Json export layer data

Questions
1

[Edited] Never mind, I found out about Global tile id’s

I’m exporting my map to json format but the layer data listed are numbers I don’t understand. For example, one of the layers the data set looks like: “data”:[129,129,129,129,0,0…etc], but there aren’t any tiles with ID 129 in my tile set. I only have tiles that go up to ID=30. And if there’s no tile on the map, shouldn’t it read -1 and not 0?
The Tile Layer Format in my map properties is CSV, so I tried others but they don’t help.
When I export to CSV format it gives the actual tile IDs as data, but these numbers here I don’t understand. I would like to use json format. I could just use csv format for tile data and json for other properties, but I would prefer 1 file for everything. Any help is appreciated. Thanks

2

Just in case somebody finds this from a search engine:

You can read about the tile ids at:

http://doc.mapeditor.org/reference/tmx-map-format/#layer

That should explain why the ids are sometimes larger / different from what you expect.

Regards,
Ablu