Microsoft DirectX 8.1 (C++) |
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