alsamixer no pcm meter

GreenFireFly · 11-29-2015, 04:48 PM

Hello Everyone,

I needed to record my desktop audio so i loaded the sound loop module

modprobe snd_aloop

then i found this asoundrc and copied it to /home/username/.asoundrc.

Code:

pcm.!default {
  type asym
  playback.pcm "LoopAndReal"
  #capture.pcm "looprec"
  capture.pcm "hw:2,1"
}

pcm.looprec {
    type hw
    card "Loopback"
    device 1
    subdevice 0
}


pcm.LoopAndReal {
  type plug
  slave.pcm mdev
  route_policy "duplicate"
}


pcm.mdev {
  type multi
  slaves.a.pcm pcm.MixReale
  slaves.a.channels 2
  slaves.b.pcm pcm.MixLoopback
  slaves.b.channels 2
  bindings.0.slave a
  bindings.0.channel 0
  bindings.1.slave a
  bindings.1.channel 1
  bindings.2.slave b
  bindings.2.channel 0
  bindings.3.slave b
  bindings.3.channel 1
}


pcm.MixReale {
  type dmix
  ipc_key 1024
  slave {
    pcm "hw:0,0"
    rate 48000
    #rate 44100
    periods 128
    period_time 0
    period_size 1024 # must be power of 2
    buffer_size 8192
  }
}

pcm.MixLoopback {
  type dmix
  ipc_key 1025
  slave {
    pcm "hw:Loopback,0,0"
    rate 48000
    #rate 44100
    periods 128
    period_time 0
    period_size 1024 # must be power of 2
    buffer_size 8192
  }
}

I changed the capture.pcm "hw:0,0" to capture.pcm "hw:2,1". I have sound and can capture it with

ffmpeg -f alsa -i hw:2,1 -codec:a libvorbis -qscale:a 6 out.ogg

Problem 1).There is no pcm level meter in the alsamixer.
Problem 2).The ogg file plays in music player but when i try to open it with mhwaveedit i get unexpected end of file.

How can i resolve this?

WLD · 11-29-2015, 08:17 PM

Not sure about problem 1; maybe you can you try moving your customised files out the way and try with a blank slate and see if PCM mixer returns?

With regards to problem 2 it's probably just a bug in mhwaveedit, you could try converting the file with MPlayer/MEncoder/ffmpeg? Maybe take it back to a WAVE then convert it to an OGG again?

# mplayer -ao pcm:file=raw.wav input.ogg
# ffmpeg -i raw.wav -acodec libvorbis output.ogg