Video formats explained

There are many video file formats available for distributing media across the Internet. The “MP4″ format is the most commonly used in the industry. The format is supported by most portable media players, Internet-connected TVs and software based media players.

We recommend MP4 format for the widest possible distribution

Below is a list of the most common video formats with a brief description and note on usage:

MP4 (MPEG-4)

MP4 is currently the most widely supported video format playable by most portable audio players, Internet-connected TVs, and software based media players.

MP4 is a video format based on Apple’s QuickTime video format and is essentially identical to the Apple QuickTimeMOV format, with additional features. MP4 video format most commonly contains AAC encoded audio and H.264 encoded video.

File extensions: .mp4

M4V (Apple’s iTunes implementation of MP4)

M4V is a non-standard file extension of the MP4 (MPEG-4) format (see above) popularized by Apple’s iPod, iPhone and the iTunes Store.

M4V is essentially identical to the MP4 except it has additional capabilities added by Apple. Since the file extension of .m4v was popularized by iTunes, the media opens in the iTunes application rather than by the default media player. The consumer of the media will typically be presented a “Save As” dialog if the iTunes application is not installed on the computer. The M4V format also allows for the inclusion of Apple’s FairPlay Digital Rights Management (DRM).

Note: Even though the .m4v and .mp4 file extensions are essentially interchangeable, we do not recommend using the .m4v file extension due to the unpredictable behavior with how the media will play on the consumer’s computer.

File extensions: .m4v

FLV (Flash video)

FLV is a format used to deliver video across  the Internet using Adobe Flash Player embedded in hardware devices and Web browsers. It is commonly paired with a HTML embed using a Flash Player (Flash Players use the .swf file extension). YouTube has one of the most popular HTML embed codes that use FLV formatted video with their own custom Flash player.

Note: Flash video is typically used to complement a podcast and is typically only used on websites. The FLV format is not recommended for syndication through a podcast feed.

File extensions: .flv, .f4v

Ogg (Theora)

Ogg Theora, not to be confused with the Ogg Vorbis audio format, is a (royalty-free) video format maintained by Xiph.Org Foundation. Even though the media file contains both Theora video-based on VP3 and Vorbis Audio, we simply refer to it as Ogg Theora to eliminate confusion.

Ogg Theora is not a widely popular format and is unable to be played by most portable media players and Internet connected TVs.

The Ogg Theora format is unrestricted by software patents. As a result, the format is very popular among open source software developers and is commonly used in gaming applications.

The Ogg Theora format is embraced by the open source and Linux community. If you are creating content for this community, it is highly recommended that you distribute versions of your media in the Ogg format, in addition to MP4.

File extensions: .ogv, .ogx

Note: Since 2007, the Xiph.Org Foundation recommends that .ogg file extension only be used for audio only Ogg Vorbis media.

WMV (Microsoft Video Media)

The WMV is a proprietary video format developed by Microsoft. The WMV format can support Digital Rights Management (DRM). The WMV format is most commonly found in Microsoft products and select portable media players.

List of WMV supported devices

File extensions: .wmv

WebM (Google Sponsored Media Format)

WebM is an (royalty-free) video format maintained by Webm.org and sponsored by Google. The video media file contains  VP8 video and Ogg Vorbis audio. It is very similar, but not identical, to Ogg Theora video.

WebM format is unrestricted by software patents. All users are granted a worldwide, non-exclusive, no-charge, royalty-free patent license.

The format was announced in 2010 and has already gained wide acceptance as a video format for future versions of Google Chrome, Firefox 4, Internet Explorer 9 and Safari Web browsers, as well as Adobe Flash, WinAmp, Miro media players and the open source FFMpeg video editing tool.

File extensions: .webm

3GP and 3G2 (Mobile H.263)

3GP and 3G2 are video formats typically found on portable media devices such as Android, Blackberry and other smartphones. The video media file contains either Mpeg-4 part 2, H.263 or a variation of H.264. Playback of such a format on a desktop computer typically requires additional updates or software for playback.

3GP and 3G2 media files are not typically used for Internet media distribution. This format is usually converted to one of the other formats above for the maximum device distribution.

File extensions: .3gp, .3g2

Other common formats not supported for podcasting

There are many more video formats, including MPEG (.mpg/.mpeg) and MOV (.mov), which are not used for podcasting. These formats are considered “raw”, meaning they contain the original recording and are not compressed or optimized for the Web in any way. In most all cases, a raw recording converted to a Web-friendly version is 10-50 times smaller in size, making the Web-friendly version the ideal choice for both bandwidth and speed of delivery.