Savegame file format

[Bjørn]

Is there somewhere in the documentation a description of the format of the save file, or must I dig through the source to piece it together?
I would like to make a small standalone utility to display information about a saved game, not unlike what already exists for grf files.

[Alberth]

The format is not stable, every now and then a setting gets added, changed, or removed, and we get a new savegame version.
I don't know all the details, but basically it is a compressed chunk-like format, the code lives in src/saveload.

It may be easier to extend the load GUI to display additional information (but not sure about that either).

[planetmaker]

See also
viewtopic.php?f=33&t=67069
http://www.tt-forums.net/viewtopic.php?f=42&t=17925

[frosch]

Maybe this can also give you some hints:
http://devs.openttd.org/~frosch/scndeps.c

It lacks support for compressed savegames though, so effectively is not useable at all

[Bjørn]

Thanks for the help. This looks messier than I had imagined. Was the format originally designed to be deliberately difficult to decode (in the old proprietary game)?

[planetmaker]

Thanks for the help. This looks messier than I had imagined. Was the format originally designed to be deliberately difficult to decode (in the old proprietary game)?

I don't think so. See also an old analysis of the TTD savegame format at http://marcin.ttdpatch.net/sv1codec/TTD-locations.html
It's quite efficient and doesn't waste space as it was written in a time where disk space was still measured in kilo- and Megabytes instead of Giga- and Terabytes.

[Eddi]

it's certainly not difficult, it's clearly structured (RIFF), just needs a lot of metainformation that is not stored in the file itself (but in the algorithm decoding it)

add to that the compression using standard libraries