libaom v3.0.0 Braeburn Finalized

[Jerome Jiang]

Hello everyone,

libaom v3.0.0 Braeburn is finalized. Here is the release note.

Thanks.

Release Note

The libaom 3.0.0 Braeburn release has been finalized. This release of libaom includes:

• Control IDs re-arranged such that ranges for encoder, common and decoder are not overlapped.

• Key & value API, aom_codec_set_option, which takes a key string of the option name and a value string of the associated value to set libaom encoding options.

• Added option --enable-dnl-denoising to skip applying denoising with denoise-noise-level. This option only takes effect when --denoise-noise-level > 0. When --enable-dnl-denoising is 1 (default), the encoder denoises the frame for noise modeling and encodes the denoise frame with film grain synthesis. When 0, the encoder denoises the frame for noise modeling, but encodes the original (noisy) frame with film grain synthesis.

• Added options --tune=vmaf and --tune=vmaf_neg to optimize the encoder’s perceptual quality by optimizing the metrics VMAF and VMAF_NEG.

The release is available from the git repository on the Braeburn branch and the v3.0.0 tarball, along with the asc file.

AV1 Compression Efficiency

Compared with libaom v2.0.0, this release produces a compression efficiency improvement of approximately 5% in terms of objective metric (SSIM/PSNR) across all resolutions. 

AV1 Encoder Speed Improvement

Since libaom 2.0.0, AV1 encoder optimization has focused on providing faster encoding without sacrificing coding gains. As shown in the table below, a new preset “speed 6” was added. While speed 0 and 1 development focused on the compression efficiency improvement, speeds 2 to 6 were optimized for faster encoding. AV1 speed 6 takes the same encoding time as VP9 speed 2, but gives 20% better bit savings.

libaom 2.1.0 encoding presets	Incremental compression efficiency loss vs prior speed preset	Speedup vs libaom 2.0.0
--cpu-used=0	N/A	-55.60%
--cpu-used=1	-2%	-51.60%
--cpu-used=2	-2%	7.60%
--cpu-used=3	-5%	17.70%
--cpu-used=4	-5%	29.60%
--cpu-used=5	-8%	39.70%
--cpu-used=6	-3%	103.80%

Real-time Mode

• New speed 9 for faster encoding and speed 5 for better quality.

• Temporal denoiser and optimizations.

• Optimizations for scaling.

• Better multi-threading performance.

• Smaller binary size with low bit depth and real-time only build.

[Jerome Jiang]

Correction:

The table of section of "AV1 Encoder Speed Improvement" in the release note should be "libaom 2.1.0 3.0.0 encoding presets".

Thanks.