"Ron Garret" wrote in message
...
I'm not an expert on codecs, but I've set up a little demo to show that
there is an mpeg format that is distinct from the mp4 format

There is no such thing as an "mpeg" format; without a version number, the
phrase "mpeg" by itself does not describe a video compression format. Your
demo simply illustrates that there are two different "Content-Type" tags.

Now, it may well be that the wrong tag is used, and on a computer where
different media players are configured to play different tags, a problem
would arise when the wrong tag is used. But Windows Media Player is
"intelligent" enough to look past the tag (and file extension) when trying
to play a file. I find it odd that the media player you're using on your
Mac is not.

Pete