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/ Windows 95 API Bible / Windows 95 API Bible 3 Disc Set.iso / Win32 API Bible Book 3 of 3 / CHAPTE15 / WAVINOUT.C < prev    next >
C/C++ Source or Header  |  1996-04-28  |  29KB  |  826 lines
  1.  
  2. #include <windows.h>
  3. #include <stdio.h>
  4. #include "WavInOut.h"
  5.  
  6. #if defined (WIN32)
  7.     #define IS_WIN32 TRUE
  8. #else
  9.     #define IS_WIN32 FALSE
  10. #endif
  11.  
  12. #define IS_NT      IS_WIN32 && (BOOL)(GetVersion() < 0x80000000)
  13. #define IS_WIN32S  IS_WIN32 && (BOOL)(!(IS_NT) && (LOBYTE(LOWORD(GetVersion()))<4))
  14. #define IS_WIN95   (BOOL)(!(IS_NT) && !(IS_WIN32S)) && IS_WIN32
  15.  
  16. HINSTANCE hInst;   // current instance
  17.  
  18. LPCTSTR lpszAppName = "MyApp";
  19. LPCTSTR lpszTitle   = "Wave In/Out"; 
  20.  
  21.  
  22. BOOL RegisterWin95( CONST WNDCLASS* lpwc );
  23.  
  24.  
  25. int APIENTRY WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance,
  26.                       LPTSTR lpCmdLine, int nCmdShow)
  27. {
  28.    MSG      msg;
  29.    HWND     hWnd; 
  30.    WNDCLASS wc;
  31.  
  32.    wc.style         = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
  33.    wc.lpfnWndProc   = (WNDPROC)WndProc;       
  34.    wc.cbClsExtra    = 0;                      
  35.    wc.cbWndExtra    = 0;                      
  36.    wc.hInstance     = hInstance;              
  37.    wc.hIcon         = LoadIcon (hInstance, lpszAppName); 
  38.    wc.hCursor       = LoadCursor(NULL, IDC_ARROW);
  39.    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
  40.    wc.lpszMenuName  = lpszAppName;              
  41.    wc.lpszClassName = lpszAppName;              
  42.  
  43.    if ( IS_WIN95 )
  44.    {
  45.       if ( !RegisterWin95( &wc ) )
  46.          return( FALSE );
  47.    }
  48.    else if ( !RegisterClass( &wc ) )
  49.       return( FALSE );
  50.  
  51.    hInst = hInstance; 
  52.  
  53.    hWnd = CreateWindow( lpszAppName, 
  54.                         lpszTitle,    
  55.                         WS_OVERLAPPEDWINDOW, 
  56.                         CW_USEDEFAULT, 0, 
  57.                         CW_USEDEFAULT, 0,  
  58.                         NULL,              
  59.                         NULL,              
  60.                         hInstance,         
  61.                         NULL               
  62.                       );
  63.  
  64.    if ( !hWnd ) 
  65.       return( FALSE );
  66.  
  67.    ShowWindow( hWnd, nCmdShow ); 
  68.    UpdateWindow( hWnd );         
  69.  
  70.    while( GetMessage( &msg, NULL, 0, 0) )   
  71.    {
  72.       TranslateMessage( &msg ); 
  73.       DispatchMessage( &msg );  
  74.    }
  75.  
  76.    return( msg.wParam ); 
  77. }
  78.  
  79.  
  80. BOOL RegisterWin95( CONST WNDCLASS* lpwc )
  81. {
  82.     WNDCLASSEX wcex;
  83.  
  84.    wcex.style         = lpwc->style;
  85.    wcex.lpfnWndProc   = lpwc->lpfnWndProc;
  86.    wcex.cbClsExtra    = lpwc->cbClsExtra;
  87.    wcex.cbWndExtra    = lpwc->cbWndExtra;
  88.    wcex.hInstance     = lpwc->hInstance;
  89.    wcex.hIcon         = lpwc->hIcon;
  90.    wcex.hCursor       = lpwc->hCursor;
  91.    wcex.hbrBackground = lpwc->hbrBackground;
  92.    wcex.lpszMenuName  = lpwc->lpszMenuName;
  93.    wcex.lpszClassName = lpwc->lpszClassName;
  94.  
