The CBaseControlVideo class implements the IBasicVideo dual interface and controls the video properties of a generic video window. Generally, a CBaseControlVideo object is a video renderer that draws video into a window on the display.
The CBaseControlVideo class supports both properties and methods. Properties are more easily accessible from many Automation controllers (such as the Microsoft® Visual Basic® programming system). However, some operations require applications to be able to change several properties simultaneously; for this reason, methods are provided that enable a number of related properties to be changed.
Many CBaseControlVideo member functions require only that the video renderer be connected to a filter graph. If it is not connected, member functions will return VFW_E_NOT_CONNECTED. Properties set on a video renderer persist between successive connections and disconnections. All applications should ensure that they reset the renderer properties before starting a presentation.
When working with video, the application can select a portion of the video to use. This portion is the source rectangle that the CBaseControlVideo object controls. CBaseControlVideo enables your application to set and retrieve the source rectangle. All the rectangles that CBaseControlVideo uses employ top, left, width, and height rather than top, left, right, and bottom, which is favored in Microsoft Win32® programming. When no source rectangle has been set, the properties of the source rectangle return the full, native video size.
Protected Data Members
| Name | Description |
| m_pFilter | Pointer to an owning media filter. |
| m_pInterfaceLock | Externally defined critical section. |
| m_pPin | Control of the media types for connection. |
Member Functions
| Name | Description |
| CBaseControlVideo | Constructs a CBaseControlVideo object. |
| CopyImage | Creates a memory copy of a video image. |
| GetImageSize | Retrieves video image size information. |
| SetControlVideoPin | Sets the pin with which this object should synchronize. |
Overridable Member Functions
| Name | Description |
| CheckSourceRect | Determines if a source rectangle is valid. |
| CheckTargetRect | Determines if a target rectangle is valid. |
| GetSourceRect | Retrieves the current source video rectangle (pure virtual). |
| GetStaticImage | Returns the current image in a memory buffer (pure virtual). |
| GetTargetRect | Retrieves the current target video rectangle (pure virtual). |
| GetVideoFormat | Retrieves the VIDEOINFOHEADER structure containing the video format. |
| IsDefaultSourceRect | Determines if the renderer is using the default source rectangle (pure virtual). |
| IsDefaultTargetRect | Determines if the renderer is using the default target rectangle (pure virtual). |
| OnUpdateRectangles | Called when the source or target rectangle changes. |
| OnVideoSizeChange | Passes EC_VIDEO_SIZE_CHANGED to the application. |
| SetDefaultSourceRect | Sets the default source video rectangle (pure virtual). |
| SetDefaultTargetRect | Sets the default target video rectangle (pure virtual). |
| SetSourceRect | Sets the current source video rectangle (pure virtual). |
| SetTargetRect | Sets the current target rectangle (pure virtual). |
Implemented IBasicVideo Methods
| Name | Description |
| get_AvgTimePerFrame | Returns an approximate average time per frame. |
| get_BitErrorRate | Returns an approximate bit error rate. |
| get_BitRate | Returns an approximate bit rate for the video. |
| GetCurrentImage | Returns a memory rendering of the current image. |
| get_DestinationHeight | Retrieves the current destination rectangle's height. |
| get_DestinationLeft | Retrieves the current destination rectangle's left coordinate. |
| GetDestinationPosition | Retrieves the current destination position. |
| get_DestinationTop | Retrieves the current destination rectangle's top coordinate. |
| get_DestinationWidth | Retrieves the current destination rectangle's width. |
| get_SourceHeight | Retrieves the current source rectangle's height. |
| get_SourceLeft | Retrieves the current source rectangle's left coordinate. |
| GetSourcePosition | Retrieves the current source position. |
| get_SourceTop | Retrieves the current source rectangle's top coordinate. |
| get_SourceWidth | Retrieves the current source rectangle's width. |
| get_VideoHeight | Retrieves the native video height. |
| GetVideoPaletteEntries | Retrieves a range of palette entries for the video. |
| GetVideoSize | Retrieves the width and height of the native video. |
| get_VideoWidth | Retrieves the native video width. |
| IsUsingDefaultDestination | Determines if the renderer is using the default destination window. |
| IsUsingDefaultSource | Determines if the renderer is using the default source window. |
| put_DestinationHeight | Sets the destination rectangle's height. |
| put_DestinationLeft | Sets the destination rectangle's left coordinate. |
| put_DestinationTop | Sets the destination rectangle's top coordinate. |
| put_DestinationWidth | Sets the destination rectangle's width. |
| put_SourceHeight | Sets the source rectangle's height. |
| put_SourceLeft | Sets the source rectangle's left coordinate. |
| put_SourceTop | Sets the source rectangle's top coordinate. |
| put_SourceWidth | Sets the source rectangle's width. |
| SetDefaultDestinationPosition | Sets the default destination position again. |
| SetDefaultSourcePosition | Sets the default source position again. |
| SetDestinationPosition | Sets the destination rectangle position. |
| SetSourcePosition | Sets the source rectangle position. |
Constructs a CBaseControlVideo object.
