# ab-av1
AV1 video encoding tool with fast VMAF sampling & automatic encoder crf calculation. 
Uses _ffmpeg_, _svt-av1_ & _vmaf_.

![](https://user-images.githubusercontent.com/2331607/151695971-d36f55a7-a157-4d5d-ae06-4cc9e2c0d46f.png "Find the best crf encoding setting for VMAF 95 quality")

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](#command-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](#command-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](#command-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](./stdout-format-json.md).

## Install
### Arch Linux
Available in the [AUR](https://aur.archlinux.org/packages/ab-av1).

### Linux
Pre-built statically linked x86_64-unknown-linux-musl binary included in the [latest release](https://github.com/alexheretic/ab-av1/releases/latest).

### Windows
Pre-built **ab-av1.exe** included in the [latest release](https://github.com/alexheretic/ab-av1/releases/latest).

### Using cargo
Latest release
```sh
cargo install ab-av1
```

Latest code direct from git
```sh
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](https://gist.github.com/alexheretic/d1e98d8433b602e57f5d0a9637927e0c).