IMiniportMidi::NewStream method (portcls.h)
The NewStream method creates a new instance of a logical stream associated with a specified physical channel.
Syntax
NTSTATUS NewStream(
[out] PMINIPORTMIDISTREAM *Stream,
[in, optional] PUNKNOWN OuterUnknown,
[in] POOL_TYPE PoolType,
[in] ULONG Pin,
[in] BOOLEAN Capture,
[in] PKSDATAFORMAT DataFormat,
[out] PSERVICEGROUP *ServiceGroup
);
Parameters
[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.
Remarks
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.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Universal |
| Header | portcls.h (include Portcls.h) |
| IRQL | PASSIVE_LEVEL |