why: to enhance va video encoding quality
how: use va encoding quality_level interface, and provide default value and encoding quality adjustment options, so that users can finetune encoding quality and performance from va quality interface.
There are 3 settings added: -- preset modes: speed, balance, quality they are using different encoding strategies -- vbaq modes: vbaq mode is using variance based strategy to improve the subjective image quality -- pre-encoding modes: Using scaled down input image for pre-encoding to have better rate-control reaction and consume more memory in the same time. Only preencoding-4x mode is enabled.
Signed-off-by: Ruijing Dong email@example.com