IAudioInputEndpointRT::GetInputDataPointer method (audioengineendpoint.h)

The GetInputDataPointer method gets a pointer to the buffer from which data will be read by the audio engine.

Syntax

void GetInputDataPointer(
  [in, out] APO_CONNECTION_PROPERTY *pConnectionProperty,
  [in, out] AE_CURRENT_POSITION     *pAeTimeStamp
);

Parameters

[in, out] pConnectionProperty

A pointer to an APO_CONNECTION_PROPERTY structure.

The caller sets the member values as follows:

• pBuffer is set to NULL.
• u32ValidFrameCount contains the number of frames that need to be in the retrieved data pointer. The endpoint object must not cache this information. The audio engine can change this number depending on its processing needs.
• u32BufferFlags is set to BUFFER_INVALID.

• pBuffer points to valid memory where the data has been read. This could include silence depending on the flags that were set in the u32BufferFlags member.
• u32ValidFrameCount is unchanged.
• u32BufferFlags is set to BUFFER_VALID if the data pointer contains valid data or to BUFFER_SILENT if the data pointer contains only silent data. The data in the buffer does not actually need to be silence, but the buffer specified in pBuffer must be capable of holding all the frames of silence contained in u32ValidFrameCount to match the required frame count.

[in, out] pAeTimeStamp

A pointer to an AE_CURRENT_POSITION structure that contains the time stamp of the data that is captured in the buffer. This parameter is optional.

Return value

None

Remarks

This method returns a pointer from the endpoint to the buffer pConnectionProperty->pBuffer, which contains data that needs to be passed into the engine as input. The data and the buffer pointer must remain valid until the IAudioInputEndpointRT::ReleaseInputDataPointer method is called. The endpoint object must set the requested amount of information and insert silence if no valid data exists. The buffer pointer, pConnectionProperty->pBuffer, returned by the endpoint object must be frame aligned. Endpoints do not support the extra space, which may be available in the APO_CONNECTION_PROPERTY associated with the connection properties passed in the pConnectionProperty parameter.

Passing zero in the u32ValidFrameCount member is a valid request. In this case, the input pointer must be valid but the endpoint does not read from it. The pConnectionProperty->u32ValidFrameCount value must be less than or equal to the maximum frame count supported by the endpoint. To get the supported number of frames, call the IAudioEndpoint::GetFramesPerPacket method.

This method can be called from a real-time processing thread. The implementation of this method must not block, access paged memory, or call any blocking system routines.

The Remote Desktop Services AudioEndpoint API is for use in Remote Desktop scenarios; it is not for client applications.

Requirements

See also

IAudioInputEndpointRT