for information : what is the size of the pixel buffer?
thx Cyrille Le 06/06/2010 16:49, Claude Heiland-Allen a écrit :
Hi list, Is there any way in current Gem to use asynchronous readback of pixel buffer objects to speed up recording (or other GPU<->CPU transfer)? In one of my projects in plain C/OpenGL I used this technique successfully: 1) naive (blocking) glReadPixels direct to CPU ram and piped via stdout to ppmtoy4m|y4mscaler|mpeg2enc -> about 5fps 2) async glReadPixels to pixel buffer object mapped into the CPU with one frame latency and piped via stdout to same encoder -> about 20fps 3) async glReadPixels to PBO to CPU piped via stdout to /dev/null -> about 25fps (laptop with 4GB ram, intel core2 dual core cpu, nvidia g105m gpu, tested with 32bit gnu/linux/ubuntu/karmic generic-pae kernel) Thanks for any tips, Claude
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