The recording audio bitrate was hardcoded to 192 kbps regardless of
channel layout. For a 5.1 mix this yields ~32 kbps per channel which is
very low quality. Scale proportionally from the stereo reference (192
kbps) using the active channel count, snapping to the closest bitrate
supported by the selected encoder (AAC or Opus).
Stereo recordings are unchanged (192 * 2 / 2 = 192 kbps).
The bitrate interpolation points are sent in JSON configuration and
need to be forwarded to `create_video_encoders()`. Also remove the
`HandleIncompatibleSettings()` handler because there are no longer any
incompatible settings.
Implicitly capturing "this" with the capture default "=" is deprecated
with C++20. We fix this by either explicitly passing this, or by copying
the required members manually.
While this exposes some rather expensive copies like the QList
selectedItems in OBSBasic_Preview, it doesn't introduce them ("=" copies
implicitly).
"Enable network optimizations" in the Advanced Settings is referred to
as `NewSocketLoop` in the code. This feature was incompatible with
multitrack video but now works properly. Remove it from the
incompatible settings check.
Nick von Kaenel