08-01-2020, 06:45 PM
I've done a bit of work figuring out the .MED file format and pretty sure I can fully uncompress the .IOB file data and and other data files that have the ZLIB_1 tag in them.
The .M1, .M2, etc. files are concatenated and slightly proprietary JPEG files. The .MED file gives the name of each page and an address noting the CD number and offset into a .M# file. Useful, but the .M# files can be easily broken down into a single page per file by looking for the $FF $D8 JPEG marker.
I've not figured out how to decompress the proprietary JPEG format. Based on this Stack Overflow question they used a commercial library from Accusoft.
https://stackoverflow.com/questions/5602...arker-0xb9
My guess is that the JPEG files use arithmetic compression (as opposed to the common and slightly less efficient Huffman compression) for the quantized DCT data.
It is possible some modern JPEG library supports this format. But it may be that the proprietary version is just different enough that it won't work. Looking at the DLL's that ship with the product it may be just as easy to figure out how to call them and get them to do the decompression.
I'll try and remember to post I update if I manage to get anything working.
The .M1, .M2, etc. files are concatenated and slightly proprietary JPEG files. The .MED file gives the name of each page and an address noting the CD number and offset into a .M# file. Useful, but the .M# files can be easily broken down into a single page per file by looking for the $FF $D8 JPEG marker.
I've not figured out how to decompress the proprietary JPEG format. Based on this Stack Overflow question they used a commercial library from Accusoft.
https://stackoverflow.com/questions/5602...arker-0xb9
My guess is that the JPEG files use arithmetic compression (as opposed to the common and slightly less efficient Huffman compression) for the quantized DCT data.
It is possible some modern JPEG library supports this format. But it may be that the proprietary version is just different enough that it won't work. Looking at the DLL's that ship with the product it may be just as easy to figure out how to call them and get them to do the decompression.
I'll try and remember to post I update if I manage to get anything working.