Adjusted default choice of audio driver.

If a driver can definitely see available devices, it is chosen. Otherwise,
 we'll take the first driver that initializes but saw no devices...this might
 be because it can't enumerate them, or there really aren't any available.

This prevents the dsp driver from hogging control when there are no /dev/dsp*
 nodes (for example, on a Linux box with ALSA and no OSS emulation).

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%403400

src/audio/SDL_audio.c

@@ -589,6 +589,8 @@ SDL_AudioInit(const char *driver_name)
     int i = 0;
     int initialized = 0;
     int tried_to_init = 0;
+    int rc = 0;
+    int best_choice = -1;
 
     if (SDL_WasInit(SDL_INIT_AUDIO)) {
         SDL_AudioQuit();        /* shutdown driver if already running. */
@@ -614,7 +616,25 @@ SDL_AudioInit(const char *driver_name)
         SDL_memset(&current_audio, 0, sizeof(current_audio));
         current_audio.name = backend->name;
         current_audio.desc = backend->desc;
-        initialized = backend->init(&current_audio.impl);
+        rc = backend->init(&current_audio.impl);
+        if (rc == 2) {  /* init'd, and devices available. Take it! */
+            initialized = 1;
+            best_choice = i;
+        } else if (rc == 1) { /* init'd, but can't see any devices. */
+            current_audio.impl.Deinitialize();
+            if (best_choice == -1) {
+                best_choice = i;
+            }
+        }
+    }
+
+    /* No definite choice. Pick one that works but can't promise a device. */
+    if ((!initialized) && (best_choice != -1)) {
+        const AudioBootStrap *backend = bootstrap[best_choice];
+        SDL_memset(&current_audio, 0, sizeof(current_audio));
+        current_audio.name = backend->name;
+        current_audio.desc = backend->desc;
+        initialized = (backend->init(&current_audio.impl) > 0);
     }
 
     if (!initialized) {

src/audio/alsa/SDL_alsa_audio.c

@@ -607,7 +607,7 @@ ALSA_Init(SDL_AudioDriverImpl * impl)
     impl->Deinitialize = ALSA_Deinitialize;
     impl->OnlyHasDefaultOutputDevice = 1;       /* !!! FIXME: Add device enum! */
 
-    return 1;
+    return 1;  /* !!! FIXME: return 2 once device enum is implemented. */
 }
 
 

src/audio/bsd/SDL_bsdaudio.c

@@ -444,7 +444,7 @@ BSDAUDIO_Init(SDL_AudioDriverImpl * impl)
     impl->Deinitialize = BSDAUDIO_Deinitialize;
 
     build_device_lists();
-    return 1;
+    return (outputDeviceCount > 0) ? 2 : 1;
 }
 
 

src/audio/dma/SDL_dmaaudio.c

@@ -524,7 +524,7 @@ DMA_Init(SDL_AudioDriverImpl * impl)
     impl->Deinitialize = DMA_Deinitialize;
 
     build_device_lists();
-    return 1;
+    return (outputDeviceCount > 0) ? 2 : 1;
 }
 
 AudioBootStrap DMA_bootstrap = {

src/audio/dsp/SDL_dspaudio.c

@@ -381,7 +381,7 @@ DSP_Init(SDL_AudioDriverImpl * impl)
     impl->Deinitialize = DSP_Deinitialize;
 
     build_device_lists();
-    return 1;
+    return (outputDeviceCount > 0) ? 2 : 1;
 }
 
 

src/audio/esd/SDL_esdaudio.c

@@ -341,7 +341,7 @@ ESD_Init(SDL_AudioDriverImpl * impl)
     impl->Deinitialize = ESD_Deinitialize;
     impl->OnlyHasDefaultOutputDevice = 1;
 
-    return 1;
+    return 2;  /* return 2 (definitely have a "device"). */
 }
 
 

src/audio/iphoneos/SDL_coreaudio_iphone.c

@@ -329,7 +329,7 @@ COREAUDIO_Init(SDL_AudioDriverImpl * impl)
     impl->OnlyHasDefaultOutputDevice = 1;
     impl->HasCaptureSupport = 0;        /* still needs to be written */
 
