Encoder Buffer Requirements - 2023.1 English

H.264/H.265 Video Codec Unit v1.2 Solutions LogiCORE IP Product Guide (PG252)

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2023.1 English

The encoder input and output requirements are shown in the following table.

Table 1. Encoder Buffer Requirements
Requirement Description
Input Buffer
No of Buffers

For AVC: 2 + no. of B Frames(num-B).

For HEVC: 1 + no. of B Frames(num-B).

Note: In look-ahead mode, add this value by number of look-ahead frames.
Contiguous Yes
Alignment 32

stride * slice-height * chroma-mode.

stride should be 32-aligned.

slice-height should be 16-aligned for AVC and 32-aligned for HEVC.

Note: It works with a slice-height 8-aligned, however hardware's harmless requests may be outside of the buffer.
Output Buffer
No of Buffers

For AVC: 2 + no. of B-Frames(num-B).

For HEVC: 1 + no. of B-Frames (num-B).

Note: In the subframe mode, multiply this value by num-slices.
Contiguous Yes
Alignment 32

Use below API to get size.

AL_GetMitigatedMaxNalSize (AL_TDimension tDim, AL_EChromaMode eMode, int iBitDepth)

Note: Because the VCU uses multiple internal encoder engines, it is not possible to reduce the output buffer requirements.