Moc has random static when playing 24bit files and ForceSampleRate is enabled

Submitted by l0vot on Mon, 2013-07-22 19:25

Forums:

I am trying to circumnavigate the crappy re-sampling done by dmix by making sure the stream does not need to be re-sampled in. Moc has ForceSampleRate as an option in it's config file, so I used ForceSampleRate = 48000 in the moc config file. This appeared to work, until one of my 24bit 44100hz files began to play. There were random little pops for the duration of any of the 24 bit files. disabling re-sampling by commenting out the ForceSampleRate option immediately got rid of the pops. the rest of my config file is (or at least the possibly relevant parts):
[code
]ReadTags = yes
Sort = FileName
ShowStreamErrors = no
Mp3IgnoreCRCErrors = yes
OutputBuffer = 1024
InputBuffer = 1024
Prebuffering = 128
SoundDriver = ALSA
JackOutLeft = "alsa_pcm:playback_1"
JackOutRight = "alsa_pcm:playback_2"
OSSDevice = /dev/dsp
OSSMixerDevice = /dev/mixer
OSSMixerChannel1 = pcm
OSSMixerChannel2 = master
AlsaMixer1 = PCM
AlsaMixer2 = Master
AlsaDevice = default
UseMmap = no
ResampleMethod = SincBestQuality
ForceSampleRate = 48000
Allow24bitOutput = yes
UseRealtimePriority = yes
ModPlug_Oversampling = yes

Am I just doing it wrong, or is this a bug.

PS. I already tried to increase the buffer sizes, it didn't help.

tomaszg

Tue, 2013-07-23 14:13

What moc version are you using? You could try to upgrade to latest svn version since a similar bug with 24bit audio was recently fixed (commit 2511). Also you could check out this patch http://moc.daper.net/node/901 which addresses several audio quality related issues and provides more debug information as well.

In any case, also you should run moc by "mocp -D" to produce log files (if it's compiled with debug enabled). Most interesting part would be lines from mocp_server_log about "print_output_capabilities" and other audio.c messages.

l0vot

Tue, 2013-07-23 19:03

<br /> Version : 2.5.0-beta1<br /> Revision : 2506<br /> Built : Feb 19 2013 23:57:36<br />

This is the newest version in the Arch repo, and it appears to be quite old for an Arch package.

l0vot

Tue, 2013-07-23 19:32

I installed moc-svn from the AUR, problem solved. Thanks for the help. This isn't the first time the AUR has been the solution to my problems, maybe there should be a note in the bug section to install the SVN version of MOC before posting any bugs...