An Interview With The Developers Of FFmpeg

FFV1 & Snow

While the FFmpeg developers have been focused on implementing industry-standard codecs, through the development process of FFmpeg they created two video codecs of their own: FFV1 and Snow. FFV1 is a lossless intra-frame video format while Snow is a wavelet video codec. FFV1 is very performance oriented, noted Baptiste Coudurier, while development on Snow has been stalled for some time. A bounty was made available to finalize the Snow specification, but nothing had come out of that. FFV1 though is able to achieve better compress than H.264 lossless in x264 and performs very well.

Legal Issues

FFmpeg is used in many popular open-source projects like MPlayer, GStreamer, XBMC, VLC Media Player, and others like Wii Video 9. However, the most prominent implementation that the FFmpeg developers have been proud of is Google's use of FFmpeg with YouTube, Sony's XDCAM EX clip browser, and of course the closely-tied MPlayer. FFmpeg is licensed under the GPL and LGPL, but there are a number of software projects violating these licenses with their FFmpeg usage. Recently they started displaying a Hall of Shame on the FFmpeg web-site where they list companies and projects in violation. Diego Biurrun is the one spearheading this work and he has been successful in resolving a handful of legal issues. Sometimes the violators work quickly to respond and rectify the problem, but in other cases it can take months. Some companies have even found themselves on their hall of shame and then contacted FFmpeg to work out the issues. Diego is uncertain though whether they will be able to resolve all license violation cases. FFmpeg also recently partnered up with the Software Freedom Law Center where they will be representing these multimedia developers in their formal legal affairs. So far, everything has been settled through friendly negotiations, but soon things could inevitably get nasty.

The Challenges

The biggest challenge the FFmpeg developers have found is getting people to pull through with long-term projects. Writing codecs is very complex and FFmpeg developers acknowledge that some features might be useful, but they cannot work on them all due to the lack of time and/or motivation. There is also a time-consuming review process. What has been successful with some of the FFmpeg developers is receiving bounties for the more challenging work and they have received support from outside companies. FFmpeg has no corporate sponsor, but companies like the BBC funded work on the VC-3 encoder. Open Source Partners Oy is funding Robert to implement HE AAC extension in the FFmpeg AAC decoder and is now working on Open IPTV Forum standardized IPTV support in MythTV. Google's Summer of Code project is also very important to the continued success of FFmpeg.

Diego Biurrun, Baptiste Coudurier, and Robert Swain are just three of the active FFmpeg developers. In the past six months there have been 42 people that made at least one commit to their SVN server while 31 of those made ten or more commits. Of the 42 developers, about a dozen of those are extremely active within the FFmpeg community making 50 or more commits during the same period. There are also other open-source enthusiasts involved with providing support through IRC, maintaining the mailing list, running FFmpeg tests, and related activities.