symbian-qemu-0.9.1-12/libsdl-trunk/src/audio/windx5/SDL_dx5audio.c
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0:ffa851df0825 1:2fb8b9db1c86
       
     1 /*
       
     2     SDL - Simple DirectMedia Layer
       
     3     Copyright (C) 1997-2006 Sam Lantinga
       
     4 
       
     5     This library is free software; you can redistribute it and/or
       
     6     modify it under the terms of the GNU Lesser General Public
       
     7     License as published by the Free Software Foundation; either
       
     8     version 2.1 of the License, or (at your option) any later version.
       
     9 
       
    10     This library is distributed in the hope that it will be useful,
       
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
       
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
       
    13     Lesser General Public License for more details.
       
    14 
       
    15     You should have received a copy of the GNU Lesser General Public
       
    16     License along with this library; if not, write to the Free Software
       
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
       
    18 
       
    19     Sam Lantinga
       
    20     slouken@libsdl.org
       
    21 */
       
    22 #include "SDL_config.h"
       
    23 
       
    24 /* Allow access to a raw mixing buffer */
       
    25 
       
    26 #include "SDL_timer.h"
       
    27 #include "SDL_audio.h"
       
    28 #include "../SDL_audio_c.h"
       
    29 #include "SDL_dx5audio.h"
       
    30 
       
    31 /* Define this if you want to use DirectX 6 DirectSoundNotify interface */
       
    32 //#define USE_POSITION_NOTIFY
       
    33 
       
    34 /* DirectX function pointers for audio */
       
    35 HRESULT (WINAPI *DSoundCreate)(LPGUID, LPDIRECTSOUND *, LPUNKNOWN);
       
    36 
       
    37 /* Audio driver functions */
       
    38 static int DX5_OpenAudio(_THIS, SDL_AudioSpec *spec);
       
    39 static void DX5_ThreadInit(_THIS);
       
    40 static void DX5_WaitAudio_BusyWait(_THIS);
       
    41 #ifdef USE_POSITION_NOTIFY
       
    42 static void DX6_WaitAudio_EventWait(_THIS);
       
    43 #endif
       
    44 static void DX5_PlayAudio(_THIS);
       
    45 static Uint8 *DX5_GetAudioBuf(_THIS);
       
    46 static void DX5_WaitDone(_THIS);
       
    47 static void DX5_CloseAudio(_THIS);
       
    48 
       
    49 /* Audio driver bootstrap functions */
       
    50 
       
    51 static int Audio_Available(void)
       
    52 {
       
    53 	HINSTANCE DSoundDLL;
       
    54 	int dsound_ok;
       
    55 
       
    56 	/* Version check DSOUND.DLL (Is DirectX okay?) */
       
    57 	dsound_ok = 0;
       
    58 	DSoundDLL = LoadLibrary(TEXT("DSOUND.DLL"));
       
    59 	if ( DSoundDLL != NULL ) {
       
    60 		/* We just use basic DirectSound, we're okay */
       
    61 		/* Yay! */
       
    62 		/* Unfortunately, the sound drivers on NT have
       
    63 		   higher latencies than the audio buffers used
       
    64 		   by many SDL applications, so there are gaps
       
    65 		   in the audio - it sounds terrible.  Punt for now.
       
    66 		 */
       
    67 		OSVERSIONINFO ver;
       
    68 		ver.dwOSVersionInfoSize = sizeof (OSVERSIONINFO);
       
    69 		GetVersionEx(&ver);
       
    70 		switch (ver.dwPlatformId) {
       
    71 			case VER_PLATFORM_WIN32_NT:
       
    72 				if ( ver.dwMajorVersion > 4 ) {
       
    73 					/* Win2K */
       
    74 					dsound_ok = 1;
       
    75 				} else {
       
    76 					/* WinNT */
       
    77 					dsound_ok = 0;
       
    78 				}
       
    79 				break;
       
    80 			default:
       
    81 				/* Win95 or Win98 */
       
    82 				dsound_ok = 1;
       
    83 				break;
       
