Google Releases libaom 3.7 AV1 Encoder With More Optimizations

Following the releases this week of Intel's SVT-AV1 1.7 encoder and the libavif 1.0 AV1 Image File Format release, Google engineers are out with libaom 3.7 as the newest feature release to that AV1 encode library.

The libaom 3.7 release focuses on new codec interfaces, compression efficiency and perceptual improvements, and speed-ups and memory optimizations. There is also a new speed (--cpu-used 11) and other enhancements.

Some of the key takeaways for libaom 3.7 include:

- Compression Efficiency Improvements
* Improved VoD encoding performance
* 0.1-0.6% BDrate gains for encoding speeds 2 to 6
* Rate control accuracy improvement in VBR mode
* RTC encoding improvements
* Screen content mode: 10-19% BDrate gains for speeds 6 - 10
* Temporal layers video mode, for speed 10:
* 2 temporal layers on low resolutions: 13-15% BDrate gain
* 3 temporal layers on VGA/HD: 3-4% BDrate gain

- Speedup and Memory Optimizations
* Speed up the VoD encoder
* 2-5% for encoding speed 2 to 4
* 9-15% for encoding speed 5 to 6
* ARM
* Standard bitdepth
* speed 5: +31%
* speed 4: +2%
* speed 3: +9%
* speed 2: +157%
* High bitdepth
* speed 5: +85%
* RTC speedups
* Screen content mode
* 15% IC speedup for speeds 6-8
* ARM: 7% for speed 9, 3% for speed 10
* Temporal layers video mode
* 7% speedup for 3 temporal layers on VGA/HD, for speed 10
* Single layer video
* x86: 2% IC speedup for speeds 7-10
* ARM: 2-4% speedup across speeds 5-10

It's great seeing all of the AV1 encoding optimizations not letting up at all.

Downloads and more details on all of the libaom 3.7 changes via the v3.7.0 Git tag. I'll be trying out libaom 3.7 against the other open-source AV1 encoders on a few different CPUs.