Difference between revisions of "Save disk space for ISOs"

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There are many ways. Some alter the dump copy forever. Some are playable on only some specific emulators. And many light dumps are unplayable on real hardware (though a bunch are). All depending on the method and the console. So you might want to consider all of this before.
 
There are many ways. Some alter the dump copy forever. Some are playable on only some specific emulators. And many light dumps are unplayable on real hardware (though a bunch are). All depending on the method and the console. So you might want to consider all of this before.
  
=Audio-CD=
+
This page was based partially on this [https://www.reddit.com/r/emulation/comments/3g933n/guide_reduce_the_size_of_your_ps2_gc_wii_x360_ds/ guide].
  
Sega-CD, PC-Engine, PlayStation, Sega Saturn... what did these have in common was their reliance on the regular CD format. Game developers stored often orchestrated/Redbook music and occasionally voice acting, using the Audio-CD format. Of course, the CD contained also game data.
+
Archive-quality dump means that the resulting compressed dump, when reverted back to its original state, will be the same checksum as the official uncompressed release. Compressions that can't be reversed, or those that can be but will have missing or altered content, whether it interferes with functionality (rebuilt table of content) or not, are not archive quality dumps. For example, the WBFS format is not archive quality since it may be missing padding content and upgrade partitions (which have their uses in 3DS/Wii modding) compared to an intact uncompressed dump.
  
But it was terribly inefficient when it comes to disk storage. Even a 700 MB CD containing nothing but Audio-CD data can hold at most around 80 minutes worth of sound data.  
+
==Applicable to All Platforms==
 +
===Audio-CD===
 +
Sega-CD, PC-Engine, PlayStation, Sega Saturn... what did these have in common was their reliance on the regular CD format. Game developers stored often orchestrated/Redbook music and occasionally voice acting, using the Audio-CD format. Of course, the CD contained also game data. But it was terribly inefficient when it comes to disk storage. Even a 700 MB CD containing nothing but Audio-CD data can hold at most around 80 minutes worth of sound data.  
  
 
That's why devs no longer used it, preferring custom audio formats included in the "game data" part of the disk. By the time the PS1 gen came, the Audio-CD part was just used for messages like "Don't put this in a CD player, dumb user!" and little else (exceptions exist, of course!)
 
That's why devs no longer used it, preferring custom audio formats included in the "game data" part of the disk. By the time the PS1 gen came, the Audio-CD part was just used for messages like "Don't put this in a CD player, dumb user!" and little else (exceptions exist, of course!)
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<br />CUE is the datasheet file
 
<br />CUE is the datasheet file
  
* '''Archive-quality dump?''' No
+
* '''Archive-quality dump?''' No (unless audio is converted to and from uncompressed formats, which is unlikely)
* '''Gain:''' Several hundreds of MBs to just a few dozen, depending on how much this specific game relies on the Audio-CD sound format
+
* '''Gain:''' Several hundreds of MBs to just a few dozens, depending on how much this specific game relies on the Audio-CD sound format
 
* '''Tools Used:''' Load the BIN+CUE using a virtual drive, then use a CD dumping tool
 
* '''Tools Used:''' Load the BIN+CUE using a virtual drive, then use a CD dumping tool
* '''Can be reverted?''' Yes, just burn the ISO+MP3/WAV+CUE again using a CD burner tool (ImgBurner) either to a physical disk, or as a ISO+BIN file.
+
* '''Can be reverted?''' Yes, just burn the ISO+MP3/WAV+CUE again using a CD burner tool (ImgBurner) either to a physical disk or as an ISO+BIN file. Lossy audio formats will result in data loss.
 
* '''Playable on Hardware?''' No, but can be reverted to be
 
* '''Playable on Hardware?''' No, but can be reverted to be
 
* '''Playable on Emulators?''' Yes (use virtual drive if needed). Some aren't compatible with MP3 so convert to WAV with MP32WAV if that's the case. You may need Sega Cue Maker.
 
* '''Playable on Emulators?''' Yes (use virtual drive if needed). Some aren't compatible with MP3 so convert to WAV with MP32WAV if that's the case. You may need Sega Cue Maker.
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* Captain Tsubasa (SCD): 512 MB > 146 MB (Game Data) + 3 MB (audio as MP3) > (as 7zip) 34 MB (Game Data) + 3 MB (audio)
 
* Captain Tsubasa (SCD): 512 MB > 146 MB (Game Data) + 3 MB (audio as MP3) > (as 7zip) 34 MB (Game Data) + 3 MB (audio)
  
=Padding=
+
M3U (playlist) files may be used too for this distribution scheme.
 +
 
 +
Sometimes dumps that come this way may not work on some emulators. This is often due to incorrect CUE files sometimes using wrong filenames or MP3 files instead of WAV files.
  
 +
===Padding===
 
Devs often have their games much, much bigger than they need to be. They put garbage data in the disk. Garbage data isn't game data and just bloats the disk size. It's either a sequence of 00/FF (you know what's inside a file if you open it with a hex editor) or randomized garbage data.
 
Devs often have their games much, much bigger than they need to be. They put garbage data in the disk. Garbage data isn't game data and just bloats the disk size. It's either a sequence of 00/FF (you know what's inside a file if you open it with a hex editor) or randomized garbage data.
  
 
Its purpose can be to fill in some spots in the disk so that specific parts of game data are in specific areas of the disk (like the borders) and hence the drive's reading speed is quick enough in these spots for the game to work properly. It's in the best of your interests not to mess with this data arrangement (referred to as LBA and TOC in the case of GC/Wii/PS2/PSP) or else the game might not even work in some cases (it might in others though).
 
Its purpose can be to fill in some spots in the disk so that specific parts of game data are in specific areas of the disk (like the borders) and hence the drive's reading speed is quick enough in these spots for the game to work properly. It's in the best of your interests not to mess with this data arrangement (referred to as LBA and TOC in the case of GC/Wii/PS2/PSP) or else the game might not even work in some cases (it might in others though).
  
BUT-- the most common bar none use for this is to screw with pirates and people who download ISOs off online sharing websites, by making the ISO bigger and harder to download. Some go a little step further and make that garbage data not just a sequence of 00/FF to make the ISO much, much harder to compress using regular archive formats like zip/7zip/rar... You might be overjoyed to learn this has become the industry standard nowadays.
+
BUT-- the most common bar none use for this is to screw with pirates and people who download ISOs off online sharing websites, by making the ISO bigger and harder to download. Some go a little step further and make that garbage data, not just a sequence of 00/FF to make the ISO much, much harder to compress using regular archive formats like zip/7zip/rar... You might be overjoyed to learn this has become the industry standard nowadays.
 +
 
 +
Many compression schemes remove or simplify padding patterns to allow for easier compression.
 +
 
 +
===CHD Compression===
 +
* '''Archive-quality dump?''' Yes
 +
* '''Gain:''' Immediate
 +
* '''Tools Used:'''  chdman (included with MAME)
 +
* '''Can be reverted?''' Yes, using extractcd (included with MAME)
 +
* '''Playable on Hardware?''' No.
 +
* '''Playable on Emulators?''' Only MAME and DEmul. Some libretro cores for other emulators started adding support.
 +
* '''Can process multi track bin files?''' Yes.
 +
 
 +
MAME uses the CHD format for disc images in general and includes tools to convert from and to it. It uses 7zip's LZMA compression on the game data and lossless FLAC compression for the audio data to optimize compression even further than with the BIN+CUE+MP3/WAV data separation alone.
 +
 
 +
Placing chdman and extractcd in the same directory as dumps in BIN+CUE format, the following command-line instructions can be used:
 +
* BIN/CUE to CHD: <code>for %i in (*.cue) do chdman createcd -i "%i" -o "%~ni.chd"</code> (Windows)
 +
* CHD to BIN/CUE: <code>for %i in (*.chd) do chdman extractcd -i "%i" -o "%~ni.cue"</code> (Windows)
 +
 
 +
If you have one of the European PSX games that feature LibCrypt copy protection, you have a .sbi file in addition to the .bin/cue file. The CHD creation process doesn't process the .sbi file. Thus, you will need the .sbi file in the same directory as the.CHD file for the game to run.
  
 
==PlayStation 1==
 
==PlayStation 1==
 
===ECM===
 
===ECM===
* '''Archive-quality dump?''' No
+
* '''Archive-quality dump?''' No (removes error correction data permanently)
 
* '''Gain:''' Not Immediate (ISO size doesn't change). ECM only zeroes out redundant error correction data (but in some rare cases this data may be used for anti-piracy, hence corrupting the dump!). When coupled to a compressed archive format (7zip/gzip/zip) however it achieves drastic size reductions.
 
* '''Gain:''' Not Immediate (ISO size doesn't change). ECM only zeroes out redundant error correction data (but in some rare cases this data may be used for anti-piracy, hence corrupting the dump!). When coupled to a compressed archive format (7zip/gzip/zip) however it achieves drastic size reductions.
 
* '''Tools Used:'''  PakkISO or ECM Tools (from emuparadise download page). Drag-and-drop the iso on the specific tool, then compress it with 7zip.
 
* '''Tools Used:'''  PakkISO or ECM Tools (from emuparadise download page). Drag-and-drop the iso on the specific tool, then compress it with 7zip.
  
* '''Can be reverted?''' Yes. Using same tools (unECM). There's a data loss (error correction data) which can damage a select few games. Check the hash with Redump to make sure nothing was altered.
+
* '''Can be reverted?''' Yes, using the same tools (unECM). However, there's data loss (error correction data) which can damage a select few games. Check the hash with Redump to make sure nothing was altered.
 
