epub-kindle conversion blanks svg with text

[bobb40]

I've made a fair-sized epub ebook which looks very good on Calibre E-book viewer and on Aldiko reader. But readers will want it on Kindle, so I plugged my Kindle (firmware 3.3) into PC and used Calibre (version 0.8.70) to convert/copy the ebook to the Kindle. The result was surprisingly good -- the most objectionable fault was that all multi-line text of illustrations (jpg images in svg wrappers with svg <g>, <text>, and <tspan> tags) was rendered on a single line.

Then I found that there was an update for my Kindle (generation 3 with keyboard), so I applied it and received congratulations from Amazon for updating to firmware 3.4: now I could read KF8 ebooks! And when I looked at my ebook, every illustration that had any text at all (using svg <g> and <text> tags) was rendered as a blank page. Illustrations with NO text were correctly displayed. I used Calibre to carefully convert/copy to Kindle again (AZW3 only), with same result. Epubcheck shows no errors or warnings in epub ebook. Calibre shows that the ebook sent to Kindle is AZW3 format. Conversion log (it's very long) shows no errors or warnings.

Typical illustration, which works very well in epub, is:

  <svg version="1.1" xmlns="http://www.w3.org/2000/svg"
      xmlns:xlink="http://www.w3.org/1999/xlink"
      width="100%" height="100%" viewBox="0 0 600 447"
      preserveAspectRatio="xMidYMid meet">
    <g font-size="20pt" systemLanguage="en">
      <image width="600" height="387" xlink:href="../Images/hl_i06.jpg" />

      <text style="text-anchor:middle" x="300" y="417">
        AT HOME ON PARKER AVENUE
        <tspan x="300" y="447">SAN FRANCISCO</tspan></text>
    </g>
  </svg>

Explanation or suggestion would be appreciated.

[kovidgoyal]

When converting to MOBI calibre rasterizes SVG, for KF8 it leaves it alone. Amazon's various KF8 renderers are full og bugs, you've likely come across one of them. Open your kf8 file with calibre's viewer and check the svg.

[bobb40]

Thanks, Kovid - On Calibre's E-viewer, both the AZW3 file from Calibre, and a MOBI file from KindlePreviewer, look as good as the EPUB. Kindle's 3.4 firmware is a dissappointing step backward.