23 Oct
2002
23 Oct
'02
9:44 a.m.
At Wed, 23 Oct 2002 15:16:08 +0200,
Werner Schweer wrote:
On Wednesday 23 October 2002 11:51, Takashi Iwai wrote:
...
it cost me a day of debugging to find out that my notebook with
ES1983S (Maestro3i) chip does not work well with JACK. Sometimes
all seems to be ok (no underruns) sometimes timing was horrible with
lots of underruns. Tracing shows that soundcard interrupts (JACK callbacks)
sometimes are just too late.
Takashi, are you saying that this cannot be fixed because the driver
does not get an interrupt on buffer empty?
i'm afraid that it's a driver bug. i got the similar report from
Steve, and in fact, this delay looks longer than expected.
however, in the case of maestro3, the situation is worse: we have no
enough technical information to debug this behavior...
regarding to the audio device for notebooks, a USB device is not a bad
choice nowadays.
the latency is fairly good, you'll get 1 or 2ms order response.
but the bandwidth is too narrow, so the i/o channels are limited.
and if you use other usb devices together, the behavior is
unreliable.
but, anyway, it's easy - just hook and run (as long as usb hotplug is
fixed :)
ciao,
Takashi
- SB AWE
models (ugh, crap!)
- Yamaha YMF7xx/DS-XG (some have reported that these work ok,
but in any case they have a max 3 periods limitation
similar to cs4281, which can confuse apps)
no, instead, the interrupts are generated in the fixed time-length,
not at the period boundary or the end of buffer.
thus, this chip doesn't suit for low-latency purpose at all.
the similar case is ESS chips, es1968 and maestro3 (allegro).
that is, many on-board chips on notebooks are crap, unfortunately.