[CELT-dev] Opus for audiobooks etc

[Timothy B. Terriberry]

> OK, I hadn't realized that the higher-delay SILK modes were only saving
> on frame and packet/transport overhead; I'd assumed that they'd be
> getting some kind of prediction benefit.

They do. The quantization gains and pitch lag are both predicted across 
the full 60 ms frame, but at 32 kbps this represents a relatively small 
bitrate savings.