Epub won't convert to any other format

[ThatGuy99]

I've used calibre for over a year now and this is the first time I haven't been able to figure out why a book wouldn't convert. I have a Penguin EPUB that I have tried to convert to both MOBI and AZW3. The EPUB doesn't seem to have DRM as I can view it in the calibre reader and have used the calibre book editor to look into the exploded files. The conversion process doesn't give an error, it just seems to hang at the same place (1%, Formatting scene breaks) each time I've tried. I've let it run as long as 2 hrs. before stopping. My PC is an i7-3770, 8 thread, 16GB RAM, 4TB free, Win7 x64 & calibre 1.23 x64, so it doesn't seem to be for lack of processing power. Any help would certainly be appreciated.

Here's the processing log:

Convert book 1 of 1 (HS 1: Cloche and Dagger)
Resolved conversion options
calibre version: 1.23.0
{'asciiize': False,
 'author_sort': None,
 'authors': None,
 'base_font_size': 0.0,
 'book_producer': None,
 'change_justification': u'original',
 'chapter': u"//*[((name()='h1' or name()='h2') and re:test(., '\\s*((chapter|book|section|part)\\s+)|((prolog|prologue|epilogue)(\\s+|$))', 'i')) or @class = 'chapter']",
 'chapter_mark': u'pagebreak',
 'comments': None,
 'cover': u'C:\\Users\\TERRYP~1\\AppData\\Local\\Temp\\calibre_qpgt1l\\6bzv3s.jpeg',
 'debug_pipeline': None,
 'dehyphenate': True,
 'delete_blank_paragraphs': True,
 'disable_font_rescaling': False,
 'dont_compress': False,
 'duplicate_links_in_toc': False,
 'embed_all_fonts': False,
 'embed_font_family': None,
 'enable_heuristics': True,
 'expand_css': False,
 'extra_css': None,
 'extract_to': None,
 'filter_css': u'',
 'fix_indents': True,
 'font_size_mapping': None,
 'format_scene_breaks': True,
 'html_unwrap_factor': 0.4,
 'input_encoding': None,
 'input_profile': <calibre.customize.profiles.KindleInput object at 0x0000000004C62DD8>,
 'insert_blank_line': False,
 'insert_blank_line_size': 0.5,
 'insert_metadata': False,
 'isbn': None,
 'italicize_common_cases': True,
 'keep_ligatures': False,
 'language': None,
 'level1_toc': None,
 'level2_toc': None,
 'level3_toc': None,
 'line_height': 0.0,
 'linearize_tables': False,
 'margin_bottom': 5.0,
 'margin_left': 5.0,
 'margin_right': 5.0,
 'margin_top': 5.0,
 'markup_chapter_headings': True,
 'max_toc_links': 50,
 'minimum_line_height': 120.0,
 'mobi_file_type': u'both',
 'mobi_ignore_margins': False,
 'mobi_keep_original_images': False,
 'mobi_toc_at_start': False,
 'no_chapters_in_toc': False,
 'no_inline_navbars': True,
 'no_inline_toc': True,
 'output_profile': <calibre.customize.profiles.KindleDXOutput object at 0x0000000004C702B0>,
 'page_breaks_before': u"//*[name()='h1' or name()='h2']",
 'personal_doc': u'[PDOC]',
 'prefer_author_sort': True,
 'prefer_metadata_cover': False,
 'pretty_print': False,
 'pubdate': None,
 'publisher': None,
 'rating': None,
 'read_metadata_from_opf': u'C:\\Users\\TERRYP~1\\AppData\\Local\\Temp\\calibre_qpgt1l\\xd2yot.opf',
 'remove_fake_margins': True,
 'remove_first_image': True,
 'remove_paragraph_spacing': False,
 'remove_paragraph_spacing_indent_size': 1.5,
 'renumber_headings': True,
 'replace_scene_breaks': u'',
 'search_replace': '[]',
 'series': None,
 'series_index': None,
 'share_not_sync': False,
 'smarten_punctuation': False,
 'sr1_replace': None,
 'sr1_search': None,
 'sr2_replace': None,
 'sr2_search': None,
 'sr3_replace': None,
 'sr3_search': None,
 'start_reading_at': None,
 'subset_embedded_fonts': False,
 'tags': None,
 'timestamp': None,
 'title': None,
 'title_sort': None,
 'toc_filter': None,
 'toc_threshold': 6,
 'toc_title': None,
 'unsmarten_punctuation': False,
 'unwrap_lines': True,
 'use_auto_toc': False,
 'verbose': 2}
InputFormatPlugin: EPUB Input running
on C:\Users\TERRYP~1\AppData\Local\Temp\calibre_qpgt1l\mr0w4n.epub
Found HTML cover titlepage.xhtml
Parsing all content...
Parsing OEBPS/Text/CR!NSPXT0JJXN0DQ0KEDV0XQ2XJMDT5_split_040.html ...
*********  Heuristic processing HTML  *********
There are 0 blank lines. 0.0 percent blank
minimum chapters required are: 1
found 1 pre-existing headings
Total wordcount is: 6006, Average words per section is: 6006, Marked up 1 chapters
Hard line breaks check returned True
Median line length is 147, calculated with html format
Unwrapping required, unwrapping Lines
Fixing hyphenated content
Formatting scene breaks

[eschwartz]

You appear to have heuristics turned on. Try turning it off, it should skip the current step altogether.

