Noice on analouge audio with mpd


18 posts
by naicheben » Fri Jun 15, 2012 7:35 pm
I'm using latest Kernel from pacman update 18:00 UTC:
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[root@alarmpi ~]# uname -a
Linux alarmpi 3.1.9-21-ARCH+ #1 PREEMPT Fri Jun 15 03:44:09 UTC 2012 armv6l GNU/Linux

MPD plays mp3 and inet radio. When I switch inet-radiostation with
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mpc clear && mpc load SMOOTHLOUNGE && mpc play
I get glitches or what it's called. I just installed my RPi in case and placed it at the amplifier. In my former tests I had it play through HDMI on the TV and had no trouble when switching radio channels.

Am I alone with this? Or is this a known bug of the analouge jack?
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by naicheben » Fri Jun 15, 2012 8:01 pm
I just checkt on the TV via HDMI: no problems. So it must be related to the analouge audio jack

EDIT: and it's not when a mp3 playlist plays. Only when hitting "next" key on the remote ... :
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mpc next
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by naicheben » Fri Jun 15, 2012 9:21 pm
Oh, it does make noisy sounds on pressing next in mp3 playlists, but it's not so loud as when I do
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mpc stop && mpc load bla.mp3 && mpc play
via irexec
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by felixfurtak » Tue Jun 19, 2012 4:37 am
Same issue here. white noise at the beginning of playback when using analogue output.

The issue is not confined to mpd. Also hear the same behaviour using speaker-test or aplay

I suspect it is due to the alpha status of the bcm sound module.

To make matters worse, I also now hear glitches during playback, only after the latest udev update.

Felix
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by naicheben » Wed Jun 20, 2012 6:54 pm
Ah, yes, I can hear them too. I thought it was an network/internet issue, but I agree this could be related to the alpha driver. Wonder if we should open a bugreport?
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by chmurli » Wed Jun 20, 2012 8:09 pm
These white noised are couse bad driver (hopefully it will be improved).
I have got rid of them by using USB sound card, audio quality is much better and no noises!
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by abel31 » Sun Jun 24, 2012 2:50 pm
chmurli, which USB-audio card do you use? Does it have SPDIF?
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by The_Dark_Zim-.- » Mon Jun 25, 2012 8:13 am
Hey,

Same issues here. Sounds like it is powering up the audio chip, when it is getting an audio stream. I'm using Mplayer/Gnome-Mplayer.

Greetings Zim
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by dom » Mon Jun 25, 2012 8:36 am
There has been an improvement to pops when starting/stopping audio through analogue jack.

Please update firmware and test again:
http://elinux.org/R-Pi_Troubleshooting# ... g_firmware
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by pepedog » Mon Jun 25, 2012 9:16 am
That page mentions Linux RPi 3.2.18, but official github is 3.1.10
Arch is current with latest 3.1.10 but not latest firmware, just version same date as linux, can't run "/opt/vc/bin/vcgencmd version" as Pi is down, newer firmware will be rebuilt soon to try that
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by moobsen » Wed Jun 27, 2012 8:19 pm
I have the same problem, noise on the analogue output. The weird thing is that with the original kernel from the debian 19-04 image I did not notice any problems. But with the newer kernel versions (built from source from the original repo) the noise started. I also tried the 3.2.21 kernel from Chris Boot (http://www.bootc.net/projects/raspberry-pi-kernel/), but without success, the noise is still there. Downgrading is also not an option, as I had different problems there (kernel panics...).

:cry:
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by abel31 » Thu Jun 28, 2012 8:50 pm
A solution the problems with analogue audio would off-course be to use an external USB soundcard. Does anybody have a suggestion for such a soundcard with SPDIF?
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by felixfurtak » Sun Jul 01, 2012 12:40 pm
I have had some success with a Creative Labs Soundblaster Live! 24-bit, USB sound card (Model Number SB0490). It works without any additional kernel modules in Arch and has both coaxial and optical SPDIF. The sound quality is much better than the analogue sound on the Pi. However, the support in Linux is only quite basic, with many of the features of the device not supported (like 6 channel output, volume and mic wheels, etc), so I'm not sure if I would recommend it. But if you find one cheap on Ebay, and need discrete SPDIF and can't use the Pi's digital audio over HDMI then this could work for you.
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by dom » Sun Jul 01, 2012 12:45 pm
@moobsen
There was another analogue audio fix a few days ago. Any better?
If there is still a problem, explain how I can reproduce it.
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by felixfurtak » Mon Jul 02, 2012 6:04 am
dom wrote:@moobsen
There was another analogue audio fix a few days ago. Any better?
If there is still a problem, explain how I can reproduce it.


Dom, can you point me towards the fix that you are talking about? Is it in the main Arch repositories?

Thanks.
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by pepedog » Mon Jul 02, 2012 8:26 am
Yes, just pacman -Syu
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by contractorwolf » Thu Jul 19, 2012 11:19 pm
Hmm, when I first got mpc and mpd up and running I heard some slight issues (minor) with the quality and noticed that the "mpc volume" command would have strange behaviors (i.e. would set the volume to 167% instead of whatever integer I put in).

After the latest round of updates I had to do in order to install OpenCV I noticed that the "mpc volume 80" would actually set the volume to 80% instead of what it was doing before BUT the quality is a lot worse. Lots of hissing and pops in the background. Something in the updates made the quality go down. Anybody else notice what I am seeing (or hearing)? Anybody got something I can try to test?
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by naicheben » Thu Jul 19, 2012 11:41 pm
I can confirm the bad quality of the analouge output (kernel 3.1.9-22 - 3.1.9-30). When I switch playlist with mpc load BlaList && mpc play I get a short crackling noice. And then the playback is also distored. It gets worse when I change the volume.
It's still not usable, I guess we will have to wait much longer for a stable sound driver to come up. At least for analouge sound. My test via HDMI were OK (with kernel 3.1.9-22).
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