* '''Playable on Hardware?''' No.
 
* '''Playable on Hardware?''' No.
 
* '''Playable on Emulators?''' Only recent SVN builds of PCSX-R and ePSXe (they also support 7zip/gzip/zip archives so use them with ECM). Other emulators don't, so you convert manually the ECM dump to an ISO dump whenever you want to play it.
 
* '''Playable on Emulators?''' Only recent SVN builds of PCSX-R and ePSXe (they also support 7zip/gzip/zip archives so use them with ECM). Other emulators don't, so you convert manually the ECM dump to an ISO dump whenever you want to play it.
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===PBP (PSP Format for PS1 Images)===
 
===PBP (PSP Format for PS1 Images)===
 
* '''Archive-quality dump?''' No
 
* '''Archive-quality dump?''' No
* '''Gain:''' Immediate (ISO size decreases a lot). Official format used by Sony for PS1 dumps on PSP.
+
* '''Gain:''' Immediate (ISO size decreases a lot).
* '''Tools Used:''' PSX2PSP. Generates an EBOOT.PBP file.
+
* '''Tools Used:''' [https://www.reddit.com/r/PSP/wiki/psx2psp PSX2PSP], Popstation MD GUI, [https://www.psx-place.com/threads/w-i-p-utilities-cdda-enabler-for-psx-eboots-on-ps3.23539/ CDDA-ENABLER] (optimized for PS3) ...
  
* '''Can be reverted?''' Yes. Using same tool, to generate BIN+CUE files. There's negligible data loss.
+
* '''Can be reverted?''' Yes. (For homemade EBOOTs) by using the same tool, to generate BIN+CUE files; (for commercial releases from PSN) [https://github.com/xdotnano/PSXtract PSXtract]. There's data loss, although it's negligible in terms of functionality.
 
* '''Playable on Hardware?''' On PSP, not on PS1.
 
* '''Playable on Hardware?''' On PSP, not on PS1.
* '''Playable on Emulators?''' Retroarch, mednafen, PCSX-R and ePSXe.
+
* '''Playable on Emulators?''' RetroArch, PCSX-R, and ePSXe. PlayStation 3's ps1_netemu (after packaging into a PS1 Classic and installation of said package).
 
+
 
 +
Official format used by Sony for PS1 Classics on PSP and PS3. Audio tracks may be compressed in ATRAC3, or as raw PCM (unsupported on PS3's ps1_netemu, supported on PSP only by the earliest versions of POPS or the newest ones with the [http://wololo.net/talk/viewtopic.php?f=28&t=41330&start=60 cdda_enabler plugin])
 +
 
 
==PlayStation 2==
 
==PlayStation 2==
 
===Manual Scrubbing + GZIP Compression===
 
===Manual Scrubbing + GZIP Compression===
Often, you can open the ISO in UltraISO and find the dummy files. Sometimes they're obvious looking files like DUMMY.BIN, DATA0.BIN (or .DAT), DUMMY.DAT, etc. Or folders named "PADDING" and stuff like that. You can look into the files (with a hex editor) to see if they're obvious padding data (full of 00/FF, though sometimes it's not as obvious).
+
Often, you can open the ISO in UltraISO and find the dummy files. Sometimes they're obviously looking files like DUMMY.BIN, DATA0.BIN (or .DAT), DUMMY.DAT, etc. Or folders named "PADDING" and stuff like that. You can look into the files (with a hex editor) to see if they're obvious padding data (full of 00/FF, though sometimes it's not as obvious).
  
However, you must never mess with LBA and TOC when removing padding. So you try change the size of the padding file inside the ISO to 0 MB, or alter it directly with a hex editor so that it's all zeroed out.
+
However, you must never mess with LBA and TOC when removing padding. So you try to change the size of the padding file inside the ISO to 0 MB or alter it directly with a hex editor so that it's all zeroed out.
  
* '''Archive-quality dump?''' Yes
+
* '''Archive-quality dump?''' No (missing data)
 
* '''Gain:''' Not Immediate (ISO dump size the same). Coupled with compression, however... the gain is really noticeable.
 
* '''Gain:''' Not Immediate (ISO dump size the same). Coupled with compression, however... the gain is really noticeable.
 
* '''Tools Used:'''  UltraISO
 
* '''Tools Used:'''  UltraISO
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The PCSX2 emulator supports opening compressed archives containing ISOs. The best format it supports would be '''GZIP'''.  
 
The PCSX2 emulator supports opening compressed archives containing ISOs. The best format it supports would be '''GZIP'''.  
  
Use 7zip ("Add to archive..." then choose gzip) or Pigz (multi-threaded, much faster compression) to generate gzip archives containing the ISO file in question. PCSX2 will build an index of each gzip compressed game it loads (as a file in the same directory as the gzip archive), so after the first time where you'll have to wait for the decompression, in all subsequent times there is no speed difference between playing an uncompressed and compressed game. Of course, you can extract the ISO back from the GZIP archive.
+
Use 7zip ("Add to archive..." then choose to gzip) or Pigz (multi-threaded, much faster compression) to generate gzip archives containing the ISO file in question. PCSX2 will build an index of each gzip compressed game it loads (as a file in the same directory as the gzip archive), so after the first time where you'll have to wait for the decompression, in all subsequent times there is no speed difference between playing an uncompressed and compressed game. Of course, you can extract the ISO back from the GZIP archive.
  
 
===CSO (aka CISO)===
 
===CSO (aka CISO)===
* '''Archive-quality dump?''' Yes
+
* '''Archive-quality dump?''' No (missing data)
 
* '''Gain:''' Immediate (ISO dump size the same). Coupled with manual scrubbing, it can be bigger. Not as much of a gain as GZIP though.
 
* '''Gain:''' Immediate (ISO dump size the same). Coupled with manual scrubbing, it can be bigger. Not as much of a gain as GZIP though.
 
* '''Tools Used:''' maxcso
 
* '''Tools Used:''' maxcso
* '''Can be reverted?''' Yes. Using same tool.
+
* '''Can be reverted?''' Yes, using the same tool. No data loss.
 
* '''Playable on Hardware?''' NO
 
* '''Playable on Hardware?''' NO
 
* '''Playable on Emulators?''' Yes - PCSX2.
 
* '''Playable on Emulators?''' Yes - PCSX2.
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==PlayStation Portable==
 
==PlayStation Portable==
 
===CSO (aka CISO)===
 
===CSO (aka CISO)===
* '''Archive-quality dump?''' Yes
+
* '''Archive-quality dump?''' Maybe: while the actual compression is inherently lossless, depending on the conversion software and/or its configuration, so-called ripping (deletion or zero-resizing of the system update, videos, or other files) may be performed on the fly.
* '''Gain:''' Immediate (ISO dump size lowers). Substantial, depending on game. Increases load times on real hardware but not emulators.
+
* '''Gain:''' Immediate (ISO dump size lowers). Substantial, depending on game. Higher compression levels generally produce decreasing space gains while potentially increasing load times. Some tools allow for leaving audio/video content uncompressed.
* '''Tools Used:'''  CISO, CISO GUI, UMDGen or PSP ISO Compressor
+
* '''Tools Used:'''  CISO, CISO GUI, maxcso, UMDGen, PSP ISO Compressor, CISO Multi Compressor, CISO XP, ...
 
<br />CISO GUI (CISO is command line-based): Drag-and-drop ISO file on program, Select compression level (1 to 9 (Max)), "Compress", and choose directory for saving the new CSO file.   
 
<br />CISO GUI (CISO is command line-based): Drag-and-drop ISO file on program, Select compression level (1 to 9 (Max)), "Compress", and choose directory for saving the new CSO file.   
 
<br />UMDGen is a PSP ISO editor. You can save to either the CSO format with this.
 
<br />UMDGen is a PSP ISO editor. You can save to either the CSO format with this.
 +
* '''Can be reverted?''' Yes, using the same tools and saving in ISO (uncompressed) format. No data loss.
 +
* '''Playable on Hardware?''' Yes - most CFWs (Possibly longer load times though).
 +
* '''Playable on Emulators?''' Yes - PPSSPP.
 +
 +
===DAX, JSO, ZSO===
 +
Three different compressed-ISO formats. Significantly lower popularity/support than CSO.
 +
 +
===PBP===
 +
* '''Archive-quality dump?''' ???
 +
* '''Gain:''' Immediate (ISO dump size lowers).
 +
* '''Tools Used:'''  ISO~PBP Converter, or Sign~Fake NP Expert
 +
* '''Can be reverted?''' Yes
 +
* '''Playable on Hardware?''' Yes - CFWs (and, if signed, OFWs too).
 +
* '''Playable on Emulators?''' Yes - PPSSPP.
  
* '''Can be reverted?''' Yes. Using same tools, but saving to ISO (Uncompressed) format. No data loss.
+
Official format for digitally distributed PSP/minis (partially related to the one used for PS1 games), containing a compressed disc image and optionally a custom boot logo.
* '''Playable on Hardware?''' Yes. Longer load times though.
 
* '''Playable on Emulators?''' Yes. PPSSPP.
 
  
==DreamCast==
+
==Dreamcast==
 
===CHD Archive Format===
 
===CHD Archive Format===
* '''Archive-quality dump?''' Yes
+
* '''Archive-quality dump?''' No (missing data, no gameplay issues)
 
* '''Gain:''' Immediate (ROM dump size lowers).
 
* '''Gain:''' Immediate (ROM dump size lowers).
 
* '''Tools Used:''' GDI to CHD converter.
 
* '''Tools Used:''' GDI to CHD converter.
 
* '''Can be reverted?''' No.
 
