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IOCTL_CS_BUFFERS (Compact 2013)

  • 아티클

3/26/2014

This I/O control message sends a buffer to a driver. It can be used both during initialization and also when the stream is running. Send this message with DeviceIoControl.

Syntax

BOOL DeviceIoControl(
    HANDLE hDevice,           // handle to device
    DWORD dwIoControlCode,    // use IOCTL_CS_BUFFERS
    LPVOID lpInBuffer,        // pointer to input buffer
    DWORD nInBufferSize,      // input buffer size
    LPVOID lpOutBuffer,       // pointer to output buffer
    DWORD nOutBufferSize,     // output buffer size
    LPDWORD lpBytesReturned,  // number of bytes returned
    OVERLAPPED lpOverlapped   // pointer to OVERLAPPED structure
);

Parameters

  • hDevice
    [in] Handle to the device.
  • dwIoControlCode
    [in] Control code for the operation. Use IOCTL_CS_BUFFERS for this operation.
  • lpInBuffer
    [in] Pointer to a DWORD that specifies the type of buffer operation that the driver should perform. Set the value to an element of the BUFFER_COMMANDS enumeration.
  • nInBufferSize
    [in] Set to sizeof(DWORD).

  • lpOutBuffer
    [out] The value of this pointer depends on the buffer command specified in lpInBuffer as shown in the following table.

    lpInBuffer

    lpOutBuffer

    CS_ALLOCATE

    A pointer to a CS_STREAM_DESCRIPTOR structure that will be populated by the driver with the list of buffers it allocated.

    CS_ENQUEUE

    A pointer to the buffers that the client is sending to the driver.
    • CS_DEALLOCATE

    A pointer the buffers that the client is releasing.
  • lpBytesReturned
    Ignored.
  • lpOverlapped
    [in] Set to NULL.

Return Values

Returns TRUE if successful; otherwise, returns FALSE. If it returns TRUE, then the bUnitReady member of CDROM_TESTUNITREADY is also set to TRUE.

Remarks

To get extended error information, call GetLastError. GetLastError may return other standard error messages as appropriate.

Remarks

If the driver allocates the buffers, then the client calls IOCTL_CS_BUFFERS when the driver is in the paused state. If the client allocates the buffers, then the client allocates the buffers when the driver is in paused state and sends down the buffers to the driver by calling IOCTL_CS_BUFFERS.

Requirements

Header

csmedia.h

See Also

Reference

Camera Driver IOCTLs
DeviceIoControl