Unable to open/convert MOBI files

[MontyJ]

Environment: Mint Linux

I downloaded a nice collection of MOBI ebooks. I can import the books into my working library w/o any errors, but most of the ebooks simply will not open for reading or converting in Calibre.

The error: MobiError: Unknown book type: '\x00\x00\x00\x00\x00\x00\x00\x00

The files appear the right size, etc, and I can open and read the books in the Linux version of FBReader, so I know the files are not corrupt.

Any ideas?

Monty

[kovidgoyal]

That error indicates the file you are trying to read is full of null bytes. Almost certainly a damaged file. Try opening the *exact same file* in fbreader.

[MontyJ]

Originally Posted by kovidgoyal

That error indicates the file you are trying to read is full of null bytes. Almost certainly a damaged file. Try opening the *exact same file* in fbreader.

Yes, that is what I did...exact same file. FB opens and I can read it fine, but not in Calibre.

Here are the details:

calibre, version 1.25.0
ERROR: Could not open ebook: Unknown book type: '\x00\x00\x00\x00\x00\x00\x00\x00'

Traceback (most recent call last):
File "/usr/lib/calibre/calibre/gui2/viewer/main.py", line 40, in run
Thread.run(self)
File "/usr/lib/python2.7/threading.py", line 763, in run
self.__target(*self.__args, **self.__kwargs)
File "/usr/lib/calibre/calibre/ebooks/oeb/iterator/book.py", line 99, in __enter__
{}, self.base)
File "/usr/lib/calibre/calibre/customize/conversion.py", line 241, in __call__
log, accelerators)
File "/usr/lib/calibre/calibre/ebooks/conversion/plugins/mobi_input.py", line 33, in convert
options.debug_pipeline, try_extra_data_fix=True)
File "/usr/lib/calibre/calibre/ebooks/mobi/reader/mobi6.py", line 83, in __init__
raise MobiError('Unknown book type: %s' % repr(self.ident))
MobiError: Unknown book type: '\x00\x00\x00\x00\x00\x00\x00\x00'

[PeterT]

You have a very old version of calibre. It's quite possible that there are fixes since then which might handle this.

[MontyJ]

Originally Posted by PeterT

You have a very old version of calibre. It's quite possible that there are fixes since then which might handle this.

Yea, noticed that. I had done a normal package install from the default distribution source. I didn't think too much of it, as an experienced member had posted, re a different issue:

Installing the official binaries vs. the repository version will not interfere with your configuration!

In any case, I just went through the binary install from the Calibre site (V 2.45) using Kovid's script. It installed just fine, but the error is still similar on the same file! Here is the errors with 2.45:

calibre, version 2.45.0
ERROR: Could not open ebook: Unknown book type: '\x00\x00\x00\x00\x00\x00\x00\x00'

Traceback (most recent call last):
File "site-packages/calibre/gui2/viewer/main.py", line 37, in run
File "threading.py", line 763, in run
File "site-packages/calibre/ebooks/oeb/iterator/book.py", line 112, in __enter__
File "site-packages/calibre/customize/conversion.py", line 241, in __call__
File "site-packages/calibre/ebooks/conversion/plugins/mobi_input.py", line 33, in convert
File "site-packages/calibre/ebooks/mobi/reader/mobi6.py", line 78, in __init__
MobiError: Unknown book type: '\x00\x00\x00\x00\x00\x00\x00\x00'

[eschwartz]

Warning! Distro version of calibre ahead!

Please uninstall your distro calibre and re-install the version on calibre's website.
There is no official support for distro calibre packages, only errors which can be duplicated with the official binaries.

Distros mess around with the sources too much -- besides for being terribly out of date usually.



EDIT: crosspost, and I see you still have the problem.
Must reload page more often.

[eschwartz]

Well, if you are certain the same file works in fbreader but not in calibre, then there isn't much more we can do without a way to duplicate the problem. You'll need to upload a copy of the faulty book: http://calibre-ebook.com/bugs

[gbm]

I just downloaded a azw from Amazon and it loaded and converted find in calibre.
Delete and re-download.

Using Mint 17.2 Cinnamon.

bernie

p.s.
Tried one of my old prc files off the original Baen CD no problems.

[eschwartz]

Originally Posted by gbm

I just downloaded a azw from Amazon and it loaded and converted find in calibre.
Delete and re-download.

Using Mint 17.2 Cinnamon.

bernie

p.s.
Tried one of my old prc files off the original Baen CD no problems.

Just because your books were fine, does not mean another book wasn't.
Some files are outliers, and have weird oddnesses that calibre doesn't expect. If another application can read them, it is worth seeing if calibre can figure out how to read them as well.

Now, calibre has a long history, and the chances of such a book are low. Not completely impossible though, and @MontyJ has stated the same files do open in FBReader.

[kovidgoyal]

Need the file

[gbm]

Originally Posted by eschwartz

Just because your books were fine, does not mean another book wasn't.
Some files are outliers, and have weird oddnesses that calibre doesn't expect. If another application can read them, it is worth seeing if calibre can figure out how to read them as well.

Now, calibre has a long history, and the chances of such a book are low. Not completely impossible though, and @MontyJ has stated the same files do open in FBReader.

That is why I said delete--should have said rename-- and redownload. If calibre can read my 13 year-old prc files it should read newer non drm MOBI with no problems.


bernie

[eschwartz]

Originally Posted by gbm

That is why I said delete--should have said rename-- and redownload. If calibre can read my 13 year-old prc files it should read newer non drm MOBI with no problems.


bernie

The OP made it sound as though they were just downloaded.
And redownloading will most likely just get the same exact file again especially as Amazon are not the only source of MOBI.
And you are assuming that whatever the source, they are regenerating the MOBI from scratch on each download. Which may not necessarily be the case even with Amazon.

...

Age has little or nothing to do with it.



Bottom line -- Kovid needs to see the file, then maybe something could be done.

[MontyJ]

Apologies for the delay!

Do I need to register at ubuntu to upload the file? The link above takes me to their login page and I do not have an ubuntu login.

I will gladly upload the .mobi file in question.

Just to clarify:

I downloaded a batch of .mobi ebooks. All of them will import into Calibre and show correct metadata. But when I try to open the book to read or convert, I get the error message I posted previously. This is in version 2.45.0.

With FBReader, I can open and read the book normally. It displays normally, as did a few others I tried that Calibre would not display.

Monty

[PeterT]

Bug tracker is here --> http://calibre-ebook.com/bugs

[MontyJ]

I created a bug report and uploaded one of the ebooks that produced the error.

MontyJ