Some of the fields in encoder_control_t were simply copies of the
corresponding fields in kvz_config. This commit drops the copied fields
in favor of using the fields in encoder_control_t.cfg directly.
The kvz_config struct is created by the user but kvazaar keeps a pointer
to it. It is easy to break things by modifying the configuration outside
kvazaar. In addition, kvazaar modifies the struct even though it is has
a const modifier.
This commit changes the field cfg in encoder_control_t to be a copy of
the kvz_config struct instead of a pointer, removing modifications to
the const struct and allowing users to do whatever they want with it
after opening the encoder.
When rate control is enabled, enable cu_qp_delta_enabled_flag in PPS
with diff_cu_qp_delta_depth set to 0. Also adds code for writing the QP
deltas and a new cabac context.
Write bitstream without chroma when encoding with --input-format=P400.
This reduces bitstream size by 0-1 %, compared to coding monochrome in
420 format, and speeds up encoding slightly due to not processing
chroma.
