Youtube Music Premium sample rate and codec on WiiM Pro

[zbik]

What codec is used and with what sample rate when playing Youtube Music Premium on WiiM Pro via Chromecast from app on Android phone?
When I play YTM on WiiM mini via bluetooth it's 44.1 kHz and mp4a 141 AAC codec.
When I play on Chromecast Audio via Chromecast function it's 48 kHz and can't determine codec.
When I play on MiBox (Android box) via Chromecast function it's 48 kHz and opus (251) codec .
Thx.

 

[Brantome]

The sample rate is a bit moot really when Youtube Music is being played since at its best, it’s still only a max bitrate of 256kbps lossy AAC

Select or change your audio quality - YouTube Music Help

YouTube Music Premium members can select the bitrate at which music is streamed and downloaded. If you haven't selected a quality setting, it will automatically be set to the 'Normal' bitrate for your

support.google.com