* '''Can be reverted?''' No.
 
* '''Playable on Hardware?''' No
 
* '''Playable on Hardware?''' No
* '''Playable on Emulators?''' Yes - Demul and Reicast
+
* '''Playable on Emulators?''' Yes - DEmul, Reicast and Redream
  
 
==GameCube / Wii==
 
==GameCube / Wii==
 +
 
Some examples:
 
Some examples:
 
* Super Mario Anniversary (Wii): 4.7 GB (original) > 12 MB (GCZ) (!!)
 
* Super Mario Anniversary (Wii): 4.7 GB (original) > 12 MB (GCZ) (!!)
 
* Super Smash Bros Brawl (Wii): 7.8 GB (original) > 7.1 GB (GCZ) (main cause is FMV's low compression)
 
* Super Smash Bros Brawl (Wii): 7.8 GB (original) > 7.1 GB (GCZ) (main cause is FMV's low compression)
* Xenoblade PAL (Wii): 7.8 GB (original) > 6.3 GB (GCZ)  
+
* Xenoblade PAL (Wii): 7.8 GB (original) > 6.3 GB (GCZ)
* Super Mario Galaxy 2 (Wii): 4.7 GB (original) > 1.8 GB (GCZ)  
+
* Super Mario Galaxy 2 (Wii): 4.7 GB (original) > 1.8 GB (GCZ)
 
* Tales of Graces (Wii): 4.7 GB (original) > 4.2 GB (GCZ) (game data already fills the disk)
 
* Tales of Graces (Wii): 4.7 GB (original) > 4.2 GB (GCZ) (game data already fills the disk)
 
 
* Animal Crossing (GC): 1.4 GB (original) > 26 MB (GCZ)
 
* Animal Crossing (GC): 1.4 GB (original) > 26 MB (GCZ)
 
* Zelda Four Swords Plus Japan (GC): 1.4 GB (original) > 480 MB (GCZ)
 
* Zelda Four Swords Plus Japan (GC): 1.4 GB (original) > 480 MB (GCZ)
 
* Zelda Twilight Princess (GC): 1.4 GB (original) > 1.4 GB (GCZ) (game data already fills the disk)
 
* Zelda Twilight Princess (GC): 1.4 GB (original) > 1.4 GB (GCZ) (game data already fills the disk)
* Megaman Collection (GC): 1.4 GB (original) > 1.1 GB (original) (sound data is stored as uncompressed stream to fill disk)
+
* Megaman Collection (GC): 1.4 GB (original) > 1.1 GB (GCZ) (sound data is stored as uncompressed stream to fill disk)
  
Dolphin can't play game dumps off compressed archives (7zip/zip/gzip/rar...) directly.
+
People used to resort to WiiScrubber (Wii) and GCM Utility (GC) to scrub/trim games to end up with dumps that while they had no immediate size change, their randomized garbage data (like "dummy", "padding" or "znull") was still there but zeroed out making archived dumps using zip/7zip/rar formats have stunning gains (from 1.4GB uncompressed to 26MB zipped for Animal Crossing for example!). Of course, the file still needed to be uncompressed to its full size everytime you wanted to play it.
  
People used to resort to WiiScrubber (Wii) and GCM Utility (GC) to scrub/trim games to end up with dumps that while they had no immediate size change, their randomized garbage data (like "dummy", "padding" or "znull") was still there but zeroed out making archived dumps using zip/7zip/rar formats have stunning gains (from 1.4GB uncompressed to 26MB zipped for Animal Crossing for example!). Of course the file still needed to be uncompressed to its full size everytime you wanted to play it.
+
Trimming and scrubbing (in Wiiscrubber terms) aren't the same! While they both are terms for "zeroing garbage data" to make it more compression-friendly, trimming does not just that like scrubbing but takes the extra step of relocating the garbage data to the end of the file, hence altering its TOC and requiring the disc to be fakesigned, for a not-so-big compression gain. Hence why scrubbing is by far the most authentic and safe way to solve the garbage data problem.
  
'''NOTE:''' Trimming and scrubbing (in Wiiscrubber terms) aren't the same! While they both are terms for "zeroing garbage data" to make it more compression-friendly, trimming does not just that like scrubbing, but takes the extra step of relocating the garbage data to the end of the file, hence altering its TOC and requiring the disc to be fakesigned, for a not-so-big compression gain. Hence why scrubbing is by far the most authentic and safe way to solve the garbage data problem.
+
However compressed formats incorporating the "padding zeroing" part were made since then, and Dolphin supports them! These are the WBFS and GCZ formats.
  
However compressed formats incorporating the "padding zeroing" part were made since then, and Dolphin supports them! (Of course, if you're into modding/rom-hacking games, the previous tools might be of interest to you, but this is a story for another time...) 
+
===GCZ (Dolphin native archive format) - GC/Wii===
  
===GCZ (Dolphin native archive format) - GC/Wii===
+
Dolphin can't play games directly from compressed archives (7zip/zip/gzip/rar...). Instead, it utilizes its own compression method.
* '''Archive-quality dump?''' Yes for GC games, No for Wii games (doesn't keep MD5 hash)
 
* '''Gain:''' Immediate (ISO dump size lowers). Considerable, depending on game.
 
* '''Tools Used:''' Dolphin emulator<br />You need to add the games in your game list under Dolphin (Configuration/Paths).
 
<br />Select game in game list (you can hold Shift and select multiple ones).
 
<br />Right-click and choose "Compress selected ISOs". Choose a directory.
 
<br />It saves a compressed GCZ copy. You might want to delete the original uncompressed ISO.
 
  
* '''Can be reverted?''' Yes. You can right-click on the GCZ-compressed (in blue) ISOs in Dolphin and choose "Uncompress selected ISOs". Garbage data is still there but zeroed out, which has no effect since it's randomized anyways.
+
* '''Archive-quality dump?''' Yes for GC games, Not directly for Wii games (Can be restored with NKit).
 +
* '''Gain:''' Immediate (ISO dump size lowers). Considerable, depending on the game.
 +
* '''Tools Used:''' Dolphin (right-click the game(s) in the games list and select "Compress ISO..." (or "Compressed selected ISOs..." if more than one is selected)), [https://wiki.gbatemp.net/wiki/NKit NKit], or [https://wit.wiimm.de/ wit (Wiimms ISO Tools)]
 +
* '''Can be reverted?''' Yes. You can right-click on the GCZ-compressed (in blue) ISOs in Dolphin and choose "Uncompress selected ISOs". Garbage data for Wii titles will be zeroed out and thus different from the official dump but will have no effect on gameplay in most cases - if desired can be unscrubbed [https://gbatemp.net/threads/new-app-nkit-restore-shrink-and-preserve-disc-images-in-playable-formerly-swiit.533402/ NKitRestore].
 
* '''Playable on Hardware?''' No
 
* '''Playable on Hardware?''' No
 
* '''Playable on Emulators?''' Only Dolphin.
 
* '''Playable on Emulators?''' Only Dolphin.
  
===WBFS - Wii-only===
+
===Scrubbing and Trimming - GC/Wii===
* '''Archive-quality dump?''' Yes
+
* '''Archive-quality dump?''' Not directly, see note about reversing.
* '''Gain:''' Immediate (ISO dump size lowers). Considerable, depending on game.
+
* '''Gain:''' Not Immediate for just scrubbing (ISO dump size the same); Immediate for trimming (ISO dump size lowers).
* '''Tools Used:''' Wii Backup Manager<br />Under the "Files" section, choose "Add" then choose the ISO file you're converting.
+
* '''Tools Used:''' GC-Tool ("wipe garbage data..." - Scrubbing for GameCube), GameCube ISO Trimmer (scrubbing and trimming for GameCube), WiiScrubber (scrubbing for Wii, although compressing with Dolphin will scrub it anyways).
<br />Tool is compatible with ISO, CSO (aka CISO) and WBFS disk dumps. When you're done, select the ISO files you added.
+
* '''Can be reverted?''' Yes, with WiiScrubber's undo file or NKit.
<br />Under "Transfer", use the destination format. So, in our case, WBFS. Choose the directory to save it.
+
* '''Playable on Hardware?''' Yes for scrubbing; some games won't work trimmed.
<br />It saves a copy in the WFBS format. You might want to delete the original uncompressed ISO.
+
* '''Playable on Emulators?''' Yes for scrubbing; some games won't work trimmed.
 +
 
 +
Scrubbing games zeros out garbage/dummy data in the ISO file. The resulting file will be the same size, but it will be able to compress better than unmodified ISOs. The difference can be huge depending on the game. Animal Crossing, for instance, will compress to just a 26 MB .gcz file after being scrubbed!
 +
 
 +
Trimming (also known as "trucha scrubbing", and substantially different from the definition of "trimming" used in ROM-based systems) games will also defragment the files moving them towards the start of the disc image, resulting in a smaller ISO file. The trimmed file can be used immediately at a smaller size without compression, but the game's internal structure will be wholly modified. '''Games relying on direct sector access (as opposed to consulting the filesystem) will break if you trim them.'''
 +
 
 +
===WBFS - Wii only===
 +
* '''Archive-quality dump?''' Not directly, see note about reversing.
 +
* '''Gain:''' Immediate (ISO dump size lowers). Considerable, depending on the game.
 +
* '''Tools Used:''' [http://www.wiibackupmanager.co.uk/downloads.html Wii Backup Manager] (after adding your game, go to "Transfer" and select "WBFS") or wit (Wiimms ISO Tools).
 +
* '''Can be reverted?''' Maybe. WBFS files can always be converted back to ISO, but they will remain scrubbed (can be unscrubbed with NKitRestore) and, depending on settings at the time of conversion to WBFS, may be missing update/extras partitions (can be laboriously readded with wit and a copy of the missing data).
 +
* '''Playable on Hardware?''' '''Yes - Preferred format by most SD/USB loaders'''
 +
* '''Playable on Emulators?''' Yes - Dolphin
 +
 
 +
A scrubbed and sparse (gap-dropping) format directly derived from the one used in the obsolete WBFS file system.
  
