common.c

嵌入式操作系统wince5.0下的声卡驱动

//
// Copyright (c) Microsoft Corporation.  All rights reserved.
//
//
// Use of this source code is subject to the terms of the Microsoft end-user
// license agreement (EULA) under which you licensed this SOFTWARE PRODUCT.
// If you did not accept the terms of the EULA, you are not authorized to use
// this source code. For a copy of the EULA, please see the LICENSE.RTF on your
// install media.
//
// -----------------------------------------------------------------------------
//
//      THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
//      ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
//      THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
//      PARTICULAR PURPOSE.
//  
// -----------------------------------------------------------------------------
//
//  @doc    WDEV_EXT
//
//  @module common.c | Implements the WODM_XXX and WIDM_XXX messages that are 
//          passed to the wave audio driver via the <f WAV_IOControl> function.
//          This module contains code that is common or very similar between
//          input and output functions.
//
//  @xref   <t Wave Input Driver Messages> (WIDM_XXX) <nl>
//          <t Wave Output Driver Messages> (WODM_XXX)
//
// -----------------------------------------------------------------------------
#include <wavemdd.h>


// -----------------------------------------------------------------------------
//
//  @doc    WDEV_EXT
//
//  @msg    WIDM_ADDBUFFER |
//          The WIDM_ADDBUFFER requests a waveform input driver to 
//          add an empty input buffer to its input buffer queue.
//
//  @parm   UINT | uDeviceId |
//          Device identifier (0, 1, 2, and so on) for the target device.
//
//  @parm   UINT | uMsg |
//          WIDM_ADDBUFFER
//
//  @parm   DWORD | dwUser |
//          Device instance identifier.
//
//  @parm   DWORD | dwParam1 |
//          Pointer to a WAVEHDR structure identifying the buffer.
//
//  @parm   DWORD | dwParam2 |
//          Size of the WAVEHDR structure.
//
//  @rdesc  The driver should return MMSYSERR_NOERROR if the operation succeeds. 
//          Otherwise it should return one of the MMSYSERR or WAVERR error 
//          codes defined in mmsystem.h. See <f waveInAddBuffer> return values 
//          in the Win32 SDK.
//
//  @comm   The Wave API Manager (WAVEAPI.DLL) sends the WIDM_ADDBUFFER message
//          by calling the audio driver's (WAVEDEV.DLL) <f WAV_IOControl>() entry
//          point via DeviceIoControl().
//
//          If the WHDR_PREPARED flag is not set in the dwFlags member of the 
//          WAVEHDR structure, the driver should return WAVERR_UNPREPARED. If 
//          the flag is set, the driver should:<nl>
//          <tab>