IDirectSoundBuffer8::Unlock Method
[The feature associated with this page, DirectSound, is a legacy feature. It has been superseded by WASAPI and Audio Graphs. Media Casting have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use Media Casting instead of DirectSound, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]
The Unlock method releases a locked sound buffer.
Syntax
HRESULT Unlock(
LPVOID pvAudioPtr1,
DWORD dwAudioBytes1,
LPVOID pvAudioPtr2,
DWORD dwAudioBytes2
)
Parameters
- pvAudioPtr1
Address of the value retrieved in the ppvAudioPtr1 parameter of the Lock method. - dwAudioBytes1
Number of bytes written to the portion of the buffer at pvAudioPtr1. See Remarks. - pvAudioPtr2
Address of the value retrieved in the ppvAudioPtr2 parameter of the IDirectSoundBuffer8::Lock method. - dwAudioBytes2
Number of bytes written to the portion of the buffer at pvAudioPtr2. See Remarks.
Return Value
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:
| Return code |
| DSERR_INVALIDCALL |
| DSERR_INVALIDPARAM |
| DSERR_PRIOLEVELNEEDED |
Remarks
An application must pass both pointers, pvAudioPtr1 and pvAudioPtr2, returned by the IDirectSoundBuffer8::Lock method to ensure the correct pairing of IDirectSoundBuffer8::Lock and IDirectSoundBuffer8::Unlock. The second pointer is needed even if nothing was written to the second pointer.
The values in dwAudioBytes1 and dwAudioBytes2 must specify the number of bytes actually written to each part of the buffer, which might be less than the size of the lock. DirectSound uses these values to determine how much data to commit to the device.
Requirements
Header: Declared in DSound.h.
Library: Use Dsound3d.dll.