Specific blocks can be forced to be encoded in intra prediction mode. The
AL_Encoder_Process API function forces intra at
block level and can be controlled with the provided QP table. The QP table buffer must
contain a byte per MB/CTB, in raster scan format.- In AVC, one byte per 16x16 MB
- In HEVC, one byte per 32x32 CTB
- The 6 lowest bits of each byte are used for QP: absolute QP in [0;51] or relative QP in [-32;31]
- The 2 highest bits are reserved for the prediction mode. With values 0. Encoder free choice, 1. Force Intra Prediction mode. Other values are reserved.
To force intra prediction at the block level, external QP tables must be enabled and provided for each frame.
In ROI_QP mode, the entire ROI region can be encoded as
Intra.
<quality> = INTRA_QUALITY