High computation cost for vorbis decoding. Is it possible to keep decompressed SFX in memory?

Question

Hello, we are having performance issues on Switch with vorbis decoding when many SFXs must be played at once.
Attached screenshots with the most expensive functions.
We would like to know if it's a good idea and if it's possible to decode some SFXs once (the most used and shortest ones, like gunshots) and keep them in memory uncompressed.
We are using our version of UE4.27 and WWise version 2022.1.9.8365.
Thanks!

Edit: I've also seen this page https://www.audiokinetic.com/en/courses/wwise301/?source=wwise301&id=Saving_a_Decoded_SoundBank for unity that allows to save decoded soundbanks from the unity editor that will be used instead of the encoded once. Is there a way to do this in UE4?

Answer 1

Hello,

The callstacks you quoted exhibit signs of being compiled in Debug (i.e. no optimization). I'd recommend evaluating performance with the Profile or Release configuration. Well, Profile is best during development given you can connect Wwise with it.

Also, these performance numbers need more context: how many sounds are active? Check the Wwise Profiler for the "Physical Voices" counter. A reasonable number on Switch would be around 150. Use Virtual Voices and Limits to manage that. If you are running 1000 voices, sure, decoding cost will be major.

You can obviously use another Codec for very short files (ADPCM or PCM) if you'd like.