* '''Can be reverted?''' Yes. You "Add" the WBFS disk dump and "Transfer" it to the "ISO" format. Garbage data is still there but zeroed out, which has no effect since it's randomized anyways.
+
===CSO (aka CISO) - GC/Wii===
* '''Playable on Hardware?''' Yes!! WBFS dumps are playable on Wii.
+
* '''Archive-quality dump?''' (Gamecube) Not clear; (Wii) Not directly, see note about reversing.
 +
* '''Gain:''' Immediate (ISO dump size lowers). Less than WBFS.
 +
* '''Tools Used:''' Wii Backup Manager (same as above, but select "CISO" - possibly Wii only), wit
 +
* '''Can be reverted?''' Maybe. CISO files can always be converted back to ISO, but they will remain scrubbed (can be unscrubbed with NKitRestore).
 +
* '''Playable on Hardware?''' Yes (on Wii/Vwii only) - Nintendont for Gamecube games, uLoader for Wii games
 
* '''Playable on Emulators?''' Yes - Dolphin
 
* '''Playable on Emulators?''' Yes - Dolphin
  
===CSO (aka CISO) - Wii-only===
+
A scrubbed and sparse (gap-dropping) format. Unrelated to the PSP's CSO format.
* '''Archive-quality dump?''' Yes
+
 
 +
===WIA (Wii ISO Archive) - Wii only?===
 +
* '''Archive-quality dump?''' Not directly unless --raw option is given, effectively preventing any space savings.
 
* '''Gain:''' Immediate (ISO dump size lowers). Less than WBFS.
 
* '''Gain:''' Immediate (ISO dump size lowers). Less than WBFS.
* '''Tools Used:''' Wii Backup Manager. Same as above, but "Transfer" to "CISO".
+
* '''Tools Used:''' wit
* '''Can be reverted?''' Yes. You "Add" the CSO disk dump and "Transfer" it to the "ISO" format. Garbage data is still there but zeroed out, which has no effect since it's randomized anyways.
+
* '''Can be reverted?''' Maybe. Just as the previous formats, WIA files can always be converted back to ISO, but the conversion may be lossy (reversible with added work) depending on conversion settings.
 
* '''Playable on Hardware?''' No
 
* '''Playable on Hardware?''' No
 +
* '''Playable on Emulators?''' No
 +
 +
A scrubbed and compressed format designed for maximum space savings without cutting corners on corruption detection, but it's not directly playable or editable. Never really caught on and may be considered de facto deprecated by NKit.
 +
 +
===NKit formats - GC/Wii===
 +
* '''Archive-quality dump?''' '''Yes - by explicit design choice!'''
 +
* '''Gain:''' Immediate or not depending on choice of GCZ- or ISO-based output.
 +
* '''Tools Used:''' NKit.
 +
* '''Can be reverted?''' Yes!
 +
* '''Playable on Hardware?''' (GC) Yes? (Wii) No
 
* '''Playable on Emulators?''' Yes - Dolphin
 
* '''Playable on Emulators?''' Yes - Dolphin
  
==GameBoy Advance / Nintendo DS / Nintendo 3DS==
+
Apart from its previously mentioned unscrubbing/untrimming features mentioned in the above formats' descriptions, NKit is able to convert any ISO (clean dump or otherwise) to and from an [https://wiki.gbatemp.net/wiki/NKit/NKitFormat intermediate format applying various reversible changes] that optimize the image for lossless compression, including various options such as splitting the often non-unique update partitions to separate files.
 +
 
 +
==Wii U==
 +
All uncompressed WUD dumps are 23.3GB, which makes compression needed de facto. Some examples:
 +
* Super Mario World 3D: 23.3GB > 2.61GB (88% gain)
 +
* New Super Mario Bros. U: 23.3GB > 1.8GB (92% gain)
 +
* Donkey Kong Country Tropical Freeze: 23.3GB > 11.7GB (49% gain)
 +
 
 +
===WUX (Wii U Compressed Image Dump Archive)===
 +
* '''Archive-quality dump?''' Yes (lossless, doesn't actually alter the data).
 +
* '''Gain:''' Immediate (smaller file than WUD): Around 50% gain usually (depending on the game)
 +
* '''Tools Used:''' [http://mega.nz/#!llQwyQQZ!58fErjqM7pyQZKFKe0Qlu1yLP5EbtmOmiDUN1ElW07c wud tool]. To use, drag-and-drop the ISO on the executable.
 +
* '''Can be reverted?''' Yes. The wud tool includes a decompression utility, which recreates the original file.
 +
* '''Playable on Hardware?''' No (can be converted to an installable format using [https://github.com/FIX94/wud2app wud2app])
 +
* '''Playable on Emulators?''' Yes - Future releases of Cemu (and potentially other [[Wii U emulators]])
 +
 
 +
By Exzap, Cemu's author ([http://gbatemp.net/threads/wii-u-image-wud-compression-tool.397901/ release thread]). The tool detects duplicate sectors and only stores them once: all the empty ranges end up removed, storing only ranges which contain file or filesystem data. Of course, the original ISO can be reconstituted.
 +
 
 +
===APP (aka NUS/Installable Format)===
 +
* '''Archive-quality dump?''' No, with respect to a disc image (update partition and padding dropped); Most accurate format for CDN dumps (digital titles).
 +
* '''Gain:''' Immediate (Total size decreases, compared to disc image)
 +
* '''Tools Used:''' wud2app (disc image to APP), disc2app (original disc to APP), NUSPacker (extracted format to APP), Teconmoon's WiiVC Injector (Wii/Gamecube disc image to Enhanced Vwii APP), ...
 +
* '''Can be reverted?''' No, if starting from a WiiU disc image; Yes (see below) if starting from extracted files
 +
* '''Playable on Hardware?''' Yes (after installation)
 +
* '''Playable on Emulators?''' ?
 +
 
 +
Consisting of a folder containing *.app, *.h3, title.cert, title.tik, and title.tmd files, this official Nintendo format intended for development use (and closely related to how digital titles are sold in) is equivalent to the 3DS's CIA format; however unlike a 3DS application, converting a disc title to digital does not require modifying the title itself, thus leaving the title's signatures valid.
 +
 
 +
===RPX/RPL (aka Installed/Extracted/Loadiine Format)===
 +
* '''Archive-quality dump?''' No (dump is extracted to individual files)
 +
* '''Gain:''' Immediate (Total size decreases). Can be less than a WUX depending on the game.
 +
* '''Tools Used:''' see below
 +
* '''Can be reverted?''' No, any padding/signature information is lost.
 +
* '''Playable on Hardware?''' Yes, use [https://github.com/dimok789/loadiine_gx2/releases Loadiine GX2]
 +
* '''Playable on Emulators?''' Yes
 +
 
 +
Titles installed to USB or MLC are stored in this format, comprised of three "code", "content", and "meta" folders.
 +
 
 +
Can be extracted from disc images with DiscU, UWizard ([http://digiex.net/guides-reviews/console-guides/nintendo-wii-u-guides/14680-wii-u-wud-loadiine-gx2-conversion-extract-wud-images-loadiine-use.html follow this guide for usage information]) or JWUDTool, and from the installable format using JNUSTool. Can be converted to installable format with NUSPacker.
 +
 
 +
Ideal format for game modding, less so for playing on console due to Loadiine's intrinsic modus operandi (appearing to the OS as the host title, with potentially different permissions) leading to poor compatibility.
 +
 
 +
==Game Boy Advance / Nintendo DS / Nintendo 3DS==
 
===Trimming===
 
===Trimming===
* '''Archive-quality dump?''' ABSOLUTELY NOT
+
* '''Archive-quality dump?''' No (data removed)
 
* '''Gain:''' Immediate (ROM dump size lowers).
 
* '''Gain:''' Immediate (ROM dump size lowers).
* '''Tools Used:''' NDSTokyoTrim (GBA/DS/3DS), rom_tool (3DS)<br />NDSTokyoTrim: Drag-and-drop roms, and press "Trim". The original file will be overwritten!  
+
* '''Tools Used:''' NDSTokyoTrim (GBA/DS/3DS), rom_tool (3DS), GodMode9 (can directly dump DS/3DS cards in trimmed format)<br />NDSTokyoTrim: Drag-and-drop roms, and press "Trim". The original file will be overwritten!  
* '''Can be reverted?''' No. Sometimes it damages the game's functionality irreversibly.
+
* '''Can be reverted?''' No. Some GBA/DS games may be broken by meaningful data at the end of the ROM being mistaken for padding.
 
* '''Playable on Hardware?''' Yes, same file format.
 
* '''Playable on Hardware?''' Yes, same file format.
 
