Added
* Pi 5 users can now request 48-bit RGB outputs (where each R, G and B sample is 16-bit).
* Support for h.264 codec profiles.
* DNG files can be written to ioBytes objects.
* Persistent allocators added.
* Timeout support waiting for asynchronous requests to complete.
Changed
* FFmpeg thread queue size increased, to suppress warnings and improve behaviour.
* Quality argument is respected properly by start_encoder().