[MPlayer-users] high-res videos too slow, where's the bottleneck?

[Arpi]

Hi,

> If Arpi's arguments were true (which is absolutely plausible), it would imply that no full-screen
> full-framerate animation is possible which requires software-driven copiing into the video memory. In other
> words, today's videocards' resolution is beyond their interfaces' transfer-capability.
exactly. 

and the reason of hardware color conversion's speedup not the faster
conversion, it's that yv12 data is 12bpp while resulting rgb is 24/32bpp.
so, if you have hw colorspace conversion, you can send 12bpp image to the
card and teh card will convert it to 24/32. so you can use half bandwith.

unfortunatelly even a p3 1ghz system is too slow for _displaying_
800x600x32bpp at 30fps. it's 800*600*4*30 ~ 60MByte/sec. PCI bus run at
33MHz, AGP at 66. (and most linux drivers doesn't use AGP features)

Note: 720x576x12bpp (YUV) @ 30fps is 18.6 MByte/s.

Note2: Try to playback at 16bpp. Use Michael's great dithering 16bpp scaler
(-vo x11 -zoom -fs).

> Question: how about bypassing X? Could you run your experiments with framebuffer drivers on Linux Console?
Not the X is the problem. X just an API, but the API won't speed up or
slow down system bus... it's pure hardware problem.

The only way to playback DVD resolution video at acceptable speed is using
hardware colorspace conversion or low (15/16) bpp rgb.


A'rpi / Astral & ESP-team

--
mailto:arpi at thot.banki.hu
http://esp-team.scene.hu