ab-av1

AV1 video encoding tool with fast VMAF sampling & automatic encoder crf calculation. Uses ffmpeg, svt-av1 & vmaf.

Also supports other ffmpeg compatible encoders like libx265 & libx264.

Command: auto-encode

Automatically determine the best crf to deliver the --min-vmaf and use it to encode a video or image.

Two phases:

• crf-search to determine the best --crf value
• ffmpeg to encode using the settings

ab-av1 auto-encode [OPTIONS] -i <INPUT> --preset <PRESET> --min-vmaf <MIN_VMAF>

Command: crf-search

Interpolated binary search using sample-encode to find the best crf value delivering --min-vmaf & --max-encoded-percent.

Outputs:

• Best crf value
• Mean sample VMAF score
• Predicted full encode size
• Predicted full encode time

ab-av1 crf-search [OPTIONS] -i <INPUT> --preset <PRESET> --min-vmaf <MIN_VMAF>

Notable options

• --min-xpsnr <MIN_XPSNR> may be used as an alternative to VMAF.

Command: sample-encode

Encode short video samples of an input using provided crf & preset. This is much quicker than full encode/vmaf run.

Outputs:

• Mean sample VMAF score
• Predicted full encode size
• Predicted full encode time

ab-av1 sample-encode [OPTIONS] -i <INPUT> --crf <CRF> --preset <PRESET>

Notable options

• --xpsnr specifies calculation of XPSNR score instead of VMAF.

Command: encode

Invoke ffmpeg to encode a video or image.

ab-av1 encode [OPTIONS] -i <INPUT> --crf <CRF> --preset <PRESET>

Notable options

These also apply to auto-encode.

• --verify checks the finished encode before it is moved into place: decodes it in full failing on decode errors (--verify-decode) & fails if its duration does not match the input within 2s (--verify-duration). Either check can be enabled on its own. The encoder can otherwise exit successfully having written a damaged or cut short result, e.g. from a truncated input.
• --fail-fast stops the encode at the first ffmpeg reported error instead of writing a damaged result.

Command: vmaf

Full VMAF score calculation, distorted file vs reference file. Works with videos and images.

• Auto sets model version (4k or 1k) according to resolution.
• Auto sets n_threads to system threads.
• Auto upscales lower resolution videos to the model.

ab-av1 vmaf --reference <REFERENCE> --distorted <DISTORTED>

Command: xpsnr

Full XPSNR score calculation, distorted file vs reference file. Works with videos and images.

ab-av1 xpsnr --reference <REFERENCE> --distorted <DISTORTED>

JSON output

See --stdout-format json docs.

Install

Arch Linux

Available in the AUR.

Linux

Pre-built statically linked x86_64-unknown-linux-musl binary included in the latest release.

Windows

Pre-built ab-av1.exe included in the latest release.

Using cargo

Latest release

cargo install ab-av1

Latest code direct from git

cargo install --git https://github.com/alexheretic/ab-av1

Requirements

ffmpeg newer than git-2022-02-24 with libsvtav1, libvmaf, libopus enabled.

ffmpeg should be in $PATH.

Debug

Enable debug logs by setting env var RUST_LOG=ab_av1=debug. This includes all ffmpeg calls.

$ RUST_LOG=ab_av1=debug ab-av1 auto-encode -i vid.mkv

Minimum supported rust compiler

Maintained with latest stable rust.