[fluid-dev] Re: Timing revisited

[jimmy]

> Date: Saturday, April 11, 2009, 9:00 AM
> . . . 
> Okay, I stand corrected. Judging from the design of the
> audio drivers
> and the player/sequencer, it seems like those parts were
> designed for
> live usage only (up to now).

Whatever changes made, please do keep in mind, and test the live usage 
scenario.  The test can be simple as playing a midi file, and have vkeybd 
(conneted to same fluidsynth) plays live at the sametime.  Any serious lags 
from the time of vkeybd note is played and the sound is heard would be bad for 
live playing.  vkeybd is very small and fairly simple to try.  I am learning to 
play along, so live playing is prefered, and much needed.

As for faster than real time rendering, it is nice to have, but please don't 
break live playing feature.  If you have only a few files, what's the hurry?  
If you have a few hundred (or thousand) files to convert, what about overnight, 
or weekend batch convert?  


Don't know if the following may affect Fluidsynth in any way now, or later.  
Some note on new system/kernel timer module, I saw in kernel 2.6.29, there a 
new module:  snd-hrtimer .  I did a web search, and read a few blurbs.  I 
haven't load the latest Alsa, or latest jackd/qjackctl yet.  But the following 
already works with my (not up to date) Debian Sid:

   kernel 2.6.29 SMP PREEMPT (high-res timer)
   alsa-base 1.0.16-1.1
   jackd 0.116.1-2

jackd can make use of the snd-hrtimer after:

   sudo modprobe  snd-hrtimer

   jackd  -c h  -Xseq  (and other args)

I think audio group may need to own  /dev/hpet .  One can get some info from 
running:

   cho " ---  /proc/asound/timers  ---"
   cat /proc/asound/timers
   echo " ---  /proc/asound/seq/timer  ---"
   cat  /proc/asound/seq/timer

before and after starting jackd and note any differences.

Jimmy