  95.    // Added elements for Windows 95.
  96.    //...............................
  97.    wcex.cbSize = sizeof(WNDCLASSEX);
  98.    wcex.hIconSm = LoadImage(wcex.hInstance, lpwc->lpszClassName, 
  99.                             IMAGE_ICON, 16, 16,
  100.                             LR_DEFAULTCOLOR );
  101.             
  102.    return RegisterClassEx( &wcex );
  103. }
  104.  
  105.  
  106.  
  107. LRESULT CALLBACK About( HWND hDlg,           
  108.                         UINT message,        
  109.                         WPARAM wParam,       
  110.                         LPARAM lParam)
  111. {
  112.    switch (message) 
  113.    {
  114.        case WM_INITDIALOG: 
  115.                return (TRUE);
  116.  
  117.        case WM_COMMAND:                              
  118.                if (   LOWORD(wParam) == IDOK         
  119.                    || LOWORD(wParam) == IDCANCEL)    
  120.                {
  121.                        EndDialog(hDlg, TRUE);        
  122.                        return (TRUE);
  123.                }
  124.                break;
  125.    }
  126.  
  127.    return (FALSE); 
  128. }
  129.  
  130.  
  131. #define PLAYBACK_BUFFER_SIZE   327680L
  132. #define DATABLOCK_SIZE          32768L
  133. #define MAX_BUFFERS                 2  // double buffer
  134. #define MSG_LEN                   128
  135.  
  136. // global variables
  137. //.................
  138.  
  139. enum Status
  140. {
  141.   StatusOkay,
  142.   StatusError,
  143.   StatusDone,
  144. } eStatus;
  145.  
  146. char msg[MSG_LEN+1];
  147.  
  148. static HWAVEIN  hwi;
  149. static HWAVEOUT hwo;
  150. static WAVEHDR* wh[MAX_BUFFERS];
  151.  
  152. // temp buffer for this example
  153. //.............................
  154.  
  155. static VOID*    pPlaybackBuffer;  
  156. static DWORD    nPlaybackBufferPos = 0L;  // position in playback buffer  
  157. static DWORD    nPlaybackBufferLen = 0L;  // total data in playback buffer
  158.  
  159. BOOL TestOpenInputDevice();
  160. BOOL TestOpenOutputDevice();
  161.  
  162. VOID StartRecordTest  (HWND hWnd);
  163. VOID StopRecordTest   (HWND hWnd);
  164. VOID StartPlayBackTest(HWND hWnd);
  165. VOID StopPlayBackTest (HWND hWnd);
  166. VOID LoadDataBlock(WAVEHDR* lpwh);
  167.  
  168. VOID AllocBuffers();
  169. VOID CleanUpBuffers();
  170.  
  171. VOID CALLBACK waveInProc( HWAVEOUT hwo, UINT uMsg, DWORD dwInstance, DWORD dwParam1, DWORD dwParam2 );
  172.  
  173. /*****************************************************************************
  174. *  WndProc
  175. *
  176. *
  177. *
  178. ******************************************************************************/
  179.  
  180. #define USR_INBLOCK           (WM_USER+101)
  181. #define USR_OUTBLOCK          (WM_USER+102)
  182.  
  183. LRESULT CALLBACK WndProc( HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam )
  184. {
  185.    switch( uMsg )
  186.    {
  187.       case WM_COMMAND :
  188.               switch( LOWORD( wParam ) )
  189.               {
  190.                  case IDM_TEST :
  191.                         {
  192.                            int i;
  193.  
  194.                            for (i = 0; i < MAX_BUFFERS; i++)                                        
  195.                                wh[i] = NULL;
  196.  
  197.                            eStatus = StatusOkay;
  198.                            AllocBuffers();
  199.  
