Question about combining autoGainControl (from mediaDevices.getUserMedia) and DynamicsCompressorNode

[grazder]

Hello! I need help understanding the gain parameters for autoGainControl (from mediaDevices.getUserMedia) and DynamicsCompressorNode.

I have a pipeline of

Source -> `autoGainControl: True` -> some other nodes -> `DynamicsCompressorNode` -> Destination

autoGainControl sets the volume of the source audio to a certain volume range. Then I run several nodes that change this volume range (for example, I make the audio quieter). After that, I use DynamicsCompressorNode to compress the audio AND to boost the volume of the audio, since auto makeup gain is built into DynamicsCompressorNode.

And with this pipeline I want that at the destination after the full pipeline (Source -> autoGainControl: True -> some other nodes -> DynamicsCompressorNode) I have the same volume as after autoGain (Source -> autoGainControl: True -> Destination).

Can I do this? Can you help me understand what DynamicsCompressorNode parameters I should use for this? And with what limitations?

[grazder]

https://chromium.googlesource.com/external/webrtc/+/lkgr/modules/audio_processing/agc/agc.cc#24

If autoGainControl forces audio to -18dB, so I need to set DynamicsCompressorNode.threshold.value = -18? Is this the solution or am I missing something?

[grazder]

@padenot

[padenot]

The only way to do this is to measure what you have at the output of your pipeline and adjust. autoGainControl isn't specified precisely and it will differ frequently from one situation to the next (browsers, OS, browser version, OS version, etc.).

[grazder]

Thank you!