how to get a stream instead of a download

To get a stream instead of a download, you want to pass the URL to the
renderer instead of the file. A common way to do that is with a playlist
that contains the URL.

Create a file like called makemedia01.m4u containing this one line:

Then make sure the mime type is set correctly by adding this to .htaccess:
AddType .m4u video/vnd.mpegurl

(See for
documentation on that mime type.)

Lastly, point to your .m4u file instead of the .mp4 file.