talklittle/ffmpex

---

talklittle/ffmpex.json

{
  "createdAt": "2016-07-27T23:14:14Z",
  "defaultBranch": "master",
  "description": "Elixir wrapper for FFmpeg command line interface",
  "fullName": "talklittle/ffmpex",
  "homepage": "https://hexdocs.pm/ffmpex/",
  "language": "Elixir",
  "name": "ffmpex",
  "pushedAt": "2024-06-30T22:15:29Z",
  "stargazersCount": 238,
  "topics": [],
  "updatedAt": "2025-10-10T23:14:36Z",
  "url": "https://github.com/talklittle/ffmpex"
}

FFmpex

An Elixir wrapper for the FFmpeg command line interface.

Documentation: https://hexdocs.pm/ffmpex/

Usage notes

The API is a builder, building up the list of options per-file, per-stream(-per-file), and globally.

Note that adding options is backwards from using the ffmpeg CLI; when using ffmpeg CLI, you specify the options before each file. But with FFmpex (this library), you add the file/stream first, then add the relevant options afterward.

Examples

import FFmpex
use FFmpex.Options

command =
  FFmpex.new_command
  |> add_global_option(option_y())
  |> add_input_file("/path/to/input.avi")
  |> add_output_file("/path/to/output.avi")
    |> add_stream_specifier(stream_type: :video)
      |> add_stream_option(option_b("64k"))
    |> add_file_option(option_maxrate("128k"))
    |> add_file_option(option_bufsize("64k"))

{:ok, output} = execute(command)

It is possible to obtain ffmpeg’s output with:

command =
  FFmpex.new_command
  |> add_input_file("/path/to/input.mp4")
  |> to_stdout()
  |> add_file_option(option_f("avi"))

{:ok, output} = execute(command)

do_something(output)

You can use the FFprobe module to query for file info:

FFprobe.duration("/path/to/input.avi")
# => result in seconds, e.g., 228.456939

See silent_video and thumbnex for more usage examples.

Prerequisites

FFmpeg must be installed.

Installation

Add ffmpex to your list of dependencies in mix.exs:

def deps do
  [
    {:ffmpex, "~> 0.11.0"}
  ]
end

Configuration

You can specify some options in config.exs:

config :ffmpex, ffmpeg_path: "/path/to/ffmpeg"
config :ffmpex, ffprobe_path: "/path/to/ffprobe"

Release notes

See the [Changelog]!(./CHANGELOG.md) for changes between versions.

Disclaimer

FFmpex is not affiliated with nor endorsed by the FFmpeg project.

FFmpeg is a trademark of Fabrice Bellard, originator of the FFmpeg project.

Copyright and License

Copyright (c) 2016 Andrew Shu

FFmpex source code is licensed under the [MIT License]!(./LICENSE.md).