ARCHIVED: Best file format for podcasting

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Because of its compatibility with computers and mobile devices, MPEG-4 Part 14 (MP4) is the file format best suited for podcasting. MP4 is a multimedia container format commonly used for digital audio and video streams, and can also store subtitles and images. It's based on Apple's QuickTime container format, and became an international standard in 2000.

Variations of the MP4 format offer different features:

.mp4: The .mp4 extension usually indicates a video file, but there is no way to know for sure what specific part or codec is used for the audio or video tracks inside this file.
.m4a: The .m4a extension indicates an .aac (Advanced Audio Coding) audio file inside an MP4 envelope.
.m4b: The .m4b extension indicates an .aac audio file inside an MP4 envelope, with the ability to add bookmarks.
.m4p: The .m4p extension indicates an .aac audio file inside an MP4 envelope, with Digital Rights Management (DRM) enabled.

Note:

Although the .m4a and .m4v formats are common, they are non-standard. Their use was initially popularized by Apple's iTunes store. After MP4 support was added, the use of .m4a and .m4v was deprecated.