[opus] Opus Tools -- low bitrates, new features in 1.5, "expect-loss"

[Petr Pařízek]

I wrote:

 > First, the fact that the original frequency and the undesired 
frequency actually meet at 8 kHz.
 > Next, the fact that the undesired frequency is falling,
 > not rising. Finally, the fact that first the undesired frequency 
comes in pretty quickly and then
 > the original frequency disappears very quickly; so at
 > one point, they're both there (and this point happens to be at 8 kHz).

So, one more observation in Opusenc. If I either set the bitrate lower 
than 12 or if I set the "--expect-loss" switch to anything other than 0 
and keep the bitrate at 12, the additional noise (occupying the 
frequencies up to 12 kHz) actually disappears completely! This makes the 
phenomenon I described yesterday even more noticeable.

Petr