[PlanetCCRMA] Planet boxes as ogg client/server

Mark Knecht Mark Knecht <markknecht@gmail.com>
Tue Feb 1 09:05:02 2005

   I wonder if anyone has tried to use their Planet boxes as ogg file
servers and clients. We're trying to do this here but it's not working
well enough to be useful as we're getting major dropouts on the audio.
Logically I think this may be a networking problem but I'm not sure
how to prove it. Here's the setup:

1) My wife's FC2 machine 'dragonfly' has the ogg database. We've
ripped a couple hundred CDs and they reside on her hard drive. The
drive does about 45MB/S under hdparm.  She's running the following

[mark@dragonfly mark]$ uname -r

I've done no real configuration on her machine as she doesn't do audio
today other than rip ogg files and listen to music. The long term
intention is to tie this machine into the main stereo in our house
through some sort of spdif connection so I had intended to worry about
good performance when I did that as I'll have to install a second
sound card.

2) On her end we can play ogg files all day with no issues.

3) I run Samba on her end and share the ogg file directory. I mount it
from the command line on my end like this:

[root@Godzilla root]# mount -t smbfs -o username=mark
//dragonfly/MusicLib /home/mark/music

[mark@Godzilla mark]$ df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/hda4              6759524   5625628    790524  88% /
/dev/hda1                99043     19923     74006  22% /boot
/dev/hda6              4032064   3246424    580816  85% /home
none                    387652         0    387652   0% /dev/shm
none                    387652         0    387652   0% /var/lib/jack/tmp
//dragonfly/MusicLib  50394112  17705984  32688128  36% /home/mark/music

4) At this point I attempt to play stuff from her machine using either
alsaplayer or Aqualung. Both player work but both have major audio
dropouts occurring. I've run the players using OSS emulation, straight
Alsa interfaces and Jack. When using Jack (with or without real-time
options) I've set latencies as high as just under 200mS but it doesn't
matter. I get these long dropouts sometimes lasting as long as 20-30
seconds. What's interesting to me is that I can ping her machine while
the dropouts are happening and the delays are on the order of 1-5mS
and are no worse than while the dropout are nt happening.

5) There is no similar dropout problem when the same files reside on
my studio machine so I assume the problem is dragonfly itself or the
network but I'm open to any other ideas.

One interesting point is that eve when using Jack and being in the
middle of a 20 second dropout I get no xruns.

6) Her machine is a wireless connection and doesn't seem to have any
problems connecting to the net. My machines are all hard wired.

   So, if I wanted to optimize her Planet box to be a networked file
server with possibly some read ahead capabilities (is that possible?)
what would I do?

   I'd possibly be OK with turning around the operation and putting
some sort of broadcasting software on her machine, setting up the play
list on her end and then pushing the audio data out as long as I can
use my local D/A's on this end. That solution would require the
ability to broadcast to multiple locations in the house though as we
need to go to three different computers as well as the stereo, all
possibly with different play lists. (That's slightly above 4Mb/S (for
the 3 computers) and would probably be pushing wireless networking
from dragonfly pretty hard if we went that far...)

   Still, I'd prefer to pull the data if possible.

   Any ideas how to solve this?

Thanks in advance,