[Mplayer-cvslog] CVS: main/DOCS documentation.html,1.268,1.269
Attila Kinali
kinali at gmx.net
Sat Jun 29 12:07:30 CEST 2002
On Sat, 29 Jun 2002 04:43:30 +0200
Diego Biurrun CVS <diego at mplayerhq.hu> wrote:
> +<LI>There are three timing methods in <B>MPlayer</B>.
> + <UL>
> + <LI><B>To use the old method</B>, you don't have to do anything. It uses
> + <CODE>usleep()</CODE> to tune A/V sync, with +/- 10ms accuracy. However
> + sometimes the sync has to be tuned even finer.</LI>
> + <LI><B>The new timer</B> code uses PC's RTC (Real Time Clock) for this task,
> + because it has precise 1ms timers. This requires root privileges, or a
> + <I>setuid root</I> <B>MPlayer</B> binary. If you are running kernel
> + 2.4.19pre8 or later you can adjust the maximum RTC frequency for normal
> + users through the <CODE>/proc</CODE> filesystem. Use this command to enable
> + RTC for normal users:
> + <P>
> + <CODE>echo 1025 > /proc/sys/dev/rtc/max-user-freq</CODE>
> + </P>
> + If you do not have such a new kernel, you can also change one line in
> + <CODE>drivers/char/rtc.c</CODE> and recompile your kernel. Find the line
> + <P>
> + <CODE>if ((rtc_freq > 64) && (!capable(CAP_SYS_RESOURCE)))</CODE>
> + </P>
> + and change the 64 to 1024. You should really know what you are doing, though.
> + <BR>
> + You can see the new timer's efficiency in the status line. In some hardware
> + combinations (confirmed during usage of non-DMA DVD drive on an ALi1541 board)
> + usage of the RTC timer causes skippy playback. It's recommended to use the
> + following method in these cases.</LI>
> + <LI><B>The third timer code</B> is turned on with the <CODE>-softsleep</CODE>
> + option. It has the efficiency of the RTC, but it doesn't use RTC. On the other
> + hand, it requires more CPU.</LI>
> + </UL>
> +</LI>
> +</UL>
There should be also stated that RTC is automagicaly used when available and that it
can cause problems on laptops with speedstep (see also FAQ)
> Note: <B>NEVER install setuid MPlayer binary on a
Shouldnt this be "setuid root" ? I mean setuid nobody doesnt harm anyone :)
Attila Kinali
--
Israel, where the first genocide of this century takes place.
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