WebM is an open-source, royalty-free multimedia format for streaming content online. It contains compressed video streams of either VP8 or VP9 codec and compressed audio streams of Oupus or Vorbis codec. Today, it’s one of the most widely used file formats to stream videos online because of its lightweight and real-time delivery nature.
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M4V is a digital video container format developed by Apple Inc. It is pretty similar to the popular MP4 in terms of structure, but M4V files can sometimes be DRM protected. Today, M4V is the primary video format for iTunes Store videos and can multiplex together multiple audio and video data.
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