IWICMetadataBlockReader interface (wincodecsdk.h)

Exposes methods that provide access to all of the codec's top level metadata blocks.


The IWICMetadataBlockReader interface inherits from the IUnknown interface. IWICMetadataBlockReader also has these types of members:


The IWICMetadataBlockReader interface has these methods.


Retrieves the container format of the decoder.

Retrieves the number of top level metadata blocks.

Retrieves an enumeration of IWICMetadataReader objects representing each of the top level metadata blocks.

Retrieves an IWICMetadataReader for a specified top level metadata block.


IWICMetadataBlockReader and IWICMetadataBlockWriter operate at the root level only; that is, they provide read and write access, respectively, to the top level metadata blocks. They are implemented by IWICBitmapFrameDecode and IWICBitmapFrameEncode, respectively. To handle any metadata blocks that are not at the top level of the hierarchy, use IWICMetadataReader or IWICMetadataWriter.

Note  The codec's decoder and encoder implement this interface to expose the enumeration of all top level metadata blocks. While the codec parses the image stream, it calls services like CreateMetadataReaderFromContainer to instantiate metadata readers for any block that is recognized as being able to be embedded in the decoder's container format. The collection of metadata readers is exposed through this interface. For more info, see How to Write a WIC-Enabled CODEC.


Minimum supported client Windows XP with SP2, Windows Vista [desktop apps | UWP apps]
Minimum supported server Windows Server 2008 [desktop apps | UWP apps]
Target Platform Windows
Header wincodecsdk.h

See also


Metadata Extensibility Overview

Overview of Reading and Writing Image Metadata

WIC Metadata Overview