    84 		}
       
    85 		/* Now check for DirectX 5 or better - otherwise
       
    86 		 * we will fail later in DX5_OpenAudio without a chance
       
    87 		 * to fall back to the DIB driver. */
       
    88 		if (dsound_ok) {
       
    89 			/* DirectSoundCaptureCreate was added in DX5 */
       
    90 			if (!GetProcAddress(DSoundDLL, TEXT("DirectSoundCaptureCreate")))
       
    91 				dsound_ok = 0;
       
    92 
       
    93 		}
       
    94 		/* Clean up.. */
       
    95 		FreeLibrary(DSoundDLL);
       
    96 	}
       
    97 	return(dsound_ok);
       
    98 }
       
    99 
       
   100 /* Functions for loading the DirectX functions dynamically */
       
   101 static HINSTANCE DSoundDLL = NULL;
       
   102 
       
   103 static void DX5_Unload(void)
       
   104 {
       
   105 	if ( DSoundDLL != NULL ) {
       
   106 		FreeLibrary(DSoundDLL);
       
   107 		DSoundCreate = NULL;
       
   108 		DSoundDLL = NULL;
       
   109 	}
       
   110 }
       
   111 static int DX5_Load(void)
       
   112 {
       
   113 	int status;
       
   114 
       
   115 	DX5_Unload();
       
   116 	DSoundDLL = LoadLibrary(TEXT("DSOUND.DLL"));
       
   117 	if ( DSoundDLL != NULL ) {
       
   118 		DSoundCreate = (void *)GetProcAddress(DSoundDLL,
       
   119 					TEXT("DirectSoundCreate"));
       
   120 	}
       
   121 	if ( DSoundDLL && DSoundCreate ) {
       
   122 		status = 0;
       
   123 	} else {
       
   124 		DX5_Unload();
       
   125 		status = -1;
       
   126 	}
       
   127 	return status;
       
   128 }
       
   129 
       
   130 static void Audio_DeleteDevice(SDL_AudioDevice *device)
       
   131 {
       
   132 	DX5_Unload();
       
   133 	SDL_free(device->hidden);
       
   134 	SDL_free(device);
       
   135 }
       
   136 
       
   137 static SDL_AudioDevice *Audio_CreateDevice(int devindex)
       
   138 {
       
   139 	SDL_AudioDevice *this;
       
   140 
       
   141 	/* Load DirectX */
       
   142 	if ( DX5_Load() < 0 ) {
       
   143 		return(NULL);
       
   144 	}
       
   145 
       
   146 	/* Initialize all variables that we clean on shutdown */
       
   147 	this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));
       
   148 	if ( this ) {
       
   149 		SDL_memset(this, 0, (sizeof *this));
       
   150 		this->hidden = (struct SDL_PrivateAudioData *)
       
   151 				SDL_malloc((sizeof *this->hidden));
       
   152 	}
       
   153 	if ( (this == NULL) || (this->hidden == NULL) ) {
       
   154 		SDL_OutOfMemory();
       
   155 		if ( this ) {
       
   156 			SDL_free(this);
       
   157 		}
       
   158 		return(0);
       
   159 	}
       
   160 	SDL_memset(this->hidden, 0, (sizeof *this->hidden));
       
   161 
       
   162 	/* Set the function pointers */
       
   163 	this->OpenAudio = DX5_OpenAudio;
       
   164 	this->ThreadInit = DX5_ThreadInit;
       
   165 	this->WaitAudio = DX5_WaitAudio_BusyWait;
       
   166 	this->PlayAudio = DX5_PlayAudio;
       
   167 	this->GetAudioBuf = DX5_GetAudioBuf;
       
   168 	this->WaitDone = DX5_WaitDone;
       
   169 	this->CloseAudio = DX5_CloseAudio;
       
   170 
       
   171 	this->free = Audio_DeleteDevice;
       
   172 
       
   173 	return this;
       
   174 }
       
   175 
       
   176 AudioBootStrap DSOUND_bootstrap = {
       
   177 	"dsound", "Win95/98/2000 DirectSound",
       
   178 	Audio_Available, Audio_CreateDevice
       
   179 };
       
   180 
       
   181 static void SetDSerror(const char *function, int code)
       
   182 {
       
   183 	static const char *error;
       
   184 	static char  errbuf[1024];
       
   185 
       
   186 	errbuf[0] = 0;
       
