Help with emu10k1, ALSA knowledge, routing?

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Hi there,

I'd like to ask some questions regarding various things centred around a Sound Blaster Live! Value (CT4780) card.  My set up is as follows:

- I have a PC running Debian with a 2.6.32-5-686 kernel
- /proc/asound/version is "Advanced Linux Sound Architecture Driver Version 1.0.21."
- I have two amplifiers connected, each with two speakers, one amplifier is connected to the green 'front' output, the other to the black 'surround' output.

Note:

- I have no interest in proper surround sound playback.
- I apologise in advance for using the incorrect terminology.
- I have a background in sound desks / mixers, and would like to use my card (if possible) to replicate the functionality of auxilliary sends.
- I know almost nothing about ALSA and have struggled to find good documentation aimed at a non-developer user.
- I don't mind writing a C program or two if need be to make my sound card do certain things.

The story:

I installed the card in the PC and it seems to be doing basic functions fine.  I can open alsamixer and adjust various volumes correctly (once I'd figured out which were which) and I can play mp3s with mplayer for example.

I am not sure what the correct term is, so from here on, I will refer to the source of sounds that come from applications like mplayer as the 'software source'.

I can hear music from both the front and surround speakers when I play mp3s with mplayer, and it seems that the 'Playback' part of Alsamixer gives me the following useful controls:

Master        - allows me to adjust the overall output volume of the card.
PCM           - seems to be a sort of submaster volume control for both 'software source' and 'capture sounds'.
Wave          - seems to control how much of the 'software source' is sent to the front speakers.
Wave Surround - seems to control how much of the 'software source' is sent to the surround speakers.

This is great and I have no complaint.  Now, I plugged in my TV PC into the sound card's Line-In socket.  I can hear this in either of the following two ways:

1) unmute the Line channel on the Playback mixer, turn the volume up
2) set the Line channel's capture flag on the Recording mixer, set the 'Capture' channel's capture flag on the Recording mixer, adjust its volume.

In either scenario, the sound from the TV PC only is sent to the front speakers.  In scenario 2) I can also adjust the volume of the Line signal using the PCM channel on the Playback mixer.

The end goal:

I'd like if I could the other stereo inputs on the sound card (internal MPC2? connections) to allow me to connect two additional sources of sound and use the soundcard hardware to do the appropriate routing so I can choose which sources of sound are routed to which pair of speakers.

In a sound desk mixer, this is easily achieved with 1 aux send.

The question:

Is it possible to control the routing of the input channels to the various outputs on the card?  I'd like to avoid using real time software like sox to continuously copy sound from one place to another.  Does this card even support what I'm asking or is it simply not possible?

Kind regards,

Justin



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