4

I noticed a problem with certain video files where speech volume component is just too low. I googled a bit and it seems that the problem is that it tries to play surround sound on stereo speakers and it fails to blend everything in as it should. If I play the same video in mplayer, everything is normal.

Does anyone else have the same problem? Anyone know how to fix this? I tried changing the output module in vlc audio settings, but the problem would remain no matter what I chose. Thanks.

Version of VLC that I am using is 1.1.12 on Arch-Linux (KDE 4.7.2).
If you any additional info is needed, I will provide it.

1

1 Answer 1

1

Downmixing/Adjust from 5.1 to 'true' 2.1

I use ALSA and Pulse Audio on my Arch Linux machine.

You want to control how downmixing to 2.0 is done, so you're going to define a custom sound device in /etc/asound.conf

You can use this output configuration:

(add the custom function to the file /etc/asound.conf)

pcm.51to20
{
  type route
  slave.pcm surround51
  slave.channels 6

  # Front and rear, at 33% of original signal strength
  ttable.0.0 0.33
  ttable.1.1 0.33
  ttable.2.0 0.33
  ttable.3.1 0.33

  # Center channel routing (routed to front-left and front-right),
  # 6dB gaindrop (gain half of main channels) per channel
  ttable.4.0 0.16
  ttable.4.1 0.16

  # LFE channel routing (routed to front-left and front-right),
  # 6dB gaindrop (gain half of main channels) per channel
  ttable.5.0 0.16
  ttable.5.1 0.16
}

Then in VLC

Go to the audio preferences

Tools -> Preferences -> Audio

Set Outputmodel to Alsa audio output

and

Set Device to Default ALSA Output (currently PulseAudio Sound Server)

Save and restart VLC

1
  • This does not seem to work for me. Not even when testing it with aplay with some 5.1 file: aplay -D 51to20 file.wav. Why would this new audio device become default just from adding it? Btw. the source of the config should be cited here too.
    – miyalys
    Feb 28, 2017 at 10:44

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .