Ed2k-hash
Why does anidb require ed2k-hashs?!
The main reason for this is that it avoids adding of double db entries. AniDB will not allow you to add a file with the same ed2k-hash as an existing one.
The file size and ed2k-hash of a file is used to identify it globally.
You are allowed to add files without ed2k-hashs to AniDB, however you should edit those files later and add the missing ed2k-hashs. Once you added a certain number of files without ed2k-hashs you may no longer add new files without ed2k-hashs until you edit your old files first.
Why use ed2k instead of another type of hash if you do not support downloads?!
- The combination of ed2k-hash and file size makes ed2k effective for uniquely identifying files.
- Since ed2k-hashes can be passed back and forth within a URL with both the hash and file size in a widely recognized format it is a convenient method for adding or checking files.
- Other hashes are good for validating if a file is corrupt if you already know what file you are comparing it against, but cannot necessarily globally identify a file in the system like the ed2k.
- AniDB was designed around ed2k, although other hashes have been added to the file records for validation, the internal structure is based on ed2k. If the site goes through a complete redesign then maybe another hash will be made the primary hash, but at this point, this is not likely to change.
Which software can be used to generate them?!
If you have the file(s) on your hard disk or on CD you can use all kinds of tools to generate the ed2k-hash and other additional info:
- AniDB_O'Matic by BennieB/PetriW can generate ed2k-hashs. It generates ed2k-hashs, md5, sha-1, crc32 in one go and also lists stuff like codec, resolution, bitrates, ...
- ed2k_hash another tool which is commandline based and also available for Linux.
- Filehash a little java program written by Malich. for further info on it read here
- Hashcalc can create md5, sha-1, crc32, ed2k-hashs and various other hashes in 1 go. though at least 1 case is known in which it created a wrong ed2k!