MPA is an audio file that closely resembles thte audio-only formats like MP2. This audio format is small in size but with minimal quality loss. Technically, MPA files use MPEG-2 compression, which is known to offer small file size with original sound quality. MPA can be opened on most OS platforms and come with a .mpa filename extension.
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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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