE -Dgstprojectm_EXPORTS -I/usr/include/gstreamer-1.0 -I/usr/lib/x86_64-linux-gnu/gstreamer-1.0/include -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/home/user/work/hack-s/gst-projectm-fbo -fPIC -MD -MT CMakeFiles/gstprojectm.dir/src/plugin.c.o -MF CMakeFiles/gstprojectm.dir/src/plugin.c.o.d -o CMakeFiles/gstprojectm.dir/src/plugin.c.o -c /home/user/work/hack-s/gst-projectm-fbo/src/plugin.c
/home/user/work/hack-s/gst-projectm-fbo/src/plugin.c: In function ‘wrap_gl_texture’:
/home/user/work/hack-s/gst-projectm-fbo/src/plugin.c:61:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
   61 |   glTextures[0] = (gpointer)plugin->priv->texture_id;
      |                   ^  

[rootnotez]

Getting a crash while exiting test.sh --audio Attaching crash dump, some gdb, and some Claude proposed fixes. Opps, realizing this is with ctrl-c quitting.

Sending SIGTERM (15) instead of CTRL-C / SIGINT (2) I do not get a crash.

I'm not confident this is a bug that needs fixing at the moment. Maybe we turn this into an issue for long term fixing?

2025-06-04_gstreamer_projectm_debug_session.md

[hack-s]

Getting a crash while exiting test.sh --audio Attaching crash dump, some gdb, and some Claude proposed fixes. Opps, realizing this is with ctrl-c quitting.

Sending SIGTERM (15) instead of CTRL-C / SIGINT (2) I do not get a crash.

I'm not confident this is a bug that needs fixing at the moment. Maybe we turn this into an issue for long term fixing?

2025-06-04_gstreamer_projectm_debug_session.md

turned out there was a memory error. I have back-ported a fix for it from gst.

[hack-s]

Getting this compile warning with build.sh on debian12.

[6/7] /usr/bin/cc -DPROJECTM_STATIC_DEFINE -Dgstprojectm_EXPORTS -I/usr/include/gstreamer-1.0 -I/usr/lib/x86_64-linux-gnu/gstreamer-1.0/include -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/home/user/work/hack-s/gst-projectm-fbo -fPIC -MD -MT CMakeFiles/gstprojectm.dir/src/plugin.c.o -MF CMakeFiles/gstprojectm.dir/src/plugin.c.o.d -o CMakeFiles/gstprojectm.dir/src/plugin.c.o -c /home/user/work/hack-s/gst-projectm-fbo/src/plugin.c
/home/user/work/hack-s/gst-projectm-fbo/src/plugin.c: In function ‘wrap_gl_texture’:
/home/user/work/hack-s/gst-projectm-fbo/src/plugin.c:61:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
   61 |   glTextures[0] = (gpointer)plugin->priv->texture_id;
      |                   ^  

That's some api weirdness, basically storing an int value (OpenGL texture id) in a pointer var. But that's what's needed..