[Alsa-user] rate coverter after dmix

[remu kelly]

Hi,

I need to implement a rate converter after dmix, means dmix will mix 3
channels as input, and the output will be of 48KHz, but then i need to
convert it to 96KHz output and send to HW.
How this can be achieved, seeing that we can't have a plugin after dmix.

or we can do somethings like below:-

pcm.sl1{
type hw
card 0
device 0
}

pcm_slave.sl2 {
pcm sl1
rate 96000
}

pcm.mix1{
type dmix
ipc_key 1024
slave sl2
}

pcm_slave.sl3{
pcm mix1
}

pcm.play{
type plug
slave sl3
rate_converter "myconverter"
}

here rate converter "myconverter" will be specific to my audio HW.

is the above config allowed?


Regards

[Clemens Ladisch]

Post by remu kelly
I need to implement a rate converter after dmix, means dmix will mix 3
channels as input, and the output will be of 48KHz, but then i need to
convert it to 96KHz output and send to HW.

Why do you think you need to do this?

Post by remu kelly
pcm.sl1{
type hw
card 0
device 0
}
pcm_slave.sl2 {
pcm sl1
rate 96000
}

This says that the the hardware device must run at 96 kHz.

Post by remu kelly
pcm.mix1 {
type dmix
ipc_key 1024
slave sl2
}

Because of the above, the dmix plugin also runs at 96 kHz.

Why don't you want this?


Regards,
Clemens

[James Shatto]

Post by remu kelly
How this can be achieved, seeing that we can't have a plugin after dmix.

Couldn't you use snd-aloop and have a plugin AFTER dmix? It basically
creates a loopback interface who's output channel is the input
channel. Although I've never used it (yet). But one way to pulse
over jack without using the jack module part of pulse.