CBaseControlVideo(
CBaseFilter *pFilter,
CCritSec *pInterfaceLock,
TCHAR *pName,
LPUNKNOWN pUnk,
HRESULT *phr
);
No return value.
The object implements the IBasicVideo control interface.
All the interface methods from IBasicVideo that this class implements require that the filter be connected correctly. For this reason, the class is passed a pin with which it should synchronize with. Whenever an interface method is called, the object determines that the pin is still connected.
Determines if a source rectangle is valid.
virtual HRESULT CheckSourceRect(
RECT *pSourceRect
);
Returns E_INVALIDARG if not valid; otherwise, returns NOERROR (S_OK).
This member function checks that the source rectangle requested does not exceed the available source video. The left and top coordinates cannot be negative, and the width and height cannot exceed the right and bottom of the video.
Determines if a target rectangle is valid.
virtual HRESULT CheckTargetRect(
RECT *pTargetRect
);
Returns E_INVALIDARG if not valid; otherwise, returns NOERROR (S_OK).
This member function determines if the target rectangle requested is valid. Because the destination rectangle specifies a position in the logical client of the window, the coordinates can be negative, although the overall width and height cannot be zero or a negative value.
Creates a memory copy of an image.
HRESULT CopyImage(
IMediaSample *pMediaSample,
VIDEOINFOHEADER *pVideoInfo,
LONG *pBufferSize,
BYTE *pVideoImage,
RECT *pSourceRect
);
If the pVideoImage parameter is NULL, the pBufferSize parameter is filled in with the number of bytes the output buffer requires to store the image. If the buffer passed in is too small or the member function fails to allocate sufficient memory, the member function returns E_OUTOFMEMORY.
The member function retrieves the image from the sample and copies it into the output buffer. The section of video copied into the output buffer reflects the source rectangle that is set through the IBasicVideo interface (although it does not reflect the destination rectangle).
Retrieves the average time per frame.
HRESULT get_AvgTimePerFrame(
REFTIME *pAvgTimePerFrame
);
Returns NOERROR if successful or E_OUTOFMEMORY if there is not enough memory available.
This member function implements the IBasicVideo::get_AvgTimePerFrame method. It calls the pure virtual CBaseControlVideo::GetVideoFormat member function to retrieve the VIDEOINFOHEADER structure from the derived class.
Returns an approximate bit error rate for the video.
HRESULT get_BitErrorRate(
long *pBitErrorRate
);
Returns NOERROR if successful or E_OUTOFMEMORY if there is not enough memory available.
This member function implements the IBasicVideo::get_BitErrorRate method. It calls the pure virtual CBaseControlVideo::GetVideoFormat to retrieve the VIDEOINFOHEADER structure from the derived class.
Returns an approximate bit rate for the video.
HRESULT get_BitRate(
long *pBitRate
);
Returns NOERROR if successful or E_OUTOFMEMORY not enough memory is available.
This member function implements the IBasicVideo::get_BitRate method. It calls the pure virtual CBaseControlVideo::GetVideoFormat to retrieve the VIDEOINFOHEADER structure from the derived class.
Retrieves the current destination rectangle height.
HRESULT get_DestinationHeight(
long *pDestinationHeight
);
Returns an HRESULT value.
This member function implements the IBasicVideo::get_DestinationHeight method.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where it will be played. The destination rectangle is relative to the client area of the window that it is playing in. The upper-left corner of the window is coordinate (0,0).
Retrieves the left coordinate of the current destination rectangle.
HRESULT get_DestinationLeft(
long *pDestinationLeft
);
Returns an HRESULT value.
This member function implements the IBasicVideo::get_DestinationLeft method.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Retrieves the top coordinate of the current destination rectangle.
