OpenJay Forums

Terratec 5.1 USB && Linux - 2005/01/11 22:14

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[quote:c259b5f1fe="J_Zar"]Sure it is possible to use 6 channel with Alsa. The problem is configuring with .asoundrc, that is not so clean and easy as configure method.
[/quote:c259b5f1fe]

Ok, I've been googleling and with help of FrankBarknecht and I've found that in order to use all the 6 channels it's no necessary to do anymore than send a 6 channel audio file. The sound card is already to use 2 or 6 channels (it has two "alt settings"), as it can be seen in

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> cat /proc/asound/card1/stream0
USB Audio at usb-0000:00:10.0-1, full speed : USB Audio

Playback:
Status: Stop
Interface 1
Altset 1
Format: S16_LE
Channels: 2
Endpoint: 1 OUT (ADAPTIVE)
Rates: 48000
Interface 1
Altset 2
Format: S16_LE
Channels: 6
Endpoint: 1 OUT (ADAPTIVE)
Rates: 48000
(...)
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The driver chooses the better 'altset' to fit the audio stream. If you want to access some particular channel with, for example, a stereo (2 channel) sound file, you must use, indeed, the .asoundrc file. I attach my own; my Terratec is card1 in my computer.

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> cat ~/.asoundrc
pcm.aureon_front {
type route
slave.pcm "hw:1"
slave.channels 6
ttable.0.0 1
ttable.1.1 1
}

pcm.aureon_rear {
type route
slave.pcm "hw:1"
slave.channels 6
ttable.0.4 1
ttable.1.5 1
}

pcm.aureon_mid {
type route
slave.pcm "hw:1"
slave.channels 6
ttable.0.2 1
ttable.1.3 1
}

pcm.mixxx {
type route
slave.pcm "hw:1"
slave.channels 6
ttable.0.0 1
ttable.1.1 1
ttable.2.4 1
ttable.3.5 1
}

pcm.ch51dup {
type route
slave.pcm "hw:1"
slave.channels 6
ttable.0.0 1
ttable.1.1 1
ttable.0.2 1
ttable.1.3 1
ttable.0.4 0.5
ttable.1.4 0.5
ttable.0.5 0.5
ttable.1.5 0.5
}

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In each line of ttable, the first number refers to the channel of the input stream, the second to the channel of the soundcard, and the third is the "weight" assigned (0 to 1).

To test it you can try:

> aplay -Dplug:aureon_front test.wav
> aplay -Dplug:aureon_mid test.wav
> aplay -Dplug:aureon_rear test.wav
> aplay -Dplug:ch51dup test.wav
...

The 'plug' plugin is used to convert sampling rate, format, etc...

I hope to have been helpful...

Regards,

ßingen.

Terratec 5.1 USB && Linux - 2005/01/12 01:17

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Really wonderful Holonauta!!!

I must try your .asoundrc this week_end to mixxx. Thank you for your posting.

Your experience will surely be useful to others (as me!).

Terratec 5.1 USB && Linux - 2005/03/03 21:18

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thx

Terratec 5.1 USB && Linux - 2005/08/08 04:26

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Thx a lot for the .asoundrc, now I can listen to my MP3s in true surround. But DVD playback is still not working with surround (in analog mode). Maybe anyone has a solution for this?

(Tried it with xine, surround51 wasn't recognized, and I only get garbage if I try to play it with ch51dup)

Greets Jeriko

Terratec 5.1 USB && Linux - 2005/08/10 17:14

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Jeriko: actually I don't use the dvd player with a full sorround. So I can't help in this. I think a solution could be achieved through the Alsa plugins with Xine. Let us know!

Terratec 5.1 USB && Linux - 2005/12/05 21:02

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Where can I buy one of these soundcards at? all my google results come up in the UK.