How i use DSDecmp?

[BattleLegendRed]

Hi guys, I was able to open the DSDecmp .exe, but I don't know how to decompress and compress an NDS rom.
I would like a simple explanation as it seems complicated to me, since I can't find any information on the internet...

 

[FAST6191]

Compressing a ROM and what dsdecmp does are two different concepts.

If you want to unpack a DS ROM into its constituent files to further explore then any number of tools for this ranging from ndstool and frontends for it like dsbuff and dslazy, crystaltile2 (click the little DS icon on the right hand side of the upper toolbar, there are some other build and rebuild options in it as well), tinke, the nitro explorer family, mkds course modifier, ndsts (more for single file export and same size import) and much more besides.

Nobody really compresses whole DS ROMs for anything other than distribution online or storage on their computer -- flash carts are too slow to do this sensibly and don't work in the same way that other systems (which also by and large have far smaller ROMs) if you have had it somewhere before. Some emulators, frontends and ROM managers might do it for you though if you want to use in conjunction with an emulator.
You may have encountered an old discussion when some Scene groups took it upon themselves to compress the binary inside the ROM where by default it was not (some games do, some don't) and thus gain a tiny bit of space over the as the devs made it version and usually caused some aggravations with various things and possible extra load time. Don't do it.
That would also bring you onto the topic of ROM ripping, not many people do it nowadays (flash carts with massive SDHC cards making it obsolete) but https://gbatemp.net/threads/gbatemp...ew-2016-edition-out.73394/page-2#post-1799596 if you were curious.

DSdecmp is then a tool aimed at decompressing individual files within the ROM -- unlike many older systems the DS features compression in the BIOS and was provided to the devs of games, to this end many games will use it and thus compression in DS ROMs is rather less of a hurdle than when you encounter it say hacking a megadrive game where it is bound to be quite custom.
All that said while dscemp will still do things for you then most would suggest you use Cue's GBA/DS compressors instead, and if you are using the crystaltile2 program mentioned above it will also offer to try to decompress things (though sometimes it gets confused and will detect things as compressed when they are not).
https://www.romhacking.net/utilities/826/

 

[BattleLegendRed]

Compressing a ROM and what dsdecmp does are two different concepts.

So these programs you mention are better? I need to mess with the ROM decompressed files

 

[FAST6191]

Some serve slightly different purposes and have different approaches*, but yes if your ambition is to look at the files which make up most DS games then all those programs mentioned will achieve that goal.

*ndstool being a homebrew focused unpacker but clean and easy for most things so forms the default option in the "I just need a tool to look at this" stakes, nitroexplorer3 doing better for the few games that use file ordering (New Super Mario Brothers being a noted example), crystaltile2 is a bit clunky but is based around you providing settings to decode things but with a few known formats, tinke leans very much into the known formats thing and suffers a bit in options for non standard things as a result, mkds course modifier originally started life as a mario kart tool but morphed into something more, ndsts as mentioned only imports things of the same size as what is there which can be limiting but also makes for the cleanest insertions if you can manage it...

My personal setup consists primarily of ndstool with a batch file and crystaltile2, with ndsts if I do want that clean insertion option. Have tinke waiting in the wings (it does better with some texture formats) and everything else as and when.