David Chou
Coding tools are added as experiments into the AV1 codebase.
The hardware team reviews the experiments to ensure it can be implemented in hardware.
Each experiment also needs to pass an IP review to ensure no IPs are violated.
Once reviews are passed the experiment can be enabled by default.
| Profiles | Color sampling | Bit depth |
| Main | 4:2:0 | 8, 10 |
| High | 4:2:0, 4:4:4 | 8, 10 |
| Professional | 4:2:0, 4:2:2, 4:4:4 | 8, 10, 12 |
| Levels | Mbps | Examples |
|---|---|---|
| 2.0 | 1.5 | 426x240@30fps |
| 4.1 | 20.0 | 1920x1080@60fps |
| 5.3 | 60.0 | 3840x2160@120fps |
| 6.3 | 160.0 | 7680x4320@120fps |
More block sizes
Prediction blocks
from 128x128 down to 4x4
Rectangular blocks:
1:2, 2:1 and 1:4, 4:1 ratio
Transform sizes
from 64x64 down to 4x4
Rectangular transforms:
1:2, 2:1 and 1:4, 4:1 ratios
More transform type
4 transform types
DCT, ADST, FlipADST, Identity
More prediction modes
Intra:
56 directions
Chroma from luma prediction
Inter:
Expanded reference list
Compound mode
New adaptive multi-symbol entropy coding
Spatial and temporal scalability
This scientific evaluation puts AV1 to the test against industry standard codecs and shows that AV1 is able to outperform VP9 and even HEVC by up to 40%
AV1 has extremely high encoding quality inapproachable to other encoders and extremely low encoding speed due to lack of speed optimization.
Users watching AV1 content will enjoy better quality at the same bit rate or see 30% to 50% less buffering at the same quality compared with VP9 or H.264/AVC content.