This library provides decoding and encoding of audio on a playlist. It is intended to be used as a backend for music player applications. That said, it is also generic enough to be used as a backend for any streaming audio processing utility.

• Uses ffmpeg for robust decoding and encoding. See supported file formats and codecs.
• Add and remove entries on a playlist for gapless playback.
• Supports idempotent pause, play, and seek.
• Per-playlist-item gain adjustment so you can implement loudness compensation without audio glitches.
• Read and write metadata tags.
• Choose between smooth mode and exact mode during playback.
  • smooth mode - open the audio device once and resample everything to fit that sample rate and format.
  • exact mode - open and close the audio device as necessary in effort to open the audio device with parameters matching the incoming audio data.
• Extensible sink-based interface. A sink provides resampling and keeps its buffer full. Types of sinks:
  • raw sink - Provides reference-counted raw audio buffers you can do whatever you like with. For example a real-time audio visualization. All other sink types are built on top of this one.
  • player sink - Sends frames to a sound device.
  • encoder sink - Provides encoded audio buffers. For example, you could use this to create an HTTP audio stream.
  • loudness scanner sink - Uses the EBU R 128 standard to detect loudness. The values it produces are compatible with the ReplayGain specification.
  • fingerprint sink - Uses chromaprint to generate unique song IDs that can be used with the acoustid service.
  • waveform sink - Generates a visual representation of a song.
• Example programs included:
  • playlist - Play a series of songs with gapless playback.
  • metadata - Read or update song metadata.
  • replaygain - Report the suggested replaygain for a set of files.
  • transcode - Transcode one or more files into one output file.
  • fingerprint - Generate acoustid fingerprints for one or more files.
  • metadata_checksum - Read or update song metadata. This program scans the audio of the file before the metadata change, changes the metadata in a temporary file, scans the audio of the temporary file to make sure it matches the original, and then atomically renames the temporary file over the original file.

Dependencies:

• cmake >= 2.8.5
• ffmpeg >= 3.0
  • suggested flags: --enable-shared --disable-static --enable-libmp3lame --enable-libvorbis --enable-gpl
• libebur128
  • make sure it is compiled with the speex dependency so that true peak functions are available.
• libsoundio
• libchromaprint-dev

mkdir build
cd build
cmake ..
make
sudo make install

API Reference

Join #libgroove on irc.freenode.org and ask questions.

To build the documentation:

make doc

Feel free to make a pull request adding yours to this list.

• Groove Basin is a music player with lazy multi-core replaygain scanning, a web interface inspired by Amarok 1.4, http streaming, upload, download and a dynamic playlist mode.
• waveform generates PNG waveform visualizations.
• node-groove provides Node.js bindings to libgroove.
• playa OS X Audio Player that thinks in albums.
• groove-rs provides rust bindings to libgroove.
• ruby-groove provides Ruby FFI bindings to libgroove.
• TrenchBowl is a simple Qt GUI on top of libgroove.