AIiF (Apple Interchange File Format/Audio Interchange File) is a sound format used on Mac OS X. It comes with a .aiif filename extension and .aif when used on Windows. An AIF file features raw sound data like sample rate, bit depth, and channel (mono/stereo). This file format is also accepted on most CD writers.
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MP4 (MPEG-4 Part 14) is a video container format based on QuickTime MOV. But unlike MOV, it adds support for other MPEG features. MP4 supports video (MPEG-4 Part 2 and MPEG-4 Part 10/H.264), audio (MP3, AAC, SLS, TTSI, and ALAC), and subtitles (MPEG-4 timed text). It’s this codec combination that gives MP4 its flexibility.
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