This forces specific blocks to be encoded in intra prediction mode. The
bool AL_Encoder_Process (AL_HEncoder hEnc, AL_TBuffer* pFrame, AL_TBuffer*
pQpTable) API forces Intra at block level and can be controlled with the QP
table in the API. 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 LSBs of each byte are used for QP: absolute QP in [0;51] or
relative QP in [-32;31]
- The 2 MSBs are reserved for the prediction mode, as shown in the
following table.
| Bit 7 |
Bit 6 |
Bit 5 |
Bit 4 |
Bit 3 |
Bit 2 |
Bit 1 |
Bit 0 |
| Prediction mode |
QP |
Table 1. Prediction Mode and Description
| Prediction mode |
Description |
| 0 |
Encoder free choice |
| 1 |
Force Intra Prediction mode |
| 2 |
Reserved |
| 3 |
Reserved |