I'm curious if I2S bus can transfer PCM data only in SigmaDSP, or it can also transfer encoded data like Dolby AC-3 etc.?
SigmaDSP cannot decode data that is in a format like Dolby AC-3, etc. However, as long as you do not use ASRCs or any digital processing in the DSP, the serial ports should pass through that data without modifying it. I think this will work, but it's not something that we test since it's not a common use case. So, you could do something like Serial In -> DSP (no processing) -> Serial Out and the data should come out exactly the same as it went in.
No guarantees, but in theory that should work fine.
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