ma_engine_set_volume doesn't affect all sounds

[SelfishOlex]

What can explain a case where ma_engine_set_volume doesn't affect the volume of all sounds the same?

Context:
My sounds are setup by loading the data with ma_resource_manager_register_encoded_data then configuring with ma_sound_init_from_file. It's the same path for all sounds. This works wonderfully.
https://github.com/AMZN-Olex/MiniAudioO3DE/blob/826d7d1fd0ffbbdbed8618c6e3ef65e1ab50a383/MiniAudio/Code/Source/Clients/MiniAudioPlaybackComponentController.cpp#L193

I am currently adding a setting option to control the volume within my game at runtime. I am doing that via ma_engine_set_volume. Some sounds obey this volume and other sounds are not. What could be the cause and where should I look for the cause?

P.S. I have checked issues and discussion for this question but have not found anything on this topic so far.

[mackron]

Hmm, this is very suspicious. ma_engine_set_volume() simply sets the volume of the endpoint in the graph. Sounds are connected to a graph, with all sounds eventually being connected to the endpoint (you can have nodes in between the sounds and the endpoint for grouping and effect processing). The endpoint does not do any per-sound volume control - it simply adjusts the volume of the raw audio data after mixing all of it's inputs into an intermediary buffer. By the time the endpoint is applying it's volume, it doesn't look at it's inputs at all. If you're curious you can look at ma_node_read_pcm_frames() and scroll down to the bottom to see where the volume is applied - it's done right at the end and is applied to the raw data post-mixing.

Looking at your code I can't see anything obviously wrong there. Have you noticed any kind of pattern, such as whether or not it happens only to spatialized sounds or whatever?

When you say "Some sounds obey this volume and other sounds are not", do you mean some sounds just don't have the volume applied whatsoever? Or does it seem like each sound is being applied with different volumes? Just to clarify how it works, the volume of each sound is applied first (the volume set with ma_sound_set_volume()), and then the engine's global volume control is applied last after everything has been mixed. Is it possible that the local volume control of the individual sound is causing confusion?

It's highly unlikely to fix your issue but you could also try the dev branch. I don't recall having touch any volume stuff for a long time though.