HRESULT get_DestinationTop(
long *pDestinationTop
);
Returns an HRESULT value.
This member function implements the IBasicVideo::get_DestinationTop method.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Retrieves the width of the current destination rectangle.
HRESULT get_DestinationWidth(
long *pDestinationWidth
);
Returns an HRESULT value.
This member function implements the IBasicVideo::get_DestinationWidth method.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Retrieves the height of the current source rectangle.
HRESULT get_SourceHeight(
long *pSourceHeight
);
Returns an HRESULT value.
This member function implements the IBasicVideo::get_SourceHeight method.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Retrieves the left coordinate of the current source rectangle.
HRESULT get_SourceLeft(
long *pSourceLeft
);
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Retrieves the top coordinate of the current source rectangle.
HRESULT get_SourceTop(
long *pSourceTop
);
Returns an HRESULT value.
This member function implements the IBasicVideo::get_SourceTop method.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Retrieves the width of the current source rectangle.
HRESULT get_SourceWidth(
long *pSourceWidth
);
Returns an HRESULT value.
This member function implements the IBasicVideo::get_SourceWidth method.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Retrieves the height of the native video.
HRESULT get_VideoHeight(
long *pVideoHeight
);
Returns NOERROR if successful or E_OUTOFMEMORY if there is not enough memory available.
This member function implements the IBasicVideo::get_VideoHeight method. It calls the pure virtual CBaseControlVideo::GetVideoFormat to retrieve the VIDEOINFOHEADER structure from the derived class.
Retrieves the width of the native video.
HRESULT get_VideoWidth(
long *pVideoWidth
);
Returns NOERROR if successful or E_OUTOFMEMORY if there is not enough memory available.
This member function implements the IBasicVideo::get_VideoWidth method. It calls the pure virtual CBaseControlVideo::GetVideoFormat to retrieve the VIDEOINFOHEADER structure from the derived class.
Returns a copy of the current image at the renderer.
HRESULT GetCurrentImage(
long *pBufferSize,
long *pVideoImage
);
Returns an HRESULT value.
This member function retrieves the image from the sample and copies it into the output buffer. The section of video copied into the output buffer reflects the source rectangle set through the IBasicVideo interface. It does not reflect the destination rectangle.
Retrieves the destination rectangle.
HRESULT GetDestinationPosition(
long *pLeft,
long *pTop,
long *pWidth,
long *pHeight
);
Returns an HRESULT value.
This member function can be used in place of separate calls to the CBaseControlVideo::get_DestinationLeft, CBaseControlVideo::get_DestinationTop, CBaseControlVideo::get_DestinationWidth, and CBaseControlVideo::get_DestinationHeight member functions. An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Retrieves video image size information.
HRESULT GetImageSize(
VIDEOINFOHEADER *pVideoInfo,
long *pBufferSize,
RECT *pSourceRect
);
Returns an HRESULT value.
This member function is a helper function used for creating memory image renderings of DIB images. It is called from the base class implementation of CBaseControlVideo::GetCurrentImage when a null pVideoImage parameter is passed to that member function. As a result, this member function constructs and returns a VIDEOINFOHEADER structure, using the information in pBufferSize and pSourceRect.
Retrieves the source rectangle in one atomic operation.
HRESULT GetSourcePosition(
long *pLeft,
long *pTop,
long *pWidth,
long *pHeight
);
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Returns the source rectangle. This is an internal method.
virtual HRESULT GetSourceRect(
RECT *pSourceRect
) PURE;
Returns an HRESULT value.
This member function must be overridden in the derived class to return the source rectangle held by the video renderer. It is called from the following CBaseControlVideo member functions.
The following example from the video renderer sample, SampVid, demonstrates an implementation of this function in a derived class.
// Return the current source rectangle
HRESULT CVideoText::GetSourceRect(RECT *pSourceRect)
{
ASSERT(pSourceRect);
m_pRenderer->m_DrawImage.GetSourceRect(pSourceRect);
return NOERROR;
}
In this example, CVideoText is a class derived from CBaseControlVideo, m_pRenderer holds an object of a class derived from CBaseVideoRenderer, and the m_DrawImage data member, defined in the derived class, holds a CDrawImage object.
Pure virtual method that derived classes override.
virtual HRESULT GetStaticImage(
long *pBufferSize,
long *pDIBImage
) PURE;
Returns an HRESULT value.
