Backport from 1.3: most of the audio drivers can now handle data

 conversion at a higher level when they can't open the hardware in the
 exact format requested.

src/audio/amigaos/SDL_ahiaudio.c

@@ -220,47 +220,50 @@ static void AHI_CloseAudio(_THIS)
 
 static int AHI_OpenAudio(_THIS, SDL_AudioSpec *spec)
 {	
-//	int width;
-
-	D(bug("AHI opening...\n"));
-
-	/* Determine the audio parameters from the AudioSpec */
-	switch ( spec->format & 0xFF ) {
-
-		case 8: { /* Signed 8 bit audio data */
-			D(bug("Samples a 8 bit...\n"));
-			spec->format = AUDIO_S8;
-			this->hidden->bytespersample=1;
-			if(spec->channels<2)
-				this->hidden->type = AHIST_M8S;
-			else
-				this->hidden->type = AHIST_S8S;
-		}
-		break;
-
-		case 16: { /* Signed 16 bit audio data */
-			D(bug("Samples a 16 bit...\n"));
-			spec->format = AUDIO_S16MSB;
-			this->hidden->bytespersample=2;
-			if(spec->channels<2)
-				this->hidden->type = AHIST_M16S;
-			else
-				this->hidden->type = AHIST_S16S;
-		}
-		break;
-
-		default: {
-			SDL_SetError("Unsupported audio format");
-			return(-1);
-		}
-	}
-
-	if(spec->channels!=1 && spec->channels!=2)
-	{
-		D(bug("Wrong channel number!\n"));
-		SDL_SetError("Channel number non supported");
-		return -1;
-	}
+    SDL_AudioFormat test_format = SDL_FirstAudioFormat(spec->format);
+    int valid_datatype = 1;
+
+    D(bug("AHI opening...\n"));
+
+    /* Determine the audio parameters from the AudioSpec */
+    while ((!valid_datatype) && (test_format)) {
+        valid_datatype = 1;
+        switch (test_format) {
+            case AUDIO_S8:
+                D(bug("AUDIO_S8...\n"));
+                spec->format = AUDIO_S8;
+                this->hidden->bytespersample = 1;
+                if (spec->channels < 2)
+                    this->hidden->type = AHIST_M8S;
+                else
+                    this->hidden->type = AHIST_S8S;
+                break;
+
+            case AUDIO_S16MSB:
+                D(bug("AUDIO_S16MSB...\n"));
+                spec->format = AUDIO_S16MSB;
+                this->hidden->bytespersample = 2;
+                if (spec->channels < 2)
+                    this->hidden->type = AHIST_M16S;
+                else
+                    this->hidden->type = AHIST_S16S;
+                break;
+
+            default:
+                valid_datatype = 0;
+                test_format = SDL_NextAudioFormat();
+                break;
+        }
+    }
+
+    if (!valid_datatype) { /* shouldn't happen, but just in case... */
+        SDL_SetError("Unsupported audio format");
+        return (-1);
+    }
+
+    if (spec->channels > 2) {
+        spec->channels = 2;  /* will convert at higher level. */
+    }
 
 	D(bug("Before CalculateAudioSpec\n"));
 	/* Update the fragment size as size in bytes */

src/audio/baudio/SDL_beaudio.cc

@@ -152,38 +152,55 @@ void BE_CloseAudio(_THIS)
 
 int BE_OpenAudio(_THIS, SDL_AudioSpec *spec)
 {
-	media_raw_audio_format format;
+    int valid_datatype = 0;
+    media_raw_audio_format format;
+    SDL_AudioFormat test_format = SDL_FirstAudioFormat(spec->format);
+
+    /* Parse the audio format and fill the Be raw audio format */
+    memset(&format, '\0', sizeof (media_raw_audio_format));
+    format.byte_order = B_MEDIA_LITTLE_ENDIAN;
+    format.frame_rate = (float) spec->freq;
+    format.channel_count = spec->channels;  /* !!! FIXME: support > 2? */
+    while ((!valid_datatype) && (test_format)) {
+        valid_datatype = 1;
+        spec->format = test_format;
+        switch (test_format) {
+            case AUDIO_S8:
+                format.format = media_raw_audio_format::B_AUDIO_CHAR;
+                break;
+
+            case AUDIO_U8:
+                format.format = media_raw_audio_format::B_AUDIO_UCHAR;
+                break;
+
+            case AUDIO_S16LSB:
+                format.format = media_raw_audio_format::B_AUDIO_SHORT;
+                break;
+
+            case AUDIO_S16MSB:
+                format.format = media_raw_audio_format::B_AUDIO_SHORT;
+                format.byte_order = B_MEDIA_BIG_ENDIAN;
+                break;
+
+            default:
+                valid_datatype = 0;
+                test_format = SDL_NextAudioFormat();
+                break;
+        }
+    }
+
+    if (!valid_datatype) { /* shouldn't happen, but just in case... */
+        SDL_SetError("Unsupported audio format");
+        return (-1);
+    }
+
+    /* Initialize the Be Application, if it's not already started */
+    if (SDL_InitBeApp() < 0) {
+        return (-1);
+    }
+
+    format.buffer_size = spec->samples;
 
