The GetNextPacketSize method retrieves the number of frames in the next data packet in the capture endpoint buffer.
public:
HRESULT GetNextPacketSize(
UINT32 *pNumFramesInNextPacket
)
pNumFramesInNextPacket
Type: UINT32 *
[out]
Pointer to a UINT32 variable into which the method writes the frame count (the number of audio frames in the next capture packet).
Type: HRESULT
If the method succeeds, it returns S_OK. If it fails, possible return codes include, but are not limited to, the values shown in the following table.
| Return code | Description |
|---|---|
| AUDCLNT_E_DEVICE_INVALIDATED | The audio endpoint device has been unplugged, or the audio hardware or associated hardware resources have been reconfigured, disabled, removed, or otherwise made unavailable for use. |
| AUDCLNT_E_SERVICE_NOT_RUNNING | The audio service is not running. |
| E_POINTER | Parameter pNumFramesInNextPacket is NULL. |
Refer to WASAPI error codes.
Before calling the IAudioCaptureClient::GetBuffer method to retrieve the next data packet, the client can call GetNextPacketSize to retrieve the number of audio frames in the next packet. The count reported by GetNextPacketSize matches the count retrieved in the GetBuffer call (through the pNumFramesToRead output parameter) that follows the GetNextPacketSize call.
A packet always consists of an integral number of audio frames.
GetNextPacketSize must be called in the same thread as the GetBuffer and IAudioCaptureClient::ReleaseBuffer method calls that get and release the packets in the capture endpoint buffer.
For a code example that uses the GetNextPacketSize method, see Capturing a Stream.
Header: Declared in audioclient.h.
Library: Use mmdevapi.lib.