How to build an Audio compressor with SPDIF (Toslink) Input / Output

[wavoigt]

Hi,
I plan to make an audio compressor with ESP32 and Arduino IDE with SPDIF (Toslink) Input / Output.
I found some examples like:
examples/examples-dsp/examples-maximilian/17-Compressor/17-Compressor.ino,
examples/examples-stream/streams-generator-spdif/streams-generator-spdif.ino and
examples/examples-stream/streams-i2s-filter-i2s
I know, for the SPDIF Input i probably need a converter like DIR9001. (SPDIF -> I2S)
Now, how to combine the obove examples like i2s-compressor-spdif ?
Could anyone pls give me some hints how to get the job done?

[pschatzmann]

If you are ok with mono 16bits you can use the Compressor provided by the AudioEffects: if you have a stereo imput it mixes the input into mono and just provides 2 identical mono outputs.
If you want something else, I suggest that you implement your own Stereo Compressor Stream class: you can use the exististing implementation as starting point, just using a separate Compressor for each channel.

You could also try to implement your own logic chaining a VolumeMeter and VolumeStream and updating the volume based on what's provided by the meter.

[wavoigt]

Thank you for your response.
16bit will be ok, but i need a stereo compressor.
If i use a separate Compressor for each channel, how can i split the input into the 2 stereo channels?

[pschatzmann]

This can be found in The most important basics!