* '''Playable on Emulators?''' Yes
 
* '''Playable on Emulators?''' Yes
  
While it doesn't affect the game's functionality by much other than being a smaller regular ROM, it's not advisable though to trim in many cases, including GBA games in general. Rebuilding the internal structure of the rom might even destroy the game's functionality in the few games where it does matter (for example Golden Sun DS).
+
Trimming involves deleting bytes from the end of the ROM up to until the first different one.
 +
 
 +
However, with no mandatory allocation table, it's not intrinsecally possible to identify the true end of the used area, and therefore some GBA/DS games can be broken by naive automated trimming (for example Golden Sun DS).
 +
 
 +
===CIA (CTR Importable Archive, 3DS and DSiWare only)===
 +
* '''Archive-quality dump?''' No (data removed and edited), compared to a gamecard dump. Potentially most accurate format for CDN (digitally distributed) titles.
 +
* '''Gain:''' Immediate (smaller than original ROM - not applicable to digital titles).
 +
* '''Tools Used:''' GodMode9 (can directly dump 3DS cards or installed titles to CIA, as well as converting 3DS to CIA), 3dsconv or 3DS Simple CIA Converter 5.0+ (3DS rom to CIA); makerom (3DS to/from CIA, NCCHs/DSiWare/ELF+RSF to 3DS/CIA), make_cia (DSiWare to CIA)
 +
* '''Can be reverted?''' No, if starting from a gamecard dump (update partitions removed, main content's ExHeader modified to change the media type from CARD/NAND to SD Application)
 +
* '''Playable on Hardware?''' Yes, after installation.
 +
* '''Playable on Emulators?''' Yes?
 +
 
 +
Official Nintendo format for developers to install digital titles, later became the most popular format for installable homebrew and game backups owing to the relatively low marketshare of flashcards and emulators (and, for the former, strong impopularity) in favor of CFW.
 +
 
 +
 
 +
===NCCHs (CXIs and CFAs, 3DS only)===
 +
* '''Archive-quality dump?''' No (partition table/ticket/signatures... removed), compared to CCI/3DS and CIA
 +
* '''Gain:''' Immediate (smaller than original ROM - not applicable to digital titles).
 +
* '''Tools Used:''' GodMode9, ctrtool, ...
 +
* '''Can be reverted?''' No (result will be unsigned)
 +
* '''Playable on Hardware?''' Not really, unless packaged back into a CIA or 3DS.
 +
* '''Playable on Emulators?''' Yes
 +
 
 +
3DS and CIA files, as well as already installed digital titles, are comprised of one or more NCCHs (also called "partitions" or  "contents"): the main content (number 0) can either be an executable CXI for software, or a non-executable CFA for a data title. Additional CFAs may be present, [https://www.3dbrew.org/wiki/NCSD#Overview with conventional index numbers]. [[Citra]] can run CXIs directly.
  
 
==Xbox 360==
 
==Xbox 360==
It's certainly better than keeping 8.5GB images, but the conversion is too substantial and irreversible to be suitable for archival purposes, since it affects data structure tables as well.
+
It's certainly better than keeping 8.5GB images, but the conversion is too substantial and irreversible to be suitable for archival purposes since it affects data structure tables as well.
  
 
===XEX (Xbox Executable) + Data folder (a.k.a Spilling The ISO Guts)===
 
===XEX (Xbox Executable) + Data folder (a.k.a Spilling The ISO Guts)===
* '''Archive-quality dump?''' ABSOLUTELY NOT
+
* '''Archive-quality dump?''' No (dump is collapsed to individual files)
 
* '''Gain:''' Immediate (total file size decreases). It still works with Xenia
 
* '''Gain:''' Immediate (total file size decreases). It still works with Xenia
 
* '''Tools Used:''' XBOX 360 ISO Extract, Exiso-GUI or Exiso. (These might be useful for rom-hacking too I guess?)
 
* '''Tools Used:''' XBOX 360 ISO Extract, Exiso-GUI or Exiso. (These might be useful for rom-hacking too I guess?)
 
* '''Can be reverted?''' ISO could be rebuilt, though not accurately.
 
* '''Can be reverted?''' ISO could be rebuilt, though not accurately.
* '''Playable on Hardware?''' Probably Not.
+
* '''Playable on Hardware?''' Yes. Using a JTAG or RGH exploited console.
 
* '''Playable on Emulators?''' Yes - Xenia.
 
* '''Playable on Emulators?''' Yes - Xenia.
  
 
===Rebuilt ISO===
 
===Rebuilt ISO===
* '''Archive-quality dump?''' ABSOLUTELY NOT
+
* '''Archive-quality dump?''' No (missing data)
 
* '''Gain:''' Immediate (total file size decreases). It still works with Xenia.
 
* '''Gain:''' Immediate (total file size decreases). It still works with Xenia.
* '''Tools Used:''' ISO2GOD (also a "Games on Demand" X360 image convertor). <br />Under Settings, set the output and rebuild path to the same location. Check "Always save rebuilt ISO" and set Padding to "Full (ISO Rebuild)", then save changes.<br />"Add ISO", and press "Convert". Keep generated ISO, and delete generated folder.
+
* '''Tools Used:''' ISO2GOD (also a "Games on Demand" X360 image converter). <br />Under Settings, set the output and rebuild path to the same location. Check "Always save rebuilt ISO" and set Padding to "Full (ISO Rebuild)", then save changes.<br />"Add ISO", and press "Convert". Keep generated ISO, and delete generated folder.
 
* '''Can be reverted?''' The padding quantity information alongside the original data structure is lost forever.
 
* '''Can be reverted?''' The padding quantity information alongside the original data structure is lost forever.
 
* '''Playable on Hardware?''' Yes. If the rebuilding process didn't damage anything vital.
 
* '''Playable on Hardware?''' Yes. If the rebuilding process didn't damage anything vital.
Line 198: Line 328:
 
===NTFS Compression===
 
===NTFS Compression===
 
You can enable filesystem-level compression (like "NTFS Compression" in Windows) for the directory containing your ISOs/ROMs. This has a very noticeable space gain and doesn't affect the emulator's functionality. It's surprisingly more effective than many people would like to give this credit.
 
You can enable filesystem-level compression (like "NTFS Compression" in Windows) for the directory containing your ISOs/ROMs. This has a very noticeable space gain and doesn't affect the emulator's functionality. It's surprisingly more effective than many people would like to give this credit.
 +
 +
* '''Archive-quality dump?''' Yes
  
 
===Decompression on Demand===
 
===Decompression on Demand===
 
You can keep your ROMs/ISOs compressed in a 7zip archive and use RocketLauncher or any other [[Frontends]] to decompress 7zip archives and pass the contents onto the emulator.
 
You can keep your ROMs/ISOs compressed in a 7zip archive and use RocketLauncher or any other [[Frontends]] to decompress 7zip archives and pass the contents onto the emulator.
  
==LET'S PLAY GAME BUTCHERING GAME==
+
* '''Archive-quality dump?''' Yes
Of course, there are also the devs who don't merely use garbage data for padding, but also bloat '''the game data part'''. For instance, Tengai Makyou IV PSP has a specific FMV movie duplicated a dozen times, and the Megaman Collection on GC stores its sound data using an uncompressed format bringing the size of that portion alone to 1GB. In many of these cases, there's just not much you can do about it without destructively altering game data.
+
 
 +
==Destructive Modification==
 +
Of course, there are also the devs who don't merely use garbage data for padding but also bloat the game data part. For instance, many PSP JRPGs have a specific FMV movie duplicated a dozen times, and the Megaman Collection on GC stores its sound data using an uncompressed format bringing the size of that portion alone to 1GB. In many of these cases, there's just not much you can do about it without destructively altering game data.
  
So what do some people do? Note when I say "delete" it often means replacing the file with a 1KB dummy file to prevent the ISO file structure from collapsing on itself. Of course, it's not like some idiots care anyways about keeping the thing in a semi-playable state.
+
So what do some people do? Note when I say "delete" it often means replacing the file with a 1KB dummy file to prevent the ISO file structure from collapsing on itself, but sometimes such care isn't even put into ensuring it's still in a functional state. Some examples:
* They delete all videos: this brings Super Smash Bros Brawl to 4.7GB.
 
* They delete all voice acting and occasionally sound and music: this brings Xenoblade PAL to 4.2 GB with even only one of both dubs removed.
 
* They delete unused content you could get with emulator cheats like rooms and stuff
 
* They delete "extra" languages other than English
 
* If game has multiple quests, they delete some characters / quests they don't like. Especially seen in compilations and stuff with demos included.
 
  
Since this results in most of the case in very noticeable detrimental effects in gameplay (if the game doesn't crash outright), this is nothing short of mutilating the game image, and the fuckers doing this then instead of keeping it for personal use are instead uploading the game to "archive" it (bonus points if they remove chunks from the game to make room for a shitty intro screen) while being proud of themselves, have a special spot in Hell.
+
* delete all videos: this brings Super Smash Bros Brawl to 4.7GB.
 +
* delete all voice acting and occasionally sound and music: this brings Xenoblade PAL to 4.2 GB with even only one of both dubs removed.
 +
* delete unused content you could get with emulator cheats like rooms and stuff
 +
* delete "extra" languages other than English
 +
* If a game has multiple quests, they delete some characters/quests they don't like. Especially seen in compilations and stuff with demos included.
  
tl;dr: Avoid.
+
Tools used for this are modding tools for rebuilding file trees, like UMDGen (PSP), Tinke (DS) and also regular ISO tools (PS1, Saturn)...
  
