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Author Topic: Disabling 'Recompress Files' is not byte-exact  (Read 7580 times)

Traxx

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Disabling 'Recompress Files' is not byte-exact
« on: 02 February 2011, 15:50 »

Hallo,
1) when disabling 'Recompress Files' (Rebuilder) the output file differs by 2 bytes compared to the original. That brakes hashes (of the zips).

2) Is it possible to use external 'one argument packer' (Recompressors) like 'compressor.exe %1'?

3) When updating TOSEC/Amiga archive it has many datfiles for different folders. Many files have traveled between these folders and were placed into the backup folder (where clrmamepro has created a subfolder for every dat).
I have to take further rebuilder passes for every dat file at the end from backup folder to dat destination. When i press 'Use backup folder' it points to the backup/subfolder not the backup folder itself. Could you add an option that the button outputs the parent backup path? Or is there any easier method?

Using batch rebuilder (as final pass) solves the problem.
« Last Edit: 02 February 2011, 17:24 by Traxx »
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Roman

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Re: Disabling 'Recompress Files' is not byte-exact
« Reply #1 on: 02 February 2011, 20:00 »

1) No recompress means that only compressed data block within a zip is copied without decompress/recompress. The file structure (i.e. localfile header, central dir entry, zip eof etc) are newly created of course. Since such structures have a fixed length, you shouldn't end with a different length. Comments get ripped out and data descriptor tags (rarely used and not needed), too.

Of course a hash of the zip itself changes but noone cares about the hash of a zip....besides maybe torrentzip users ....but noone actually cares about this.

2) no
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Zandro

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Re: Disabling 'Recompress Files' is not byte-exact
« Reply #2 on: 13 February 2011, 07:20 »

Hee, I hit this 1) snag today actually. Or so I think... Across a mapped network path, torrentzip did not catch any differences after clrmamepro's simpler rename operation because I believe the comments field was retained, and despite the listed CRC no longer matching the file's. However, it did seem to work correctly when the files were on local disk.  But Roman, torrentzip is not your responsibility--I'm moreso answering to Traxx if it helps.  I believe he was talking about the zip file's hash, not the file contained within the zip.

And in an attempt to make myself useful to you, and decidedly failing, 'avatar 92' is listed twice in the Avatar Select box in user profile configuration.

Oh, and Traxx: for 3) I create a fixdat and point the rebuilder with that loaded to my backup folder.  ;)
« Last Edit: 13 February 2011, 07:27 by Zandro »
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