Through the IBasicVideo interface, an application can request that it be given a copy of the current image in a memory buffer (some renderers can return E_NOTIMPL to this if they do not support it). The derived class determines how to retrieve the image. When the application calls CBaseControlVideo::GetStaticImage, it calls this pure virtual method that the derived class should override to implement it. This is also called by the CBaseControlVideo::GetCurrentImage member function.
The class provides a helper member function, CBaseControlVideo::CopyImage, that can be given a sample that contains an image, and the member function will copy the relevant section of it (based on the current source rectangle) into the output buffer supplied by the application.
The following example from the video renderer sample, SampVid, demonstrates an implementation of this member function in a derived class. In this example, m_pRenderer holds an object of a class derived from CBaseVideoRenderer.
// Return a copy of the current image in the video renderer
HRESULT CVideoText::GetStaticImage(long *pBufferSize,long *pDIBImage)
{
// Get any sample the renderer may be holding
IMediaSample *pMediaSample = m_pRenderer->GetCurrentSample();
if (pMediaSample == NULL) {
return E_UNEXPECTED;
}
// Call the base class helper method to do the work
HRESULT hr = CopyImage(pMediaSample, // Buffer containing image
&m_pRenderer->m_mtIn, // Type representing bitmap
pBufferSize, // Size of buffer for DIB
(BYTE*) pDIBImage); // Data buffer for output
pMediaSample->Release();
return hr;
}
Returns the destination rectangle. This is an internal helper member function.
virtual HRESULT GetTargetRect(
RECT *pTargetRect
) PURE;
Returns an HRESULT value.
This member function must be overridden in the derived class to return the target rectangle held by the video renderer. It is called from the following CBaseControlVideo member functions.
The following example from the video renderer sample, SampVid, demonstrates an implementation of this function in a derived class.
// Return the current destination rectangle
HRESULT CVideoText::GetTargetRect(RECT *pTargetRect)
{
ASSERT(pTargetRect);
m_pRenderer->m_DrawImage.GetTargetRect(pTargetRect);
return NOERROR;
}
In this example, CVideoText is a class derived from CBaseControlVideo, m_pRenderer holds an object of a class derived from CBaseVideoRenderer, and the m_DrawImage data member, defined in the derived class, holds a CDrawImage object.
Retrieves a video sample that represents the current video format.
virtual VIDEOINFOHEADER * GetVideoFormat( ) PURE;
Returns a pointer to a VIDEOINFOHEADER structure that contains the current video format.
To return and check certain information through IBasicVideo, the object must know the current video format. It gets this information by calling this pure virtual method that derived classes must override. This member function is called by the following CBaseControlVideo member functions.
Retrieves a range of palette entries for the video.
HRESULT GetVideoPaletteEntries(
long StartIndex,
long Entries,
long *pRetrieved,
long *pPalette
);
Returns NOERROR if successful, VFW_E_NO_PALETTE_AVAILABLE if the video samples has no color palette, E_OUTOFMEMORY if there is not enough memory available, E_INVALIDARG if StartIndex is invalid, or S_FALSE if there are no colors in the palette.
This member function returns the current palette of the video as an array allocated by the user. To remain consistent, use the members in the Win32 PALETTEENTRY structure to return the colors, rather than the members in the RGBQUAD structure (although the parameter is a LONG). The memory is allocated by the caller, so simply copy each in turn. Determine that the number of entries requested and the start position offset are both valid. If the number of entries evaluates to zero, return an S_FALSE code.
Retrieves the native video's width and height.
HRESULT GetVideoSize(
long *pWidth,
long *pHeight
);
Returns an HRESULT value.
Determines if the renderer is using the default source rectangle (pure virtual).
virtual HRESULT IsDefaultSourceRect(void) PURE;
Returns an HRESULT value.
This member function must be implemented in the derived class. It is called by the CBaseControlVideo::IsUsingDefaultSource member function.
The following example from the video renderer sample, SampVid, demonstrates an implementation of this function in a derived class.