This page was based partially on this [https://www.reddit.com/r/emulation/comments/3g933n/guide_reduce_the_size_of_your_ps2_gc_wii_x360_ds/ guide].
+
Since this results in most of the case in very noticeable detrimental effects in gameplay (if the game doesn't crash outright), this is nothing short of mutilating the game image. Some of these dumps make it to sharing sites sadly enough.
 +
 
 +
Avoid resorting to destructive modifications since it can lead to random crashes and unexpected behavior, especially in games with lots of shared assets. [[http://emulation.gametechwiki.com/index.php/File_Hashes Verify]] your dumps to make sure you don't have these, and if you want to compress those prefer other methods or using decompression on demand. One reason to use a destructively modified dump is for burning your own Dreamcast games, as GD-ROMs were over a gigabyte in size and CD-Rs top out at 850MB.
 +
 
 +
* '''Archive-quality dump?''' No (destructive mod)
 +
 
 +
[[Category:FAQs]]

Revision as of 10:52, 21 September 2019

ISOs are faithful software recreations of game disks. However, at 700 MB (CD) / 1.4 GB (GC Mini-DVD) / 4.7 GB (single-layered DVD) / 25 GB (Blu-Ray), they can get pretty taxing to disk storage, as newer generations of consoles come.

It wouldn't be so bad if not for the fact that the actually useful game data is often only a fraction of that data size - for instance, the Mario 25th Anniversary Wii disk is a 4.7GB game with only a single SNES rom and nothing else (12 MB of useful data, to be precise). So naturally, one would want to trim the extra fat as much as possible. This is what this improved version of a previous guide aims to help for.

How does one lighten ISO / ROM dumps?

There are many ways. Some alter the dump copy forever. Some are playable on only some specific emulators. And many light dumps are unplayable on real hardware (though a bunch are). All depending on the method and the console. So you might want to consider all of this before.

This page was based partially on this guide.

Archive-quality dump means that the resulting compressed dump, when reverted back to its original state, will be the same checksum as the official uncompressed release. Compressions that can't be reversed, or those that can be but will have missing or altered content, whether it interferes with functionality (rebuilt table of content) or not, are not archive quality dumps. For example, the WBFS format is not archive quality since it may be missing padding content and upgrade partitions (which have their uses in 3DS/Wii modding) compared to an intact uncompressed dump.

Applicable to All Platforms

Audio-CD

Sega-CD, PC-Engine, PlayStation, Sega Saturn... what did these have in common was their reliance on the regular CD format. Game developers stored often orchestrated/Redbook music and occasionally voice acting, using the Audio-CD format. Of course, the CD contained also game data. But it was terribly inefficient when it comes to disk storage. Even a 700 MB CD containing nothing but Audio-CD data can hold at most around 80 minutes worth of sound data.

That's why devs no longer used it, preferring custom audio formats included in the "game data" part of the disk. By the time the PS1 gen came, the Audio-CD part was just used for messages like "Don't put this in a CD player, dumb user!" and little else (exceptions exist, of course!)

  • Full Dump:
    BIN/ISO + CUE


BIN/ISO is the full disk data, including Audio-CD sound data and game data
CUE is the datasheet file

  • Light Dump:
    ISO + MP3/WAV + CUE


ISO is the disk data with only the game data
MP3/WAV is the sound data from the Audio-CD, but these formats take much less disk space
CUE is the datasheet file

  • Archive-quality dump? No (unless audio is converted to and from uncompressed formats, which is unlikely)
  • Gain: Several hundreds of MBs to just a few dozens, depending on how much this specific game relies on the Audio-CD sound format
  • Tools Used: Load the BIN+CUE using a virtual drive, then use a CD dumping tool
  • Can be reverted? Yes, just burn the ISO+MP3/WAV+CUE again using a CD burner tool (ImgBurner) either to a physical disk or as an ISO+BIN file. Lossy audio formats will result in data loss.
  • Playable on Hardware? No, but can be reverted to be
  • Playable on Emulators? Yes (use virtual drive if needed). Some aren't compatible with MP3 so convert to WAV with MP32WAV if that's the case. You may need Sega Cue Maker.

Examples:

  • Princess Crown (SAT): 574 MB > 72 MB (Game Data) + 50 MB (Audio-CD data in MP3 format)
  • Captain Tsubasa (SCD): 512 MB > 146 MB (Game Data) + 3 MB (audio as MP3) > (as 7zip) 34 MB (Game Data) + 3 MB (audio)

M3U (playlist) files may be used too for this distribution scheme.

Sometimes dumps that come this way may not work on some emulators. This is often due to incorrect CUE files sometimes using wrong filenames or MP3 files instead of WAV files.

Padding

Devs often have their games much, much bigger than they need to be. They put garbage data in the disk. Garbage data isn't game data and just bloats the disk size. It's either a sequence of 00/FF (you know what's inside a file if you open it with a hex editor) or randomized garbage data.

Its purpose can be to fill in some spots in the disk so that specific parts of game data are in specific areas of the disk (like the borders) and hence the drive's reading speed is quick enough in these spots for the game to work properly. It's in the best of your interests not to mess with this data arrangement (referred to as LBA and TOC in the case of GC/Wii/PS2/PSP) or else the game might not even work in some cases (it might in others though).

BUT-- the most common bar none use for this is to screw with pirates and people who download ISOs off online sharing websites, by making the ISO bigger and harder to download. Some go a little step further and make that garbage data, not just a sequence of 00/FF to make the ISO much, much harder to compress using regular archive formats like zip/7zip/rar... You might be overjoyed to learn this has become the industry standard nowadays.

Many compression schemes remove or simplify padding patterns to allow for easier compression.

CHD Compression

  • Archive-quality dump? Yes
  • Gain: Immediate
  • Tools Used: chdman (included with MAME)
  • Can be reverted? Yes, using extractcd (included with MAME)
  • Playable on Hardware? No.
  • Playable on Emulators? Only MAME and DEmul. Some libretro cores for other emulators started adding support.
  • Can process multi track bin files? Yes.

MAME uses the CHD format for disc images in general and includes tools to convert from and to it. It uses 7zip's LZMA compression on the game data and lossless FLAC compression for the audio data to optimize compression even further than with the BIN+CUE+MP3/WAV data separation alone.

Placing chdman and extractcd in the same directory as dumps in BIN+CUE format, the following command-line instructions can be used:

  • BIN/CUE to CHD: for %i in (*.cue) do chdman createcd -i "%i" -o "%~ni.chd" (Windows)
  • CHD to BIN/CUE: for %i in (*.chd) do chdman extractcd -i "%i" -o "%~ni.cue" (Windows)

If you have one of the European PSX games that feature LibCrypt copy protection, you have a .sbi file in addition to the .bin/cue file. The CHD creation process doesn't process the .sbi file. Thus, you will need the .sbi file in the same directory as the.CHD file for the game to run.

PlayStation 1

ECM

  • Archive-quality dump? No (removes error correction data permanently)
  • Gain: Not Immediate (ISO size doesn't change). ECM only zeroes out redundant error correction data (but in some rare cases this data may be used for anti-piracy, hence corrupting the dump!). When coupled to a compressed archive format (7zip/gzip/zip) however it achieves drastic size reductions.
  • Tools Used: PakkISO or ECM Tools (from emuparadise download page). Drag-and-drop the iso on the specific tool, then compress it with 7zip.
  • Can be reverted? Yes, using the same tools (unECM). However, there's data loss (error correction data) which can damage a select few games. Check the hash with Redump to make sure nothing was altered.
  • Playable on Hardware? No.
  • Playable on Emulators? Only recent SVN builds of PCSX-R and ePSXe (they also support 7zip/gzip/zip archives so use them with ECM). Other emulators don't, so you convert manually the ECM dump to an ISO dump whenever you want to play it.

PBP (PSP Format for PS1 Images)

  • Archive-quality dump? No
  • Gain: Immediate (ISO size decreases a lot).
  • Tools Used: PSX2PSP, Popstation MD GUI, CDDA-ENABLER (optimized for PS3) ...
  • Can be reverted? Yes. (For homemade EBOOTs) by using the same tool, to generate BIN+CUE files; (for commercial releases from PSN) PSXtract. There's data loss, although it's negligible in terms of functionality.
  • Playable on Hardware? On PSP, not on PS1.
  • Playable on Emulators? RetroArch, PCSX-R, and ePSXe. PlayStation 3's ps1_netemu (after packaging into a PS1 Classic and installation of said package).

Official format used by Sony for PS1 Classics on PSP and PS3. Audio tracks may be compressed in ATRAC3, or as raw PCM (unsupported on PS3's ps1_netemu, supported on PSP only by the earliest versions of POPS or the newest ones with the cdda_enabler plugin)

PlayStation 2

Manual Scrubbing + GZIP Compression

Often, you can open the ISO in UltraISO and find the dummy files. Sometimes they're obviously looking files like DUMMY.BIN, DATA0.BIN (or .DAT), DUMMY.DAT, etc. Or folders named "PADDING" and stuff like that. You can look into the files (with a hex editor) to see if they're obvious padding data (full of 00/FF, though sometimes it's not as obvious).

However, you must never mess with LBA and TOC when removing padding. So you try to change the size of the padding file inside the ISO to 0 MB or alter it directly with a hex editor so that it's all zeroed out.

  • Archive-quality dump? No (missing data)
  • Gain: Not Immediate (ISO dump size the same). Coupled with compression, however... the gain is really noticeable.
  • Tools Used: UltraISO
  • Can be reverted? Not really. Garbage data here is zeroed out, it's not important and you still have the same disk data structure.
  • Playable on Hardware? Yes.
  • Playable on Emulators? Yes.

You may forego the manual scrubbing part entirely. If you feel adventurous you might want to do it to enhance compression though. Let's get to the meaty part though...

The PCSX2 emulator supports opening compressed archives containing ISOs. The best format it supports would be GZIP.

Use 7zip ("Add to archive..." then choose to gzip) or Pigz (multi-threaded, much faster compression) to generate gzip archives containing the ISO file in question. PCSX2 will build an index of each gzip compressed game it loads (as a file in the same directory as the gzip archive), so after the first time where you'll have to wait for the decompression, in all subsequent times there is no speed difference between playing an uncompressed and compressed game. Of course, you can extract the ISO back from the GZIP archive.

