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-   -   Need some help ripping STR file from PSX game (http://www.zophar.net/forums/showthread.php?t=17567)

Animedude5555 02-09-2015 12:59 AM

Need some help ripping STR file from PSX game
Ok first let me tell you my setup. I'm using Alcohol 52% freeware version, and have loaded a PSX BIN/CUE into it. Now it should be as easy as copying files off of any real CD-ROM disk. But it's not. I can't even copy the STR file from the disk image. When I try to copy it to my harddrive in Windows Explorer, Windows gives me this error "Invalid MS DOS Instruction". It would seem that some files are stored in the disk-image in a way that is not accessible by normal file copy commands in Windows, but not all files have this problem. For example, I can copy any file in the disk-image's root directory, any file in the DAT1 folder, and any file in the DAT2 folder. However, all the files in the DAT3 folder (XAS files) and all the files in the DAT4 folder (STR files) are not able to be copied, and I get the above mentioned error from Windows. The game in question is "Shiritsu Justice Gakuen - Legion of Heroes". Is this something fundamental to STR and XAS files in all PSX games? Or is this a particular copyprotection method used in this particular game?

PSX-MC also is not working, even though it is software designed by video game hackers, for the sole purpose of ripping STR video files off of PSX game disks. No error messages. It just simply doesn't list any discovered STR files on the disk, indicating it is unable to discover any STR files on it, using whatever mechanism it uses to find said files.

Note that I'm using Windows7 x64 as my OS. Not sure if that will be a problem, but just thought I should mention it in case.

Animedude5555 02-09-2015 01:19 AM

Ok, I fixed ONE of the problems. I used a program called MagicISO to rip these files out of the Alcohol emulated disk. This worked great. But I still have a problem. It appears that these STR files aren't standard STR files, as no program can play or convert them, except for StrConv (written by Ikskoks), but it crashes on certain frames, and other frames appear glitchy, suggesting that some sort of scrambling mechanism may have been used on these STR files as a copyprotection measure. If anybody knows of a dedicated program (or a plugin for PSX-MC) that will let me convert these STR files to AVI files, please post it here. Again the name of the game is "Shiritsu Justice Gakuen - Legion of Heroes". This is the Japanese version of the game Rival Schools.

Animedude5555 02-09-2015 04:56 AM

Ok, I got over one more hurdle. I used ISO Buster and was able to get the STR files out with that, and then convert them with StrConv (software written by Ikskoks) to AVI. But the problem is these STR files didn't come with their own sound. Instead the sound files are in separate files, most likely the XAS files. Now I also ripped the XAS files with ISO Buster, but now I have a new problem.

This new problem is, NONE of the PSX audio player or converter programs are able to handle XAS files, only XA files. And yes I already tried renaming them to XA (hoping it was just a filename difference), but it still doesn't work. In fact, I can't find any online forum discussions about reading XAS files. Maybe they are unique to this game, and nobody had enough interest in this game to reverse engineer its audio format? I don't know. What I do know is that I need to be able to convert the XAS audio files if I want sound with the AVI file that I got from converting the STR files.

Shadow 04-01-2015 03:14 PM

Hell yeah it's a long time, but I found this topic interesting.

If these XAS files are combined XA files without headers you should find out whether there are same length blocks per track, that would be easy then. It would mean that you have some start / stop codes which determine the beginning and the ending of each block. These would be the pointer adresses used by the disk IO to get the correct sound.

It could also be that there ARE some meta informations in these areas which tell the system how long the track is.

If you are unlucky you may really have the whole bunch of tracks in a line. But THEN there should be some tracklist or lookup table which point to the correct adresses. It depends on how the programmer has arranged and organized it.

To find this kind of lookup table you have to find the filenames inside another file as a list, maybe with alias names like track01 or so but in any case there must be a mapping.

If I am right you do not need to scan for each call of the proper sound but only for this list. It would make more sense in terms of system architecture to have some static list or config which can be loaded instead of calling each sound directly.

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