IMiniportMidi::NewStream method (portcls.h)

The NewStream method creates a new instance of a logical stream associated with a specified physical channel.


  [out]          PMINIPORTMIDISTREAM *Stream,
  [in, optional] PUNKNOWN            OuterUnknown,
  [in]           POOL_TYPE           PoolType,
  [in]           ULONG               Pin,
  [in]           BOOLEAN             Capture,
  [in]           PKSDATAFORMAT       DataFormat,
  [out]          PSERVICEGROUP       *ServiceGroup


[out] Stream

Output pointer for the new stream. This parameter points to a caller-allocated pointer variable into which the method writes a pointer to the stream object's IMiniportMidiStream interface.

[in, optional] OuterUnknown

Pointer to the IUnknown interface of an object that needs to aggregate the stream object. This parameter is optional. If aggregation is not required, the caller specifies this parameter as NULL.

[in] PoolType

Specifies the type of memory pool from which the storage for the DMA-channel object should be allocated. This parameter is set to one of the POOL_TYPE enumeration values.

[in] Pin

Specifies the pin ID. This parameter identifies the pin that is to be opened. If the MIDI miniport object's IMiniport::GetDescription method outputs a filter descriptor that specifies a total of n pin factories on the filter, then valid pin IDs are in the range 0 to n-1.

[in] Capture

Specifies whether the channel is to be used for capture or for playback. If TRUE, it is a capture (input) channel. If FALSE, it is a playback (output) channel.

[in] DataFormat

Pointer to a KSDATAFORMAT structure that specifies the data format to use for this stream instance.

[out] ServiceGroup

Output pointer for the service group. This parameter points to a caller-allocated pointer variable into which the method writes a pointer to the IServiceGroup interface of the stream's service group object. This is the service group that is being registered for interrupt notification.

Return value

NewStream returns STATUS_SUCCESS if the call was successful. Otherwise, the method returns an appropriate error code.


The NewStream method sets the initial state of the stream to KSSTATE_STOP.

The Stream, OuterUnknown, and ServiceGroup parameters follow the reference-counting conventions for COM objects.


Target Platform Universal
Header portcls.h (include Portcls.h)

See also