How to get a pixel buffer from OpenGL so that I can run H264 compression on the buffer on ARM (DM8148)?

Kim Steiner

I am using openGL on a dm8148 and would like to keep using openGL to do some rotation/scaling. Once these operations are done in openGL, I want to get a pointer to the rotated/scaled image buffer (frame buffer?) and have the ARM perform H264 compression on this buffer. I have looked through the TI Render to Texture examples but they do not show how to get a pointer to the buffer that has been rotated/scaled. I am not very familiar with openGL so I am not sure of the best approach. I have looked at a pixmap scene but it does not seem fast enough (~20fps). Is there a way to get a pointer to the opengl rendered image buffer? If so, what do you suggest as the best (and fastest approach)?

Thanks,

Kim

over 10 years ago

0 Margarita Gashova over 10 years ago

TI__Guru* 80190 points

Hello,

Please provide information like the software release that you are using?

Best Regards,
Margarita

0 Kim Steiner over 10 years ago in reply to Margarita Gashova

Intellectual 770 points

Hi Margarita,

I am using Graphics SDK 4.06.00.03, opengl 2.0.

Thanks,
Kim

0 Margarita Gashova over 10 years ago in reply to Kim Steiner

TI__Guru* 80190 points

Hello,

I am not a Graphics expert but you could check here:

http://processors.wiki.ti.com/index.php/Render_to_Texture_with_OpenGL_ES

Let me know if it helps.

Best Regards,
Margarita

0 Kim Steiner over 10 years ago in reply to Margarita Gashova

Intellectual 770 points

Hi Margarita,

I have looked through that document to see how to use off-screen rendering surfaces. But the document only shows the Pixmap as a possible way to get a pointer to the rendered pixels. The other types, pbuffer and FramebufferObject, do not seem to provide a way to the pointer of the rendered pixels. I have tried using Pixmap and it works ok, but it does not seem to support double buffering so I have to call eglWaitGL at the end of the rendering code, versus eglSwapBuffers and this is taking ~36ms for a 1080p image. Can you ask someone more familiar with graphics if the Pixmap is the best way to get a buffer to the rendered pixels? Also, is there a way to do double buffering with a Pixmap or is there another option?

Thanks,

Kim

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How to get a pixel buffer from OpenGL so that I can run H264 compression on the buffer on ARM (DM8148)?