15 Jul
2010
15 Jul
'10
4:31 p.m.
Robin Gareus wrote:
On 07/15/2010 01:07 PM, Ralf Mardorf wrote:
Jack can read the current time from /dev/hpet, but it does not use it to
generate interrupts. As far as I know, there is no program that does.
On Thu, 2010-07-15 at 12:55 +0200, Clemens
Ladisch wrote:
> Ralf Mardorf wrote:
>> dev.hpet.max-user-freq
>
> This parameter will not have any effect on anything because there is no
> program that uses the HPET timers from userspace.
That'd be correct if Ralf would stick to 'amidiplay' and friends for his
tests.
There are a couple of audio-tools who can use either RTC or HPET for
timing, although most of them need an option to explicitly enable it. BTW. Do you know the unit of these values?
cat /sys/class/rtc/rtc0/max_user_freq
cat /proc/sys/dev/hpet/max-user-freq
are they Hz?
Yes.
> IIRC someone on jack-devel mailing list had issues
when using mplayer
> with the value 64 and it was solved when using the value 1024.
This has nothing to do with MIDI timing; mplayer can use the RTC (not
HPET) for audio/video synchronization to work around the 100 Hz limit of
the system timer on old Linux kernels.
Regards,
Clemens