Convert SQL Server .ldf + .mdf into MySQL scripts
Nope.

Your best bet is to not do that.

Your next best bet is to restore the backup to a SQL Server installation and use SSIS to migrate your objects.

If you like pain and punishment ( you are going to MySQL from MSSQL, so I'm assuming "yes" ), you can use the generate scripts wizard on the restored DB and try to adjust for all of the syntax / feature differences.

An .mdf ( or .ndf ) is a data file, complete with compression options and the like.  There's pretty much not even a non-trivial way to turn the storage file into scripts, much less for an entirely different engine.