Issues Changing PDF to MOBI via Calibre & Transferring to Kindle Fire See latest pos

[Warren_Harding]

Hello, I have two issues regarding using Calibre to change PDF files into MOBI files.

1. For one PDF (18 MB unconverted, 160 MB converted; took 100+ minutes to convert), after converting it to MOBI format, it turns out that it had put each page into a thumbnail instead of actually putting it in Kindle Fire format. Yet, this process works flawlessly with other PDF's I converted.

2. Cover pages for MOBIs don't appear on Kindle Fire. I've tried e-mailing it to Kindle Fire, but downloading the attachment doesn't seem to work (when going to the "Downloads" tab, it just shows the attachment name without any progress bar, and you can't actually open it). I've tried converting it from MOBI to MOBI, both while uploading the cover before the EPUB to MOBI conversion, and uploading the cover before the MOBI to MOBI conversion. It doesn't show in the cover page when reading the book via Calibre Library either.

Thank you for help in advance.

[AnemicOak]

Originally Posted by Warren_Harding

1. For one PDF (18 MB unconverted, 160 MB converted; took 100+ minutes to convert), after converting it to MOBI format, it turns out that it had put each page into a thumbnail instead of actually putting it in Kindle Fire format. Yet, this process works flawlessly with other PDF's I converted.

Sounds like maybe you're trying to convert an image based PDF (each page is an image) instead of a text based one?

[Warren_Harding]

And I suppose so: I can't tell if it's an image-based PDF or a text-based PDF. How can I find out? And either way, how can I get it to transfer to a text-based MOBI properly (with cover too)? Thanks again.

[theducks]

Originally Posted by Warren_Harding

And I suppose so: I can't tell if it's an image-based PDF or a text-based PDF. How can I find out? And either way, how can I get it to transfer to a text-based MOBI properly (with cover too)? Thanks again.

In the PDF (using a PDF viewer like Acrobat:

Try and select a just few words.
Now paste those into a blank (notepad page)

if the first is afailure= Image

if I know if only the second fails

[eschwartz]

I have seen PDF's where you CAN copy and paste that text, but somehow the main text is images and calibre cannot reconcile that. Your test would insist that it's not images, yet calibre sees it as images.

In calibre's conversion window, choose search and replace, then click the wand icon. It will allow you to see what calibre sees when it unpacks the book.

[Warren_Harding]

Originally Posted by theducks

In the PDF (using a PDF viewer like Acrobat:

Try and select a just few words.
Now paste those into a blank (notepad page)

if the first is afailure= Image

if I know if only the second fails

I highlighted some text from the PDF and copied it to a notepad - it was successful.

[Warren_Harding]

Originally Posted by eschwartz

I have seen PDF's where you CAN copy and paste that text, but somehow the main text is images and calibre cannot reconcile that. Your test would insist that it's not images, yet calibre sees it as images.

In calibre's conversion window, choose search and replace, then click the wand icon. It will allow you to see what calibre sees when it unpacks the book.

I clicked on the Wand button (with all the fields empty) and it fails to generate a preview.

[BetterRed]

Try converting the PDF to text with Google Docs, you will probably have to do some editing on the output, and then convert the text to mobi with calibre

BR

[eschwartz]

Originally Posted by Warren_Harding

I clicked on the Wand button (with all the fields empty) and it fails to generate a preview.

Do you mean it didn't do anything, or it opened up a blank window?

It should open up a window titled Regex Builder. Looks something like the attached screenshot. If the Preview window is blank, maybe calibre doesn't see anything? Although seriously, it should at least show html and body tags.

If it doesn't open this window, maybe you need to wait longer for calibre to parse the entire PDF. The one I've shown is a 91 KB, 10-page short story offered for free from the author's website and opened pretty fast, but for a full-blown novel over 200x that size, it might take far longer to load.

[Warren_Harding]

Originally Posted by eschwartz

Do you mean it didn't do anything, or it opened up a blank window?

It should open up a window titled Regex Builder. Looks something like the attached screenshot. If the Preview window is blank, maybe calibre doesn't see anything? Although seriously, it should at least show html and body tags.

If it doesn't open this window, maybe you need to wait longer for calibre to parse the entire PDF. The one I've shown is a 91 KB, 10-page short story offered for free from the author's website and opened pretty fast, but for a full-blown novel over 200x that size, it might take far longer to load.

It says that it fails to generate a preview, then the Regex Builder window shows up, but its empty. Yes, the book is ~935 pages, but since I don't see a progress bar or anything I have no idea whether it's still loading something or not.

[eschwartz]

Originally Posted by Warren_Harding

It says that it fails to generate a preview, then the Regex Builder window shows up, but its empty. Yes, the book is ~935 pages, but since I don't see a progress bar or anything I have no idea whether it's still loading something or not.

Well, I have no idea why it should show an error message.

Unless someone here knows of some reason why that should happen, you might want to post a bug report.

Meanwhile, I would just assume it is pictures and try BetterRed's Google Drive suggestion. I never thought of that to be honest, but they do actually perform decent OCR for free. Or if you happen to have any OCR software lying around you can try that...

[chaley]

Originally Posted by Warren_Harding

It says that it fails to generate a preview, then the Regex Builder window shows up, but its empty. Yes, the book is ~935 pages, but since I don't see a progress bar or anything I have no idea whether it's still loading something or not.

Originally Posted by eschwartz

Well, I have no idea why it should show an error message.

It there is no text in the document then it will generate an empty preview. I don't have the code in front of me at the moment, but I wouldn't be surprised if a book with no text produces some error message.

BTW: some PDFs are a combination of images and underlying text. The image is the "main" document and the text is used when selecting. The text is often generated by OCR and equally often has a very weak relationship with the text shown in the image. I don't remember if in this situation, calibre will try to grab the underlying text.