Is a media container format designed for streaming over the Internet. Used on popular video hosting sites. Video is usually stored in h.263 and h.264 formats, audio is a in MP3 or other less popular codecs. FLV-file format is a bit stream, which provides high-quality image even at low bit rates.
AOMedia Video 1 (AV1) - is an open, royalty-free high efficiency video coding format designed for video transmissions over the Internet. AV1 is more efficient than H.264, H.265, HEVC, VP8, VP9. In a comparison of AV1 against H.264 (x264) and VP9 (libvpx), AV1 showed about 45–50% bitrate savings over H.264 and about 40% over VP9 when using a constant quality encoding mode. AV1 is intended to be able to be used together with the audio format Opus in a future version of the WebM container format for HTML5 web video and WebRTC