octatool

A streamlined command-line tool for creating Octatrack-compatible one-shot sample chains with advanced audio processing. Inspired by OctaChainer, DigiChain, and AudioHit.

Core Features

• Sample Chaining: Concatenates multiple audio files into a single chain, perfect for drum kits and one-shots.
• Automatic .ot File Generation: Always creates a .ot slice file alongside your chain for instant loading on the Octatrack.
• Advanced Silence Trimming: Uses a configurable threshold to trim leading and trailing silence, ensuring tight samples.
• Fade In/Out: Applies smooth fades to prevent clicks.
• Audio Normalization: Normalizes the final chain to a user-defined headroom.
• Format Support: Reads .wav, .aif, .aiff, and .mp3 files.
• High-Quality Output: Exports to 16 or 24-bit WAV at the Octatrack's native 44.1kHz sample rate.

Requirements

• Python 3
• FFmpeg: Must be installed and accessible in your system's PATH.
• pydub Python library.

Installation

1. Install FFmpeg: Follow the instructions on the official FFmpeg website to install it for your operating system. Make sure it's added to your system's PATH.

2. Install Python dependencies: Navigate to the project directory and install the required library using pip:

   pip install pydub
   

Usage

To see all available commands and options, run:

python octatool.py -h

chain Command

Finds all audio files in a source directory, processes them, and concatenates them into a single output WAV file. An .ot slice file is always created automatically.

Syntax:

python octatool.py chain <input_dir> <output_file.wav> [options]

Options:

• --no-normalize: Disables the audio normalization step.
• --no-trim: Disables the trimming of leading silence.
• --headroom <dBFS>: Sets the normalization headroom in dBFS (default: 1.0).
• --mono: Converts the output file to mono.
• --bit-depth <16|24>: Sets the output bit depth (default: 24).
• --slices <2|4|...|64>: Pads the sample chain with silent slices to a specific total.
• --max-slice-length <ms>: Sets the maximum length for each slice in milliseconds.
• --no-padding: Joins samples without padding to uniform length (creates variable-length slices).
• --threshold <dB>: Silence threshold in dB for advanced trimming (default: -48).
• --fade-in <ms>: Fade in duration in milliseconds (default: 0).
• --fade-out <ms>: Fade out duration in milliseconds (default: 0).
• --ot-gain <dB>: Gain setting for the .ot file in dB (default: +12).

info Command

Scans a directory and displays technical information about each audio file without performing any processing.

Syntax:

python octatool.py info <input_dir>

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Examples

Basic Usage

Create a chain from all samples in the my-kicks directory and pad it to 16 slices. A kicks.wav and kicks.ot file will be created.

python octatool.py chain path/to/my-kicks kicks.wav --slices 16

Advanced Trimming and Fades

Create a chain with a tighter silence threshold, a 10ms fade-in, and a 25ms fade-out.

python octatool.py chain path/to/my-snares snares.wav --slices 16 --threshold -32 --fade-in 10 --fade-out 25

No Padding

Create a chain where each sample retains its original length. The .ot file will have slices of varying lengths.

python octatool.py chain path/to/vocal-chops chops.wav --no-padding

License

This project is licensed under the MIT License.