Currently this is restricted to high bitrates.
<rdar://problem/69129142>
Is any info available on what the minimum bitrates are for audio and video?
This is limited so far to 128000, 192000 or 256000 for now.
Created attachment 410104 [details] Patch
Committed r267822: <https://trac.webkit.org/changeset/267822> All reviewed patches have been landed. Closing bug and clearing flags on attachment 410104 [details].