The QImageFormat class is an incremental image decoder for a specific image format.
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Detailed Description
The QImageFormat class is an incremental image decoder for a specific image format.
By making a derived class of QImageFormatType, 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 QMovie or for the first frame of the image
stream to be loaded as a QImage or QPixmap.
Your new subclass must reimplement the decode() function in order
to process your new format.
New QImageFormat objects are generated by new QImageFormatType
factories.
See also Graphics Classes, Image Processing Classes, and Multimedia Classes.
Member Function Documentation
int QImageFormat::decode ( QImage & img, QImageConsumer * consumer, const uchar * buffer, int length ) [pure virtual]
New subclasses must reimplement this method.
It should decode some or all of the bytes from buffer into img, calling the methods of consumer as the decoding proceeds
to inform that consumer of changes to the image. The length of the
data is given in length. The consumer may be 0, in which case
the function should just process the data into img 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.
The function should return without processing all the data if it
reaches the end of a frame in the input.
The function must return the number of bytes it has processed.
This file is part of the Qt toolkit.
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