Calibre won't read pdf books

[abrogard]

Not sure if this should be in this category but here goes:

I find I cannot open and read some pdf books I'd thought were successfully imported into calibre.

The error message talks about dedrm but there's no drm on these at all or shouldn't be.

I checked a couple of them and sure enough, there's nothing. They're just straight pdf's.

I wonder if this means my whole calibre library is corrupt or suspect in some way? Bit of a worry. I've been thinking of the calibre library as my 'backup', my ultimate definitive collection.

Had the naive idea that if it was listed in there it'd be readable (and therefore capable of manipulation: export etc ) but that's apparently not true.

so is there a routine or a function we can/should employ that will check each book as imported to the library for 'readability' ?

Can't do them one by one manually, just too many.

Here's a sample error message from one of them:

calibre, version 5.16.1
ERROR: Loading book failed: Failed to open the book at D:\calibrelibrary\A Fire In The Sun\George Alec Effinger - Marid 2 (17112)\George Alec Effinger - Marid 2 - A Fire In The Sun.pdf. Click "Show details" for more info.

Failed to convert book: D:\calibrelibrary\A Fire In The Sun\George Alec Effinger - Marid 2 (17112)\George Alec Effinger - Marid 2 - A Fire In The Sun.pdf with error:
DeDRM v7.1.0: Trying to decrypt George Alec Effinger - Marid 2 - A Fire In The Sun.pdf
DeDRM v7.1.0: George Alec Effinger - Marid 2 - A Fire In The Sun.pdf is a PDF ebook
DeDRM v7.1.0: Trying Encryption key default_key
DeDRM v7.1.0: Exception when decrypting after 0.1 seconds
Traceback (most recent call last):
File "calibre_plugins.dedrm.__init__", line 434, in PDFDecrypt
File "calibre_plugins.dedrm.ineptpdf", line 2178, in decryptBook
File "calibre_plugins.dedrm.ineptpdf", line 1983, in __init__
File "calibre_plugins.dedrm.ineptpdf", line 1791, in __init__
File "calibre_plugins.dedrm.ineptpdf", line 1416, in set_parser
File "calibre_plugins.dedrm.ineptpdf", line 1917, in read_xref
File "calibre_plugins.dedrm.ineptpdf", line 1874, in find_xref
calibre_plugins.dedrm.ineptpdf.PDFNoValidXRef: Unexpected EOF
DeDRM v7.1.0: Failed to decrypt with key default_key after 0.1 seconds
DeDRM v7.1.0: Looking for new default Adobe Digital Editions Keys after 0.1 seconds
Found 1 keys
DeDRM v7.1.0: Trying a new default key
DeDRM v7.1.0: Exception when decrypting after 0.1 seconds
Traceback (most recent call last):
File "calibre_plugins.dedrm.__init__", line 485, in PDFDecrypt
File "calibre_plugins.dedrm.ineptpdf", line 2178, in decryptBook
File "calibre_plugins.dedrm.ineptpdf", line 1983, in __init__
File "calibre_plugins.dedrm.ineptpdf", line 1791, in __init__
File "calibre_plugins.dedrm.ineptpdf", line 1416, in set_parser
File "calibre_plugins.dedrm.ineptpdf", line 1917, in read_xref
File "calibre_plugins.dedrm.ineptpdf", line 1874, in find_xref
calibre_plugins.dedrm.ineptpdf.PDFNoValidXRef: Unexpected EOF
DeDRM v7.1.0: Failed to decrypt with new default key after 0.1 seconds
DeDRM v7.1.0: Ultimately failed to decrypt after 0.1 seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/...master/FAQs.md
Syntax Error: Document stream is empty