   187 	switch (code) {
       
   188 		case E_NOINTERFACE:
       
   189 			error = 
       
   190 		"Unsupported interface\n-- Is DirectX 5.0 or later installed?";
       
   191 			break;
       
   192 		case DSERR_ALLOCATED:
       
   193 			error = "Audio device in use";
       
   194 			break;
       
   195 		case DSERR_BADFORMAT:
       
   196 			error = "Unsupported audio format";
       
   197 			break;
       
   198 		case DSERR_BUFFERLOST:
       
   199 			error = "Mixing buffer was lost";
       
   200 			break;
       
   201 		case DSERR_CONTROLUNAVAIL:
       
   202 			error = "Control requested is not available";
       
   203 			break;
       
   204 		case DSERR_INVALIDCALL:
       
   205 			error = "Invalid call for the current state";
       
   206 			break;
       
   207 		case DSERR_INVALIDPARAM:
       
   208 			error = "Invalid parameter";
       
   209 			break;
       
   210 		case DSERR_NODRIVER:
       
   211 			error = "No audio device found";
       
   212 			break;
       
   213 		case DSERR_OUTOFMEMORY:
       
   214 			error = "Out of memory";
       
   215 			break;
       
   216 		case DSERR_PRIOLEVELNEEDED:
       
   217 			error = "Caller doesn't have priority";
       
   218 			break;
       
   219 		case DSERR_UNSUPPORTED:
       
   220 			error = "Function not supported";
       
   221 			break;
       
   222 		default:
       
   223 			SDL_snprintf(errbuf, SDL_arraysize(errbuf),
       
   224 			         "%s: Unknown DirectSound error: 0x%x",
       
   225 								function, code);
       
   226 			break;
       
   227 	}
       
   228 	if ( ! errbuf[0] ) {
       
   229 		SDL_snprintf(errbuf, SDL_arraysize(errbuf), "%s: %s", function, error);
       
   230 	}
       
   231 	SDL_SetError("%s", errbuf);
       
   232 	return;
       
   233 }
       
   234 
       
   235 /* DirectSound needs to be associated with a window */
       
   236 static HWND mainwin = NULL;
       
   237 /* */
       
   238 void DX5_SoundFocus(HWND hwnd)
       
   239 {
       
   240 	mainwin = hwnd;
       
   241 }
       
   242 
       
   243 static void DX5_ThreadInit(_THIS)
       
   244 {
       
   245 	SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_HIGHEST);
       
   246 }
       
   247 
       
   248 static void DX5_WaitAudio_BusyWait(_THIS)
       
   249 {
       
   250 	DWORD status;
       
   251 	DWORD cursor, junk;
       
   252 	HRESULT result;
       
   253 
       
   254 	/* Semi-busy wait, since we have no way of getting play notification
       
   255 	   on a primary mixing buffer located in hardware (DirectX 5.0)
       
   256 	*/
       
   257 	result = IDirectSoundBuffer_GetCurrentPosition(mixbuf, &junk, &cursor);
       
   258 	if ( result != DS_OK ) {
       
   259 		if ( result == DSERR_BUFFERLOST ) {
       
   260 			IDirectSoundBuffer_Restore(mixbuf);
       
   261 		}
       
   262 #ifdef DEBUG_SOUND
       
   263 		SetDSerror("DirectSound GetCurrentPosition", result);
       
   264 #endif
       
   265 		return;
       
   266 	}
       
   267 
       
   268 	while ( (cursor/mixlen) == lastchunk ) {
       
   269 		/* FIXME: find out how much time is left and sleep that long */
       
   270 		SDL_Delay(1);
       
   271 
       
   272 		/* Try to restore a lost sound buffer */
       
   273 		IDirectSoundBuffer_GetStatus(mixbuf, &status);
       
   274 		if ( (status&DSBSTATUS_BUFFERLOST) ) {
       
   275 			IDirectSoundBuffer_Restore(mixbuf);
       
   276 			IDirectSoundBuffer_GetStatus(mixbuf, &status);
       
   277 			if ( (status&DSBSTATUS_BUFFERLOST) ) {
       
   278 				break;
       