  200.                            if ( TestOpenInputDevice(hWnd) )
  201.                                StartRecordTest(hWnd);
  202.                            else
  203.                                CleanUpBuffers();
  204.                                                     
  205.                         }
  206.                         break;
  207.  
  208.                  case IDM_ABOUT :
  209.                         DialogBox( hInst, "AboutBox", hWnd, About );
  210.                         break;
  211.  
  212.                  case IDM_EXIT :
  213.                         DestroyWindow( hWnd );
  214.                         break;
  215.               }
  216.               break;
  217.  
  218.       case USR_INBLOCK :
  219.               {
  220.                  // received data buffer block with recorded data,
  221.                  // copy to playback buffer for use later
  222.                  //...............................................
  223.  
  224.                  MMRESULT  rc;
  225.                  MMTIME    mmtime;
  226.                  LPWAVEHDR lpwh = (LPWAVEHDR)lParam;
  227.  
  228.                  
  229.  
  230.                  if (eStatus == StatusOkay)
  231.                  {
  232.                      if (nPlaybackBufferPos + lpwh->dwBytesRecorded <= PLAYBACK_BUFFER_SIZE)
  233.                      {
  234.                          // copy data buffer block to playback buffer
  235.                          //..........................................
  236.  
  237.                          memcpy( ((char*)pPlaybackBuffer+nPlaybackBufferPos), lpwh->lpData, lpwh->dwBytesRecorded);
  238.                          nPlaybackBufferPos += lpwh->dwBytesRecorded;
  239.                          nPlaybackBufferLen += lpwh->dwBytesRecorded;
  240.  
  241.                          mmtime.wType = TIME_BYTES;
  242.                          waveInGetPosition(hwi, &mmtime, sizeof(MMTIME));
  243.                          wsprintf(msg, "%s - Recorded %ld bytes", lpszTitle, mmtime.u.cb);
  244.                          SetWindowText(hWnd, msg);
  245.                      
  246.                          // reuse data buffer block
  247.                          //........................ 
  248.  
  249.                          rc = waveInPrepareHeader(hwi, lpwh, sizeof(WAVEHDR));       
  250.                                                                      
  251.                          if (rc == MMSYSERR_NOERROR)                                  
  252.                              rc = waveInAddBuffer(hwi, lpwh, sizeof(WAVEHDR));       
  253.                                                                      
  254.                          if (rc != MMSYSERR_NOERROR)
  255.                          {                                                            
  256.                              waveInGetErrorText(rc, msg, MSG_LEN),                        
  257.                              MessageBox(hWnd, msg, NULL, MB_OK);
  258.                              eStatus = StatusError;    // signal to shut down the process
  259.                          }
  260.                      }
  261.                      else
  262.                      {
  263.                         eStatus = StatusDone;
  264.                         StopRecordTest(hWnd);
  265.                      }
  266.                  }
  267.                  
  268.                  break;
  269.               }
  270.  
  271.  
  272.       case MM_WOM_DONE :
  273.               {
  274.                  PostMessage(hWnd, USR_OUTBLOCK, 0, lParam);
  275.   
  276.                  break;
  277.               }
  278.  
  279.       case USR_OUTBLOCK :
  280.               {
  281.                  // received data buffer block that has
  282.                  // completed playback, reload and requeue
  283.                  //.......................................
  284.  
  285.                  MMRESULT  rc;
  286.                  MMTIME    mmtime;
  287.                  LPWAVEHDR lpwh = (LPWAVEHDR)lParam;
  288.  
  289.                  mmtime.wType = TIME_BYTES;
  290.                  waveOutGetPosition(hwi, &mmtime, sizeof(MMTIME));
  291.                  wsprintf(msg, "%s - Played %ld bytes", lpszTitle, mmtime.u.cb);
  292.                  SetWindowText(hWnd, msg);
  293.  
  294.                  if (eStatus == StatusOkay)
  295.                  {
  296.                      LoadDataBlock(lpwh);   // changes eStatus to StatusDone when 
  297.                                             // playback buffer is exhausted
  298.  
