why do some WMVs play inside the browser.....
 

...and some need to be downloaded before playing externally in windows media player? What's the secret?

it's easy

if you just link to a wmv it will open separatly

if you use the right code it will play in browser

here is the code, you need to change that Movie.wmc part twice:

<object id="MMPlayer1" width=460 height=400
classid="CLSID:22d6f312-b0f6-11d0-94ab-0080c74c7e95"
codebase="http://activex.microsoft.com/activex/controls/
mplayer/en/nsmp2inf.cab#Version=5,
1,52,701" standby="Loading Microsoft Windows Media Player components..."
type="application/x-oleobject">
<param name="FileName"
value="Movie.wmv" />
<param name="ShowControls" value="1" />
<param name="ShowAudioControls" value="1" />
<param name="ShowPositionControls" value="1" />
<param name="ShowTracker" value="1" />
<param name="ShowStatusBar" value="1" />
<param name="ShowDisplay" value="0" />
<param name="DefaultFrame" value="Slide" />
<param name="Autostart" value="1" />
<PARAM NAME="EnableContextMenu" VALUE="false">
<embed type="application/x-mplayer2"
pluginspage="http://www.microsoft.com/Windows/
MediaPlayer/download/default.asp"
src="Movie.wmv"
name=MMPlayer1 autostart=1
showcontrols=1 showdisplay=0 showstatusbar=1 defaultframe="Slide"
width=460 height=400> </embed>
</object>

Thanks greg80, I can use that.

That's not what I mean... it's when I click on a linked WMV... in most cases, it opens the download prompt, but sometimes the wmv behaves like an mpeg and streams in my browser window...

when I click a .mpeg file, it opens my media player, when I click on a .mpg file, it plays it in the browser.

hate that shit.

That's server side settings, You can set up whether You want streaming or downloading of different file types, I think it's Apache handlers doing it.

Also explains why AdvertisingSex gets this with .mpg, but that with .mpeg... .mpg is set up for streaming/embedding behavior.

Basically it's because of MIME-type handlers as Diligent said, but in my experience it's usually because the WMV is a wrapper for streamed MMS content.

ah, now things become a little clearer :)