[linux-audio-user] Maudio audiophile USB

[Ronny]

Hi Paul and All,

> if its like aplay, use the -v argument to get a verbose listing of the
> h/w config that the device ends up with.

Unfortunately this device is Big Endian so I need to use plughw also
using a play:

$ aplay -D plughw:2 /usr/share/sounds/shutdown1.wav -v
Playing WAVE '/usr/share/sounds/shutdown1.wav' : Signed 16 bit Little
Endian, Rate 44100 Hz, Stereo
Plug PCM: Linear conversion PCM (S16_BE)
Its setup is:
stream       : PLAYBACK
access       : RW_INTERLEAVED
format       : S16_LE
subformat    : STD
channels     : 2
rate         : 44100
exact rate   : 44100 (44100/1)
msbits       : 16
buffer_size  : 16384
period_size  : 4096
period_time  : 92879
tick_time    : 1000
tstamp_mode  : NONE
period_step  : 1
sleep_min    : 0
avail_min    : 4096
xfer_align   : 4096
start_threshold  : 16384
stop_threshold   : 16384
silence_threshold: 0
silence_size : 0
boundary     : 1073741824
Slave: Hardware PCM card 2 'Audiophile USB (tm)' device 0 subdevice 0

Its setup is:
stream       : PLAYBACK
access       : MMAP_INTERLEAVED
format       : S16_BE
subformat    : STD
channels     : 2
rate         : 44100
exact rate   : 44100 (44100/1)
msbits       : 16
buffer_size  : 16384
period_size  : 4096
period_time  : 92879
tick_time    : 1000
tstamp_mode  : NONE
period_step  : 1
sleep_min    : 0
avail_min    : 4096
xfer_align   : 4096
start_threshold  : 16384
stop_threshold   : 16384
silence_threshold: 0
silence_size : 0
boundary     : 1073741824

> then try to replicate that using the hw:N device with JACK (not the
> plughw device). JACK can use plughw devices, but it is intended to
> work better with a hw device.

>> Problems rise when I try using Jack.
>> even if I managed to get it starting with jackd -dalsa -dplughw:2,0 
>> -r44100 -p1024 -n4 -Pplughw:2,0 -S -o2

> this is a very very odd way to start JACK. the -Pplughw:2,0 seems 
> redundant.

You're right, I'll try to start with a better setup
using the parameters above, first block, and using plughw because BE,

jackd -v -dalsa -dplughw:2 -r44100 -p4096 -n4 -S

the problem is that I get the card playing few milliseconds of audio
continuously even without using any player connected to Jack. A sort of
tic -tac - tic -tac ....
if I reduce p to 1024 then it seems to work fine but the quality is
still lousy.
See below part of the output, any suggestion is most welcome. 

$ jackd -v -dalsa -dplughw:2 -r44100 -p4096 -n4 -S
getting driver descriptor from /usr/lib/jack/jack_dummy.so
getting driver descriptor from /usr/lib/jack/jack_alsa.so
getting driver descriptor from /usr/lib/jack/jack_oss.so
jackd 0.100.1
Copyright 2001-2005 Paul Davis and others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details

JACK compiled with System V SHM support.
server `default' registered
loading driver ..
apparent rate = 44100
creating alsa driver ... plughw:2|plughw:2|4096|4|44100|0|0|nomon|
swmeter|-|16bit
control device hw:2
configuring for 44100Hz, period = 4096 frames, buffer = 4 periods
You appear to be using the ALSA software "plug" layer, probably
a result of using the "default" ALSA device. This is less
efficient than it could be. Consider using a hardware device
instead rather than using the plug layer. Usually the name of the
hardware device that corresponds to the first soun
nperiods = 4 for capture
registered builtin port type 32 bit float mono audio
new client: alsa_pcm, id = 1 type 1 @ 0x8746a78 fd = -1
You appear to be using the ALSA software "plug" layer, probably
a result of using the "default" ALSA device. This is less
efficient than it could be. Consider using a hardware device
instead rather than using the plug layer. Usually the name of the
hardware device that corresponds to the first soun
nperiods = 4 for playback
new buffer size 4096
registered port alsa_pcm:capture_1, offset = 16384
registered port alsa_pcm:capture_2, offset = 32768
registered port alsa_pcm:playback_1, offset = 0
registered port alsa_pcm:playback_2, offset = 0
++ jack_rechain_graph():
client alsa_pcm: internal client, execution_order=0.
-- jack_rechain_graph()
4167 waiting for signals
late driver wakeup: nframes to process = 8192.
load = 0.2853 max usecs: 530.000, spare = 92349.000
.....

Thank You in advance 

Ronny