  299.                      if (eStatus == StatusOkay)
  300.                      {
  301.                          rc = waveOutPrepareHeader(hwo, lpwh, sizeof(WAVEHDR));       
  302.                                                                     
  303.                           // write buffers to the queue                            
  304.                                                                     
  305.                           if (rc == MMSYSERR_NOERROR)                                  
  306.                               rc = waveOutWrite(hwo, lpwh, sizeof(WAVEHDR));       
  307.                                                                     
  308.                           if (rc != MMSYSERR_NOERROR)                                  
  309.                           {
  310.                               waveOutGetErrorText(rc, msg, MSG_LEN),                        
  311.                               MessageBox(hWnd, msg, NULL, MB_OK);
  312.                              StopPlayBackTest(hWnd);  // free allocated memory
  313.                              eStatus = StatusError;
  314.                           }
  315.                      }
  316.                  }
  317.                  else
  318.                  {
  319.                      // check if all of the buffers have come back yet
  320.                      //...............................................
  321.  
  322.                      int i;
  323.  
  324.                      for (i = 0; i < MAX_BUFFERS; i++)
  325.                      {
  326.                         if (wh[i]->dwFlags & WHDR_INQUEUE)
  327.                             return(0L);  // not done yet, wait
  328.                      }
  329.  
  330.                      StopPlayBackTest(hWnd);
  331.                  }
  332.                  break;
  333.               }
  334.         
  335.       case WM_DESTROY :
  336.               PostQuitMessage(0);
  337.               break;
  338.  
  339.       default :
  340.             return( DefWindowProc( hWnd, uMsg, wParam, lParam ) );
  341.    }
  342.  
  343.    return( 0L );               
  344. }
  345.  
  346. /*****************************************************************************
  347. *  waveInProc
  348. *
  349. *
  350. *
  351. ******************************************************************************/
  352.  
  353. VOID CALLBACK waveInProc( HWAVEIN hwi, UINT uMsg, DWORD dwInstance, DWORD dwParam1, DWORD dwParam2 )
  354. {
  355.    switch (uMsg)
  356.    {
  357.       case WIM_OPEN :
  358.       case WIM_CLOSE: 
  359.               break;  // don't care
  360.  
  361.       case WIM_DATA :
  362.               {
  363.                  // post message to process this input block received
  364.                  // NOTE: callback cannot call other waveform functions
  365.                  //....................................................
  366.                  
  367.                  PostMessage((HWND)dwInstance, USR_INBLOCK, 0, dwParam1);
  368.   
  369.                  break;
  370.               }
  371.    }
  372. }
  373.  
  374. /*****************************************************************************
  375. *  TestOpenInputDevice
  376. *
  377. *
  378. *
  379. ******************************************************************************/
  380.  
  381. BOOL TestOpenInputDevice(HWND hWnd)
  382. {
  383.    WAVEINCAPS   wic;                                               
  384.     WAVEFORMATEX wfx;
  385.     UINT         nDevId;
  386.     MMRESULT     rc;                                                
  387.     UINT         nMaxDevices = waveInGetNumDevs();                  
  388.     
  389.     hwi = NULL;
  390.     nPlaybackBufferPos = 0L;  // position in playback buffer
  391.    nPlaybackBufferLen = 0L;  // total data in playback buffer
  392.    eStatus = StatusOkay;     // reset status                                            
  393.                                                                     
  394.     for (nDevId = 0; nDevId < nMaxDevices; nDevId++)                         
  395.     {                                                               
  396.        rc = waveInGetDevCaps(nDevId, &wic, sizeof(wic));               
  397.        if (rc == MMSYSERR_NOERROR)                                  
  398.        {
  399.           // attempt 44.1 kHz stereo if device is capable
  400.  
