Platform SDK: DirectX

IDirectSoundBuffer::Play

The IDirectSoundBuffer::Play method causes the sound buffer to play from the current position.

HRESULT Play(
  DWORD dwReserved1,  
  DWORD dwPriority,   
  DWORD dwFlags       
);

Parameters

dwReserved1

This parameter is reserved. Its value must be zero.

dwPriority

Priority for the sound, used by the voice manager when assigning hardware mixing resources. The lowest priority is zero, and the highest priority is 0xFFFFFFFF. If the buffer was not created with the DSBCAPS_LOCDEFER flag, this value must be zero.

dwFlags

Flags specifying how to play the buffer. The following flags are defined:

DSBPLAY_LOOPING: Once the end of the audio buffer is reached, play restarts at the beginning of the buffer. Play continues until explicitly stopped. This flag must be set when playing primary sound buffers.
Voice Allocation flags: The voice allocation flags are valid only for buffers created with the DSBCAPS_LOCDEFER flag. One of the following flags can be used to force the processing of the sound into hardware or software. If neither DBSPLAY_LOCHARDWARE nor DBSPLAY_LOCSOFTWARE is set, the sound is played in either software or hardware, depending on the availability of resources at the time the method is called. See Remarks.
DSBPLAY_LOCHARDWARE: Play this voice in a hardware buffer only. If the hardware has no available voices and no voice management flags are set, the call to IDirectSoundBuffer::Play fails. This flag cannot be combined with DSBPLAY_LOCSOFTWARE.
DSBPLAY_LOCSOFTWARE: Play this voice in a software buffer only. This flag cannot be combined with DSBPLAY_LOCHARDWARE or any voice management flag.
Voice Management flags: The voice management flags are valid only for buffers created with the DSBCAPS_LOCDEFER flag, and are used for sounds that are to play in hardware. These flags enable hardware resources that are in use to be yielded to the current sound. Only buffers created with the DSBCAPS_LOCDEFER flag are candidates for premature termination. See Remarks.
DSBPLAY_TERMINATEBY_TIME: If the hardware has no available voices, a currently playing buffer is stopped to make room for the new buffer. The buffer prematurely terminated is the one with the least time left to play.
DSBPLAY_TERMINATEBY_DISTANCE: If the hardware has no available voices, a currently playing buffer is stopped to make room for the new buffer. The buffer prematurely terminated is selected from buffers that have the buffer's DSBCAPS_ MUTE3DATMAXDISTANCE flag set and are beyond their maximum distance. If there are no such buffers, the method fails.
DSBPLAY_TERMINATEBY_PRIORITY: If the hardware has no available voices, a currently playing buffer is stopped to make room for the new buffer. The buffer prematurely terminated is the one with the lowest priority as set by the dwPriority parameter passed to IDirectSoundBuffer::Play for the buffer.

Return Values

If the method succeeds, the return value is DS_OK.

If the method fails, the return value may be one of the following error values:

DSERR_PRIOLEVELNEEDED

Remarks

If IDirectSound::SetCooperativeLevel has not been called, the method returns DS_OK, but no sound is produced until a cooperative level has been set.

If the buffer specified in the method is already playing, the call to the method succeeds and the buffer continues to play. However, the flags defined in the most recent call supersede flags defined in previous calls.

When called on the primary buffer, this method causes the buffer to start playing to the sound device. If the application has set the DSSCL_WRITEPRIMARY cooperative level, any audio data put in the primary buffer by the application is sent to the sound device. Under any other cooperative level, the primary buffer plays silence if no secondary buffers are playing. Primary buffers must be played with the DSBPLAY_LOOPING flag set. For more information, see Playing the Primary Buffer Continuously.

If the method is called with a voice allocation or voice management flag set on a buffer that was not created with the DSBCAPS_LOCDEFER flag, the call fails with DSERR_INVALIDPARAM.

DSBPLAY_TERMINATEBY_TIME and DSBPLAY_TERMINATEBY_DISTANCE cannot be combined, but either may be combined with DSBPLAY_TERMINATEBY_PRIORITY, in which case the DSBPLAY_TERMINATEBY_TIME or DSBPLAY_TERMINATEBY_DISTANCE flag is used to determine which buffer should be terminated in the event of a priority tie.

The following table shows the behavior of the method under various combinations of the voice allocation and voice management flags when no free hardware voices are available.

	DSBPLAY_LOCHARDWARE	Neither DSBPLAY_LOCHARDWARE nor DSBPLAY_LOCSOFTWARE	DSBPLAY_LOCSOFTWARE
DSBPLAY_TERMINATEBY_TIME	Sound with least time left to play is terminated and the new sound plays on the released voice.	Sound with least time left to play is terminated and the new sound plays on the released voice.	New sound plays in software.
DSBPLAY_TERMINATEBY_DISTANCE	If any sounds currently playing in hardware are beyond their maximum distance and have the DSBCAPS_MUTE3DATMAXDISTANCE flag set, one of them is terminated and the new sound plays in hardware. Otherwise, the call fails.	If any sounds currently playing in hardware are beyond their maximum distance and have the DSBCAPS_MUTE3DATMAXDISTANCE flag set, one of them is terminated and the new sound plays in hardware. Otherwise, the new sound plays in software.	New sound plays in software.
DSBPLAY_TERMINATEBY_PRIORITY	If the new sound's priority is higher than or equal to that of any sound currently playing in hardware, one of the lowest-priority sounds is terminated and the new sound plays in hardware. Otherwise, the call fails.	If the new sound's priority is higher than or equal to that of any sound currently playing in hardware, one of the lowest-priority sounds is terminated and the new sound plays in hardware. Otherwise, the new sound plays in software.	New sound plays in software.

Requirements

  Windows NT/2000: Requires Windows NT 4.0 SP3 or later.
  Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
  Header: Declared in dsound.h.
  Import Library: Use dsound.lib.

IDirectSoundBuffer::Play

Parameters

Return Values

Remarks

Requirements

See Also