File Upload, convert from other application

Hi,
I am migrating an application to PHP runner.
The old datebase contains links to files in a pure string form e.g. "files/image.jpg".

I am looking for a tool to migrate the database in a batch job to the format PHPRunner uses e.g."[{"name":"files\/image_rj3kgln8.jpg","usrName":"document.doc","size":1000222,"type":"image\/jpeg","searchStr":"image.jpg,!:sStrEnd"}]".
It would be fine to know the script whithin PHP runner that does the job.

Thanks for help

Ulrich