[opus] Stereo channel separation

[Timothy B. Terriberry]

O'Connor, Kevin wrote:
> Is this bleedover expected? I found an older copy of opus-tools (0.1.6, libopus 1.0.2) and it does not appear to
> have the bleedover between channels, so I think this was introduced in 1.0.3 or 1.1.

This bleed-over should not be possible with the CELT layer (_especially_ 
not during silence), but it is possible with the SILK layer. 1.1 added 
automatic speech detection, so it is possible that this is caused by 
switching to SILK in places 1.0.2 would have defaulted to CELT based on 
your bitrate.

Can you reproduce the issue when you encode with
   --set-ctl-int 4000=2051
?