IDirectDrawMediaSample Interface

The IDirectDrawMediaSample interface is supported by objects that also support IMediaSample and allocate samples whose memory is represented by Microsoft® DirectDraw® surfaces. It enables access to the DirectDraw surface that the media sample represents. It also enables the application to unlock the surface but still hold on to it, so that other applications can access it.

Methods in Vtable Order

IUnknown methods Description
QueryInterface Retrieves pointers to supported interfaces.
AddRef Increments the reference count.
Release Decrements the reference count.

IDirectDrawMediaSample methods Description

GetSurfaceAndReleaseLock Retrieves and unlocks the surface that the sample represents.

LockMediaSamplePointer Locks the surface that the sample represents.

IUnknown methods	Description
QueryInterface	Retrieves pointers to supported interfaces.
AddRef	Increments the reference count.
Release	Decrements the reference count.
IDirectDrawMediaSample methods	Description
GetSurfaceAndReleaseLock	Retrieves and unlocks the surface that the sample represents.
LockMediaSamplePointer	Locks the surface that the sample represents.

IDirectDrawMediaSample::GetSurfaceAndReleaseLock

IDirectDrawMediaSample Interface

Retrieves and unlocks the surface that the sample represents.

Syntax

HRESULT GetSurfaceAndReleaseLock(
    IDirectDrawSurface **ppDirectDrawSurface
    RECT *pRect
);

Parameters

ppDirectDrawSurface
[out] Address of a pointer to the sample's IDirectDrawSurface interface.
pRect
[out] Pointer to a variable that receives the address of the rectangle defining the part of the surface that the sample represents.

Return Value

Returns an HRESULT value.

Remarks

The caller should release the returned surface pointer, except when calling the Overlay Mixer filter's implementation of this interface.

IDirectDrawMediaSample::LockMediaSamplePointer

IDirectDrawMediaSample Interface

Locks the surface that the sample represents.

Syntax

HRESULT LockMediaSamplePointer(void);

Return Value

Returns an HRESULT value.

Remarks

This method should be called only after calling GetSurfaceAndReleaseLock.