The improvement of the existing features in H. h.264,h.265 has greatly improved the complexity of the algorithm compared with the standard, which results in better compression performance. H.265 has made significant improvements in many features, as shown in the table:
|
H . |
MB/CU size |
4x4 ~ 16x16 |
4x4 ~ 64x64 |
Luminance interpolation |
Luma-1/2 pixels | {1,-5,20,20,-5,1} LUMA-1/4 pixels} |
Luma-1/2 pixels | { -1,4,-11,40,40,-11,4,-1} LUMA-1/4 pixels { -1,4,-10,57,19,-7,3,-1} luma-1/4 pixels { -1,3,-7,19,57,-10,4,-1} |
MVP Prediction Method |
Airspace MVP Forecast |
Airspace + Time domain MVP prediction amvp\merge |
Luminance Intra Prediction |
4X4/8X8/16X16:9/9/4 mode |
34-Angle Prediction + Planar Predictive DC prediction |
chromaticity Intra Prediction |
DC, Horizontal, Vertical, Plane |
DM, LM, planar, Vertical, horizontal, DC, diagonal |
Transform |
dct4x4/8x8 |
dct4x4/8x8/16x16/32x32 dst4x4 |
Go to block filter |
4x4 and 8x8 boundary deblock filtering |
Large CU size, no filtering on 4x4 boundaries |
The key characteristics of the table H. h.265 and the main sizes are shown above.