DDR memory buffer size depends on the following:
- Video resolution
- Chroma sub-sampling
- Color depth
- Coding standard
The number of buffers depend on the following:
- Coding standard – H.264 or H.265
- Group of Picture (GOP) pattern
The following table shows the worst-case memory footprint for various encoding schemes.
| Examples with Two B-Frames | 720p | 1080p | 2160p | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Buffers | Per Buffer | Total | Buffers | Per Buffer | Total | Buffers | Per Buffer | Total | |
| Source Frame | 5 | 2.3 MB | 12 MB | 5 | 5.3 MB | 27 MB | 5 | 21.1 MB | 106 MB |
| Reference Frames | 3 | 2.2 MB | 7 MB | 3 | 5.0 MB | 15 MB | 3 | 19.9 MB | 60 MB |
| Reconstructed Frame | 1 | 2.2 MB | 3 MB | 1 | 5.0 MB | 5 MB | 1 | 19.9 MB | 20 MB |
| Intermediate Buffers | 2 | 0.0 MB | 0 MB | 2 | 0.0 MB | 0 MB | 2 | 41.0 MB | 83 MB |
| Motion Vector Buffer | 4 | 0.1 MB | 1 MB | 4 | 0.3 MB | 1 MB | 4 | 1.0 MB | 4 MB |
| Bitstream Buffer | 2 | 1.1 MB | 3 MB | 2 | 2.5 MB | 5 MB | 2 | 9.9 MB | 20 MB |
| Other Buffers | 1 | 0.0 MB | 1 MB | 1 | 0.0 MB | 1 MB | 1 | 0.1 MB | 1 MB |
| Total | 27 MB | 54 | 294 | ||||||