VLC surround to stereo problem

pootzko · 2011-10-28 19:25:18

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

Last edited by pootzko (2011-10-28 19:30:00)

brebs · 2011-10-28 20:36:58

Use downmix_51to20 in my ~/.asoundrc

toad · 2011-10-29 06:51:10

I had the same problem, found a different stanza for .asoundrc but it didn't work. Kaffeine, however, did so I used that for a while. Will now try downmix - thanks

pootzko · 2011-10-30 08:47:10

brebs wrote:

Use downmix_51to20 in my ~/.asoundrc

Should I just put this:

pcm.downmix_51to20 {
	# From http://www.halfgaar.net/surround-sound-in-linux
	type route
	#slave.pcm "default"
	slave.pcm "dmixed"

	# 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
}

into my .asoundrc (I didn't have one before, I just created it in my home directory), or do I need to put anything else into my asoundrc?

Last edited by pootzko (2011-10-30 08:47:43)

toad · 2011-10-30 09:08:49

That is my understanding. I just copied that as well.

brebs · 2011-10-30 09:09:55

If you're gonna do that, switch the commented slave.pcm line to be the "dmixed" line.

Test with:

speaker-test -D downmix_51to20 -c 6 -t wav

pootzko · 2011-10-30 11:08:39

this is what I get:

$ speaker-test -D downmix_51to20 -c 6 -t wav

speaker-test 1.0.24.2

Playback device is downmix_51to20
Stream parameters are 48000Hz, S16_LE, 6 channels
WAV file(s)
ALSA lib pcm.c:2212:(snd_pcm_open_noupdate) Unknown PCM dmixed
Playback open error: -2,No such file or directory

I don't get it which file am I missing? hm..

Last edited by pootzko (2011-10-30 11:09:01)

brebs · 2011-10-30 14:11:39

I was kinda hoping this would be blatantly obvious to everyone:

slave.pcm "default"

A hash at the start of the line means it's a commented line, and doesn't take effect.

pootzko · 2011-10-30 14:24:51

aaah, ok. sorry.. I know what hashes are for, but how I read it, I thought you wanted the default one to be commented out, and dmixed to be active, which was strange to me because it was already like that.. now when I read your post more carefully, I see what you meant. sorry for that, and thank you for your patience.

this is what I get now:

$ speaker-test -D downmix_51to20 -c 6 -t wav

speaker-test 1.0.24.2

Playback device is downmix_51to20
Stream parameters are 48000Hz, S16_LE, 6 channels
WAV file(s)
Broken configuration for playback: no configurations available: Invalid argument
Setting of hwparams failed: Invalid argument

brebs · 2011-10-30 15:06:22

Have you got other stuff in your ~/.asoundrc? Messed around with pcm.!default, for example? Show your full file.

Also, try adding plug: like so:

speaker-test -D plug:downmix_51to20 -c 6 -t wav

pootzko · 2011-10-31 14:46:54

my full asoundrc is just your downmix_51to20 function and nothing else

pcm.downmix_51to20 {
	# From http://www.halfgaar.net/surround-sound-in-linux
	type route
	slave.pcm "default"
	#slave.pcm "dmixed"

	# 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
}

with plug i get this:

$ speaker-test -D plug:downmix_51to20 -c 6 -t wav

speaker-test 1.0.24.2

Playback device is plug:downmix_51to20
Stream parameters are 48000Hz, S16_LE, 6 channels
WAV file(s)
ALSA lib pcm_params.c:2162:(snd1_pcm_hw_refine_slave) Slave PCM not usable
Broken configuration for playback: no configurations available: Invalid argument
Setting of hwparams failed: Invalid argument

Last edited by pootzko (2011-10-31 15:26:09)

brebs · 2011-10-31 15:16:59

#slave.pcm "default"
slave.pcm "dmixed"

Shirley you can't be serious. I just told ya!!

If you haven't defined "dmixed", then don't try to use it. It's - that - simple.

pootzko · 2011-10-31 15:25:54

sorry, I just copied the one from my previous post.. forgot that I changed it after you told me to set it to "default". so it is set to "default" atm.

Arch Linux

#1 2011-10-28 19:25:18

VLC surround to stereo problem

#2 2011-10-28 20:36:58

Re: VLC surround to stereo problem

#3 2011-10-29 06:51:10

Re: VLC surround to stereo problem

#4 2011-10-30 08:47:10

Re: VLC surround to stereo problem

#5 2011-10-30 09:08:49

Re: VLC surround to stereo problem

#6 2011-10-30 09:09:55

Re: VLC surround to stereo problem

#7 2011-10-30 11:08:39

Re: VLC surround to stereo problem

#8 2011-10-30 14:11:39

Re: VLC surround to stereo problem

#9 2011-10-30 14:24:51

Re: VLC surround to stereo problem

#10 2011-10-30 15:06:22

Re: VLC surround to stereo problem

#11 2011-10-31 14:46:54

Re: VLC surround to stereo problem

#12 2011-10-31 15:16:59

Re: VLC surround to stereo problem

#13 2011-10-31 15:25:54

Re: VLC surround to stereo problem

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