  401.           if (wic.dwFormats & WAVE_FORMAT_4S16)
  402.           {
  403.               wfx.nChannels      = 2;      // stereo
  404.               wfx.nSamplesPerSec = 44100;  // 44.1 kHz (44.1 * 1000)
  405.           }
  406.           else
  407.           {   
  408.               wfx.nChannels      = wic.wChannels;  // use DevCaps # channels
  409.               wfx.nSamplesPerSec = 22050;  // 22.05 kHz (22.05 * 1000)
  410.           }
  411.  
  412.            wfx.wFormatTag      = WAVE_FORMAT_PCM;                          
  413.             wfx.wBitsPerSample  = 8;                                        
  414.            wfx.nBlockAlign     = wfx.nChannels * wfx.wBitsPerSample / 8;   
  415.            wfx.nAvgBytesPerSec = wfx.nSamplesPerSec * wfx.nBlockAlign;     
  416.            wfx.cbSize          = 0;
  417.            
  418.           // open waveform input device
  419.           //...........................
  420.  
  421.            rc = waveInOpen(&hwi, nDevId, &wfx, (DWORD)(VOID*)waveInProc, (DWORD)hWnd,                   
  422.                            CALLBACK_FUNCTION);                                          
  423.            
  424.            if (rc == MMSYSERR_NOERROR)                              
  425.                break;                                               
  426.            else                                                     
  427.            {                                                        
  428.                waveInGetErrorText(rc, msg, MSG_LEN),                    
  429.                MessageBox(hWnd, msg, NULL, MB_OK);
  430.                return(FALSE);
  431.            }                                                        
  432.        }                                                            
  433.     }                                                               
  434.     
  435.    // device not found, error condition
  436.    //..................................
  437.  
  438.     if (hwi == NULL)
  439.     {
  440.        eStatus = StatusError;
  441.         return(FALSE);
  442.    }
  443.  
  444.  
  445.    return(TRUE);
  446. }
  447.  
  448. /*****************************************************************************
  449. *  StartRecordTest
  450. *
  451. *
  452. *
  453. ******************************************************************************/
  454.  
  455. VOID StartRecordTest(HWND hWnd)
  456. {
  457.     MMRESULT rc;
  458.    int      i;
  459.    MMTIME   mmtime;
  460.  
  461.     // prepare buffer blocks and add to input queue
  462.     //.............................................
  463.  
  464.     for (i = 0; i < MAX_BUFFERS; i++)                                        
  465.     {                                                               
  466.        rc = waveInPrepareHeader(hwi, wh[i], sizeof(WAVEHDR));
  467.                                                                     
  468.        // add buffers to the input queue                            
  469.                                                                     
  470.        if (rc == MMSYSERR_NOERROR)
  471.            rc = waveInAddBuffer(hwi, wh[i], sizeof(WAVEHDR));
  472.                                                                     
  473.        if (rc != MMSYSERR_NOERROR)                                  
  474.        {                                                            
  475.            waveInGetErrorText(rc, msg, MSG_LEN),                        
  476.            MessageBox(hWnd, msg, NULL, MB_OK);
  477.           StopRecordTest(hWnd);  // free allocated memory
  478.            return;                                              
  479.        }                                                            
  480.     }                                                               
  481.                                                                     
  482.     // start recording                                              
  483.     //................                                              
  484.                                                                     
  485.     rc = waveInStart(hwi);
  486.     
  487.     // test waveInGetPosition() function
  488.  
  489.    mmtime.wType = TIME_SAMPLES;
  490.  
  491.    rc = waveInGetPosition(hwi, &mmtime, sizeof(MMTIME));
  492.  
  493.    if (rc != MMSYSERR_NOERROR)                                  
  494.     {                                                            
  495.         waveInGetErrorText(rc, msg, MSG_LEN),                        
  496.         MessageBox(hWnd, msg, NULL, MB_OK);
  497.     }                                          
  498. }
  499.  
  500. /*****************************************************************************
  501. *  StopRecordTest
  502. *
  503. *
  504. *
  505. ******************************************************************************/
  506.  