   279 			}
       
   280 		}
       
   281 		if ( ! (status&DSBSTATUS_PLAYING) ) {
       
   282 			result = IDirectSoundBuffer_Play(mixbuf, 0, 0, DSBPLAY_LOOPING);
       
   283 			if ( result == DS_OK ) {
       
   284 				continue;
       
   285 			}
       
   286 #ifdef DEBUG_SOUND
       
   287 			SetDSerror("DirectSound Play", result);
       
   288 #endif
       
   289 			return;
       
   290 		}
       
   291 
       
   292 		/* Find out where we are playing */
       
   293 		result = IDirectSoundBuffer_GetCurrentPosition(mixbuf,
       
   294 								&junk, &cursor);
       
   295 		if ( result != DS_OK ) {
       
   296 			SetDSerror("DirectSound GetCurrentPosition", result);
       
   297 			return;
       
   298 		}
       
   299 	}
       
   300 }
       
   301 
       
   302 #ifdef USE_POSITION_NOTIFY
       
   303 static void DX6_WaitAudio_EventWait(_THIS)
       
   304 {
       
   305 	DWORD status;
       
   306 	HRESULT result;
       
   307 
       
   308 	/* Try to restore a lost sound buffer */
       
   309 	IDirectSoundBuffer_GetStatus(mixbuf, &status);
       
   310 	if ( (status&DSBSTATUS_BUFFERLOST) ) {
       
   311 		IDirectSoundBuffer_Restore(mixbuf);
       
   312 		IDirectSoundBuffer_GetStatus(mixbuf, &status);
       
   313 		if ( (status&DSBSTATUS_BUFFERLOST) ) {
       
   314 			return;
       
   315 		}
       
   316 	}
       
   317 	if ( ! (status&DSBSTATUS_PLAYING) ) {
       
   318 		result = IDirectSoundBuffer_Play(mixbuf, 0, 0, DSBPLAY_LOOPING);
       
   319 		if ( result != DS_OK ) {
       
   320 #ifdef DEBUG_SOUND
       
   321 			SetDSerror("DirectSound Play", result);
       
   322 #endif
       
   323 			return;
       
   324 		}
       
   325 	}
       
   326 	WaitForSingleObject(audio_event, INFINITE);
       
   327 }
       
   328 #endif /* USE_POSITION_NOTIFY */
       
   329 
       
   330 static void DX5_PlayAudio(_THIS)
       
   331 {
       
   332 	/* Unlock the buffer, allowing it to play */
       
   333 	if ( locked_buf ) {
       
   334 		IDirectSoundBuffer_Unlock(mixbuf, locked_buf, mixlen, NULL, 0);
       
   335 	}
       
   336 
       
   337 }
       
   338 
       
   339 static Uint8 *DX5_GetAudioBuf(_THIS)
       
   340 {
       
   341 	DWORD   cursor, junk;
       
   342 	HRESULT result;
       
   343 	DWORD   rawlen;
       
   344 
       
   345 	/* Figure out which blocks to fill next */
       
   346 	locked_buf = NULL;
       
   347 	result = IDirectSoundBuffer_GetCurrentPosition(mixbuf, &junk, &cursor);
       
   348 	if ( result == DSERR_BUFFERLOST ) {
       
   349 		IDirectSoundBuffer_Restore(mixbuf);
       
   350 		result = IDirectSoundBuffer_GetCurrentPosition(mixbuf,
       
   351 								&junk, &cursor);
       
   352 	}
       
   353 	if ( result != DS_OK ) {
       
   354 		SetDSerror("DirectSound GetCurrentPosition", result);
       
   355 		return(NULL);
       
   356 	}
       
   357 	cursor /= mixlen;
       
   358 #ifdef DEBUG_SOUND
       
   359 	/* Detect audio dropouts */
       
   360 	{ DWORD spot = cursor;
       
   361 	  if ( spot < lastchunk ) {
       
   362 	    spot += NUM_BUFFERS;
       
   363 	  }
       
   364 	  if ( spot > lastchunk+1 ) {
       
   365 	    fprintf(stderr, "Audio dropout, missed %d fragments\n",
       
   366 	            (spot - (lastchunk+1)));
       
   367 	  }
       
   368 	}
       
   369 #endif
       
   370 	lastchunk = cursor;
       
