BSD-3-Clause licensed and maintained by Mark Karpov
This version can be pinned in stack with:flac-0.2.1@sha256:f2e2c148f06908b9e6bb4981682a57ab2208891bfa28155bc7901b304d22d8af,3431
Used by 1 package in nightly-2024-06-18(full list with versions):

FLAC for Haskell

License BSD3 Hackage Stackage Nightly Stackage LTS CI

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.


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.


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:


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

Pull requests are also welcome.


Copyright © 2016–present Mark Karpov

Distributed under BSD 3 clause license.


FLAC 0.2.1

  • Maintenance release with more modern and minimal dependencies.

FLAC 0.2.0

  • Got rid of data-default-class dependency. Now default values for various settings are exported explicitly. This may be a breaking change for you if use def.

FLAC 0.1.2

  • Documentation and metadata improvements.

FLAC 0.1.1

  • Added support for DiscTotal Vorbis comment field.

FLAC 0.1.0

  • Initial release.