  507. VOID StopRecordTest(HWND hWnd)
  508. {
  509.    int i;
  510.    int nReply;
  511.  
  512.    // stop recording                                               
  513.     //...............                                               
  514.                                                                     
  515.     waveInStop(hwi);
  516.    waveInReset(hwi);
  517.  
  518.     // Unprepare headers                                                      
  519.     //..................
  520.                                                                     
  521.     for (i = 0; i < MAX_BUFFERS; i++)
  522.       waveInUnprepareHeader(hwi, wh[i], sizeof(WAVEHDR));
  523.                                                                     
  524.     waveInClose(hwi);
  525.  
  526.    // check if user wants to hear what was recorded
  527.    //..............................................
  528.  
  529.    nReply = MessageBox(hWnd, "Do you want to playback what has been recorded?",
  530.                        "Test", MB_ICONQUESTION|MB_YESNO);
  531.  
  532.    if (nReply == IDYES && TestOpenOutputDevice(hWnd) )
  533.        StartPlayBackTest(hWnd);
  534.    else
  535.    {
  536.        CleanUpBuffers();
  537.        SetWindowText(hWnd, lpszTitle);
  538.    }
  539. }
  540.  
  541. //@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
  542. //@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
  543. //@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
  544.  
  545. /*****************************************************************************
  546. *  TestOpenOutputDevice
  547. *
  548. *
  549. *
  550. ******************************************************************************/
  551.  
  552. BOOL TestOpenOutputDevice(HWND hWnd)
  553. {
  554.    WAVEOUTCAPS  woc;                                               
  555.     WAVEFORMATEX wfx;
  556.     UINT         nDevId;
  557.     MMRESULT     rc;                                                
  558.     UINT         nMaxDevices = waveOutGetNumDevs();                  
  559.     
  560.     hwo = NULL;
  561.     nPlaybackBufferPos = 0L;  // position in playback buffer
  562.    eStatus = StatusOkay;     // reset status                                                 
  563.                                                                         
  564.     for (nDevId = 0; nDevId < nMaxDevices; nDevId++)                         
  565.     {                                                               
  566.        rc = waveOutGetDevCaps(nDevId, &woc, sizeof(woc));
  567.        if (rc == MMSYSERR_NOERROR)                                  
  568.        {
  569.           // attempt 44.1 kHz stereo if device is capable
  570.  
  571.           if (woc.dwFormats & WAVE_FORMAT_4S16)
  572.           {
  573.               wfx.nChannels      = 2;      // stereo
  574.               wfx.nSamplesPerSec = 44100;  // 44.1 kHz (44.1 * 1000)
  575.           }
  576.           else
  577.           {   
  578.               wfx.nChannels      = woc.wChannels;  // use DevCaps # channels
  579.               wfx.nSamplesPerSec = 22050;  // 22.05 kHz (22.05 * 1000)
  580.           }
  581.  
  582.           wfx.wFormatTag      = WAVE_FORMAT_PCM;                          
  583.            wfx.wBitsPerSample  = 8;                                        
  584.            wfx.nBlockAlign     = wfx.nChannels * wfx.wBitsPerSample / 8;   
  585.            wfx.nAvgBytesPerSec = wfx.nSamplesPerSec * wfx.nBlockAlign;     
  586.            wfx.cbSize          = 0;                                        
  587.  
  588.            rc = waveOutOpen(&hwo, nDevId, &wfx, (DWORD)hWnd, 0,                   
  589.                             CALLBACK_WINDOW);
  590.                                                       
  591.            if (rc == MMSYSERR_NOERROR)
  592.           {
  593.               DWORD dwVol;
  594.  
  595.               // set volume level to at least 80%
  596.  
  597.               rc = waveOutGetVolume( hwo, &dwVol );
  598.  
  599.               if (rc == MMSYSERR_NOERROR)
  600.                   if ( LOWORD(dwVol) < 0xCCCC ||
  601.                      ( wfx.nChannels == 2 && HIWORD(dwVol) < 0xCCCC )  )
  602.                       rc = waveOutSetVolume( hwo, (DWORD)MAKELONG( 0xCCCC, 0xCCCC ) );
  603.           }
  604.            
