ITStreamControl::CreateStream method (tapi3if.h)

Article
02/22/2024

The CreateStream method creates a new media stream.

Syntax

HRESULT CreateStream(
  [in]  long               lMediaType,
  [in]  TERMINAL_DIRECTION td,
  [out] ITStream           **ppStream
);

Parameters

[in] lMediaType

Indicates media type for stream.

[in] td

Indicates the TERMINAL_DIRECTION.

[out] ppStream

Pointer to pointer for newly created ITStream interface.

Return value

This method can return one of these values.

Value	Meaning
S_OK	Method succeeded.
E_POINTER	The ppStream parameter is not a valid pointer.
E_OUTOFMEMORY	Insufficient memory exists to perform the operation.
TAPI_E_INVALIDMEDIATYPE	The lMediaType parameter is not a valid media type.
TAPI_E_INVALIDDIRECTION	The td parameter is not a valid terminal direction.
TAPI_E_MAXSTREAMS	The maximum number of streams supported has already been reached.
TAPI_E_NOTSUPPORTED	This operation is not supported.

Remarks

Many MSPs do not support dynamic creation of streams, and simply return TAPI_E_MAXSTREAMS in their implementation of this method. Default streams are automatically available when a call is created, so most applications do not have to use this method.

Stream creation or removal may involve interaction with a remote endpoint, resulting in a CMC_REMOTE_REQUEST rather than the CMC_LOCAL_REQUEST messages that are received when a stream is stopped or started.

TAPI calls the AddRef method on the ITStream interface returned by ITStreamControl::CreateStream. The application must call Release on the ITStream interface to free resources associated with it.

Requirements

Requirement	Value
Target Platform	Windows
Header	tapi3if.h (include Tapi3.h)