Proprietary Audio/Video formats, should we use them on the web?

Should we worry about accessibility?

Recently a war not unlike the browser war has been fought over audio/video formats. This time it's RealNetworks not Netscape who Microsoft has attempted to blast out of the water. MS deployed the same technique that they used to nuke Netscape, they pretended to provide author and client software for "free" and then made it "part of the operating system" (thereby charging for it via another way). The result has been equally successful, already far more people use Windows Media and its Player compared to RealPlayer. As was the case with Netscape, RealNetworks going the way of the Dodo is in itself not something that should be mourned. Both Netscape and RealNetworks made a play for enslaving the world to their products just as Microsoft did, Microsoft simply beat them at their own game.

The loser in this battle for world domination are the users and the accessibility of web content. It's for this reason that web authors should use non proprietary media formats and transport protocols. Ease of use for the author and user familiarity are traditionally advantages of the proprietary methods marketed by the big corporations, but creating and using accessible alternatives is not as difficult as sometimes thought. Nowadays the quality to bandwidth ratio of non proprietary formats is just as good as the proprietary ones.

Players that automatically fetch codecs/filters

Both MS MediaPlayer and RealPlayer have the capability to fetch additional codecs/filters via the net. There's a catch however, the manufacturers of the player software mainly provide commercial and proprietary media decoders. Open source format decoding filters can usually not be obtained this way. This should not be used as an excuse for using proprietary formats since with little assistance from your web site users can easily obtain and install the necessary filters for their preferred player.

Media file formats

Wrapper formats: WAV, AVI and Ogg

Wrapper file formats can contain all types of media, uncompressed and compressed. Some formats are for audio only, others can contain audio and video, or even subtitling.

  • WAV is for audio content only
  • AVI (Audio Video Interleave) can contain audio and/or video
  • Ogg is a relatively new and very flexible format, it can contain multiple video streams, multilingual audio streams and also subtitles in multiple languages

Wrapper format file extensions do not provide any clues to what sort of media file format(s) they contain. This can be a problem if we want to be able to launch them by associating them with an application capable of handling the content.

Windows Media

Windows, Macintosh and Solaris only. Decent to good quality audio/video, high compression ratios.

RealMedia

Windows, Macintosh and Nix. Decent to good quality audio/video, high compression ratios.

Quicktime

Available to Windows and Mac users. Decent to good quality audio/video, high compression ratios.

MPEG layer I, II, III & MP3Pro (audio only)

  • MPEG Layer I: High quality, low latency, poor compression, outdated format, not suitable for use on the web.
  • MPEG Layer II: High quality, low latency, poor compression, not really suitable for use on the web.
  • MPEG Layer III: High quality, reasonable compression, nasty licensing issues, not really suitable for use on the web.
  • MP3Pro Highest quality at low bitrates. Regular MP3's sound poor at low bitrates (« 96kbps for stereo, « 56kbps mono), MP3Pro provides a solution to that problem. MP3Pro files need an MP3Pro decoder to experience the benefits, MP3Pro content can be played on a regular MP3 player, but without the quality benefits (MP3Pro files actually sound slightly worse when played via a regular MP3 decoder compared to normal MP3's). There is no advantage in using MP3Pro above and beyond a certain bitrate (approx. 96kbps for stereo). The format is a closed proprietary format currently only available on Windows clients. Money is being charged for usage of the technology in software encoders AND decoders (free or otherwise), on top of that a licensing fee is charged for content providers who want to use the format to distribute content.

Formats to avoid

The following proprietary audio/video formats should be avoided because of the accessibility issues they cause:

  • Windows Media (based on MPEG-4)
  • RealMedia
  • QuickTime
  • DivX (based on MPEG-4)
  • MP3pro (audio only)

Non commercial open formats

  • Uncompressed AVI Unsuitable for the web due to huge file size.
  • MPEG-1 Very good quality is possible, but for comparable quality MPEG-1 requires approximately 2.5 times the size of more modern compression formats like XviD. Not really suitable for the web if your target audience includes modem users. Accessibility in terms of client support for MPEG-1 is however excellent. The format also requires less powerful hardware to decode when compared to more modern formats.
  • MPEG-2 MPEG-2 Video is not suitable for use on the web.
  • MPEG-4 Very good quality/file size ratio. Not many users will have the necessary decoder software pre-installed, but filter/decoder software is available for commonly used players like MS MediaPlayer.
  • Ogg Vorbis Audio only, good to excellent quality. Not many users will have the necessary decoder software pre-installed, but filter/decoder software is available for commonly used players like MS MediaPlayer.

Recommendation

Audio : Ogg Vorbis
Video : XviD, an open source, non commercial, non proprietary MPEG-4 compliant compressor. Note that XviD does video only, so an additional audio compressor like Ogg Vorbis is required for the inclusion of audio. See this guide for creating XviD/Ogg multimedia for the web.
An interesting future option: Theora (by Xiph, creators of Ogg Vorbis, scheduled for release before the end of 2003).

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