-	/* Initialize the Be Application, if it's not already started */
-	if ( SDL_InitBeApp() < 0 ) {
-		return(-1);
-	}
-
-	/* Parse the audio format and fill the Be raw audio format */
-	format.frame_rate = (float)spec->freq;
-	format.channel_count = spec->channels;
-	switch (spec->format&~0x1000) {
-		case AUDIO_S8:
-			/* Signed 8-bit audio unsupported, convert to U8 */
-			spec->format = AUDIO_U8;
-		case AUDIO_U8:
-			format.format = media_raw_audio_format::B_AUDIO_UCHAR;
-			format.byte_order = 0;
-			break;
-		case AUDIO_U16:
-			/* Unsigned 16-bit audio unsupported, convert to S16 */
-			spec->format ^= 0x8000;
-		case AUDIO_S16:
-			format.format = media_raw_audio_format::B_AUDIO_SHORT;
-			if ( spec->format & 0x1000 ) {
-				format.byte_order = 1; /* Big endian */
-			} else {
-				format.byte_order = 2; /* Little endian */
-			}
-			break;
-	}
-	format.buffer_size = spec->samples;
-
 	/* Calculate the final parameters for this audio specification */
 	SDL_CalculateAudioSpec(spec);
 

src/audio/dart/SDL_dart.c

@@ -75,6 +75,8 @@ LONG APIENTRY DARTEventFunc(ULONG ulStatus,
 
 int DART_OpenAudio(_THIS, SDL_AudioSpec *spec)
 {
+  SDL_AudioFormat test_format = SDL_FirstAudioFormat(spec->format);
+  int valid_datatype = 0;
   MCI_AMP_OPEN_PARMS AmpOpenParms;
   MCI_GENERIC_PARMS GenericParms;
   int iDeviceOrd = 0; // Default device to be used
@@ -106,26 +108,39 @@ int DART_OpenAudio(_THIS, SDL_AudioSpec *spec)
   iDeviceOrd = AmpOpenParms.usDeviceID;
 
   // Determine the audio parameters from the AudioSpec
-  switch ( spec->format & 0xFF )
-  {
-    case 8:
-        /* Unsigned 8 bit audio data */
-        spec->format = AUDIO_U8;
+  if (spec->channels > 2)
+    spec->channels = 2;  // !!! FIXME: more than stereo support in OS/2?
+
+  while ((!valid_datatype) && (test_format)) {
+    spec->format = test_format;
+    valid_datatype = 1;
+    switch (test_format) {
+      case AUDIO_U8:
+        // Unsigned 8 bit audio data
         iSilence = 0x80;
         iBits = 8;
         break;
-    case 16:
-        /* Signed 16 bit audio data */
-        spec->format = AUDIO_S16;
+
+      case AUDIO_S16LSB:
+        // Signed 16 bit audio data
         iSilence = 0x00;
         iBits = 16;
         break;
-    default:
-        // Close DART, and exit with error code!
-        mciSendCommand(iDeviceOrd, MCI_CLOSE, MCI_WAIT, &GenericParms, 0);
-        SDL_SetError("Unsupported audio format");
-        return(-1);
+
+      default:
+        valid_datatype = 0;
+        test_format = SDL_NextAudioFormat();
+        break;
+    }
   }
+
+  if (!valid_datatype) { // shouldn't happen, but just in case...
+    // Close DART, and exit with error code!
+    mciSendCommand(iDeviceOrd, MCI_CLOSE, MCI_WAIT, &GenericParms, 0);
+    SDL_SetError("Unsupported audio format");
+    return (-1);
+  }
+
   iFreq = spec->freq;
   iChannels = spec->channels;
   /* Update the fragment size as size in bytes */

src/audio/dc/SDL_dcaudio.c

@@ -201,13 +201,30 @@ static void DCAUD_CloseAudio(_THIS)
 
 static int DCAUD_OpenAudio(_THIS, SDL_AudioSpec *spec)
 {
-	switch(spec->format&0xff) {
-	case  8: spec->format = AUDIO_S8; break;
-	case 16: spec->format = AUDIO_S16LSB; break;
-	default:
-		SDL_SetError("Unsupported audio format");
-		return(-1);
-	}
+    SDL_AudioFormat test_format = SDL_FirstAudioFormat(spec->format);
+    int valid_datatype = 0;
+    while ((!valid_datatype) && (test_format)) {
+        spec->format = test_format;
+        switch (test_format) {
+            /* only formats Dreamcast accepts... */
+            case AUDIO_S8:
+            case AUDIO_S16LSB:
+                valid_datatype = 1;
+                break;
+
+            default:
+                test_format = SDL_NextAudioFormat();
+                break;
+        }
+    }
+
+    if (!valid_datatype) {  /* shouldn't happen, but just in case... */
+        SDL_SetError("Unsupported audio format");
+        return (-1);
+    }
+
+    if (spec->channels > 2)
+        spec->channels = 2;  /* no more than stereo on the Dreamcast. */
 
 	/* Update the fragment size as size in bytes */
 	SDL_CalculateAudioSpec(spec);