--- Billy Biggs <vektor@xxxxxxxxxxxx> a écrit : > I am the~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^
author of tvtime, a TV application with advanced
image
processing algorithms. Some users are complaining about poor
performance under Linux 2.6, and I would like more information
about how
tvtime will be treated by the scheduler. Here is an example
of the
intended usage:
- Program running as root and SCHED_FIFO
- NTSC, input ~30 fps, each field processed for an output of ~60 fps
[___snip___]- CPU intensive processing, say 9 ms per field on my P3-733
- with a typical AGP card, the X driver takes 4 ms to draw
- Wait using /dev/rtc set to 1024 Hz
for(;;)
9 ms : process frame
4 ms : draw frame
3 ms : wait until next field time using /dev/rtc
9 ms : process frame
4 ms : draw frame
3 ms : block on /dev/video0 for next frame
-----
33 ms : time per NTSC frame
For me it works ok~~~~~~~~~~~~~~~~^^^
Running tvtime with 2.6.6-mm5 load average 26 (twenty six) it
works almost perfect (no frame skipped -- at least not reported by
tvtime)
at full rate (50 frames/sec). Computer: AMD Duron 700 MHz, 256MB
Ram,
VIA KT133 chipset, AGP 4x, Ati Radeon 7200