audio2json

Generate sample peak data in JSON format from audio files.

Pure Nim score 15/100 · tests present · no docs generated

Summary

Latest Version 0.1.1
License MIT
CI Status Failing
Downloads 0
Last Indexed 2026-09-04 07:26

Tags

audio command-line library waveform nim

Authors

  • SpotlightKid

Installation

nimble install audio2json
choosenim install audio2json
git clone https://codeberg.org/SpotlightKid/audio2json

OS Compatibility

Platform Linux macOS Windows FreeBSD OpenBSD NetBSD Android iOS WASM Embedded
audio2json ✓ ✓ ✓ - - - - - - -

Dependencies

Package Version Optional
nim >= 2.0 No
sndfile - No

Source

Repository https://codeberg.org/SpotlightKid/audio2json
Homepage https://codeberg.org/SpotlightKid/audio2json
Registry Source nimble_official

README

audio2json

Generate sample peak data in JSON format from audio files, which can be used with e.g. wavesurfer.js.

Implemented in Nim using the sndfile binding for libsndfile, so all audio file formats supported by libsndfile can be used as input.

Demo

To see the output used by wavesurfer.js to render an interactive waveform, check out the live version of the example.

Build

Install Nim (includes nimble) if you dont have it yet, check out this repository and then in the root of the repo run:

nimble install

to build the audio2json command and and install it and the library to your ~/.nimble dir.

Run:

nimble build

to just compile audio2json (will be placed in the bin sub-directory).

Usage

Example:

audio2json [options] input_file.wav

Options:

General options:
  -v | --version          Print version string
  -h | --help             Print this help message and exit

Configuration:
  -C | --channels <ch>    Comma-separated list of channel identifiers which
                          should be computed and included in the output:
                          left, right, mid, side, min, max
                          (default: left, right)
  -d | --db-scale         Use logarithmic (e.g. decibel) scale instead of
                          linear scale for peak values.
  --db-min <dB>           Minimum value of the signal in dB, that will be
                          visible in the waveform (default: -48)
  --db-max <dB>           Maximum value of the signal in dB, that will be
                          visible in the waveform (default: 0)
                          Useful if the signal peaks at a certain level.
  -o | --output <path>    Name of output file, use "-" for standard output
                          (defaults to basename of input file and its extension
                          replaced with '.json')
  -n | --no-generator     Do not include the '_generator' key in the output.
  -q                      Do not report progress to standard error output.
  -s | --samples <num>    Number of samples to generate (default: 800)
  -p | --precision <num>  Precision (i.e. the number of digits after the comma)
                          of the floating point numbers in the output. Reducing
                          the precision yields smaller output files and 2 or 3
                          is usually sufficient (1..9, default: 6)

Further examples:

audio2json -s 800 --channels left right input.wav
audio2json --db-scale --db-min -48 --db-max 0 input.wav -o out.json

License

This project is released under the MIT license. Please see the LICENSE file for details.

Authors

Christopher Arndt (@SpotlightKid)

Acknowledgements

This project was re-implemented in Nim using beschulz/wav2json as a model for the code structure. No code from the aforementioned project is used.