Mute compressed audio
I am using an ADAU1452. When the DSP receives compressed audio, e.g. AC3, on the S/P-DIF interface a nasty noise is heard. I would like to mute the DSP when compressed audio is received.
Muting ASRC when lock is lost doesn't help as there is a lock on a valid signal. So how can I mute when the DSP cannot handle the signal?
Best regards
Ivan Johansen
Audio Signal Processors
adau1452
SigmaDSP Audio Processors
Hello Ivan,
There is a register on the ADAU1452 that updates with the compression mode on an incoming S/PDIF signal; its address is 0XF603.
By monitoring this register, you would be able to take appropriate action if the audio received was compressed. However, to monitor this register you would either need to use an external MCU, or a custom-developed block in SigmaStudio. At this time, SigmaStudio does not have included support for polling this register within a schematic.
Regards,
Tyler
Thanks for answering, Tyler.
It sounds strange that the DSP can detect that there is compressed sound, which it cannot handle, but it cannot mute based on that knowledge. Isn't it possible to mute the signal based on the contents of a register?
We have an MCU in the design. But I am not sure if we can poll the DSP fast enough to avoid the noise getting through, and as far as I know it is not possible to get an interrupt when a register changes.
Best regards
Ivan Johansen
Hello Ivan,
It is possible to have the DSP take action on its own, but since there is no existing block in SigmaStudio that monitors that register, it would need to be custom coded. The advantage of this would be that it would react instantaneously to compressed audio being sent.
Regards,
Tyler
Okay. Thank you for the answer, Tyler. I assume this means that we would need to ask Analog Devices to code the block. We will consider if that is the way to go.
Best regards
Ivan Johansen
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