Re: [linux-audio-user] Re: latencies

From: Wolfgang Lonien <wolfgang@email-addr-hidden>
Date: Thu Jul 21 2005 - 20:46:35 EEST

Hash: SHA1

philicorda wrote:

>> Things have moved on a little. :)

How true... :-)

>> What sort of latency problems are you having?

I have xruns in Alsa, qjackctl is reporting something about 40+msec of
latency, and even the metronome in Rosegarden isn't steady, esp. after
the screen starts scrolling while recording. Playback of some downloaded
 MIDI-only file is also not acceptable.

cat /proc/interrupts says:

  0: 38765931 XT-PIC timer 0/65931
  1: 13071 XT-PIC i8042 0/13071
  2: 0 XT-PIC cascade 0/0
  3: 37813 XT-PIC 0.0 1/37811
  8: 1 XT-PIC rtc 0/1
  9: 1318079 XT-PIC acpi, yenta, yenta, uhci_hcd:usb1 0/18079
 10: 36863 XT-PIC Allegro 0/36863
 14: 408326 XT-PIC ide0 0/8326
NMI: 0
LOC: 0
ERR: 0
MIS: 0

while I write this mail - IRQ3 is gone when I try to make music, because
then I 'cardctl eject' the wireless card...

>> Remember, latency is only a monitoring issue, and should never affect
>> timing of audio to midi etc on playback.

Hmmm here everything is nice until I hit that 'record' button. Oh and I
try to do MIDI only for a start, no fancy audio stuff.

>> If the laptop and soundcard just aint gonna play nice with jack at low
>> latencies whatever you do then use the direct analog monitoring in the
>> sound cards mixer for monitoring while recording audio rather than
>> software monitoring.

Hmmm - you mean kill all audio connections in qjackctl? Yep; btdt...

>> Softsynth latency can't be got round this way, but if your midi keyboard
>> has some sounds built in, you can record listening to them, and then
>> play back the midi parts with whatever softsynth you like.

No, my MIDI keyboard is just a keyboard and doesn't produce sounds. The
MIDI out goes to a Roland SC-33, and the headphones are inserted there.
So 'recording' for me means only MIDI-on/off events. I expected *that*
at least to work.

wjl aka Wolfgang Lonien

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Received on Fri Jul 22 00:15:06 2005

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