[chuck-users] chuck linux-alsa in Ubuntu 11.04

[Alex French]

Hi all,
I've become quite interested in procedural/fully synthesized audio for
game development, and I've tried out a lot of different tools,
including cmus, supercollider, puredata, and chuck. I really like
chuck, because it seems fairly lightweight and simple compared to the
others. The only problem is that I can't get it to work in Ubuntu
using alsa. It works with jack, which is fine for me, but I don't want
my users to have to install and deal with jack just to play my game.

So here's my situation...

I'm running 32 bit Ubuntu 11.04.

I have onboard sound on my motherboard, through the nVidia MCP55 chipset:
00:0f.1 Audio device: nVidia Corporation MCP55 High Definition Audio (rev a2)

Unfortunately, that device crapped out on me a year or so ago, so I
replaced it with this:
02:09.0 Multimedia audio controller: C-Media Electronics Inc CM8738 (rev 10)
...which is a Diamond XS51 PCI audio card.

I also have this, courtesy of my video card:
01:00.1 Audio device: ATI Technologies Inc Barts HDMI Audio [Radeon HD
6800 Series]

That makes for a fairly complex setup. Here's what chuck sees:
$ ./chuck --probe
[chuck]: found 7 device(s) ...
[chuck]: ------( chuck -- dac1 )---------------
[chuck]: device name = "hw:NVidia,0"
[chuck]: probe [success] ...
[chuck]: # output channels = 8
[chuck]: # input channels  = 2
[chuck]: # duplex Channels = 2
[chuck]: default device = YES
[chuck]: natively supported data formats:
[chuck]:   16-bit int
[chuck]:   32-bit int
[chuck]: supported sample rates:
[chuck]:   44100 Hz
[chuck]:   48000 Hz
[chuck]:   96000 Hz
[chuck]:   192000 Hz
[chuck]:
[chuck]: ------( chuck -- dac2 )---------------
[chuck]: device name = "hw:NVidia,1"
[chuck]: probe [success] ...
[chuck]: # output channels = 2
[chuck]: # input channels  = 2
[chuck]: # duplex Channels = 2
[chuck]: default device = NO
[chuck]: natively supported data formats:
[chuck]:   16-bit int
[chuck]:   32-bit int
[chuck]: supported sample rates:
[chuck]:   44100 Hz
[chuck]:   48000 Hz
[chuck]:   88200 Hz
[chuck]:   96000 Hz
[chuck]:   192000 Hz
[chuck]:
[chuck]: ------( chuck -- dac3 )---------------
[chuck]: device name = "hw:NVidia,2"
[chuck]: probe [success] ...
[chuck]: # output channels = 0
[chuck]: # input channels  = 2
[chuck]: # duplex Channels = 0
[chuck]: default device = NO
[chuck]: natively supported data formats:
[chuck]:   16-bit int
[chuck]:   32-bit int
[chuck]: supported sample rates:
[chuck]:   44100 Hz
[chuck]:   48000 Hz
[chuck]:   96000 Hz
[chuck]:   192000 Hz
[chuck]:
[chuck]: ------( chuck -- dac4 )---------------
[chuck]: device name = "hw:CMI8738,0"
[chuck]: probe [success] ...
[chuck]: # output channels = 2
[chuck]: # input channels  = 2
[chuck]: # duplex Channels = 2
[chuck]: default device = NO
[chuck]: natively supported data formats:
[chuck]:   16-bit int
[chuck]: supported sample rates:
[chuck]:   5512 Hz
[chuck]:   8000 Hz
[chuck]:   11025 Hz
[chuck]:   16000 Hz
[chuck]:   22050 Hz
[chuck]:   32000 Hz
[chuck]:   44100 Hz
[chuck]:   48000 Hz
[chuck]:   88200 Hz
[chuck]:   96000 Hz
[chuck]:
[chuck]: ------( chuck -- dac5 )---------------
[chuck]: device name = "hw:CMI8738,1"
[chuck]: probe [success] ...
[chuck]: # output channels = 6
[chuck]: # input channels  = 0
[chuck]: # duplex Channels = 0
[chuck]: default device = NO
[chuck]: natively supported data formats:
[chuck]:   16-bit int
[chuck]: supported sample rates:
[chuck]:   5512 Hz
[chuck]:   8000 Hz
[chuck]:   11025 Hz
[chuck]:   16000 Hz
[chuck]:   22050 Hz
[chuck]:   32000 Hz
[chuck]:   44100 Hz
[chuck]:   48000 Hz
[chuck]:   88200 Hz
[chuck]:   96000 Hz
[chuck]:
[chuck]: ------( chuck -- dac6 )---------------
[chuck]: device name = "hw:CMI8738,2"
[chuck]: probe [success] ...
[chuck]: # output channels = 2
[chuck]: # input channels  = 2
[chuck]: # duplex Channels = 2
[chuck]: default device = NO
[chuck]: natively supported data formats:
[chuck]:   16-bit int
[chuck]:   32-bit int
[chuck]: supported sample rates:
[chuck]:   44100 Hz
[chuck]:   48000 Hz
[chuck]:   88200 Hz
[chuck]:   96000 Hz
[chuck]:
[chuck]: ------( chuck -- dac7 )---------------
[chuck]: device name = "hw:Generic,3"
[chuck]: probe [success] ...
[chuck]: # output channels = 2
[chuck]: # input channels  = 0
[chuck]: # duplex Channels = 0
[chuck]: default device = NO
[chuck]: natively supported data formats:
[chuck]:   16-bit int
[chuck]: supported sample rates:
[chuck]:   32000 Hz
[chuck]:   44100 Hz
[chuck]:   48000 Hz
[chuck]:
[chuck]: ------( chuck -- 2 MIDI inputs )------
[chuck]:     [0] : "Midi Through Port-0"
[chuck]:     [1] : "C-Media CMI8738 MIDI"
[chuck]:
[chuck]: ------( chuck -- 4 MIDI outputs )-----
[chuck]:     [0] : "Midi Through Port-0"
[chuck]:     [1] : "C-Media CMI8738 MIDI"
[chuck]:     [2] : "OPL3 FM Port"
[chuck]:     [3] : "qjackctl"
[chuck]:

I've tried using dacs 4-6 with pasuspender to suppress pulseaudio, but
nothing seems to work. The same thing happens without pasuspender; I
don't know if it's actually required, but it's something I tried.

Anyway, in an attempt to get some more information, I increased the
log verbosity:

$ pasuspender -- ./chuck --verbose5 --dac5 moe.ck
**snip**
[chuck]:(2:SYSTEM):  | sample rate: 48000
[chuck]:(2:SYSTEM):  | buffer size: 512
[chuck]:(2:SYSTEM):  | num buffers: 8
[chuck]:(2:SYSTEM):  | devices adc: 0 dac: 5 (default 0)
[chuck]:(2:SYSTEM):  | adaptive block processing: 0
[chuck]:(2:SYSTEM):  | channels in: 2 out: 2
**snip**
[chuck]:(3:SEVERE): starting real-time audio...
[chuck]:(2:SYSTEM): RtApiAlsa: callback thread error...
[chuck]:(5:INFORM):  | (RtApiAlsa: audio read error for device
(hw:NVidia,0): Input/output error.)
[chuck]:(5:INFORM):  | closing thread...

What's going on here? I asked for the CMI8738, but I'm getting I/O
errors from the nvidia device. At this point I'm completely lost.

Help?
-Alex