Shiva Plug USB to Analog Audio

[jfk]

Hi,
I need a small device to play an online audio stream into PA systems. I was thinking I could extract the audio from the usb port in some way and access the audio stream via a headless linux audio player running on the shiva plug. Can someone tell me if the device can access an on line mp3 stream ? I.e. www.streamingaudio.com etc.
Cheers JFK

[Doug Grove]

At the risk of answering newby questions ...

1) Get a USB sound device.  I use :  http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4115644&CatId=4261
$25 and works great.  You will need to update you kernel and modules to get USB sound support.

2) Use MPD to stream audio:  http://mpd.wikia.com/wiki/Music_Player_Daemon_Wiki
Either that or PulseAudio.

Hope that helps,

Doug

[birdman]

There is no "audio on the USB port".  A USB sound device is (roughly) a sound card device on the USB bus - the audio comes out of this device, not out of USB.
I had a spare USB sound device that came with a Logitech wireless keyboard.  I just plugged it in and (with a bit of configuration and volume setting) it worked.  I'm using cxbiker61's kernels (2.67.32..x).
In terms of plugging this into a PA system - it has a headphone socket, so if you had similar you might be able to  plug that output into the PA?

[jfk]

Thnx to the gents, that replied. I now have more than enough info to get done what I need, much appriciated
Rgds JFK

[jvp]

Hey,

I'm trying to get mpd working with sheevaplug. I got it installed and up-and-running but with a very slow & bad quality and heavy cpu-load. I was browsing through the wiki for the mpd-page (http://plugcomputer.org/plugwiki/index.php/USB_Audio) and it started with Kernel Config -section:

Code:

Start by adding kernel sound support:
CONFIG_SOUND=y
CONFIG_SND=y
CONFIG_SND_TIMER=y
CONFIG_SND_PCM=y
CONFIG_SND_HWDEP=y
CONFIG_SND_RAWMIDI=y
CONFIG_SND_SEQUENCER=y
CONFIG_SND_HRTIMER=y
CONFIG_SND_SEQ_HRTIMER_DEFAULT=y
CONFIG_SND_SUPPORT_OLD_API=y
CONFIG_SND_VERBOSE_PROCFS=y
CONFIG_SND_DRIVERS=y
CONFIG_SND_ARM=y
CONFIG_SND_SPI=y
CONFIG_SND_USB=y
CONFIG_SND_USB_AUDIO=y
CONFIG_SND_USB_CAIAQ=y
USB sound support:
CONFIG_SND_USB=y
CONFIG_SND_USB_AUDIO=y
CONFIG_SND_USB_CAIAQ=y

I'm such a noobie still that could someone please explain what I should do. I'm guessing the wiki-guide means compiling kernel with the audio-support. Is there a good how-to for kernel-compiling for sheevaplug? The quoted post from this topic (see below) also mentions updating kernel for audio-support.

Or do I have something else wrong because I'm getting audio from speakers but with a very bad quality and high cpu-load.

Running sheevaplug with debian (squeeze, 2.6.32-trunk-kirkwood).

At the risk of answering newby questions ...

1) Get a USB sound device.  I use :  http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4115644&CatId=4261
$25 and works great. You will need to update you kernel and modules to get USB sound support.

2) Use MPD to stream audio:  http://mpd.wikia.com/wiki/Music_Player_Daemon_Wiki
Either that or PulseAudio.

-jvp-

[MarkF]

Does the MP3 decoder you are using do floating point math or fixed point?  You may need something like the MAD decoder (http://www.underbit.com/products/mad/) since the plug has no hardware floating point support.

[jvp]

Got my problem fixed by installing alsamixer and alsa-oss and by configuring mpd to use oss. Runs now perfectly.

-jvp-

[ryazor]

Hi guys.

I also want to enable sound functionality. So I followed the instructions in [ http://plugcomputer.org/plugwiki/index.php/USB_Audio ] by adding the lines into the guruplug_defconfig and build the kernel again. Unfortunately it seems, that the sound modules are neither built nor loaded.

Code:

$ sudo modprobe -l | grep snd # returns no result

#---------------------------------------------------------------------------

$ lsmod
Module                  Size  Used by
ipv6                  232630  16
libertas_sdio           6744  0
libertas               80674  1 libertas_sdio
btmrvl_sdio             7712  0
btmrvl                 10683  1 btmrvl_sdio
bluetooth              48589  2 btmrvl_sdio,btmrvl
uap8xxx                42344  0
mv_cesa                 4552  0

#---------------------------------------------------------------------------

$ sudo alsaconf # leads to a 'No supported PnP or PCI card found.' dialog box

#---------------------------------------------------------------------------

# but the listing in 'aplay' makes me wondering:
$ sudo aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: default [C-Media USB Headphone Set  ], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

#---------------------------------------------------------------------------

$ dmesg | grep snd
usbcore: registered new interface driver snd-usb-audio
usbcore: registered new interface driver snd-usb-caiaq

#---------------------------------------------------------------------------

$ dmesg | grep C-Media
input: C-Media USB Headphone Set   as /devices/platform/orion-ehci.0/usb1/1-1/1-1.3/1-1.3:1.3/input/input0
generic-usb 0003:0D8C:000C.0001: input: USB HID v1.00 Device [C-Media USB Headphone Set  ] on usb-orion-ehci.0-1.3/input3

#---------------------------------------------------------------------------

# also the restart of 'alsa' seems to be successful
$ sudo /etc/init.d/alsa-utils restart
Shutting down ALSA...done.
Setting up ALSA...done.

Sorry, I do not have that much experience configuring alsa, since my main machine uses the OSS layer and my netbook worked out of the box using alsa. What did I overlook?

Thanks in advance,
ryazor

Edit: I don't know why, but now ALSA seems to work. Thanks!