opus - Jul 2017 - Opus doesn't like the frame size 1024

I am getting "invalid argument" error from 'opus_encode'.

The frame size 960 works, which is 20 ms for 48,000 sample rate. But the 
problem is that I am getting frames from Jack, and Jack only supports 
frame sizes which are a power of 2.

Documentation talks about frame rates in milliseconds, not in sample 
counts. So how to match Jack's supported frame sizes?


Yuri