I have eventually managed to finalize my upload module. I have
compromised all the requirements for the metadata format passed to
backend and it is now being generated in more or less universal form.
Please see module manual page on English or my nginx modules page:
or use the short links to download sources in gzipped tar or zip
I expect minor issues to pop up in near future, therefore I advise you
to test module before putting into production mode.
I hope you’ll enjoy it!
And your feedback is always welcomed.