// Return S_OK if using the default source otherwise S_FALSE
HRESULT CVideoText::IsDefaultSourceRect()
{
RECT SourceRect;
VIDEOINFO *pVideoInfo = (VIDEOINFO *) m_pRenderer->m_mtIn.Format();
BITMAPINFOHEADER *pHeader = HEADER(pVideoInfo);
m_pRenderer->m_DrawImage.GetSourceRect(&SourceRect);
// Check the coordinates that match the video dimensions
if (SourceRect.left != 0 || SourceRect.top != 0 ||
SourceRect.right != pHeader->biWidth ||
SourceRect.bottom != pHeader->biHeight) {
return S_FALSE;
}
return S_OK;
}
In this example, CVideoText is a class derived from CBaseControlVideo, m_pRenderer holds an object of a class derived from CBaseVideoRenderer, and the m_DrawImage data member, defined in the derived class, holds a CDrawImage object. The m_mtIn data member, also defined in the derived class, holds a CMediaType object with the media type of the input pin.
Determines if the renderer is using the default target rectangle (pure virtual).
virtual HRESULT IsDefaultTargetRect(void) PURE;
Returns an HRESULT value.
This member function must be implemented in the derived class. It is called by the CBaseControlVideo::IsUsingDefaultDestination member function.
The following example from the video renderer sample, SampVid, demonstrates an implementation of this function in a derived class.
// Return S_OK if using the default target; otherwise S_FALSE
HRESULT CVideoText::IsDefaultTargetRect()
{
RECT TargetRect;
VIDEOINFO *pVideoInfo = (VIDEOINFO *) m_pRenderer->m_mtIn.Format();
BITMAPINFOHEADER *pHeader = HEADER(pVideoInfo);
m_pRenderer->m_DrawImage.GetTargetRect(&TargetRect);
// Check the destination that matches the initial client area
if (TargetRect.left != 0 || TargetRect.top != 0 ||
TargetRect.right != m_Size.cx ||
TargetRect.bottom != m_Size.cy) {
return S_FALSE;
}
return S_OK;
}
In this example, CVideoText is a class derived from CBaseControlVideo, m_pRenderer holds an object of a class derived from CBaseVideoRenderer, and the m_DrawImage data member, defined in the derived class, holds a CDrawImage object. The m_mtIn data member, also defined in the derived class, holds a CMediaType object with media type of the input pin.
Determines if the renderer is using the default source window.
virtual HRESULT IsUsingDefaultSource(void);
Returns an HRESULT value.
Determines if the renderer is using the default destination window.
virtual HRESULT IsUsingDefaultDestination(void);
Returns an HRESULT value. Returns S_OK if using the default destination; otherwise, returns S_FALSE.
Called when either the source or destination rectangle changes.
virtual HRESULT OnUpdateRectangles( );
Returns an HRESULT value.
Passes an EC_VIDEO_SIZE_CHANGED message to the filter graph manager.
virtual HRESULT OnVideoSizeChange( );
Returns an HRESULT value.
A video renderer should call this member function each time the video size is changed; this will typically be called once after initial connection. If the renderer can support dynamic format changes (from 320x240 to 160x120), it should also call it after each change.
Sets the destination rectangle height.
HRESULT put_DestinationHeight(
long DestinationHeight
);
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Sets the left coordinate of the destination rectangle.
HRESULT put_DestinationLeft(
long DestinationLeft
);
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Sets the top coordinate of the destination rectangle.
HRESULT put_DestinationTop(
long DestinationTop
);
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Sets the width of the destination rectangle.
HRESULT put_DestinationWidth(
long DestinationWidth
);
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Sets the source rectangle height.
HRESULT put_SourceHeight(
long SourceHeight
);
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Sets the source rectangle left coordinate.
HRESULT put_SourceLeft(
long SourceLeft
);
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Sets the top coordinate of the source rectangle.
HRESULT put_SourceTop(
long SourceTop
);
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Sets the width of the source rectangle.
HRESULT put_SourceWidth(
long SourceWidth
);
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Sets the pin used by the filter.
void SetControlVideoPin(
CBasePin *pPin
);
No return value.
The interface can be called only when the filter has been connected successfully. The object is passed through this method to the pin with which it is synchronized; in most cases it will determine if the pin is connected when it has an interface method called and will return VFW_E_NOT_CONNECTED if it fails.
Sets the renderer back to using the default destination position (typically the entire window client area).
HRESULT SetDefaultDestinationPosition( );
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Sets the renderer back to using the default source position (typically all the native video).
HRESULT SetDefaultSourcePosition( );
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Sets the default source video rectangle (pure virtual). This in an internal member function that gets called when the source rectangle is reset.
virtual HRESULT SetDefaultSourceRect( ) PURE;
Returns an HRESULT value.
