IImageSink::GetPixelDataBuffer
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4/8/2010
This method is used by an image source to request that the image sink allocate a memory buffer for image pixel data.
Your image source must fill the buffer with the pixel data and then call IImageSink::ReleasePixelDataBuffer to pass the data to the image sink.
If the image source obtains a buffer for pixel data in some other way, it should call IImageSink::PushPixelData to pass the data to the image sink.
Important
For best performance use IImageSink::GetPixelDataBuffer to obtain the buffer because it will align the buffer on a 128-byte boundary as required by some hardware decoders. If IImageSink::PushPixelData is used instead, that method will create a separate buffer that is 128-byte aligned and copy the pixel data to it. It does this even if the buffer passed to it by the image source is 128-byte aligned.
Syntax
HRESULT GetPixelDataBuffer(
const RECT* rect,
PixelFormatID pixelFormat,
BOOL lastPass,
BitmapData* bitmapData
);
Parameters
- rect
[in] A pointer to a RECT structure specifying the dimensions of the buffer for the pixel data.
- pixelFormat
[in] A PixelFormatID value specifying the data format for the pixels in the buffer.
lastPass
[in] A BOOL value that tells the sink whether this is the last pass over the specified image area.Set this value to TRUE if this call to IImageSink::GetPixelDataBuffer is the last pass; otherwise, set to FALSE.
- bitmapData
[out] A pointer to a BitmapData object representing the pixel data buffer.
Return Value
If successful, this method returns S_OK.
This method may return E_NOTIMPL if it fails.
Remarks
You must call IImageSink::SetPalette prior to sending data to the sink.
A source should only call this method if the negotiated format returned from IImageSink::BeginSink was the image format identifier ImageFormatMemoryBMP. For more information, see Imaging GUIDs.
Requirements
| Header | imaging.h |
| Library | Imaging.lib |
| Windows Embedded CE | Windows CE 5.0 and later |
| Windows Mobile | Windows Mobile Version 5.0 and later |
See Also
Reference
IImageSink
IImageSink::BeginSink
Imaging GUIDs
IImageSink::PushPixelData
PixelFormatID
BitmapData
IImageSink::ReleasePixelDataBuffer