This is just the minimal patch required to get something working.
There are still plenty of TODOs left to do: two-pass support, VFR
 support, golden frame support, the ability to drop frames, trial
 encodes for the first frames, quantization matrices, separate
 quantizer choices for Cb and Cr, proper lossless handling, support
 for AV1's levels, and some general refactoring to improve
 maintainability.