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<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QImageFormat Class Reference</h1>
<p>The QImageFormat class is an incremental image decoder for a specific image format.
<a href="#details">More...</a>
<p><tt>#include <<a href="qasyncimageio-h.html">qasyncimageio.h</a>></tt>
<p><a href="qimageformat-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li><div class=fn>virtual int <a href="#decode"><b>decode</b></a> ( QImage & img, QImageConsumer * consumer, const uchar * buffer, int length ) = 0</div></li>
</ul>
<hr><a name="details"></a><h2>Detailed Description</h2>
The QImageFormat class is an incremental image decoder for a specific image format.
<p>
<p> By making a derived class of <a href="qimageformattype.html">QImageFormatType</a>, which in turn
creates objects that are a subclass of QImageFormat, you can add
support for more incremental image formats, allowing such formats to
be sources for a <a href="qmovie.html">QMovie</a> or for the first frame of the image stream
to be loaded as a <a href="qimage.html">QImage</a> or <a href="qpixmap.html">QPixmap</a>.
<p> Your new subclass must reimplement the <a href="#decode">decode</a>() function in order to
process your new format.
<p> New QImageFormat objects are generated by new QImageFormatType factories.
<p>See also <a href="graphics.html">Graphics Classes</a>, <a href="images.html">Image Processing Classes</a> and <a href="multimedia.html">Multimedia Classes</a>.
<hr><h2>Member Function Documentation</h2>
<h3 class=fn>int <a name="decode"></a>QImageFormat::decode ( <a href="qimage.html">QImage</a> & img, <a href="qimageconsumer.html">QImageConsumer</a> * consumer, const uchar * buffer, int length )<tt> [pure virtual]</tt>
</h3>
<p> New subclasses must reimplement this method.
<p> It should decode some or all of the bytes from <em>buffer</em> into
<em>img</em>, calling the methods of <em>consumer</em> as the decoding proceeds to
inform that consumer of changes to the image. The length of the data is
given in <em>length</em>.
The consumer may be 0, in which case the function should just process
the data into <em>img</em> without telling any consumer about the changes.
Note that the decoder must store enough state
to be able to continue in subsequent calls to this method - this is
the essence of the incremental image loading.
<p> The function should return without processing all the data if it
reaches the end of a frame in the input.
<p> The function must return the number of bytes it has processed.
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