   371 	cursor = (cursor+1)%NUM_BUFFERS;
       
   372 	cursor *= mixlen;
       
   373 
       
   374 	/* Lock the audio buffer */
       
   375 	result = IDirectSoundBuffer_Lock(mixbuf, cursor, mixlen,
       
   376 				(LPVOID *)&locked_buf, &rawlen, NULL, &junk, 0);
       
   377 	if ( result == DSERR_BUFFERLOST ) {
       
   378 		IDirectSoundBuffer_Restore(mixbuf);
       
   379 		result = IDirectSoundBuffer_Lock(mixbuf, cursor, mixlen,
       
   380 				(LPVOID *)&locked_buf, &rawlen, NULL, &junk, 0);
       
   381 	}
       
   382 	if ( result != DS_OK ) {
       
   383 		SetDSerror("DirectSound Lock", result);
       
   384 		return(NULL);
       
   385 	}
       
   386 	return(locked_buf);
       
   387 }
       
   388 
       
   389 static void DX5_WaitDone(_THIS)
       
   390 {
       
   391 	Uint8 *stream;
       
   392 
       
   393 	/* Wait for the playing chunk to finish */
       
   394 	stream = this->GetAudioBuf(this);
       
   395 	if ( stream != NULL ) {
       
   396 		SDL_memset(stream, silence, mixlen);
       
   397 		this->PlayAudio(this);
       
   398 	}
       
   399 	this->WaitAudio(this);
       
   400 
       
   401 	/* Stop the looping sound buffer */
       
   402 	IDirectSoundBuffer_Stop(mixbuf);
       
   403 }
       
   404 
       
   405 static void DX5_CloseAudio(_THIS)
       
   406 {
       
   407 	if ( sound != NULL ) {
       
   408 		if ( mixbuf != NULL ) {
       
   409 			/* Clean up the audio buffer */
       
   410 			IDirectSoundBuffer_Release(mixbuf);
       
   411 			mixbuf = NULL;
       
   412 		}
       
   413 		if ( audio_event != NULL ) {
       
   414 			CloseHandle(audio_event);
       
   415 			audio_event = NULL;
       
   416 		}
       
   417 		IDirectSound_Release(sound);
       
   418 		sound = NULL;
       
   419 	}
       
   420 }
       
   421 
       
   422 #ifdef USE_PRIMARY_BUFFER
       
   423 /* This function tries to create a primary audio buffer, and returns the
       
   424    number of audio chunks available in the created buffer.
       
   425 */
       
   426 static int CreatePrimary(LPDIRECTSOUND sndObj, HWND focus, 
       
   427 	LPDIRECTSOUNDBUFFER *sndbuf, WAVEFORMATEX *wavefmt, Uint32 chunksize)
       
   428 {
       
   429 	HRESULT result;
       
   430 	DSBUFFERDESC format;
       
   431 	DSBCAPS caps;
       
   432 	int numchunks;
       
   433 
       
   434 	/* Try to set primary mixing privileges */
       
   435 	result = IDirectSound_SetCooperativeLevel(sndObj, focus,
       
   436 							DSSCL_WRITEPRIMARY);
       
   437 	if ( result != DS_OK ) {
       
   438 #ifdef DEBUG_SOUND
       
   439 		SetDSerror("DirectSound SetCooperativeLevel", result);
       
   440 #endif
       
   441 		return(-1);
       
   442 	}
       
   443 
       
   444 	/* Try to create the primary buffer */
       
   445 	SDL_memset(&format, 0, sizeof(format));
       
   446 	format.dwSize = sizeof(format);
       
   447 	format.dwFlags=(DSBCAPS_PRIMARYBUFFER|DSBCAPS_GETCURRENTPOSITION2);
       
   448 	format.dwFlags |= DSBCAPS_STICKYFOCUS;
       
   449 #ifdef USE_POSITION_NOTIFY
       
   450 	format.dwFlags |= DSBCAPS_CTRLPOSITIONNOTIFY;
       
   451 #endif
       
   452 	result = IDirectSound_CreateSoundBuffer(sndObj, &format, sndbuf, NULL);
       
   453 	if ( result != DS_OK ) {
       
   454 #ifdef DEBUG_SOUND
       
   455 		SetDSerror("DirectSound CreateSoundBuffer", result);
       
   456 #endif
       
   457 		return(-1);
       