CSO (aka CISO)

  • Archive-quality dump? No (missing data)
  • Gain: Immediate (ISO dump size the same). Coupled with manual scrubbing, it can be bigger. Not as much of a gain as GZIP though.
  • Tools Used: maxcso
  • Can be reverted? Yes, using the same tool. No data loss.
  • Playable on Hardware? NO
  • Playable on Emulators? Yes - PCSX2.

PlayStation Portable

CSO (aka CISO)

  • Archive-quality dump? Maybe: while the actual compression is inherently lossless, depending on the conversion software and/or its configuration, so-called ripping (deletion or zero-resizing of the system update, videos, or other files) may be performed on the fly.
  • Gain: Immediate (ISO dump size lowers). Substantial, depending on game. Higher compression levels generally produce decreasing space gains while potentially increasing load times. Some tools allow for leaving audio/video content uncompressed.
  • Tools Used: CISO, CISO GUI, maxcso, UMDGen, PSP ISO Compressor, CISO Multi Compressor, CISO XP, ...


CISO GUI (CISO is command line-based): Drag-and-drop ISO file on program, Select compression level (1 to 9 (Max)), "Compress", and choose directory for saving the new CSO file.
UMDGen is a PSP ISO editor. You can save to either the CSO format with this.

  • Can be reverted? Yes, using the same tools and saving in ISO (uncompressed) format. No data loss.
  • Playable on Hardware? Yes - most CFWs (Possibly longer load times though).
  • Playable on Emulators? Yes - PPSSPP.

DAX, JSO, ZSO

Three different compressed-ISO formats. Significantly lower popularity/support than CSO.

PBP

  • Archive-quality dump? ???
  • Gain: Immediate (ISO dump size lowers).
  • Tools Used: ISO~PBP Converter, or Sign~Fake NP Expert
  • Can be reverted? Yes
  • Playable on Hardware? Yes - CFWs (and, if signed, OFWs too).
  • Playable on Emulators? Yes - PPSSPP.

Official format for digitally distributed PSP/minis (partially related to the one used for PS1 games), containing a compressed disc image and optionally a custom boot logo.

Dreamcast

CHD Archive Format

  • Archive-quality dump? No (missing data, no gameplay issues)
  • Gain: Immediate (ROM dump size lowers).
  • Tools Used: GDI to CHD converter.
  • Can be reverted? No.
  • Playable on Hardware? No
  • Playable on Emulators? Yes - DEmul, Reicast and Redream

GameCube / Wii

Some examples:

  • Super Mario Anniversary (Wii): 4.7 GB (original) > 12 MB (GCZ) (!!)
  • Super Smash Bros Brawl (Wii): 7.8 GB (original) > 7.1 GB (GCZ) (main cause is FMV's low compression)
  • Xenoblade PAL (Wii): 7.8 GB (original) > 6.3 GB (GCZ)
  • Super Mario Galaxy 2 (Wii): 4.7 GB (original) > 1.8 GB (GCZ)
  • Tales of Graces (Wii): 4.7 GB (original) > 4.2 GB (GCZ) (game data already fills the disk)
  • Animal Crossing (GC): 1.4 GB (original) > 26 MB (GCZ)
  • Zelda Four Swords Plus Japan (GC): 1.4 GB (original) > 480 MB (GCZ)
  • Zelda Twilight Princess (GC): 1.4 GB (original) > 1.4 GB (GCZ) (game data already fills the disk)
  • Megaman Collection (GC): 1.4 GB (original) > 1.1 GB (GCZ) (sound data is stored as uncompressed stream to fill disk)

People used to resort to WiiScrubber (Wii) and GCM Utility (GC) to scrub/trim games to end up with dumps that while they had no immediate size change, their randomized garbage data (like "dummy", "padding" or "znull") was still there but zeroed out making archived dumps using zip/7zip/rar formats have stunning gains (from 1.4GB uncompressed to 26MB zipped for Animal Crossing for example!). Of course, the file still needed to be uncompressed to its full size everytime you wanted to play it.

Trimming and scrubbing (in Wiiscrubber terms) aren't the same! While they both are terms for "zeroing garbage data" to make it more compression-friendly, trimming does not just that like scrubbing but takes the extra step of relocating the garbage data to the end of the file, hence altering its TOC and requiring the disc to be fakesigned, for a not-so-big compression gain. Hence why scrubbing is by far the most authentic and safe way to solve the garbage data problem.

However compressed formats incorporating the "padding zeroing" part were made since then, and Dolphin supports them! These are the WBFS and GCZ formats.

GCZ (Dolphin native archive format) - GC/Wii

Dolphin can't play games directly from compressed archives (7zip/zip/gzip/rar...). Instead, it utilizes its own compression method.

  • Archive-quality dump? Yes for GC games, Not directly for Wii games (Can be restored with NKit).
  • Gain: Immediate (ISO dump size lowers). Considerable, depending on the game.
  • Tools Used: Dolphin (right-click the game(s) in the games list and select "Compress ISO..." (or "Compressed selected ISOs..." if more than one is selected)), NKit, or wit (Wiimms ISO Tools)
  • Can be reverted? Yes. You can right-click on the GCZ-compressed (in blue) ISOs in Dolphin and choose "Uncompress selected ISOs". Garbage data for Wii titles will be zeroed out and thus different from the official dump but will have no effect on gameplay in most cases - if desired can be unscrubbed NKitRestore.
  • Playable on Hardware? No
  • Playable on Emulators? Only Dolphin.

Scrubbing and Trimming - GC/Wii

  • Archive-quality dump? Not directly, see note about reversing.
  • Gain: Not Immediate for just scrubbing (ISO dump size the same); Immediate for trimming (ISO dump size lowers).
  • Tools Used: GC-Tool ("wipe garbage data..." - Scrubbing for GameCube), GameCube ISO Trimmer (scrubbing and trimming for GameCube), WiiScrubber (scrubbing for Wii, although compressing with Dolphin will scrub it anyways).
  • Can be reverted? Yes, with WiiScrubber's undo file or NKit.
  • Playable on Hardware? Yes for scrubbing; some games won't work trimmed.
  • Playable on Emulators? Yes for scrubbing; some games won't work trimmed.

Scrubbing games zeros out garbage/dummy data in the ISO file. The resulting file will be the same size, but it will be able to compress better than unmodified ISOs. The difference can be huge depending on the game. Animal Crossing, for instance, will compress to just a 26 MB .gcz file after being scrubbed!

Trimming (also known as "trucha scrubbing", and substantially different from the definition of "trimming" used in ROM-based systems) games will also defragment the files moving them towards the start of the disc image, resulting in a smaller ISO file. The trimmed file can be used immediately at a smaller size without compression, but the game's internal structure will be wholly modified. Games relying on direct sector access (as opposed to consulting the filesystem) will break if you trim them.

WBFS - Wii only

  • Archive-quality dump? Not directly, see note about reversing.
  • Gain: Immediate (ISO dump size lowers). Considerable, depending on the game.
  • Tools Used: Wii Backup Manager (after adding your game, go to "Transfer" and select "WBFS") or wit (Wiimms ISO Tools).
  • Can be reverted? Maybe. WBFS files can always be converted back to ISO, but they will remain scrubbed (can be unscrubbed with NKitRestore) and, depending on settings at the time of conversion to WBFS, may be missing update/extras partitions (can be laboriously readded with wit and a copy of the missing data).
  • Playable on Hardware? Yes - Preferred format by most SD/USB loaders
  • Playable on Emulators? Yes - Dolphin

A scrubbed and sparse (gap-dropping) format directly derived from the one used in the obsolete WBFS file system.

CSO (aka CISO) - GC/Wii

  • Archive-quality dump? (Gamecube) Not clear; (Wii) Not directly, see note about reversing.
  • Gain: Immediate (ISO dump size lowers). Less than WBFS.
  • Tools Used: Wii Backup Manager (same as above, but select "CISO" - possibly Wii only), wit
  • Can be reverted? Maybe. CISO files can always be converted back to ISO, but they will remain scrubbed (can be unscrubbed with NKitRestore).
  • Playable on Hardware? Yes (on Wii/Vwii only) - Nintendont for Gamecube games, uLoader for Wii games
  • Playable on Emulators? Yes - Dolphin

A scrubbed and sparse (gap-dropping) format. Unrelated to the PSP's CSO format.

WIA (Wii ISO Archive) - Wii only?

  • Archive-quality dump? Not directly unless --raw option is given, effectively preventing any space savings.
  • Gain: Immediate (ISO dump size lowers). Less than WBFS.
  • Tools Used: wit
  • Can be reverted? Maybe. Just as the previous formats, WIA files can always be converted back to ISO, but the conversion may be lossy (reversible with added work) depending on conversion settings.
  • Playable on Hardware? No
  • Playable on Emulators? No

A scrubbed and compressed format designed for maximum space savings without cutting corners on corruption detection, but it's not directly playable or editable. Never really caught on and may be considered de facto deprecated by NKit.

NKit formats - GC/Wii

  • Archive-quality dump? Yes - by explicit design choice!
  • Gain: Immediate or not depending on choice of GCZ- or ISO-based output.
  • Tools Used: NKit.
  • Can be reverted? Yes!
  • Playable on Hardware? (GC) Yes? (Wii) No
  • Playable on Emulators? Yes - Dolphin

Apart from its previously mentioned unscrubbing/untrimming features mentioned in the above formats' descriptions, NKit is able to convert any ISO (clean dump or otherwise) to and from an intermediate format applying various reversible changes that optimize the image for lossless compression, including various options such as splitting the often non-unique update partitions to separate files.

