An interesting day for everyone in the homebrew scene. Thanks to Uncle Jam, the JSO format of ISO's can be created and used in DevHook! And thanks to danny_kay1710, the newest version of ISO Compressor gives us a GUI to make these images.
JSO is a new ISO compression method, aimed at delivering faster on-the-fly decompression (so your games will
hopefully load quicker).
Downloads for both the ISO Compresser v1.4 software (the GUI for converting between ISO, CSO, DAX and JSO formats), aswell as the Beta PRX addon for DevHook to support JSO images are found attatched to this post.
As quoted:
Quote:
First beta release with JSO support. JSO is a new file format with the following features:- support of both lzo and ZLIB compression, lzo is a bit faster than zlib for decompression but files are about 10% bigger
- support of frame size of 2048 bytes (like CISO), to 16384 bytes
- memory footprint is around 15 kbyte
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So does JSO compress better than CSO or DAX? Let's take a look... These tests were only performed on a Street Fighter Alpha 3 ISO, which is a game heavily dependant on 2D graphics (that compresses rather well under CSO), and also contains an intro movie. Note that loading times were NOT tested.... i may update this thread with details on loading times soon.
Also, these files where compressed with the ISO Compressor GUI. DAX and JSO both support additional advanced command-line options, but since the GUI is used those settings will not be mentioned. All compressions are 9 (maximum), and NC is OFF for DAX.
STREET FIGHTER ALPHA 3
ISO Size : 179 MB (187,820,032 bytes)
CSO Size : 96.3 MB (100,979,642 bytes)
DAX Size : 91.8 MB (96,320,325 bytes)
JSO Size : 108 MB (113,868,435 bytes)
Well, its bigger than both CSO and DAX, but how are the loading times? I may perform tests on loading times soon, but with another game which takes a while to load each part of the game - such as Dungeon Siege : Throne of Agony (because it's a great game, and we hate waiting anxiously for the next scene to load in the best hack 'n' slash game to hit the PSP platform!).
News Source :
PSP2k
Note : The attachments have not been tampered with in any way and are direct downloads from the source.
Peace!