AlabamaEncoder

AlabamaEncoder is a powerful video encoding framework designed for macOS & Linux. It is able to leverage multi-PC setups, and currently supports various encoders such as SVT-AV1, aomenc, rav1e, x265, and x264, among others.

Note: this utility is a work in progress. It may not function as expected. Please report any issues you encounter.

Installation

Recommended way, install with pipx

pipx install alabamaEncoder

But if you are a developer

1. First, clone the upstream GitHub repository:

git clone https://github.com/kingstefan26/alabamaEncoder

2. Next, set up the Python virtual environment:

python -m venv venv
source venv/bin/activate

Note: make sure to use venv/bin/activate.fish if you use the fish shell

3. Finally, install the required dependencies:

pip install -r requirements.txt

From here, you can either run the program without building it, or build & install it.

Run Without Building

python -m alabamaEncode.cli <cli_args>

Build & Install

To build and install the local version:

pip install build
python -m build
pipx install . --editable --force

Ensure SvtAv1EncApp, ffmpeg, ffprobe, and any other encoder binaries you wish to use are available in your PATH. The program will notify you if any dependencies are missing.

Command-Line Interface (CLI)

For local or Celery-based encoding, use:

alabamaEncoder [-h] [INPUT FILE] [OUTPUT FILE] [flags]

For a more comprehensive breakdown of the arguments and flags, see our USAGE page.

Non-Mainline Encoders

To use one of the many community-built forks of mainline video encoders ( like SVT-AV1-PSY), you may do the following:

• Get the path of the binary.
• Set it in an environment variable following this pattern: <CLI_NAME_ALL_UPPER_CASE>_CLI_PATH.

Example:

export SVTAV1ENCAPP_CLI_PATH=/path/to/SvtAv1EncApp # Custom path
alabamaEncoder [arguments...]

This applies to all binaries used by AlabamaEncoder. So, to use a custom build of ffmpeg, set the FFMPEG_CLI_PATH environment variable.

Multi-System Encoding

Setup

• Ensure all paths on all PCs are the same. This can be achieved by encoding on an NFS share mounted on the same path everywhere.
• You will need a job broker for Celery. The simplest option is Redis. Run the following:

docker run -d -p 6379:6379 --rm redis

Set the Redis host environment variable for both workers and the main command:

export REDIS_HOST=192.168.1.10
alabamaEncoder worker 10

By default, the Redis host is assumed to be localhost.

To clear the Celery job queue:

alabamaEncoder clear

Notes

• Bandwidth overhead is low with smart FFmpeg seeking. A 1 Gb/s LAN is sufficient.
• Content analysis/scene detection is done on the system running the main command. This will ideally be configurable in the future, but is not at this time.

Examples

Here's an example of an Adaptive encoding command for alabamaEncoder:

alabamaEncoder input.mkv auto --autocrop -res 1080p --grain -2 --hdr --audio_params "-c:a libopus -b:a 170k -ac 6 -mapping_family 1" --vmaf_target 95 --end_offset 60 --start_offset 60 --title "TV SHOW (2023) S00E00"

Now, let's break down what this command is doing:

• alabamaEncoder input.mkv auto

This example uses the auto output path, it automatically makes up an output dir based on the title, so alabamaEncoder will encode ./input.mkv to ~/showsEncode/TV SHOW (2024)/s0/e0/TV.SHOW.2023.S00E00.AV1.OPUS.Placeholder.webm

• --autocrop

Crops black bars

• -res 1080p

Downscales to a 1080p class resolution

• --grain -2

Automatically adjusts film grain synthesis parameters on a per-scene basis

• --hdr

Preserves HDR metadata resulting in a proper HDR output

• --audio_params "-c:a libopus -b:a 170k -ac 6 -mapping_family 1"

Transcode audio to 170k 5.1 Opus

• --vmaf_target 95

Calculate the ideal CRF to achieve a VMAF score of 95 on a per-scene basis

• --end_offset 60 --start_offset 60

Cuts the first and last minute.

• --title "TV SHOW (2023) S00E00"

Adds metadata title.

• [no encoder specified]

Encodes using SvtAv1EncApp by default when an encoder is not specified.

---

Here's an example of a Constant Rate Factor encoding command for alabamaEncoder:

alabamaEncoder /path/to/movie.mkv ./dir/out.webm --audio_params "-c:a libopus -b:a 256k -ac 8 -mapping_family 1" --grain 17 -res 1080p --crf_mode --crf 24 --encoder AOMENC

This command:

• Downscales movie.mkv to a 1080p resolution.
• Tonemaps if HDR.
• Uses 7.1 256kb/s Opus audio.
• Encodes with aomenc using grain denoise at level 17, speed 4, CRF 25.
• Muxes and encodes audio with the specified ffmpeg parameters.

Notes

• If alabamaEncoder is already running, you can spin up new workers (multi-PC guide), and they will automatically connect and split the workload.
• If you crash or abort the script, rerun it with the same arguments, and it will pick up where it left off.
• Extensive testing has been done to ensure frame-perfect ffmpeg-based split/concat methods. However, if you encounter any issues, please create an issue and provide a sample.
• All feedback is welcome. Create an issue for explanations, bug fixes, or feature requests.

Credits

Thanks to all contributors and developers of the tools used in this project.