IDirectMusicBuffer8::PackUnstructured

DirectMusic

Microsoft DirectX 9.0 SDK Update (Summer 2004)

IDirectMusicBuffer8::PackUnstructured

The PackUnstructured method inserts unstructured data (typically a MIDI system-exclusive message), along with timing and routing information, into the buffer.

Syntax

HRESULT PackUnstructured(
  REFERENCE_TIME rt, 
  DWORD dwChannelGroup,
  DWORD cb, 
  LPBYTE lpb
);

Parameters

rt

Absolute time of the message.

dwChannelGroup

Channel group to which the message belongs.

cb

Size of the data, in bytes.

lpb

Address of a buffer containing the data.

Return Values

If the method succeeds, the return value is S_OK.

If it fails, the method can return one of the error values shown in the following table.

Return code
E_OUTOFMEMORY
E_POINTER

Remarks

This method can be used to send any kind of data to the port.

At least 28 bytes (the size of DMUS_EVENTHEADER) plus the size of the data, padded to a multiple of 4 bytes, must be free in the buffer. The buffer space required can be obtained by using the DMUS_EVENT_SIZE(cb) macro, where cb is the size of the data.

The rt parameter must contain the absolute time at which the data is to be sent to the port. To play a message immediately, retrieve the time from the latency clock, and use this as rt. See IDirectMusicPort8::GetLatencyClock.

Messages stamped with the same time do not necessarily play in the same order in which they were placed in the buffer.

Requirements

  Header: Declared in dmusicc.h.

See Also


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