MPEG-4 mime type on "42 Steps "

Hi Shannon, Lucas, Jay, and other MPEG-4 enthusiasts!

I've done quite a bit of work with MPEG-4. Particularly with QuickTime and the Cisco-sponsored MPEG4-IP project ( (which has made great strides since I last worked with it.)

My conclusion over a year ago was that the best way to deliver MP4 content in the short-run was to just require QT6. At the time QuickTime vastly outnumbered any other player that could handle MP4 and there appeared to be no clear standards for embedding MP4 in a web page. The situation may have changed since then.

Let's work together to figure out the best way to do it in late 2004. Lucas, you seem to have some practical experience using MP4 without tying it to QuickTime, can you provide some detail on what you have found?

I've successfully used "video/quicktime" to force it to work with QuickTime and that has worked as intended. I know this is "wrong".

Lucas suggested "video/mpeg4-generic" but this isn't supported by the QuickTime plugin. That is why when I click the "42 Steps" poster JPEG in Safari the following things happen:
1) A blank "Untitled" browser window pops up
2) The "Downloads" window pops up on top of that
3) The entire 4 mb file downloads with a progress bar
4) The QuickTime player is launched and pops up on top of everything else.
(Very distracting.)

QuickTime supports "video/mp4" which is clearly better than "video/quicktime".

To check which mime-types QuickTime is using:
1) Open the QuickTime Preferences Panel (Mac) or ControlPanel (Win)
2) Click on the "Plug-in" tab
3) Click the "MIME settings…" button

In Firefox/Mozilla you can use the "about:plugins" psuedo-URL to get a list of all plugins and the mime-types they'll accept.

Anyway, I changed the mime-type for the .mp4 file extension on one of Catalla's servers from "video/quicktime" to "video/mp4" and then posted a copy of Shannon's video to this URL:

It tried it in the following browsers and it seemed to work:
Mac: Safari, Firefox, Mozilla, Camino, Internet Explorer
Windows: IE, Firefox

It seemed to work well with the QT plugin in every case. In most cases the movie was able to start playing before the entire movie was downloaded.

How does it work for everyone else? Is there any known case where video/mpeg4-generic works but video/mp4 doesn't?



M. Sean Gilligan : 831-466-9788 x11
Catalla Systems, Inc.