TOC just wrong in random(?) ways

[raiju]

TOC positions seem to not be interpreted correctly, with an inconsistent error. Using the following code to generate a book:

$mobi = new MOBI();

$mobi_content = new MOBIFile();
$mobi_content->set("title", "My first eBook");
for($i = 0; $i < 20; $i++){
    $mobi_content->appendChapterTitle(($i+1)."这是什么鬼呀".($i+1));
    for($j = 0; $j < 20; $j++){
        $mobi_content->appendParagraph("P".($i+1).".".($j+1)." 许子晴娇嗲的戳了戳身边男子的手臂，小声抱怨了一句：“爸，你看你说的，我这不是见了偶像太兴奋了吗，哪有你这样拆自己闺女的台的……” ".($i+1).'-'.($j+1));
    }
    $mobi_content->appendPageBreak();
}
$mobi->setContentProvider($mobi_content);

$mobi->download("first.mobi");

and using the TOC for e.g. the 12th chapter breaks things.

[raiju]

@bingool

[raiju]

Sadly I can't find any documentation that might help figure out what is happening. The byte positions inside the text are exact (they point to the "<" at the start of the title entry), and yet it seems to lose more and more alignment as the book goes. Might be due to record splitting?

[raiju]

As far as I can tell the byte positions are "correct" (as in, the filepos value corresponds to the number of bytes from the start to the position that is linked to). Note that as there is no spec, I can't be sure what the value of filepos should be. Also, others seem to be using the same strategy (e.g. Calibre w/ https://github.com/kovidgoyal/calibre/blob/ac8363713b8d82b33516c3806fc142bc04b5ace6/src/calibre/ebooks/mobi/writer2/serializer.py), even though the generated files have different (non-byte-aligned?) offsets?! The difference between the "true" byte distance and the one written by Calibre is, as far as I can tell, irregular, and yet the Kindle interprets it correctly... Not sure what's happening...

[raiju]

This page: https://mokunosuke.wordpress.com/2012/03/14/%E7%AA%81%E7%A0%B4%E5%8F%A3%EF%BC%9F/ suggests that even kindlegen suffers from this problem. In any case, don't have the time to look deeper into this. Free for anyone to pick up ;)

[bingool]

thank you very much.now the file can normal work , although it has the problem .so we can slowly to solve it.