This is likely the problem. In your Flash submenu, you should find "Adobe Flash CS[version] Video Encoder." Run the encoder, convert your .mp4 to .flv, problem should be solved. It's pretty straightforward how to use it.
The other comp probably doesn't have .mp4 codecs or something . . . doesn't matter. .flv is the way to go with Flash.
I ran the below test out of curiosity, for your reference this should clear up some things.
- opened new AS3 file.
- Selected Import Video
- Selected path on the computer, select the .flv, not the .mp4. (we will change this later.)
- Left at "Progressive Download from a Web Server" (see below, important)
- Selected a skin
- Hit finish, prompts to save .fla
I see the component, press ctrl-enter to test.
Click the video playback element, then go to component inspector->parameters->source, the full path is there. Change whatever it is from C:\\whatever\video.flv to just video.flv. Verify it still runs from Flash on ctrl-enter.
At this point I cry "oops" because I never installed or have a need for the stand-alone player. Attempting to open the .swf directly gives me "select a program."
Time to hit publish. Set for AS3.0, Flash player 9.
Double clicked "component-test.html" and opens FF . . works fine . . .
Opened IE and tested, works there too.
Got comp's networked here, loaded the whole thing to a directory on the other comp . . . . works!
A list of files moved:
the .swf
the .flv version of the video
the AC_RunActiveContent.js (ugh)
Two .swf's that begin with "Skin" for my skin.
Don't embed it directly in the timeline/stage, use the progressive download. The whole idea of Flash is that it streams the data instead of having to wait for it all to load. When you put the entire video on the stage, this is probably what it will do.