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| Thread ID: 23250 | 2002-08-11 05:06:00 | Rar File Repair | Craig Bellhouse (493) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 70132 | 2002-08-11 05:06:00 | I have just downloaded a 500Mb Rar file. Inside it are many small rar files. However, one of these smaller files has a bad CRC. I do not wish to download the file again, as it took several days on dial-up. I have tried the built-in repair function with winRAR, but that didn't help. Is there any way to repair this file, and recover the contents?? Cheers, Craig. |
Craig Bellhouse (493) | ||
| 70133 | 2002-08-11 05:21:00 | from the web: "If you get a "CRC failed" message, just repair the offending file with WinRAR; if the poster was lame enough not to include recovery information in the archive, you won't be able to repair it, and you'll have to download it from a different server or ask for a repost of that file." I guess that if the info is corrupted beyond that which repair can correct, and no recovery information is included to allow it, you are stuck. |
godfather (25) | ||
| 70134 | 2002-08-11 05:33:00 | Hmmm, yeah thats what I thought, funny thing is though, the rar files are all the same size, right down to the byte level, so whatever is wrong can't be much... Is there any tool like Zipfix (for .zip files) that will repair the crc so I can extract most of the stuff from the file, as the bad file could be just a text file or something unimportant. Cheers, Craig. |
Craig Bellhouse (493) | ||
| 70135 | 2002-08-11 07:01:00 | I am not familiar with RAR, but that is what the repair facility is for. If it could have fixed it it would, but it needs info that isnt there. It might only be a few bits inverted (size is same) but without the info I assume it cannot tell which bits to re-invert. Thats the point of CRC (cyclic redundancy check) code validation. I am not aware of any way to force a CRC result, but will watch the post... |
godfather (25) | ||
| 70136 | 2002-08-12 05:09:00 | The problem is that an RAR file is like a ZIP file, a collection ("archive") of compressed files. If there is an error in a compressed file, uncompression can work only as far as the first error. The compression decoding just stops working, because it requires a perfect stream. That's the "no free lunch" aspect of compression. Compression means removing the redundancy. That's why bigger hard disks became standard, rather than disk compression: an error lost most of the disk contents, not just a file. |
Graham L (2) | ||
| 70137 | 2002-08-12 08:21:00 | Cheers for your help. I guess I will have to try and download the file again. :( | Craig Bellhouse (493) | ||
| 70138 | 2006-03-11 03:53:00 | [edit: you obviously didn't read the forum rules when you clicked "I agree" to them. No asking for cracks or warez - Jen (Moderator)] | legolas936 (1444) | ||
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