MAMEWorld Forums - EmuChat - Re: Chdman questions

> @mw: "The sha1 hashes for .iso and .cue are only defined by the person who made those
> files. There isn't necessarily a standard to adhere to."
>
> Forgive me, mw, but isn't that all a hash ever is anyway? What I'm struggling to get
> my head around is how one might quickly report on the the CHD content(like one can
> view 7z file content instantly before the lengthy extraction process).

I think the replies by rbelmont and haze have gone into more depth about the lack of standards among .iso and .cue files.

A .7z file has something called the "central directory record" (or something like that), which contains a description of the contents of each of the .7z file items. A CHD has no such record in it, other than the header. The chdman.exe "info" command shows all the contents of the header. That's all you get. If you want to do is "preview" the contents of a .chd file, all you can do is examine that header information.

A "hash" is not a descriptor of the contents of anything. A "hash" is a (hopefully unique) signature of the contents of something.

Each .chd file only contains the data for one item. It may contain various items (such as metadata) which explain the contents of the data area of the .chd file.

A .7z file is a general purpose storage archiving system. It can contain all kinds of stuff. A .chd file only contains one item, but has a variety of ways of describing it via the information in the header.