This app changed the name to Media Inspector, it's not freeware anymore and it's sold through the App Store. But the price is 3 dollars only.

Also worth checking out: VideoSpec.

And there's Zenitram's mediainfo, with a Mac OS binary under construction.

Note: to launch two instances of this app to view info side-by-side, you can use the Quicksilver 'launch a copy' action.

this is a very handy program to have around for anyone who regularly encodes or transcodes video or audio. for instance, amongst many other potential uses, if i am working with avidemux and specifying the target size for a video i am transcoding to xvid, i can use this program to find out exactly how large the video and audio streams are, respectively, thereby enabling me to specify an exact & proper target size for the video stream and a proper encoding scheme for the audio stream to reach the target size without compromising too much on quality. kudos do the developer.

p.s. i submitted an icon for this application a while back, someone should put it up.

I've been looking for something like this for quite a while. I miss having Gspot from my Windows box.

Remarkably useful if you have to deal with a lot of weird codecs. (Although once you work out why it won't play in VLC, you often find there isn't much you can do about it on the Mac.)