FLAC for Haskell

• Aims of the project
• Motivation
• Provided functionality
• Limitations
• Quick start
• Related packages
• Contribution
• License

This is a complete high-level Haskell binding to libFLAC—reference FLAC implementation.

As the maintainer of the C FLAC code base, I must say I’m impressed. Quite honestly, I think the C API is horrible.

—Erik de Castro Lopo

Aims of the project

These are the goals of the project:

• Be a complete interface for FLAC file manipulation in Haskell.
• Be as efficient as the underlying C implementation.
• Provide a safe API using type system to kindly guard against bad things, but not too much so as to remain beginner-friendly and simple.

Motivation

FLAC is awesome and Haskell is awesome, surely there should be a safe Haskell API to the fast libFLAC library!

Seriously though, we have htaglib to work with audio metadata, but it does not support FLAC-specific thing I would like to manipulate. We have hsndfile, but I don’t really want to read FLAC data into a buffer or Haskell Vector. How simple is it (if possible) to decode a FLAC file using that library? How simple is it to figure out where to begin with such a task? With flac it is one line of code.

Provided functionality

flac can work with:

• Metadata—full support for reading/writing/deleting of all audio parameters, application data, seek tables, vorbis comments of all sorts, CUE sheets, and even pictures.

• Stream decoder—simple interface for decoding to WAVE and RF64.

• Stream encoder—a lot of options to tweak, everything that libFLAC supports.

Limitations

Right now there are three main limitations:

• No Ogg FLAC support, and I do not plan to add it; I’ll accept a PR adding support for Ogg FLAC.

• It’s not possible to use custom callbacks for printing decoding/encoding progress in real-time.

• Only works on little-endian architectures so far; I’ll accept a PR lifting this limitation.

Quick start

The best way to start using flac is to take a look at the Haddocks. Encoding and decoding should be simple to understand, for metadata there are examples in the docs. Feel free to ask me a question if you get stuck with something.

Related packages

The following packages are designed to be used with flac:

• flac-picture—add pictures to FLAC metadata easier.

Contribution

Please direct all issues, bugs, and questions to the GitHub issue tracker for this project.

Pull requests are also welcome.

License

Copyright © 2016–present Mark Karpov

Distributed under BSD 3 clause license.