Maximum CD 2004 September/maximum-cd-2004-09.iso/Software/Extras/nbeep03.exe/Source/audio.cpp

C/C++ Source or Header | 2002-03-02 | 4.6 KB | 201 lines

#include <windows.h>
#include <dsound.h>

#define BUFFER_SIZE 16384

static IDirectSound *g_ds;
static IDirectSoundBuffer *primary, *second;
static HANDLE g_wave_thread;
static volatile int g_wave_quit;
static int needstart=0,write_pos=0;

static DWORD WINAPI _threadproc(LPVOID p);

extern void generate_samples(short *buf, int samplelength);

char *audioOpen(HWND hwnd)
{
  unsigned long len1,len2;
  void *pt1,*pt2;
  DSBUFFERDESC pd={sizeof(pd),};
  WAVEFORMATEX wfx;
  LPGUID lpguid=NULL;
  DWORD id;

  if (DirectSoundCreate(lpguid, &g_ds, NULL) != DS_OK)
  {
    return "Could not create DirectSound object";
  }

  if (g_ds->SetCooperativeLevel(hwnd, DSSCL_PRIORITY) != DS_OK)
  {
    g_ds->Release();
    return "Could not set cooperative level";
  }

  if (1) // create primary buffer
  {
    pd.dwFlags = DSBCAPS_PRIMARYBUFFER;
    if (g_ds->CreateSoundBuffer(&pd, &primary, NULL) != DS_OK)
    {
      g_ds->Release();
      primary = second = (LPDIRECTSOUNDBUFFER)NULL;
      return "Could not create primary buffer";
    }

    wfx.wFormatTag = WAVE_FORMAT_PCM;
    wfx.cbSize = 0;
    wfx.nChannels = 2;
    wfx.nSamplesPerSec = 44100;
    wfx.wBitsPerSample = 16;
    wfx.nBlockAlign = (wfx.wBitsPerSample/8)*2;
    wfx.nAvgBytesPerSec = wfx.nSamplesPerSec * wfx.nBlockAlign;


    if (primary->SetFormat(&wfx) != DS_OK)
    {
      primary->Release();
      g_ds->Release();
      primary = second = (LPDIRECTSOUNDBUFFER)NULL;
      return "Could not set output format";
    }
  }
  else primary=NULL;

  wfx.wFormatTag = WAVE_FORMAT_PCM;
  wfx.cbSize = 0;

  wfx.nChannels = 1;
  wfx.nSamplesPerSec = 44100;
  wfx.nAvgBytesPerSec = 2 * 44100 * 1;
  wfx.wBitsPerSample = 16;
  wfx.nBlockAlign = 2;

  pd.dwFlags = DSBCAPS_GLOBALFOCUS |
               DSBCAPS_GETCURRENTPOSITION2 | DSBCAPS_STICKYFOCUS;
  pd.dwBufferBytes = BUFFER_SIZE;
  pd.lpwfxFormat = &wfx;

  if (g_ds->CreateSoundBuffer(&pd, &second, NULL) != DS_OK)
  {
    if (primary) primary->Release();
    g_ds->Release();
    primary = second = (LPDIRECTSOUNDBUFFER)NULL;
    return "Could not create secondary buffer";
  }

  if (second->Lock(0,BUFFER_SIZE, &pt1, &len1, &pt2, &len2, 0) == DS_OK)
    {
      int wrote1=0,wrote2=0;
        wrote1=len1;
    memset(pt1,0,wrote1);
        if (pt2)
        {
            wrote2=len2;
            memset(pt2,0,wrote2);
        }
        second->Unlock(pt1, wrote1, pt2, wrote2);
    }

  if (primary && 1) // start primary
  {
    int n=10;
    HRESULT res=0;
    while (n--)
    {
      res=primary->Play(0, 0, DSBPLAY_LOOPING);
      if (res == DS_OK) break;
      if (res == DSERR_BUFFERLOST)
      {
        primary->Restore();
        Sleep(50);
      }
    }
    if (res != DS_OK)
    {
      second->Release();
      primary->Release();
      g_ds->Release();
      primary = second = (LPDIRECTSOUNDBUFFER)NULL;
      return "Could not start primary buffer";
    }
  }

  needstart=0;
  g_wave_quit=0;
    g_wave_thread=CreateThread(NULL,0,_threadproc,NULL,0,&id);
  if (!g_wave_thread)
  {
    g_ds->Release();
  }
  SetThreadPriority(g_wave_thread,THREAD_PRIORITY_HIGHEST);
  return 0;
}

void audioClose()
{
  if (!g_wave_thread) return;
  g_wave_quit=1;

  WaitForSingleObject(g_wave_thread,INFINITE);
  CloseHandle(g_wave_thread);
  g_wave_thread=0;
  if (primary) primary->Release();
  if (second) second->Release();
  g_ds->Release();
  g_ds=0;
}

static DWORD WINAPI _threadproc(LPVOID p)
{
  while (!g_wave_quit)
  {
    int wrote_bytes=0;
        void *pt1, *pt2;
        int len;
    unsigned long len2, len1;
    DWORD pp=0;
    if (needstart == -1) IDirectSoundBuffer_GetCurrentPosition(second,&pp,NULL);
    else pp=BUFFER_SIZE;

    len = pp-write_pos;
    if (len < 0) len += BUFFER_SIZE;

    if (len > 2)
    {
      HRESULT res;
      len&=~1;
      res=second->Lock(write_pos,len, &pt1, &len1, &pt2, &len2, 0);
      if (res == DS_OK)
            {
        len1 &= ~1;
        len2 &= ~1;

        generate_samples((short*)pt1,len1/2);
        write_pos+=len1;
                if (pt2)
                {
          generate_samples((short*)pt2,len2/2);
          write_pos+=len2;
                }
                second->Unlock(pt1, len1, pt2, len2);
            }
      else if (res == DSERR_BUFFERLOST)
      {
        second->Restore();
      }
      if (write_pos >= BUFFER_SIZE) write_pos-=BUFFER_SIZE;
    }

    if (needstart > -1)
    {
      switch (second->Play(0, 0, DSBPLAY_LOOPING))
      {
        case DS_OK: needstart=-1; break;
        case DSERR_BUFFERLOST: second->Restore(); break;
      }
    }
    Sleep(20);
  }
  return 0;
}