Derived classes should override this to reset the source rectangle. It is called from CBaseControlVideo::SetDefaultSourcePosition.
The following example from the video renderer sample, SampVid, demonstrates an implementation of this function in a derived class.
// This is called when we reset the default source rectangle
HRESULT CVideoText::SetDefaultSourceRect()
{
VIDEOINFO *pVideoInfo = (VIDEOINFO *) m_pRenderer->m_mtIn.Format();
BITMAPINFOHEADER *pHeader = HEADER(pVideoInfo);
RECT SourceRect = {0,0,pHeader->biWidth,pHeader->biHeight};
m_pRenderer->m_DrawImage.SetSourceRect(&SourceRect);
return NOERROR;
}
In this example, CVideoText is a class derived from CBaseControlVideo, m_pRenderer holds an object of a class derived from CBaseVideoRenderer, and the m_DrawImage data member, defined in the derived class, holds a CDrawImage object. The m_mtIn data member, also defined in the derived class, holds a CMediaType object with media type of the input pin.
Sets the default target video rectangle (pure virtual). This is an internal member function that gets called when the source rectangle is reset.
virtual HRESULT SetDefaultTargetRect( ) PURE;
Returns an HRESULT value.
Derived classes should override this to reset the destination video rectangle. It is called from the CBaseControlVideo::SetDefaultDestinationPosition member function.
The following example from the video renderer sample, SampVid, demonstrates an implementation of this function in a derived class.
// This is called when we reset the default target rectangle
HRESULT CVideoText::SetDefaultTargetRect()
{
VIDEOINFO *pVideoInfo = (VIDEOINFO *) m_pRenderer->m_mtIn.Format();
BITMAPINFOHEADER *pHeader = HEADER(pVideoInfo);
RECT TargetRect = {0,0,m_Size.cx,m_Size.cy};
m_pRenderer->m_DrawImage.SetTargetRect(&TargetRect);
return NOERROR;
}
In this example, CVideoText is a class derived from CBaseControlVideo, m_pRenderer holds an object of a class derived from CBaseVideoRenderer, and the m_DrawImage data member, defined in the derived class, holds a CDrawImage object. The m_mtIn data member, also defined in the derived class, holds a CMediaType object with the media type of the input pin.
Sets the destination rectangle for the video.
HRESULT SetDestinationPosition(
long Left,
long Top,
long Width,
long Height
);
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Sets a new source position for the video.
HRESULT SetSourcePosition(
long Left,
long Top,
long Width,
long Height
);
Returns an HRESULT value.
An application can change the source and destination rectangles for the video through the IBasicVideo interface. The source rectangle affects which section of the native video source will appear on the display; the destination rectangle affects where the video will appear when played. The destination rectangle is relative to the client area of the window in which it is playing. The upper-left corner of the window is coordinate (0,0).
Sets the current source video rectangle (pure virtual). This is an internal member function that gets called when the source rectangle changes.
virtual HRESULT SetSourceRect(
RECT *pSourceRect
) PURE;
Returns an HRESULT value.
Derived classes should override this member function to know when the source rectangle changes. It is called from the following member functions.
The following example from the video renderer sample, SampVid, demonstrates an implementation of this function in a derived class.
HRESULT CVideoText::SetSourceRect(RECT *pSourceRect)
{
m_pRenderer->m_DrawImage.SetSourceRect(pSourceRect);
return NOERROR;
}
In this example, CVideoText is a class derived from CBaseControlVideo, m_pRenderer holds an object of a class derived from CBaseVideoRenderer, and the m_DrawImage data member, defined in the derived class, holds a CDrawImage object.
Sets the current target rectangle (pure virtual). This is an internal member function that gets called when the destination rectangle changes.
virtual HRESULT SetTargetRect(
RECT *pTargetRect
) PURE;
Returns an HRESULT value.
Derived classes should override this to know when the destination rectangle changes. It is called from the following member functions.
The following example from the video renderer sample, SampVid, demonstrates an implementation of this function in a derived class.
HRESULT CVideoText::SetTargetRect(RECT *pTargetRect)
{
m_pRenderer->m_DrawImage.SetTargetRect(pTargetRect);
return NOERROR;
}
In this example, CVideoText is a class derived from CBaseControlVideo, m_pRenderer holds an object of a class derived from CBaseVideoRenderer, and the m_DrawImage data member, defined in the derived class, holds a CDrawImage object.
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