WebM is a video file format intended primarily for royalty-free use in the HTML5 video tag. The WebM Project releases WebM-related software under a BSD license and all users are granted a worldwide, non-exclusive, no-charge, royalty-free patent license. The project is sponsored by Google and has a sister project WebP. The WebM container is based on a profile of Matroska. WebM initially supported VP8 video and Vorbis audio streams. In 2013 it was updated to accommodate VP9 video and Opus audio. WebM Project licenses VP8 hardware accelerators (RTL IP) to semiconductor companies for 1080p encoding and decoding at zero cost. AMD, ARM and Broadcom have announced support for hardware acceleration of the WebM format.
Flash Video is a container file format used to deliver video over the Internet using Adobe Flash Player version 6 and newer. Flash Video content may also be embedded within SWF files. There are two different video file formats known as Flash Video: FLV and F4V. The audio and video data within FLV files are encoded in the same manner as they are within SWF files. The F4V file format is based on the ISO base media file format and is starting with Flash Player 9 update 3. Both formats are supported in Adobe Flash Player and developed by Adobe Systems. FLV was originally developed by Macromedia. Flash Video is the de facto standard for web-based streaming video (over RTMP). Notable users of it include YouTube, Hulu, VEVO, Yahoo! Video, metacafe, Reuters.com, and many other news providers.