Hi Mike,I'am working on the R2007 reader which for now just extracts the encoded data and ignores the rs parity bytes.
So I can provide you some data and give you some hints how to read it. Attached is the rs data found at offset 0x80 in a .dwg file. The data is0x3d8 bytes long and contains 3 blocks of rs data. One block contains 239 bytes of data and 16 parity bytes.
The blocks are interleaved with a factor of 3.
The given data starts like this: B3 01 68 D2 58 01 70 67 51 9E 00 7F 26 01 01 80 CD F0 68 A5 ...and so the first rs encoded block starts with: B3 D2 70 9E 26 80the rest of the data (0x3d8 - (3 * 0xFF) = 0xDB) are padded and not rs encoded.
If you need some more data feel free to ask. I will push a first version of the reader in the next weeks.
Till Am 30.08.2010 08:02, schrieb jamesmikedup...@googlemail.com:
hi all, I have started to research into this reed solomon stuff, it does not look that hard. http://en.wikipedia.org/wiki/Reed–Solomon_error_correction http://en.wikipedia.org/wiki/BCH_code http://en.wikipedia.org/wiki/Berlekamp-Massey_algorithm also MIT OCW : http://www.youtube.com/watch?v=Nnj9lHePqKM can you please provide me with a block of pure data that is in RS format and the encoding parameters. I am going to work on a decoder. mike
rsdata.dat
Description: Binary data
