HOWTO: Surround sound in pulseaudio

[MemoryDump]

MemoryDump:

That sort of usage of pulseaudio is way out of the scope of this guide - I haven't got the foggiest on how to help you I'm afraid

For that sort of thing, you will probably have better luck asking on IRC, or possibly starting a new thread.

Sam

Thanks Sam! I'll start a new post.. thanks

[neymac]

I did the easy way and for test I did

speaker-test -Dplug:surround51 -c6 -l1 -twav

and worked all the six channels.

[parthibanbls]

Hi,
I have an NVidia 7.1 Sound Card and a 2.1 Speaker System. I'm able to get sound on only one speaker (and the subwoofer works).

I tried changing the channel_map in /etc/pulse/default.pa but haven't been able to get any sound on the other speaker.

Changing the channel_map from 'left,right' to 'right,left' outputs the other channel (previously missing) on the same speaker. So, basically I've been able to get both channels (not at the same time) on one speaker, while nothing comes out of the other speaker.

Tested the speakers on a windows laptop and they worked fine.

Any help is greatly appreciated.

Thanks,
Partho.

[parthibanbls]

Hi,
I have an NVidia 7.1 Sound Card and a 2.1 Speaker System. I'm able to get sound on only one speaker (and the subwoofer works).

I tried changing the channel_map in /etc/pulse/default.pa but haven't been able to get any sound on the other speaker.

Changing the channel_map from 'left,right' to 'right,left' outputs the other channel (previously missing) on the same speaker. So, basically I've been able to get both channels (not at the same time) on one speaker, while nothing comes out of the other speaker.

Tested the speakers on a windows laptop and they worked fine.

Any help is greatly appreciated.

Thanks,
Partho.

Here's what I changed in default.pa

### Automatically load driver modules depending on the hardware available
#.ifexists module-hal-detect.so
#load-module module-hal-detect
#.else
### Alternatively use the static hardware detection module (for systems that
### lack HAL support)
#load-module module-detect
#.endif

### Load manual channel config. Uncomment the above and recomment the below to go back to defaults.

load-module module-alsa-sink device=hw:0 channels=2 channel_map=left,right


Setting channels=3 made pulseaudio fail to load.

aplay -L gave:

front:CARD=NVidia,DEV=0
HDA NVidia, ALC662 Analog
Front speakers
surround40:CARD=NVidia,DEV=0
HDA NVidia, ALC662 Analog
4.0 Surround output to Front and Rear speakers
surround41:CARD=NVidia,DEV=0
HDA NVidia, ALC662 Analog
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=NVidia,DEV=0
HDA NVidia, ALC662 Analog
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=NVidia,DEV=0
HDA NVidia, ALC662 Analog
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=NVidia,DEV=0
HDA NVidia, ALC662 Analog
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
null
Discard all samples (playback) or generate zero samples (capture)

[sammydee]

parthibanbls:

Has your sound ever worked in stereo?

This thread is really meant to specifically help people with more than two speakers get surround sound working. If pulseaudio doesn't even work in standard stereo mode, I think you probably need to make a new thread - that's a completely different problem. (Note: My sound card outputs only on one channel sometimes on startup, it is solved by changing just one volume in alsamixer - I think it's some sort of stupid bug).

I think some confusion may be arising here - if you have a standard 2.1 setup, you DON'T need this guide. This guide is only useful for people with at least four speakers. The standard 2.1 speaker sets that you get only have ONE stereo input jack - they can't accept more than two channels at all, even in windows!

Sam

[sammydee]

I did the easy way and for test I did

speaker-test -Dplug:surround51 -c6 -l1 -twav

and worked all the six channels.

neymac - I think that command tests surround sound with alsa rather than pulseaudio specifically, that's why I didn't recommend it in the guide. Believe it or not, there are scenarios where alsa will not work with surround sound but pulseaudio will. Actually this is the case in my setup - I access my 7.1 sound card across the network from another computer most of the time, but alsa only has access to the local two channel sound card.

It's a better idea for most people to use the flac test file (unfortunately I had to give it non-standard channel mapping to force gstreamer to play it properly, but that's gstreamer being non-standard, so that file won't play properly on flac decoders that use standards-compliant channel mapping ie winamp or foobar2000 on windows.)

Sam

[parthibanbls]

hi sammydee,
Thanks for the reply.

I know I only have a 2.1 speaker setup, but it seems like the problem is due to the sound card being 7.1. And that pulseaudio is not sending sound over the correct channels (out of the eight available).

I think the problem can be solved if I can there's a way to find which of the 8 channels are played by my 2.1 speakers, and have pulseaudio choose those channels.
Is there a way to find that?

I tried 'speaker-test -c8' (with pulseaudio shut down) but that too produced sound on only one speaker.

Thanks,
Partho.

[sammydee]

parthinabls:

Hmm if sound isn't working even in stereo that's a fairly major problem - if I was you I'd start a new thread with that, or ask on irc. This guide is really to help people get surround sound working once they already have stereo - you'll get more and better help if you ask on another thread I think. See if a search turns up anybody else with a similar card.

sam

[neymac]

I used the flac test file with totem-gstreamer and all speakers worked.
But with mplayer there was no sound when I select pulseaudio as audio output (mplayer -ao pulse Multichannel_test_flac_nonstandard_8.flac).
Is there any way to allow mplayer to play pulse?
There is a "pulse" option when I select preferences in mplayer, but if I select it => no sound.
By the way, at the terminal it looks like the file was playing (no error message), but no sound.

[sammydee]

neymac: This looks like a problem with mplayer, not a problem with pulseaudio afaik. I use smplayer as a frontend - set the channels to 5.1 and it works great for me.

Sam