The previous commit (672378d20) was supposed to fix issues with the
encoder releasing while data was still being processed, but did not
account for when the encoder has never started up. That was my fault.
Furthermore, the way in which it was waiting to drain events was
incorrect. The encoder may still be active even though there aren't any
events queued. The proper way to wait for an async encoder to finish up
is to process output samples until it requests more input samples.
Implements hardware encoders through the Media Foundation interface
provided by Microsoft.
Supports:
- Quicksync (Intel)
- VCE (AMD)
- NVENC (NVIDIA, might only be supported through MF on Windows 10)
Notes:
- NVENC and VCE do not appear to have proper CBR implementations. This
isn't a fault of our code, but the Media Foundation libraries.
Quicksync however appears to be fine.