Microsoft DirectX 8.0 |
Provides methods for manipulating transition objects in Microsoft® DirectShow® Editing Services (DES).
A transition is a progression between one layer and the rendered composite of all the layers with a lower priority. Objects that can have transitions implement the IAMTimelineTransable interface. To set properties on a transition, use the IPropertySetter interface. For more information about using transition, see Working with Effects and Transitions.
Requirements
Requires Qedit.h.
Methods in Vtable Order
IUnknown methods Description QueryInterface Retrieves pointers to supported interfaces. AddRef Increments the reference count. Release Decrements the reference count. IAMTimelineTrans Methods Description GetCutPoint Retrieves the cut point. GetCutPoint2 Equivalent to GetCutPoint, but takes a REFTIME value. SetCutPoint Sets the time at which the transition cuts from one source to the next, if the transition is rendered as a cut. SetCutPoint2 Equivalent to SetCutPoint, but takes a REFTIME value. GetSwapInputs Retrieves a value that indicates whether the transition inputs are swapped. SetSwapInputs Specifies whether the transition inputs are swapped. GetCutsOnly Determines whether the transition is rendered as a cut. SetCutsOnly Specifies whether the transition is rendered as a cut.
Retrieves the cut point. If you render a transition as a cut, the cut point is the time when the transition cuts from one source to the next. By default, this value is the middle of the transition. For example, in a transition that spans one second, the default cut point is 0.5 seconds into the transition.
Syntax
HRESULT GetCutPoint( REFERENCE_TIME *pTLTime );
Parameters
- pTLTime
- Pointer to a variable that receives the cut point, relative to the start time of the transition, in 100-nanosecond units.
Return Value
Returns one of the following HRESULT values:
S_FALSE The cut point was not set. The value returned is the default value. S_OK The cut point was set to a value other than the default. E_POINTER NULL pointer argument.
See Also
Retrieves the cut point. This method is equivalent to GetCutPoint, but takes a REFTIME value.
Syntax
HRESULT GetCutPoint2( REFTIME *pTLTime );
Parameters
- pTLTime
- Pointer to a variable that receives the cut point, relative to the start time of the transition, in seconds.
Return Value
Returns one of the following HRESULT values:
S_FALSE The cut point was not set. The value returned is the default value. S_OK The cut point was set to a value other than the default. E_POINTER NULL pointer argument.
Determines whether the transition is rendered as a cut. If so, the transition occurs instantaneously at the cut point.
Syntax
HRESULT GetCutsOnly( BOOL *pVal );
Parameters
- pVal
- Pointer to a variable that receives a Boolean value specifying whether the transition is rendered as a cut. If TRUE, the transition is an instantaneous cut. If FALSE, the transition occurs over its normal duration.
Return Value
Returns S_OK if successful, or E_POINTER otherwise.
See Also
Retrieves a value that indicates whether the transition inputs are swapped.
By default, a transition goes from the composite of all lower-priority layers to the layer where the transition resides. You can reverse this progression, so the transition goes from the layer where it resides back to the composite of lower-priority layers.
Syntax
HRESULT GetSwapInputs( BOOL *pVal );
Parameters
- pVal
- Pointer to a variable that receives a Boolean value. If the value is FALSE, the transition goes from the composite of all lower-priority layers to the transition layer. If the value is TRUE, the transition goes in the opposite direction. The default value is FALSE.
Return Value
Returns S_OK if successful, or E_POINTER otherwise.
Sets the time at which the transition cuts from one source to the next, if the transition is rendered as a cut.
Syntax
HRESULT SetCutPoint( REFERENCE_TIME TLTime )
Parameters
- TLTime
- Cut point relative to the start of the transition, in 100-nanosecond units. If the value falls outside the bounds of the transition, it is truncated to the nearest valid time.
Return Value
Returns S_OK.
Remarks
By default, the cut-point is the middle of the transition. For example, in a transition that spans one second, the default cut point is 0.5 seconds into the transition.
Sets the time at which the transition cuts from one source to the next, if the transition is rendered as a cut. This method is equivalent to SetCutPoint, but takes a REFTIME value.
Syntax
HRESULT SetCutPoint2( REFTIME TLTime )
Parameters
- TLTime
- Cut point relative to the start of the transition, in seconds.
Return Value
Returns S_OK.
Specifies whether the transition is rendered as a cut. If so, the transition occurs instantly at the cut point. If a transition takes a long time to render, you might want to preview it as a cut to speed preview.
Syntax
HRESULT SetCutsOnly( BOOL Val );
Parameters
- Val
- Boolean value that specifies whether to render the transition as a cut. If TRUE, the transition is rendered as an instantaneous cut. If FALSE, the transition renders over its normal duration.
Return Value
Returns S_OK.
Remarks
Rendering a transition as a cut is not compatible with swapping the inputs. (See SetSwapInputs.) If you call SetCutsOnly with a value of TRUE, it temporarily overrides the SetSwapInputs setting. The cuts-only setting is intended for preview, however, so this limitation does not affect file outputjust remember to call SetCutsOnly with the value FALSE before writing the file.
Specifies whether the transition inputs are swapped.
By default, a transition goes from the composite of all lower-priority layers to the layer where the transition resides. You can reverse this progression, so the transition goes from the layer where it resides back to the composite of lower-priority layers. For more information, see Transition Direction.
Syntax
HRESULT SetSwapInputs( BOOL Val );
Parameters
- Val
- Boolean value that specifies whether the inputs are swapped. If the value is FALSE, the transition goes from the composite of all lower-priority layers to the transition layer. If the value is TRUE, the transition goes in the opposite direction.
Return Value
Returns S_OK.
Remarks
This method does not change the direction of the visual effect. For example, a left-to-right wipe will still go from left to right. To change the direction, set the Progress property using the IPropertySetter interface.