the SEI Recovery Point, tells the decoder to "start here, decode X frames, and then start displaying the video." This hides the refresh effect from the user while the frame loads. Motion vectors are restricted so that blocks on one side of the refresh column don't reference blocks on the other side, effectively creating a demarcation line in each frame. In April 2010, the x264 project announced full Blu-ray compliant video encoding capability making x264 the first free Blu-ray compliant software H.264 encoder. x264 has always had the ability to create video streams that are playable on most Blu-ray devices. However, it was up to the user to choose appropriate conversion settings. The default x264 preset chooses adequate compatibility for Blu-ray players but it is now possible to choose more complex conversion settings while simply maintaining compatibility by explicitly enabling Blu-ray compatibility mode. Blu-ray compatibility can be useful when striving for cross device compatibility, especially in the realm of high definition hardware media players. x264 has been used to author commercial Blu-ray Disc titles released by Warner Bros. Tandberg controversy In November 2010, Fiona Glaser, an x264 developer, published information in which she claims that one of Tandberg Telecom's (a Cisco Systems subsidiary) patent applications from December 2008 contains a step-by-step description of an algorithm she committed to the x264 codebase around two months earlier. This was relayed by media, which remarked that the company who filed the patent was following the x264 project IRC development channel and was known to the project developers, leading to Tandberg claiming that they discovered the algorithm independently. x264 frontends Avidemux FFmpeg HandBrake OpenShot Gstreamer MediaCoder MeGUI MEncoder RipBot264 SUPER StaxRip Telestream Episode TMPGEnc Video Mastering Works 5 XMedia Recode Harmonic Rhozet Workflow System See also MPEG-4 — A standard of various MPEG formats including video, audio, subtitle, and interaction. Doom9 — A forum for video creation help and technical discussions. x265 — Open source HEVC/H.265 encoder that has licensed the rights to use the x264 source code. References External links C (programming language) libraries Free software primarily written in assembly language Free video codecs Free video software pt:H.264#x264