OBS31: Compressor does not work with ASIO devices on launch

[GForceWeb]

Intro:

In OBS31, if you have an ASIO source with a compressor filter using another ASIO source as the sidechain source it will not work on launch. It behaves as if the compressor is not receiving any audio from the sidechain source. Resolving this issue involves switching the sidechain source to a non-asio source and then switching back, every time OBS is opened.

Overview of my specific setup:

• Windows, OBS31, all plugins up to date
• My primary stream audio comes from a Rodecaster Pro II.
• I use the multitrack mode on the Rodecaster and OBS-ASIO plugin to add individual tracks from the Rodecaster into OBS as unique sources (DJ Dry & Microphone)
• I use Source Clone to duplicate DJ Dry as DJ Wet and apply a sidechain compressor to DJ Wet using Microphone as the source to create a ducking effect so that I don't have to try and talk over the music.
• DJ Wet goes to Twitch while DJ Dry gets recorded on a separate audio track allowing me to have a clean recording of the DJ mix, without me talking to chat over the top of it.

This setup worked perfectly in OBS30.

The Issue:

In OBS 31, when OBS first launches, the Compressor on DJ Wet does not function at all. It behaves as if it's not receiving any audio at all from the Microphone sidechain source. The only way to resolve this appears to be changing sidechain source to a non-ASIO source with audio sufficient to engage the compressor. Then, changing the sidechain source back to Microphone has it working normally. This is tedious to try and remember to do before each stream and a pain to do while live if I forget.

I verified that this issue only presents itself when both the parent source and the sidechain source on the compressor are both ASIO sources as I ran 4 separate tests with only the first causing this behaviour:

• ASIO Source w/ASIO Compressor Sidechain Source
• ASIO Source w/Standard Media Sidechain Source
• Standard Media Source w/ASIO Compressor Sidechain Source
• Standard Media Source w/Standard Media Sidechain Source

The OBS devs mentioned that no changes were made to the compressor filter in OBS31 so to me it sounds like perhaps something changed in how audio devices get initialized causing this weird edge case with the ASIO sources and the compressor? Just a thought

I have noted that you don't appear to be actively supporting this plugin right now. While C++ isn't my strong suit (web dev background) I'm motivated to try and find a way to resolve this issue. Even if you don't have the time to work on resolving this issue yourself I'd really appreciate any thoughts you can share about where you think this issue could be coming from and/or where might be a good place to start tinkering given your knowledge of the codebase.