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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SWF (Small Web Format/ShockWave Format) is a digital Adobe flash file format that stores vector-based animations, audios, and videos. Generally, it is used to stream media online, mostly browser-based games. Sadly, Adobe recently announced that they are ending Flash format support by the end of 2020 due to its shortcomings such as performance issues and lack of security.
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