  605.           if (rc != MMSYSERR_NOERROR)
  606.            {                                                        
  607.                waveOutGetErrorText(rc, msg, MSG_LEN),                    
  608.                MessageBox(hWnd, msg, NULL, MB_OK);
  609.                return(FALSE);
  610.            }
  611.            
  612.            break;                                                        
  613.        }                                                            
  614.     }                                                               
  615.     
  616.    // device not found, error condition
  617.    //..................................
  618.  
  619.     if (hwo == NULL)
  620.         return(FALSE);
  621.  
  622.    return(TRUE);
  623. }
  624.  
  625. /*****************************************************************************
  626. *  StartPlayBackTest
  627. *
  628. *
  629. *
  630. ******************************************************************************/
  631.  
  632. VOID StartPlayBackTest(HWND hWnd)
  633. {
  634.     MMRESULT    rc;
  635.     int         i;
  636.    WAVEOUTCAPS woc;                                               
  637.    UINT        nDevId;
  638.    DWORD       dwPitch;
  639.    DWORD       dwRate;
  640.  
  641.    eStatus = StatusOkay;
  642.                                                                     
  643.    rc = waveOutGetID(hwo, &nDevId);
  644.    rc = waveOutGetDevCaps(nDevId, &woc, sizeof(woc));
  645.  
  646.  
  647.    // increase pitch and playback rate by a multiplier of two
  648.    // if device supports this function
  649.    //........................................................
  650.  
  651.    if (woc.dwSupport & WAVECAPS_PLAYBACKRATE)
  652.    {
  653.        rc = waveOutGetPlaybackRate(hwo, &dwRate);
  654.        rc = waveOutSetPlaybackRate(hwo, MAKELONG(HIWORD(dwRate)*2, LOWORD(dwRate)) );
  655.    }
  656.  
  657.    if (woc.dwSupport & WAVECAPS_PITCH)
  658.    {
  659.        rc = waveOutGetPitch(hwo, &dwPitch);
  660.        rc = waveOutSetPitch(hwo, MAKELONG( HIWORD(dwPitch)*2, LOWORD(dwPitch)) );
  661.    }
  662.  
  663.    // pause the device until the first buffers have been
  664.    // written to the device's queue
  665.    //...................................................
  666.  
  667.    waveOutPause(hwo);
  668.                                                                     
  669.     // prepare output buffer blocks
  670.     //.............................
  671.                                                                     
  672.     for (i = 0; i < MAX_BUFFERS; i++)                                        
  673.     {                                                               
  674.        // load data into data buffer block.
  675.       // the remaining data will be loaded later
  676.       // by the callback.
  677.       //........................................
  678.  
  679.        LoadDataBlock(wh[i]);
  680.        
  681.        // prepare the buffers
  682.                                                                     
  683.        rc = waveOutPrepareHeader(hwo, wh[i], sizeof(WAVEHDR));       
  684.                                                                     
  685.        // write buffers to the queue                            
  686.                                                                     
  687.        if (rc == MMSYSERR_NOERROR)                                  
  688.            rc = waveOutWrite(hwo, wh[i], sizeof(WAVEHDR));       
  689.                                                                     
  690.        if (rc != MMSYSERR_NOERROR)                                  
  691.        {                                                            
  692.            waveOutGetErrorText(rc, msg, MSG_LEN),                        
  693.            MessageBox(hWnd, msg, NULL, MB_OK);
  694.           StopPlayBackTest(hWnd);  // free allocated memory
  695.           eStatus = StatusError;
  696.            return;                                              
  697.        }                                                            
  698.     }
  699.     
  700.     // start playback (device currently paused)                                                               
  701.    //.........................................
  702.  
  703.    waveOutRestart(hwo);
  704. }
  705.  
  706. /*****************************************************************************
  707. *  LoadDataBlock
  708. *
  709. *
  710. *
  711. ******************************************************************************/
  712.  
