I believe it is time to get a solution to the most plaguing issue (in my opinion) of AVPro: Audio Filters I do not think this is a "can't fix" situation. In this proposal I will go over the problem, considerations that have been discussed historically, and the solution I believe is feasible to implement with working sample code. ### Previous Cannys 1) https://feedback.vrchat.com/open-beta/p/986-avpro-player-ignores-lowpass-reverb-and-other-filters 2) https://feedback.vrchat.com/sdk-bug-reports/p/avpro-video-player-audio-filter-issue 3) https://feedback.vrchat.com/sdk-bug-reports/p/sound-effects-are-not-applied-to-audiosource-using-avpro-that-comes-with-sdk3 4) https://feedback.vrchat.com/feature-requests/p/usharpvideo-stream-audio-does-not-support-filters ### Crux of the issue As previously discussed in above canny #1, the current way of handling the AVPro speaker component (type named AudioOutput ) is that the component is implicitly created via AddComponent on the same game object. This has the critical drawback of being unable to respect any audio filters due to the DSP filter chain being _component order dependent_. The second half of this issue is that Unity has no runtime native way to change the ordering of components without fully reconstructing the references. This causes very obvious issues in regards to dependent scene references. (TCL's comment in canny #1 clarifies this as well) ### What has been considered Detecting and destroying/rebuilding known filter components after the implicit component is added. This is bad because all scene references to those components would be lost (eg: UI Events or public Udon variables). To avoid the lost components issue, a full scene search would be required in order to update the references which is costly and fragile. Placeholder components (shims) for each filter type that gets implicitly created after the implicit AudioOutput This is bad because it does not allow users to reference the actual filter components in the inspector (namely an issue for UI Events) Allow adding the AudioOutput script manually in scene and have the speaker search for it before trying to implicitly add the component. This is bad because it requires that the user import the AVProTrial package to be able to use built-in unity audio filters. This needs to be compatible with situations where the user does not wish to import that package so the dependency is decoupled from the feature itself. ### Proposed Solution A shim script that inherits from the AudioOutput class combined with a compiler flag for detecting if AVPro is present, and if not, then have a stub type of the _same namespace and type name_ which is _ONLY_ present in the sdk. Then update the VRCAVProVideoSpeaker to check for the existence of the shim component before creating an implicit AudioOutput, using it instead if found on the game object. This ensures that when the main shim script is loaded in editor, it is already a valid AudioOutput component and the component order is correctly retained so the Audio Filters will work correctly. In the SDK, the script type will check for the existence of AVPro through a version define, and if NOT present, will enable the AudioOutput stub class of the same namespace. An example of what it might be like: https://gist.github.com/techanon/41efc336604e148dde55862bff1778d9 I've tested this specific example in editor and it works there. Can't test in-client obviously.