   458 	}
       
   459 
       
   460 	/* Check the size of the fragment buffer */
       
   461 	SDL_memset(&caps, 0, sizeof(caps));
       
   462 	caps.dwSize = sizeof(caps);
       
   463 	result = IDirectSoundBuffer_GetCaps(*sndbuf, &caps);
       
   464 	if ( result != DS_OK ) {
       
   465 #ifdef DEBUG_SOUND
       
   466 		SetDSerror("DirectSound GetCaps", result);
       
   467 #endif
       
   468 		IDirectSoundBuffer_Release(*sndbuf);
       
   469 		return(-1);
       
   470 	}
       
   471 	if ( (chunksize > caps.dwBufferBytes) ||
       
   472 				((caps.dwBufferBytes%chunksize) != 0) ) {
       
   473 		/* The primary buffer size is not a multiple of 'chunksize'
       
   474 		   -- this hopefully doesn't happen when 'chunksize' is a 
       
   475 		      power of 2.
       
   476 		*/
       
   477 		IDirectSoundBuffer_Release(*sndbuf);
       
   478 		SDL_SetError(
       
   479 "Primary buffer size is: %d, cannot break it into chunks of %d bytes\n",
       
   480 					caps.dwBufferBytes, chunksize);
       
   481 		return(-1);
       
   482 	}
       
   483 	numchunks = (caps.dwBufferBytes/chunksize);
       
   484 
       
   485 	/* Set the primary audio format */
       
   486 	result = IDirectSoundBuffer_SetFormat(*sndbuf, wavefmt);
       
   487 	if ( result != DS_OK ) {
       
   488 #ifdef DEBUG_SOUND
       
   489 		SetDSerror("DirectSound SetFormat", result);
       
   490 #endif
       
   491 		IDirectSoundBuffer_Release(*sndbuf);
       
   492 		return(-1);
       
   493 	}
       
   494 	return(numchunks);
       
   495 }
       
   496 #endif /* USE_PRIMARY_BUFFER */
       
   497 
       
   498 /* This function tries to create a secondary audio buffer, and returns the
       
   499    number of audio chunks available in the created buffer.
       
   500 */
       
   501 static int CreateSecondary(LPDIRECTSOUND sndObj, HWND focus,
       
   502 	LPDIRECTSOUNDBUFFER *sndbuf, WAVEFORMATEX *wavefmt, Uint32 chunksize)
       
   503 {
       
   504 	const int numchunks = 8;
       
   505 	HRESULT result;
       
   506 	DSBUFFERDESC format;
       
   507 	LPVOID pvAudioPtr1, pvAudioPtr2;
       
   508 	DWORD  dwAudioBytes1, dwAudioBytes2;
       
   509 
       
   510 	/* Try to set primary mixing privileges */
       
   511 	if ( focus ) {
       
   512 		result = IDirectSound_SetCooperativeLevel(sndObj,
       
   513 					focus, DSSCL_PRIORITY);
       
   514 	} else {
       
   515 		result = IDirectSound_SetCooperativeLevel(sndObj,
       
   516 					GetDesktopWindow(), DSSCL_NORMAL);
       
   517 	}
       
   518 	if ( result != DS_OK ) {
       
   519 #ifdef DEBUG_SOUND
       
   520 		SetDSerror("DirectSound SetCooperativeLevel", result);
       
   521 #endif
       
   522 		return(-1);
       
   523 	}
       
   524 
       
   525 	/* Try to create the secondary buffer */
       
   526 	SDL_memset(&format, 0, sizeof(format));
       
   527 	format.dwSize = sizeof(format);
       
   528 	format.dwFlags = DSBCAPS_GETCURRENTPOSITION2;
       
   529 #ifdef USE_POSITION_NOTIFY
       
   530 	format.dwFlags |= DSBCAPS_CTRLPOSITIONNOTIFY;
       
   531 #endif
       
   532 	if ( ! focus ) {
       
   533 		format.dwFlags |= DSBCAPS_GLOBALFOCUS;
       
   534 	} else {
       
   535 		format.dwFlags |= DSBCAPS_STICKYFOCUS;
       