pdfinfo errored out with return code: 1
InputFormatPlugin: PDF Input running
on D:\calibrelibrary\A Fire In The Sun\George Alec Effinger - Marid 2 (17112)\George Alec Effinger - Marid 2 - A Fire In The Sun.pdf
Failed to run pipe worker with command: from calibre.srv.render_book import viewer_main; viewer_main()
Traceback (most recent call last):
File "calibre\customize\ui.py", line 433, in get_file_type_metadata
File "calibre\customize\builtins.py", line 346, in get_metadata
File "calibre\ebooks\metadata\pdf.py", line 126, in get_metadata
ValueError: Could not read info dict from PDF
Running file type plugin DeDRM failed with traceback:
Traceback (most recent call last):
File "calibre\customize\ui.py", line 176, in _run_filetype_plugins
File "calibre_plugins.dedrm.__init__", line 638, in run
File "calibre_plugins.dedrm.__init__", line 513, in PDFDecrypt
calibre_plugins.dedrm.DeDRMError: DeDRM v7.1.0: Ultimately failed to decrypt after 0.1 seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/...master/FAQs.md
Traceback (most recent call last):
File "runpy.py", line 194, in _run_module_as_main
File "runpy.py", line 87, in _run_code
File "site.py", line 82, in <module>
File "site.py", line 77, in main
File "site.py", line 49, in run_entry_point
File "calibre\utils\ipc\worker.py", line 197, in main
File "<string>", line 1, in <module>
File "calibre\srv\render_book.py", line 824, in viewer_main
File "calibre\srv\render_book.py", line 815, in render_for_viewer
File "calibre\srv\render_book.py", line 792, in render
File "calibre\ebooks\oeb\iterator\book.py", line 63, in extract_book
File "calibre\customize\conversion.py", line 245, in __call__
File "calibre\ebooks\conversion\plugins\pdf_input.p y", line 54, in convert
File "calibre\ebooks\pdf\pdftohtml.py", line 83, in pdftohtml
calibre.ebooks.ConversionError: pdftohtml failed with return code: 1
Syntax Error: Document stream is empty
Exception ignored in: <function NativeFunction.__del__ at 0x000001EA6FFA7940>
Traceback (most recent call last):
File "calibre_plugins.dedrm.adobekey", line 266, in __del__
TypeError: 'NoneType' object is not callable
Exception ignored in: <function NativeFunction.__del__ at 0x000001EA6FFA7940>
Traceback (most recent call last):
File "calibre_plugins.dedrm.adobekey", line 266, in __del__
TypeError: 'NoneType' object is not callable

[ownedbycats]

Try temporarily disabling/removing DeDRM and adding the book again. If that works, ask on the DeDRM Github.

[BetterRed]

@abrogard - Looks like you're trying to read a PDF with the calibre viewer, that involves an inline-conversion to an EPUBish format. Conversion of PDFs is a best avoided, read the sticky at the top of the Conversion sub-forum. Conversions can also take a long time (as in days).

Use your default PDF reader, you can do this by unchecking PDF in the Preferences->Behaviour->Use internal viewer for: list.

BR

[jhowell]

Those errors are what I would expect if the file in question is not actually a PDF.

[JSWolf]

You need to run DeDRM 7.2.1.

[PeterT]

I wonder if while the files are DRM free if some of the other PDF restrictions are in place; restrictions such as no print / no copy.

Sent from my Pixel 4a using Tapatalk

[abrogard]

Thank you. I did that config change so it doesn't use calibre for pdf.

I find now that many pdf's in the calibre listing are empty. They are empty files.

If the empty are all in the start of the listing on calibre as they seem to be then I've got abou 2000 empty pdf's and 6000 that're okay. I think. I just read a small one there and I'm not sure if it was complete or not. Little piece by Emile Zola about the 'death of blahbla' and it could be seen as complete or not. 28 pages I think.

I should add these books are complete in the original which thankfully I've still got, I think. Certainly I have for many of them. I just checked a few and they're still there and okay.


How could that happen? My fault somehow? Shut down the computer when it was busy perhaps and it doesn't close down well?

There's no internal monitoring of its success in importing wholly or partly?

What to do? I'd like to ask for some advice regarding perhaps starting over again. should I just archive all my existing calibre libraries - which are now of doubtful integrity - and start again?

If I start again what is the best procedure given I've got multiple hard drives and thousands of files spread across them rather than all conveniently in one directory?

[jhowell]

Importing books into calibre does not show many errors unless you are running in debug mode. For example DRM removal failure is not reported. It is a good idea to to check files for readability after import.

One common way that calibre libraries can become damaged is by using cloud storage or a networked drive.

[abrogard]

well I shun the cloud though sometimes that's hard - MS is very sneaky about it I feel.. tricks me into using it but I get out as soon as I can.

And though we have a home lan I've not copied any Calibre libraries over it. Takes too long. Ours is very slow. Sooner put things on a USB and sneakernet it across and then have the USB backup, too.

I think I'll have to start again. Break it down into bite sized chunks and do some checking. We can check the file size, that's a good clue. And then I could do spot checks across the range to see if they're working okay.

And I will be careful to keep my originals.