This is a listing of open-source codecs—that is, open-source software implementations of audio or video coding formats.
Audio Codecs
- FLAC: Lossless codec developed by Xiph.Org Foundation.
- LAME: Lossy compression (MP3 format).
- TooLAME/TwoLAME: Lossy compression (MP2 format).
- Musepack: Lossy compression; based on MP2 format, with many improvements.
- Speex: Low bitrate compression, primarily voice; developed by Xiph.Org Foundation. Deprecated in favour of Opus according to www.speex.org.
- CELT: Lossy compression for low-latency audio communication
- libopus: A reference implementation of the Opus format, the IETF standards-track successor to CELT. (Opus support is mandatory for WebRTC implementations.)
- libvorbis: Lossy compression, implementation of the Vorbis format; developed by Xiph.Org Foundation.
- iLBC: Low bitrate compression, primarily voice
- iSAC: Low bitrate compression, primarily voice; (free when using the WebRTC codebase)
- TTA: Lossless compression
- WavPack: Hybrid lossy/lossless
- Bonk: Hybrid lossy/lossless; supported by fre:ac (formerly BonkEnc)
- Apple Lossless: Lossless compression (MP4)
- Fraunhofer FDK AAC: Lossy compression (AAC)
- FFmpeg: codecs in the libavcodec library, e.g. AC-3, AAC, ADPCM, PCM, Apple Lossless, FLAC, WMA, Vorbis, MP2, etc.
- FAAD2: open-source decoder for Advanced Audio Coding. There is also FAAC, the same project's encoder, but it is proprietary (but still free of charge).
- libgsm: Lossy compression (GSM 06.10)
- opencore-amr: Lossy compression (AMR and AMR-WB)
- liba52: a free ATSC A/52 stream decoder (AC-3)
- libdca: a free DTS Coherent Acoustics decoder
- Codec2: Low bitrate compression, primarily voice
Video Codecs
- x264: H.264/MPEG-4 AVC implementation. x264 is not a codec (encoder/decoder); it is just an encoder (it cannot decode video).
- OpenH264: H.264 baseline profile encoding and decoding
- x265: An encoder based on the High Efficiency Video Coding (HEVC/H.265) standard.
- Xvid: MPEG-4 Part 2 codec, compatible with DivX
- libvpx: VP8 and VP9 implementation; formerly a proprietary codec developed by On2 Technologies, released by Google under a BSD-like license in May 2010.
- FFmpeg codecs: Codecs in the libavcodec library from the FFmpeg project (FFV1, Snow, MPEG-1, MPEG-2, MPEG-4 part 2, MSMPEG-4, WMV2, SVQ1, MJPEG, HuffYUV and others). Decoders in the libavcodec (H.264, SVQ3, WMV3, VP3, Theora, Indeo, Dirac, Lagarith and others).
- Lagarith: Video codec designed for strong lossless compression in RGB(A) colorspace (similar to ZIP/RAR/etc.)
- libtheora: A reference implementation of the Theora format, based on VP3, part of the Ogg Project
- Dirac as dirac-research: a wavelet based codec created by the BBC Research, and Schrödinger, an implementation developed by David Schleef.
- Huffyuv: Lossless codec from BenRG
- Daala: Experimental Video codec which was under development by the Xiph.Org Foundation and finally merged into AV1.
- Thor: Experimental royalty free video codec which was under development by Cisco Systems, and merged technologies into AV1.
- Turing: A High Efficiency Video Coding (HEVC/H.265) encoder implemented by BBC Research.
- libaom: Reference implementation for the royalty free AV1 video coding format by AOMedia, inheriting technologies from VP9, Daala and Thor.