Audio

Plugging in devices such as LAN adapters, Wi-Fi cards, printers, etc. to Arch Linux ARM.

Re: Audio

Postby aerotoad » Mon Sep 20, 2010 7:41 pm

tno wrote:I had the same problem, found a ridiculously easy solution:

I created a file /etc/asound.conf
with the following content:
Code: Select all
pcm.!default {
        type hw
        card 0
}

ctl.!default {
        type hw           
        card 0
}

I have absolutely no clue why this works. But the parameters in
/proc/asound/card0/pcm0p/sub0/hw_params

changed from
Code: Select all
access: MMAP_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 48000 (48000/1)
period_size: 1024
buffer_size: 16384

to
Code: Select all
access: RW_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 44100 (44100/1)
period_size: 5513
buffer_size: 22050


Thanks y'all--this worked for me, too. My usb sound card is: ID 0c45:17cf Microdia, and I'm running Debian Lenny. After this fix, mplayer internet radio streams are coming through fine.
aerotoad
 
Posts: 11
Joined: Fri Jul 23, 2010 3:39 am

Re: Audio

Postby falker » Wed Sep 22, 2010 8:33 pm

For anyone experiencing problems with mpd and $1 48khz usb cards:

mpd has to resample the usually 44.1khz music to 48khz. This can be very cpu-intensive depending on the chosen sampler.

mpd.conf
Code: Select all
audio_output_format             "48000:16:2"
samplerate_converter            "ZOH Interpolator"


The zoh resampler is reasonable fast on the dockstar, the default will result in very slow playback and 100% cpu load.
falker
 
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Re: Audio

Postby blurry » Fri Sep 24, 2010 4:54 am

I was able to play mp3s with "mpg123" with no interpolation issue -- I didn't check CPU consumption but there was no audible popping or crackling that I could determine. I was using a Turtle Beach USB audio advantage micro that I had lying around.
blurry
 
Posts: 17
Joined: Tue Aug 31, 2010 2:52 pm

Re: Audio

Postby LaTristesse » Sat Nov 20, 2010 6:27 pm

I'm able to play mp3-files but only with crackle. My Audio-Interface is class compilant. I've searched for the asound.conf but there is no such file.

Code: Select all
**** List of PLAYBACK Hardware Devices ****
card 0: UA25EX [UA-25EX], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0


Any suggestions?
LaTristesse
 
Posts: 35
Joined: Mon Jul 26, 2010 8:57 pm

Re: Audio

Postby tno » Sat Nov 20, 2010 11:03 pm

create that file with the contents I described.
tno
 
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Joined: Thu Aug 26, 2010 1:02 pm

Re: Audio

Postby LaTristesse » Sun Nov 21, 2010 12:12 am

Allready tried that with no success.
LaTristesse
 
Posts: 35
Joined: Mon Jul 26, 2010 8:57 pm

Re: Audio

Postby tno » Sun Nov 21, 2010 11:35 am

Did you try checking the contents of
Code: Select all
/proc/asound/card0/pcm0p/sub0/hw_params
?
Do they make sense?

If you have high cpu load, make sure that your player uses the same sampling rate as your soundcard.
If your playing files that are encoded with 44,1khz but your soundcard only supports 48khz, the CPU might be too slow to play without distortions.
tno
 
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Joined: Thu Aug 26, 2010 1:02 pm

Re: Audio

Postby LaTristesse » Tue Nov 23, 2010 9:08 pm

It works. I'm feeling lucky. I've no clue why it doesnt run at first time. Thank you.
LaTristesse
 
Posts: 35
Joined: Mon Jul 26, 2010 8:57 pm

Re: Audio

Postby peaslaker » Wed Dec 22, 2010 8:48 pm

Code: Select all
pcm.!default {
   type plug
   slave.pcm "front:CARD=Speaker"
  }
peaslaker
 
Posts: 101
Joined: Tue Sep 07, 2010 10:40 pm

Re: Audio

Postby shellwig » Wed May 04, 2011 1:41 am

For those that are interested I got one of these cheap USB audio adapters to work on my Dockstar running Arch Linux ARM.
http://www.geeks.com/details.asp?invtid=CL-USCM2&cat=SND
Image
It took a bit of tweaking to get rid of the pops and skips with mpd, than a bit more to get the processor usage down. After a few attempts to get mpd going I tried mpg123 and it was fine so I knew it was only a matter of time, I think it might have worked out of the box but I can not be sure.
  • mpg123 utilization is fairly steady at 1-2%
  • playing locally mpd runs in the 12-16% range
  • streaming mpd using the native httpd sits right around 95%, but is clean, no buffering problems.
I doubt I will stream much I just wanted to get it working, I played with the quality setting, 1.0 still sounds good and brought the cpu usage down from around 99%. I messed with the format settings for the outputs, in verbose mode the log did not show what I expected and impacted the cpu too much to make me give up any extensive testing once I found settings that worked.
I only attached a set of laptop speakers to the Dockstar not my stereo but I have no complaints about the sound quality.

asound.conf
Code: Select all
defaults.pcm.dmix.rate 44100 # Force 44.1 KHz
defaults.pcm.dmix.format S16_LE # Force 16 bits
pcm.!default {
       type hw
       card 0
}

ctl.!default {
       type hw
       card 0
}

mpd.conf
Code: Select all
input {
        plugin "curl"
}
audio_output {
        type            "alsa"
        name            "My ALSA Device"
        device          "hw:0,0"        # optional
        format          "44100:24:2"    # optional
        mixer_type      "hardware"      # optional
        mixer_device    "default"       # optional
        mixer_control   "PCM"           # optional
        mixer_index     "0"             # optional
        enabled         "yes"
}
audio_output {
        type            "httpd"
        name            "My HTTP Stream"
        encoder         "vorbis"                # optional, vorbis or lame
        port            "8000"
#       bind_to_address "0.0.0.0"               # optional, IPv4 or IPv6
        quality         "1.0"                   # do not define if bitrate is defined
#       bitrate         "128"                   # do not define if quality is defined
        format          "44100:24:1"
        max_clients     "2"                     # optional 0=no limit
        enabled         "no"
}
samplerate_converter            "3"
shellwig
 
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