   536 	}
       
   537 	format.dwBufferBytes = numchunks*chunksize;
       
   538 	if ( (format.dwBufferBytes < DSBSIZE_MIN) ||
       
   539 	     (format.dwBufferBytes > DSBSIZE_MAX) ) {
       
   540 		SDL_SetError("Sound buffer size must be between %d and %d",
       
   541 				DSBSIZE_MIN/numchunks, DSBSIZE_MAX/numchunks);
       
   542 		return(-1);
       
   543 	}
       
   544 	format.dwReserved = 0;
       
   545 	format.lpwfxFormat = wavefmt;
       
   546 	result = IDirectSound_CreateSoundBuffer(sndObj, &format, sndbuf, NULL);
       
   547 	if ( result != DS_OK ) {
       
   548 		SetDSerror("DirectSound CreateSoundBuffer", result);
       
   549 		return(-1);
       
   550 	}
       
   551 	IDirectSoundBuffer_SetFormat(*sndbuf, wavefmt);
       
   552 
       
   553 	/* Silence the initial audio buffer */
       
   554 	result = IDirectSoundBuffer_Lock(*sndbuf, 0, format.dwBufferBytes,
       
   555 	                                 (LPVOID *)&pvAudioPtr1, &dwAudioBytes1,
       
   556 	                                 (LPVOID *)&pvAudioPtr2, &dwAudioBytes2,
       
   557 	                                 DSBLOCK_ENTIREBUFFER);
       
   558 	if ( result == DS_OK ) {
       
   559 		if ( wavefmt->wBitsPerSample == 8 ) {
       
   560 			SDL_memset(pvAudioPtr1, 0x80, dwAudioBytes1);
       
   561 		} else {
       
   562 			SDL_memset(pvAudioPtr1, 0x00, dwAudioBytes1);
       
   563 		}
       
   564 		IDirectSoundBuffer_Unlock(*sndbuf,
       
   565 		                          (LPVOID)pvAudioPtr1, dwAudioBytes1,
       
   566 		                          (LPVOID)pvAudioPtr2, dwAudioBytes2);
       
   567 	}
       
   568 
       
   569 	/* We're ready to go */
       
   570 	return(numchunks);
       
   571 }
       
   572 
       
   573 /* This function tries to set position notify events on the mixing buffer */
       
   574 #ifdef USE_POSITION_NOTIFY
       
   575 static int CreateAudioEvent(_THIS)
       
   576 {
       
   577 	LPDIRECTSOUNDNOTIFY notify;
       
   578 	DSBPOSITIONNOTIFY *notify_positions;
       
   579 	int i, retval;
       
   580 	HRESULT result;
       
   581 
       
   582 	/* Default to fail on exit */
       
   583 	retval = -1;
       
   584 	notify = NULL;
       
   585 
       
   586 	/* Query for the interface */
       
   587 	result = IDirectSoundBuffer_QueryInterface(mixbuf,
       
   588 			&IID_IDirectSoundNotify, (void *)&notify);
       
   589 	if ( result != DS_OK ) {
       
   590 		goto done;
       
   591 	}
       
   592 
       
   593 	/* Allocate the notify structures */
       
   594 	notify_positions = (DSBPOSITIONNOTIFY *)SDL_malloc(NUM_BUFFERS*
       
   595 					sizeof(*notify_positions));
       
   596 	if ( notify_positions == NULL ) {
       
   597 		goto done;
       
   598 	}
       
   599 
       
   600 	/* Create the notify event */
       
   601 	audio_event = CreateEvent(NULL, FALSE, FALSE, NULL);
       
   602 	if ( audio_event == NULL ) {
       
   603 		goto done;
       
   604 	}
       
   605 
       
   606 	/* Set up the notify structures */
       
   607 	for ( i=0; i<NUM_BUFFERS; ++i ) {
       
   608 		notify_positions[i].dwOffset = i*mixlen;
       
   609 		notify_positions[i].hEventNotify = audio_event;
       
   610 	}
       
   611 	result = IDirectSoundNotify_SetNotificationPositions(notify,
       
   612 					NUM_BUFFERS, notify_positions);
       
   613 	if ( result == DS_OK ) {
       
   614 		retval = 0;
       
