What multimedia formats are supported?

Our Audio and Video player now takes advantage of built in HTML5 support for audio and video, which makes our player compatible with modern web browsers, including smartphones, (e.g. iPhone, iPad, Android, etc). For older browsers like Internet Explorer 8 (which does not support HTML5 video), and Firefox (which supports HTML5 video but is not licensed to play MP4 format yet), we will still provide the old Flash audio/video player, so your visitors will not lose any functionality.

The old Flash player will play both the old FLV and MP3 formats, as well as the new MP4 format. So for greatest compatibility we recommend using MP4 format for all videos and MP3 format for all audio files. We also recommend converting all your old videos that were uploaded as FLV to MP4, so that they will be watchable on mobile devices that don't support Flash. But if you keep old FLV files on the site, they will continue to be viewed by any browser that supports Flash (virtually all desktop browsers, but not most mobile browsers).

SUPPORTED FORMATS

MP3 Audio

Audio files in MP3 format will play in the new HTML5 player if the browser supports HTML5. Otherwise it will play in the old Flash player like it always has. We still recommend a Sampling Rate of 44.1 Khz (for compatibility with the Flash player on browsers that do not support HTML5 audio. See our FAQ on Audio Formats for more details.)

MP4 Video

We recommend that all videos be uploaded as MP4 for the best quality and compatibility across browsers. Most video software can exports MP4 with the correct settings that will be compatible with the HTML5 player. But for the record MP4 is just a container that wraps around different formats, typically the inner formats are H264 for Video and MP3 for Audio. So your MP4 must encode the video and audio in these standard formats as well. If your MP4 video does not play, it is probably a problem with incorrect encoding on your end.

FLV (deprecated)

All old videos that were in Flash Video format will continue to play in the old Flash player, but they will not be watchable on modern smartphones or other mobile devices that do not support Flash, e.g. iPhone, iPad, etc.  See our FAQ on the FLV format for more information about this deprecated format.

Quicktime (deprecated)

If you have uploaded Quicktime (.mov) files, these will still play in browsers that have the quicktime plugin. But they may not play on mobile devices. Quicktime is not a web optimized format, and so the files are very large. Also many computers do not have the Quicktime plugin. So we do not recommend this format.

UNSUPPORTED FORMATS

The MP4 container supports a wide variety of audio and video formats, not all of which are part of the HTML5 specification. The list below includes the formats most commonly found in MP4 containers which should be avoided because they are not supported by HTML5 and can not be guaranteed to play back in all situations.

AAC Audio

Although this format is valid inside an MP4 container and Flash will play it back without issues, it is not a part of the HTML5 specification and, as such, there is no guarantee that it will play back correctly in all situations. You might hold the opinion that the AAC format yields better audio quality than MP3 at the same bitrate and a direct technical comparison of the two formats would seem to agree with you. Unfortunately, we don't write the specifications, we just follow them, so we recommend that you use MP3 audio wherever possible.

DivX Video

DivX is a video format loosely based on the h.264 Advanced Simple Profile video format. When we say loosely, we mean very loosely; it's close enough that it is considered a valid format in an MP4 container but far enough that Flash and most browsers won't play it. We strongly recommend the use of h.264 Advanced Video Codec (AVC) wherever possible, but also support h.264 Advanced Simple Profile (ASP) in cases where AVC is unavailable or unsuitable for use. We recommend staying away from DivX altogether, as it only very loosely implements the less-efficient ASP profile of h.264.

Xvid Video

Xvid is a video format loosely based on both h.264 ASP and DivX (which, itself, is loosely based on h.264 ASP). As a result, it matches the specification better in some respects, but stras farther from it in others. Like DivX, Xvid is close enough to the h.264 specification to be a valid format in an MP4 container, but far enough that Flash and most browsers won't play it. The recommendations made in the paragraph about DivX video apply equally here.

COMPATIBILITY