ePub to AZW3 generates lines with warnings

[phossler]

I have a good small epub, and converted to AZW3. The ePub was OK using ADE, but the Kindle Previewer wasn't quite the same (no surprise) so I opened the AZW3 using editor and ran a check

1. The Cover jpg was duplicated, but the 00002.jpg was not referenced (easily edited out) and 0001.jpg is the real cover

2. The OPF has

  <guide>
    <reference type="toc" href="text/part0000.html#calibre_generated_inline_toc" title="Table of Contents"/>
    <reference type="cover" href="images/00001.jpeg"/>
    <reference type="other.ms-coverimage-standard" href="images/00001.jpeg"/>
    <reference type="other.ms-coverimage" href="images/00001.jpeg"/>
  </guide>

which I guess is something the Kindle needs (not sure) 3 different ways to find the cover image

3. BUT ... [Check Book] generates errors for each the 3 lines

The link "images/00001.jpeg" points to a file images/00001.jpeg that is not a text (HTML) document. Many ebook readers will be unable to follow such a link. You should either remove the link or change it to point to a text document. For example, if it points to an image, you can create small wrapper document that contains the image and change the link to point to that.

Since I was looking for problems in the output AZW3 I noticed these flagged Warnings.

Q1 - Do we need to copy the cover image twice?

Q2 - Is there any way the conversion can "create small wrapper document that contains the image and change the link to point to that"?

Q3 - Did I miss a conversion setting?


Thanks

[kovidgoyal]

1) Its not a cover image copied twice its a thumbnail, which all PRC based formats include, because they were originally designed for Palm PDAs that were too weak too dynamically generate their own thumbnails. Compare the file sizes of the two seemingly identical images.

2) There is no guide in an AZW3, the guide you see is a reconstruction the editor creates for you, dont worry about the multiple entries.

3) Again completely harmless. This is a peculiarity of the azw3 format. I need to get around to muting that warning when running check book on azw3

[phossler]