Projects / dirac


Dirac is a general-purpose video codec aimed at resolutions from QCIF (176x144) to HDTV (1920x1080), progressive or interlaced. It uses wavelets, motion compensation, and arithmetic coding, and aims to be competitive with other state-of-the-art codecs. The Open Source implementation provides a C++ library with an encoder and decoder.

Operating Systems

Recent releases

  •  12 Feb 2009 06:44

    Release Notes: Minor bugs have been fixed. Compression efficiency is improved. A DirectShow filter to play back Dirac files in Windows Media Player and MPlayer Classic has been released. A utility called ffmpeg2dirac has been released to transcode any multimedia format that can be decoded by FFmpeg to Dirac (for video) and Vorbis (audio) muxed in Ogg.

    •  17 Sep 2008 05:04

      Release Notes: Encoder classes have been refactored to make coding processes more clear. Minor bugs have been fixed. Compression efficiency is improved. A DirectShow filter to play back Dirac files in Windows Media Player has been released. Support for Dirac encoding, decoding, and muxing via Dirac libraries and Schroedinger libraries is now available in FFmpeg and MPlayer.

      •  04 Jun 2008 13:01

        Release Notes: Support for Ultra High Definition video formats was added. Compression efficiency was improved. Major bugs that caused crashes and permanent loops were fixed. Patches to enable Dirac playback in MPlayer were released. A DirectShow filter to enable playback of Dirac files in Windows Media Player was released. The API has changed, so all applications using Dirac libraries need to be rebuilt.

        •  26 Jan 2008 23:15

          Release Notes: This is a minor release that complies with Dirac Bytestream Specification 2.1.0. Bugs in the motion compensation block weighting matrix and in the constant bit rate module when encoding I-frame only sequences were fixed. Bugs in the Dirac patches for MPlayer and FFmpeg and the Dirac DirectShow Filter were fixed.

          •  23 Jan 2008 07:36

            Release Notes: This is a major release that complies with the Dirac Bytestream Specification 2.0.0. The specification can be downloaded from Quantiser selection, motion compensation, and constant bit-rate coding performance have been improved. Bugs in constant bit-rate coding mode, dc value prediction in motion decoding, and handling concatenated Dirac bytestreams have been fixed. The encoder and decoder APIs have changed. New patches have been released for MPlayer and FFMpeg. A new version of the DirectShow filter has been released to comply with Dirac 0.9.0.


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