  713. VOID LoadDataBlock(WAVEHDR* lpwh)
  714. {
  715.    DWORD nLen;
  716.  
  717.    if (nPlaybackBufferPos < nPlaybackBufferLen)
  718.    {
  719.        nLen = nPlaybackBufferLen - nPlaybackBufferPos;
  720.  
  721.        if (nLen > DATABLOCK_SIZE)
  722.            nLen = DATABLOCK_SIZE;
  723.    
  724.        memcpy(lpwh->lpData, ((char*)pPlaybackBuffer+nPlaybackBufferPos), nLen);
  725.        lpwh->dwBufferLength = nLen;
  726.        nPlaybackBufferPos  += nLen;
  727.    }
  728.    else
  729.        eStatus = StatusDone;
  730. }
  731.  
  732. /*****************************************************************************
  733. *  StopPlayBackTest
  734. *
  735. *
  736. *
  737. ******************************************************************************/
  738.  
  739. VOID StopPlayBackTest(HWND hWnd)
  740. {
  741.    MMRESULT rc;
  742.    int      i;
  743.  
  744.     // cleanup                                                      
  745.     //........                                                      
  746.                                                                     
  747.     for (i = 0; i < MAX_BUFFERS; i++)                                        
  748.       waveOutUnprepareHeader(hwo, wh[i], sizeof(WAVEHDR));           
  749.                                                                     
  750.     rc = waveOutClose(hwo);
  751.  
  752.    CleanUpBuffers();
  753.    SetWindowText(hWnd, lpszTitle);
  754. }
  755.  
  756. //@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
  757. //@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
  758. //@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
  759.  
  760. /*****************************************************************************
  761. *  AllocBuffers
  762. *
  763. *
  764. *
  765. ******************************************************************************/
  766.  
  767. VOID AllocBuffers()
  768. {
  769.    int i;
  770.  
  771.    // allocate two WAVEHDR buffer blocks
  772.     //...................................
  773.  
  774.     for (i = 0; i < MAX_BUFFERS; i++)                                        
  775.     {                                                               
  776.        wh[i] = HeapAlloc( GetProcessHeap(),                         
  777.                           HEAP_ZERO_MEMORY,                         
  778.                           sizeof(WAVEHDR) );                        
  779.        if (wh[i])                                                  
  780.        {                                                            
  781.            wh[i]->lpData = HeapAlloc( GetProcessHeap(),             
  782.                                       HEAP_ZERO_MEMORY,             
  783.                                       DATABLOCK_SIZE);                       
  784.            wh[i]->dwBufferLength = DATABLOCK_SIZE;
  785.        }
  786.     }
  787.  
  788.    // allocate playback buffer - enough space to hold
  789.    // ten data buffer blocks of waveform sound data
  790.    //................................................
  791.  
  792.    pPlaybackBuffer = HeapAlloc( GetProcessHeap(),
  793.                                 HEAP_ZERO_MEMORY,
  794.                                 PLAYBACK_BUFFER_SIZE);
  795. } 
  796.  
  797. /*****************************************************************************
  798. *  CleanUpBuffers
  799. *
  800. *
  801. *
  802. ******************************************************************************/
  803.  
  804. VOID CleanUpBuffers()
  805. {
  806.    int i;
  807.  
  808.    // free the WAVEHDR buffer blocks
  809.     //...............................
  810.  
  811.      for (i = 0; i < MAX_BUFFERS; i++)                                        
  812.     {
  813.      if (wh[i] != NULL)
  814.      {
  815.           HeapFree(GetProcessHeap(), 0, wh[i]->lpData);                 
  816.           HeapFree(GetProcessHeap(), 0, wh[i]);
  817.          wh[i] = NULL;
  818.      }
  819.     }
  820.     
  821.     // free playback buffer
  822.     //.....................
  823.     
  824.     HeapFree(GetProcessHeap(), 0, pPlaybackBuffer);
  825. }
  826.