On 14/10/16 15:34, Matt Flax wrote:

Hi there,

Problem is that I need multiplex all 6 channels out a stereo I2S line.

I have a working system ... the CPU thinks it is stereo I2S, but the codec thinks it is TDM multichannel. When I aplay a pre-interleaved wav file, it works ! Check the video here : https://www.kickstarter.com/projects/1250664710/1299781340?token=e465b540

Problem is that I need to multiplex all 6 channels down the stereo I2S line. I have tried to do this with the asoundrc by attempting to declare the same device 3 times and interleaving there, however have failed.

Does anyone know if there is a ALSA plugin which allows multiplexing of N channels to a single interleaved stream ? It is simple, it seems to do the opposite and interleave multiple sound card streams into one stream... but I can't see how to do the opposite ... have a virtual sound card of N channels which muxes down to one stream on a stereo machine/cpu/codec line.

I am happy to alter my machine driver to implement this ... Is there a way to present 3 stereo subdevices to the user, where each of these subdevcies is interleaved to form the TDM before sending to the codec ?

Is there perhaps a better or more elegant way to go about this ?

thanks

Matt

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