HydrogenAudio

Lossy Audio Compression => AAC => AAC - Tech => Topic started by: polemon on 2021-12-17 22:13:47

Title: Force CoreAudioToolbox / QAAC to switch PS (HE-AAC v1 and v2) on or off?
Post by: polemon on 2021-12-17 22:13:47
So, with QAAC you can enable HE-AAC with the --he switch, and CoreAudioToolbox automatically switches PS on (HE-AAC v2) when selecting a bitrate of below 32kbps):
Code: [Select]
qaac64 --he --cvbr 32 -o test.mp4 test.wav
This will yield a HE-AAC v2 encoded track.
Chosing anything above, will switch to HE-AAC (v1, without PS).

I was wondering, if I can force-select PS for HE-AAC, effectively switching between v1 and v2 of HE-AAC. I've yet to see if I can use HE-AAC v2 (with PS), on a mono track. Technically, this shouldn't be possible, as without stereo, there is nothing to parametrize. But it should be possible to force-select PS on higher bitrates - even though this might not make sense from an audio engineering side of things, I'd like to try if I can at all.

Is there some way to enable PS with QAAC on bitrates higer than 32kbps?