Conversion of existing tiles in .png format to .meta format

I already have all the tiles generated into ${z}/${x}/${y}.png format using generate_tiles.py script. I need to convert all these tiles into meta tile format which could be used by mod_tile. When I searched in web, I found that there was a utility 'convert_meta' which could have been used. But I noticed that this could not be used since the changes from revision: https://github.com/openstreetmap/mod_tile/commit/e8001c859f9aff20a387a57b7b3c9bee7beb921b

I would not prefer to revert my code to earlier version which had convert_meta utility and also would not prefer to regenerate all the tiles again.

Is there any other way which I could use to convert my already generated .png files into meta tiles?