   615 	}
       
   616 done:
       
   617 	if ( notify != NULL ) {
       
   618 		IDirectSoundNotify_Release(notify);
       
   619 	}
       
   620 	return(retval);
       
   621 }
       
   622 #endif /* USE_POSITION_NOTIFY */
       
   623 
       
   624 static int DX5_OpenAudio(_THIS, SDL_AudioSpec *spec)
       
   625 {
       
   626 	HRESULT      result;
       
   627 	WAVEFORMATEX waveformat;
       
   628 
       
   629 	/* Set basic WAVE format parameters */
       
   630 	SDL_memset(&waveformat, 0, sizeof(waveformat));
       
   631 	waveformat.wFormatTag = WAVE_FORMAT_PCM;
       
   632 
       
   633 	/* Determine the audio parameters from the AudioSpec */
       
   634 	switch ( spec->format & 0xFF ) {
       
   635 		case 8:
       
   636 			/* Unsigned 8 bit audio data */
       
   637 			spec->format = AUDIO_U8;
       
   638 			silence = 0x80;
       
   639 			waveformat.wBitsPerSample = 8;
       
   640 			break;
       
   641 		case 16:
       
   642 			/* Signed 16 bit audio data */
       
   643 			spec->format = AUDIO_S16;
       
   644 			silence = 0x00;
       
   645 			waveformat.wBitsPerSample = 16;
       
   646 			break;
       
   647 		default:
       
   648 			SDL_SetError("Unsupported audio format");
       
   649 			return(-1);
       
   650 	}
       
   651 	waveformat.nChannels = spec->channels;
       
   652 	waveformat.nSamplesPerSec = spec->freq;
       
   653 	waveformat.nBlockAlign =
       
   654 		waveformat.nChannels * (waveformat.wBitsPerSample/8);
       
   655 	waveformat.nAvgBytesPerSec = 
       
   656 		waveformat.nSamplesPerSec * waveformat.nBlockAlign;
       
   657 
       
   658 	/* Update the fragment size as size in bytes */
       
   659 	SDL_CalculateAudioSpec(spec);
       
   660 
       
   661 	/* Open the audio device */
       
   662 	result = DSoundCreate(NULL, &sound, NULL);
       
   663 	if ( result != DS_OK ) {
       
   664 		SetDSerror("DirectSoundCreate", result);
       
   665 		return(-1);
       
   666 	}
       
   667 
       
   668 	/* Create the audio buffer to which we write */
       
   669 	NUM_BUFFERS = -1;
       
   670 #ifdef USE_PRIMARY_BUFFER
       
   671 	if ( mainwin ) {
       
   672 		NUM_BUFFERS = CreatePrimary(sound, mainwin, &mixbuf,
       
   673 						&waveformat, spec->size);
       
   674 	}
       
   675 #endif /* USE_PRIMARY_BUFFER */
       
   676 	if ( NUM_BUFFERS < 0 ) {
       
   677 		NUM_BUFFERS = CreateSecondary(sound, mainwin, &mixbuf,
       
   678 						&waveformat, spec->size);
       
   679 		if ( NUM_BUFFERS < 0 ) {
       
   680 			return(-1);
       
   681 		}
       
   682 #ifdef DEBUG_SOUND
       
   683 		fprintf(stderr, "Using secondary audio buffer\n");
       
   684 #endif
       
   685 	}
       
   686 #ifdef DEBUG_SOUND
       
   687 	else
       
   688 		fprintf(stderr, "Using primary audio buffer\n");
       
   689 #endif
       
   690 
       
   691 	/* The buffer will auto-start playing in DX5_WaitAudio() */
       
   692 	lastchunk = 0;
       
   693 	mixlen = spec->size;
       
   694 
       
   695 #ifdef USE_POSITION_NOTIFY
       
   696 	/* See if we can use DirectX 6 event notification */
       
   697 	if ( CreateAudioEvent(this) == 0 ) {
       
   698 		this->WaitAudio = DX6_WaitAudio_EventWait;
       
   699 	} else {
       
   700 		this->WaitAudio = DX5_WaitAudio_BusyWait;
       
   701 	}
       
   702 #endif
       
   703 	return(0);
       
   704 }
       
   705