mobiDeDRM fail at my first hurdle.

[Society]

Until now my wife has only purchased ePub books to read on her netbook and I've deDRMed those using the excellent utilities so generously made available but her most recent purchase was from a publisher that didn't offer that option for the title: from Mobi, MS or PDF she chose Mobi (print/copy disabled). She has an mbp file as well as the prc.

MobiReader on the WinXP PC used for purchasing allows the book be read and states it to be PID-encrypted but, given the device PID (in 1234567$12 format), the 0,1,6 version of the Calibre plug-in reports an error in that it couldn't decode and will import the encrypted version. I'd previously thrashed around on the command-line with various versions of mobidedrm in specific directories and with the path amended for python (2.6.2) and for tools\scripts before using the plug-in.

Snookered - or have I missed something among all the threads over time here and elsewhere - or are there still avenues to investigate?

[texasnightowl]

The only immediate thing I wonder...the book site that you purchased from...do you have just the one PID from the PC registered with them or multiple PIDs? If you have multiple PIDs registered with the book site, try listing them all in the customization for the plugin.

[Society]

Originally Posted by texasnightowl

The only immediate thing I wonder...the book site that you purchased from...do you have just the one PID from the PC registered with them or multiple PIDs? If you have multiple PIDs registered with the book site, try listing them all in the customization for the plugin.

Thanks for suggestion but there's just the one PID from MobiPocketReader (which had to be installed on the PC prior to purchasing the title). This book is the first one purchased from this particular publisher's site and has been downloaded just once. It can be read on that PC in encrypted form.

All and any clues gratefully received.

[texasnightowl]

The only other thing I wonder...quite a while back I think I remember discussion where a "prc" book wasn't really a "mobi" book.

...I went off looking to see if I could find what I thought I remembered...

There are some "prc" files that if you open the file in something like notepad there is a string you will be able to see in the first line. A proper "mobi" prc file you should see "BOOKMOBI", but some prc files will show "TEXTREAD".

Try this thread to see if there is anything relevant? https://www.mobileread.com/forums/sho...t=prc+textread

[texasnightowl]

Also, curious, what publisher was this?

[wallcraft]

Originally Posted by Society

MobiReader on the WinXP PC used for purchasing allows the book be read and states it to be PID-encrypted but, given the device PID (in 1234567$12 format), the 0,1,6 version of the Calibre plug-in reports an error in that it couldn't decode and will import the encrypted version.

As texasnightowl almost asked: have you entered the PID in Preferences -> Plugins -> File Type Plugins -> MobiDeDRM -> Customization? If so, did you cut and paste it from MobiPocket Reader (if not, perhaps it is misspelled)?

[Society]

The file is, indeed, TEXtREAd but I'd somehow got the impression that this had been dealt with (it's reported by MobiReader as PID-encrypted rather than content-encrypted). I tried editing the test in the script to compare with that string rather than for BOOKMOBI as I remembered reading that suggested somewhere but, after uninstalling, editing, packing and re-installing the plug-in after a re-start, success still eluded me.

The UK website of the tandf ebookstore requires just the first 8 chars of the PID so I'd also tried that but believe that the script expects all 10. PBDShred or other available utilities don't seem to be relevant. Snookered, I guess, so a different start-point may be required.

Specific vision problems mean that reading on the PC for more than a few minutes is as problematic as print (or the dedicated reading devices that were tried) whereas reading on the netbook has been a revelation. Having to buy a higher-end netbook to run Windows just to read this title and any future purchases of similar ilk is not really an attractive option. The PDF download can be purchased but I doubt that would work well on a netbook. The LIT is also available so I guess it's worth buying that to see if we can "downconvert" the lit file using the readily-found tool and then use Calibre (which I've just satisfactorily tested using a non-DRM lit file to convert to ePub).

I'm really reluctant to give up on this mobi file but my wife is only interested in the end result so I guess she'll have to get a Passport and all the other MS stuff to test the lit start-point.

[texasnightowl]

Hmm...so far you've only used the mobidedrm as a Calibre plug-in, right? If you run the py file from a command prompt is there a different (more useful) error message?

[Society]

Originally Posted by texasnightowl

Hmm...so far you've only used the mobidedrm as a Calibre plug-in, right? If you run the py file from a command prompt is there a different (more useful) error message?

As I said, I'd previously thrashed around on the command line. I ended up using it as a Calibre plug-in (very elegant) to sidestep some common user errors that I may have fallen foul of.

The "as-is" program (0.16) gives "Error: invalid file format" (which suggests to me that the PID checksum has been found to be valid). Amending the script to test against TEXtREAd instead of BOOKMOBI forces the suppression of that error but it then returns a DrmException of "Error: cannot decode Mobipocket encryption type 1" and reports, inter alia, that the "header version = 235802126"! That looks wrong so I take it that the header is not structured in the way that the unpacking expects and that the file was created using an older method than is currently addressed by mobidedrm.

[KevinH]

Hi,

You might find this post helpful:

https://www.mobileread.com/forums/sho...&postcount=381

pdbshred seems to be the only answer for TEXtREAd

[texasnightowl]

OP: I sent you a PM

[Society]

Originally Posted by KevinH

Hi,

You might find this post helpful:

https://www.mobileread.com/forums/sho...&postcount=381

pdbshred seems to be the only answer for TEXtREAd

Ah, that's the thread (yes, I'd read the whole of it) where I saw the suggestion regarding amendment of the script's test for BOOKMOBI.

D'oh! I've just had a play with pdbshred and discovered that arguments I'd understood to be show-stoppers are optional arguments for my purposes so I've been able to extract text in html form (from this "PID-encrypted" ebook) and to generate a set of bitmaps which is small enough to work with so as to massage the whole into something to feed to Calibre for conversion. Good game!

Thanks to all for the responses.

[DMcCunney]

Originally Posted by texasnightowl

The only other thing I wonder...quite a while back I think I remember discussion where a "prc" book wasn't really a "mobi" book.

PRC files originated on Palm OS. On a Palm OS device, only a Palm Database file can be in memory. Files in memory on Palm OS devices will have either PDB or PRC extensions. A PDB file is a generic Palm Database file. The actual content may be anything. Each Pam Database file has a header record, and the header record includes database attributes like the Creator ID and the file Type, which tells the OS what program owns that file and can open and read it.

A PRC file is a Palm Resource file, which is another type of Palm database. Palm Resource files are are normally Palm OS programs, and the resources they contain are program code, but they don't have to be programs.

For whatever reason, MobiPocket chose to use the PRC extension for Mobi books. (You can actually rename a Mobi book from .PRC to .PDB, stick it on a Palm device, and the Palm Mobi reader will read it fine.)

Files with a Creator ID of READ and a Type of TeXT are in PalmDOC format, which was originated by the old Aportis reader. PalmDOC is a plain text file, compressed to save space in RAM. (It originated in the days when a Palm device had a whopping 8KB to 16KB of RAM, and space in memory was at a premium.) PalmDOC readers decompress the file on the fly as they display them. Aportis is long gone, but the format was reverse engineered, and a number of Palm OS viewers can display it, including Mobi Reader.

On other platforms than Palm OS, Mobipocket files normally have a .mobi extension.

So no, an ebook file with a .PRC extension is not necessarily a Mobipocket formatted ebook.
______
Dennis