Wii U

All uncompressed WUD dumps are 23.3GB, which makes compression needed de facto. Some examples:

  • Super Mario World 3D: 23.3GB > 2.61GB (88% gain)
  • New Super Mario Bros. U: 23.3GB > 1.8GB (92% gain)
  • Donkey Kong Country Tropical Freeze: 23.3GB > 11.7GB (49% gain)

WUX (Wii U Compressed Image Dump Archive)

  • Archive-quality dump? Yes (lossless, doesn't actually alter the data).
  • Gain: Immediate (smaller file than WUD): Around 50% gain usually (depending on the game)
  • Tools Used: wud tool. To use, drag-and-drop the ISO on the executable.
  • Can be reverted? Yes. The wud tool includes a decompression utility, which recreates the original file.
  • Playable on Hardware? No (can be converted to an installable format using wud2app)
  • Playable on Emulators? Yes - Future releases of Cemu (and potentially other Wii U emulators)

By Exzap, Cemu's author (release thread). The tool detects duplicate sectors and only stores them once: all the empty ranges end up removed, storing only ranges which contain file or filesystem data. Of course, the original ISO can be reconstituted.

APP (aka NUS/Installable Format)

  • Archive-quality dump? No, with respect to a disc image (update partition and padding dropped); Most accurate format for CDN dumps (digital titles).
  • Gain: Immediate (Total size decreases, compared to disc image)
  • Tools Used: wud2app (disc image to APP), disc2app (original disc to APP), NUSPacker (extracted format to APP), Teconmoon's WiiVC Injector (Wii/Gamecube disc image to Enhanced Vwii APP), ...
  • Can be reverted? No, if starting from a WiiU disc image; Yes (see below) if starting from extracted files
  • Playable on Hardware? Yes (after installation)
  • Playable on Emulators? ?

Consisting of a folder containing *.app, *.h3, title.cert, title.tik, and title.tmd files, this official Nintendo format intended for development use (and closely related to how digital titles are sold in) is equivalent to the 3DS's CIA format; however unlike a 3DS application, converting a disc title to digital does not require modifying the title itself, thus leaving the title's signatures valid.

RPX/RPL (aka Installed/Extracted/Loadiine Format)

  • Archive-quality dump? No (dump is extracted to individual files)
  • Gain: Immediate (Total size decreases). Can be less than a WUX depending on the game.
  • Tools Used: see below
  • Can be reverted? No, any padding/signature information is lost.
  • Playable on Hardware? Yes, use Loadiine GX2
  • Playable on Emulators? Yes

Titles installed to USB or MLC are stored in this format, comprised of three "code", "content", and "meta" folders.

Can be extracted from disc images with DiscU, UWizard (follow this guide for usage information) or JWUDTool, and from the installable format using JNUSTool. Can be converted to installable format with NUSPacker.

Ideal format for game modding, less so for playing on console due to Loadiine's intrinsic modus operandi (appearing to the OS as the host title, with potentially different permissions) leading to poor compatibility.

Game Boy Advance / Nintendo DS / Nintendo 3DS

Trimming

  • Archive-quality dump? No (data removed)
  • Gain: Immediate (ROM dump size lowers).
  • Tools Used: NDSTokyoTrim (GBA/DS/3DS), rom_tool (3DS), GodMode9 (can directly dump DS/3DS cards in trimmed format)
    NDSTokyoTrim: Drag-and-drop roms, and press "Trim". The original file will be overwritten!
  • Can be reverted? No. Some GBA/DS games may be broken by meaningful data at the end of the ROM being mistaken for padding.
  • Playable on Hardware? Yes, same file format.
  • Playable on Emulators? Yes

Trimming involves deleting bytes from the end of the ROM up to until the first different one.

However, with no mandatory allocation table, it's not intrinsecally possible to identify the true end of the used area, and therefore some GBA/DS games can be broken by naive automated trimming (for example Golden Sun DS).

CIA (CTR Importable Archive, 3DS and DSiWare only)

  • Archive-quality dump? No (data removed and edited), compared to a gamecard dump. Potentially most accurate format for CDN (digitally distributed) titles.
  • Gain: Immediate (smaller than original ROM - not applicable to digital titles).
  • Tools Used: GodMode9 (can directly dump 3DS cards or installed titles to CIA, as well as converting 3DS to CIA), 3dsconv or 3DS Simple CIA Converter 5.0+ (3DS rom to CIA); makerom (3DS to/from CIA, NCCHs/DSiWare/ELF+RSF to 3DS/CIA), make_cia (DSiWare to CIA)
  • Can be reverted? No, if starting from a gamecard dump (update partitions removed, main content's ExHeader modified to change the media type from CARD/NAND to SD Application)
  • Playable on Hardware? Yes, after installation.
  • Playable on Emulators? Yes?

Official Nintendo format for developers to install digital titles, later became the most popular format for installable homebrew and game backups owing to the relatively low marketshare of flashcards and emulators (and, for the former, strong impopularity) in favor of CFW.


NCCHs (CXIs and CFAs, 3DS only)

  • Archive-quality dump? No (partition table/ticket/signatures... removed), compared to CCI/3DS and CIA
  • Gain: Immediate (smaller than original ROM - not applicable to digital titles).
  • Tools Used: GodMode9, ctrtool, ...
  • Can be reverted? No (result will be unsigned)
  • Playable on Hardware? Not really, unless packaged back into a CIA or 3DS.
  • Playable on Emulators? Yes

3DS and CIA files, as well as already installed digital titles, are comprised of one or more NCCHs (also called "partitions" or "contents"): the main content (number 0) can either be an executable CXI for software, or a non-executable CFA for a data title. Additional CFAs may be present, with conventional index numbers. Citra can run CXIs directly.

Xbox 360

It's certainly better than keeping 8.5GB images, but the conversion is too substantial and irreversible to be suitable for archival purposes since it affects data structure tables as well.

XEX (Xbox Executable) + Data folder (a.k.a Spilling The ISO Guts)

  • Archive-quality dump? No (dump is collapsed to individual files)
  • Gain: Immediate (total file size decreases). It still works with Xenia
  • Tools Used: XBOX 360 ISO Extract, Exiso-GUI or Exiso. (These might be useful for rom-hacking too I guess?)
  • Can be reverted? ISO could be rebuilt, though not accurately.
  • Playable on Hardware? Yes. Using a JTAG or RGH exploited console.
  • Playable on Emulators? Yes - Xenia.

Rebuilt ISO

  • Archive-quality dump? No (missing data)
  • Gain: Immediate (total file size decreases). It still works with Xenia.
  • Tools Used: ISO2GOD (also a "Games on Demand" X360 image converter).
    Under Settings, set the output and rebuild path to the same location. Check "Always save rebuilt ISO" and set Padding to "Full (ISO Rebuild)", then save changes.
    "Add ISO", and press "Convert". Keep generated ISO, and delete generated folder.
  • Can be reverted? The padding quantity information alongside the original data structure is lost forever.
  • Playable on Hardware? Yes. If the rebuilding process didn't damage anything vital.
  • Playable on Emulators? Yes - Xenia.

Other Tricks

Storage Tricks

These methods have the advantage of being compatible with EVERY emulator, even those without proper support for compressed ISO/archive formats.

NTFS Compression

You can enable filesystem-level compression (like "NTFS Compression" in Windows) for the directory containing your ISOs/ROMs. This has a very noticeable space gain and doesn't affect the emulator's functionality. It's surprisingly more effective than many people would like to give this credit.

  • Archive-quality dump? Yes

Decompression on Demand

You can keep your ROMs/ISOs compressed in a 7zip archive and use RocketLauncher or any other Frontends to decompress 7zip archives and pass the contents onto the emulator.

  • Archive-quality dump? Yes

Destructive Modification

Of course, there are also the devs who don't merely use garbage data for padding but also bloat the game data part. For instance, many PSP JRPGs have a specific FMV movie duplicated a dozen times, and the Megaman Collection on GC stores its sound data using an uncompressed format bringing the size of that portion alone to 1GB. In many of these cases, there's just not much you can do about it without destructively altering game data.

So what do some people do? Note when I say "delete" it often means replacing the file with a 1KB dummy file to prevent the ISO file structure from collapsing on itself, but sometimes such care isn't even put into ensuring it's still in a functional state. Some examples:

  • delete all videos: this brings Super Smash Bros Brawl to 4.7GB.
  • delete all voice acting and occasionally sound and music: this brings Xenoblade PAL to 4.2 GB with even only one of both dubs removed.
  • delete unused content you could get with emulator cheats like rooms and stuff
  • delete "extra" languages other than English
  • If a game has multiple quests, they delete some characters/quests they don't like. Especially seen in compilations and stuff with demos included.

Tools used for this are modding tools for rebuilding file trees, like UMDGen (PSP), Tinke (DS) and also regular ISO tools (PS1, Saturn)...

Since this results in most of the case in very noticeable detrimental effects in gameplay (if the game doesn't crash outright), this is nothing short of mutilating the game image. Some of these dumps make it to sharing sites sadly enough.

Avoid resorting to destructive modifications since it can lead to random crashes and unexpected behavior, especially in games with lots of shared assets. [Verify] your dumps to make sure you don't have these, and if you want to compress those prefer other methods or using decompression on demand. One reason to use a destructively modified dump is for burning your own Dreamcast games, as GD-ROMs were over a gigabyte in size and CD-Rs top out at 850MB.

  • Archive-quality dump? No (destructive mod)