[theducks]

Calibre conversions are not multi threaded so all those cores are still waiting for you

[DoctorOhh]

Originally Posted by ThatGuy99

The conversion process doesn't give an error, it just seems to hang at the same place (1%, Formatting scene breaks) each time I've tried. I've let it run as long as 2 hrs. before stopping. My PC is an i7-3770, 8 thread, 16GB RAM, 4TB free, Win7 x64 & calibre 1.23 x64, so it doesn't seem to be for lack of processing power. Any help would certainly be appreciated.

It is not a lack of processing power but it may be a lack of patience.

1%, 47%, and 67% are spots where you can expect to see calibre when you look at the job. Frequently if a job runs long it will appear stuck at one of these points. When in reality calibre is busy working at the tasks represented by those percentages. There just aren't any in between points.

As eschwartz points out you have Heuristic processing turned on and it seems as if it is chugging away at analyzing and formatting the scene breaks. Many folks have reported times as high as 24+ hours for a conversion to complete. My longest wait was 6 hours on multiple occasions.

You can run the job with Heuristic processing turned off which should speed the job up quite a bit (my six hour conversion did not have Heuristic processing turned on) and the job may complete in minutes instead of hours. Or you can set the job to run at the end of the day and just let it go until it errors or completes.

[ThatGuy99]

Turning off Heuristic processing as suggested by eschwartz and DoctorOhh did the trick. It converted in less than 10 seconds this time where as I let it run for 6 hours after posting this thread last night and it still hadn't budged off 1%.

I got my wife a new Kindle Fire HDX 8.9 for Christmas to replace her old first gen Nook. I had to convert her entire library of 1860 EPUBs (she's a MAJOR bookworm!) to AZW3. I did all of them with Heuristic processing turned on as I found it produced a better end result.

I've used the old calibre book editor to fix the editing errors of others on my wife's EPUBs, so I'm pretty familiar with how they were built. This PENGUIN ebook didn't seem unusual until I discovered that it contained a 50 level deep series of nested <Div> statements that spanned the entire length of the ebook. I now suspect this is what caused calibre to hang.

theducks, why did you say that calibre doesn't use multiple cores ? There are settings under Advanced/Miscellaneous for using multiple cores to process simultaneous conversion jobs. I've monitored calibre's core usage with 100 cued conversions and it appeared to be using every core -- completing them all successfully in just a few minutes. Am I misunderstanding how this setting is used ?

[eschwartz]

Each job can use only one core, but with 8 cores you can run 8 jobs simultaneously, and devote a whole core to the job.

[theducks]

Originally Posted by ThatGuy99

Turning off Heuristic processing as suggested by eschwartz and DoctorOhh did the trick. It converted in less than 10 seconds this time where as I let it run for 6 hours after posting this thread last night and it still hadn't budged off 1%.

I got my wife a new Kindle Fire HDX 8.9 for Christmas to replace her old first gen Nook. I had to convert her entire library of 1860 EPUBs (she's a MAJOR bookworm!) to AZW3. I did all of them with Heuristic processing turned on as I found it produced a better end result.

I've used the old calibre book editor to fix the editing errors of others on my wife's EPUBs, so I'm pretty familiar with how they were built. This PENGUIN ebook didn't seem unusual until I discovered that it contained a 50 level deep series of nested <Div> statements that spanned the entire length of the ebook. I now suspect this is what caused calibre to hang.

theducks, why did you say that calibre doesn't use multiple cores ? There are settings under Advanced/Miscellaneous for using multiple cores to process simultaneous conversion jobs. I've monitored calibre's core usage with 100 cued conversions and it appeared to be using every core -- completing them all successfully in just a few minutes. Am I misunderstanding how this setting is used ?

IIRC 1 job, 1 core
If you queue multiple jobs, then that setting can keep things limited.

[DoctorOhh]

Originally Posted by ThatGuy99

Turning off Heuristic processing as suggested by eschwartz and DoctorOhh did the trick. It converted in less than 10 seconds this time where as I let it run for 6 hours after posting this thread last night and it still hadn't budged off 1%.
...~~~...
This PENGUIN ebook didn't seem unusual until I discovered that it contained a 50 level deep series of nested <Div> statements that spanned the entire length of the ebook. I now suspect this is what caused calibre to hang.

I'm glad you finally managed to get the book to convert.

It looks like you ran across the rare configuration that may actually have throw the Heuristic processing for a loop. Then again after 24 - 48 hours it may have finished. Truly not worth the time to find out.

I have seen this reported once or twice. It might be worth it (to prevent this from happening to others) to create a bug report and attach the book to the report so it can be investigated. After you attach the book you can mark the bug report private so the copyrighted book isn't floating for anyone to see.