There are a number of parameters that can be added to object and embed tags to embed flash videos. Most are listed here. Some of them can be accessed/changed programmatically via ActionScript (e.g. <param name="scale"> can be accessed via stage.scaleMode).
Can the value for the loop parameter be accessed/changed?
Edit to add: I know about flashvars, that’s not what I’m asking.
The general net consensus is that no, you can not access parameters other than flashvars/movie from inside Flash.
However, you can access the parameters, in some browsers at least, from JavaScript – and of course you can interface between Flash and JavaScript using an external.
Perhaps a javascript routine along the lines of:
Along with a method in Flash:
Obviously ensuring script access is enabled on the SWF and the object/embed.