Hi,
How can I calculate how much memory my frame buffer + Xv will need or actually use? I have a dual head setup on a Radeon Mobility 7500, 16 Mb memory. In my normal setup I have a panel running 1400x1050@32bpp and a TFT monitor running 1024x768@32bpp. This would imply it needs 1400x1050x4 + 1024x768x4 bytes of memory (+ some overhead), which is approx. 8.8 Mb. I can do all stuff with xv on screen #1, but Xv on screen #0 (the 1400x1050 one) fails with BadAlloc when requesting Xv for resolutions over approx 200x100.
I don't understand that, where does all that memory go?
I don't know exactly how the radeon driver shares the available memory among the two heads, but if it does that 50:50 as I would assume, the problem is obvious.
If each screen gets 8 MB, the 1400x1050x32 screen uses almost 6MB just for the visible screen. A little bit for pixmap cache, mouse cursor, perhaps command queue and the available memory soon isn't enough for Xv (which probably uses double-bufferung for avoing tearing effects). Not even speaking of memory fragmentation after a while.
For YV12/I420/NV21/NV12 video, the required memory size for one frame is calculated as follows:
Size = width * height * 3 / 2
For YUV2/YUVY/YVYV/RGB5/RGB6 it is
Size = width * 2 * height
For double buffering, multiply this by 2.
Thomas
-- Thomas Winischhofer Vienna/Austria thomas AT winischhofer DOT net http://www.winischhofer.net/ twini AT xfree86 DOT org _______________________________________________ XFree86 mailing list XFree86@xxxxxxxxxxx http://XFree86.Org/mailman/listinfo/xfree86