-    return 1;
+    return 2;  /* defitely have an audio device. */
 }
 
 AudioBootStrap COREAUDIOIPHONE_bootstrap = {

src/audio/macosx/SDL_coreaudio.c

@@ -589,7 +589,7 @@ COREAUDIO_Init(SDL_AudioDriverImpl * impl)
 
     build_device_lists();       /* do an initial check for devices... */
 
-    return 1;
+    return (outputDeviceCount > 0) ? 2 : 1;
 }
 
 AudioBootStrap COREAUDIO_bootstrap = {

src/audio/mint/SDL_mintaudio_dma8.c

@@ -338,7 +338,7 @@ MINTDMA8_Init(SDL_AudioDriverImpl * impl)
     impl->ProvidesOwnCallbackThread = 1;
     impl->SkipMixerLock = 1;
 
-    return 1;
+    return 2;  /* 2 == definitely has an audio device. */
 }
 
 AudioBootStrap MINTAUDIO_DMA8_bootstrap = {

src/audio/mint/SDL_mintaudio_gsxb.c

@@ -433,7 +433,7 @@ MINTGSXB_Init(SDL_AudioDriverImpl * impl)
     impl->ProvidesOwnCallbackThread = 1;
     impl->SkipMixerLock = 1;
 
-    return 1;
+    return 2;  /* 2 == definitely has an audio device. */
 }
 
 AudioBootStrap MINTAUDIO_GSXB_bootstrap = {

src/audio/mint/SDL_mintaudio_mcsn.c

@@ -390,7 +390,7 @@ MINTMCSN_Init(SDL_AudioDriverImpl * impl)
     impl->ProvidesOwnCallbackThread = 1;
     impl->SkipMixerLock = 1;
 
-    return 1;
+    return 2;  /* 2 == definitely has an audio device. */
 }
 
 AudioBootStrap MINTAUDIO_MCSN_bootstrap = {

src/audio/mint/SDL_mintaudio_stfa.c

@@ -297,7 +297,7 @@ MINTSTFA_Init(SDL_AudioDriverImpl * impl)
     impl->ProvidesOwnCallbackThread = 1;
     impl->SkipMixerLock = 1;
 
-    return 1;
+    return 2;  /* 2 == definitely has an audio device. */
 }
 
 AudioBootStrap MINTAUDIO_STFA_bootstrap = {

src/audio/mint/SDL_mintaudio_xbios.c

@@ -490,7 +490,7 @@ MINTXBIOS_Init(SDL_AudioDriverImpl * impl)
     impl->ProvidesOwnCallbackThread = 1;
     impl->SkipMixerLock = 1;
 
-    return 1;
+    return 2;  /* 2 == definitely has an audio device. */
 }
 
 AudioBootStrap MINTAUDIO_XBIOS_bootstrap = {

src/audio/nas/SDL_nasaudio.c

@@ -398,7 +398,7 @@ NAS_Init(SDL_AudioDriverImpl * impl)
     impl->Deinitialize = NAS_Deinitialize;
     impl->OnlyHasDefaultOutputDevice = 1;       /* !!! FIXME: is this true? */
 
-    return 1;
+    return 2;  /* 2 == definitely has an audio device. */
 }
 
 AudioBootStrap NAS_bootstrap = {

src/audio/nds/SDL_ndsaudio.c

@@ -120,7 +120,7 @@ NDSAUD_Init(SDL_AudioDriverImpl * impl)
     impl->OnlyHasDefaultOutputDevice = 1;
     impl->OnlyHasDefaultInputDevice = 1;
 
-    return 1;
+    return 2;  /* 2 == definitely has an audio device. */
 }
 
 AudioBootStrap NDSAUD_bootstrap = {

src/audio/nto/SDL_nto_audio.c

@@ -434,6 +434,7 @@ NTO_OpenDevice(_THIS, const char *devname, int iscapture)
 static int
 NTO_Init(SDL_AudioDriverImpl * impl)
 {
+    /* !!! FIXME: not right for device enum? */
     /*  See if we can open a nonblocking channel. */
     snd_pcm_t *handle = NULL;
     int rval = snd_pcm_open_preferred(&handle, NULL, NULL, OPEN_FLAGS);
@@ -455,7 +456,8 @@ NTO_Init(SDL_AudioDriverImpl * impl)
     impl->CloseDevice = NTO_CloseDevice;
     impl->OnlyHasDefaultOutputDevice = 1;       /* !!! FIXME: add device enum! */
 
-    return 1;
+    /* !!! FIXME: device enum might make this 1. */
+    return 2;  /* 2 == definitely has an audio device. */
 }
 
 AudioBootStrap QNXNTOAUDIO_bootstrap = {

src/audio/paudio/SDL_paudio.c

@@ -528,6 +528,7 @@ PAUDIO_OpenDevice(_THIS, const char *devname, int iscapture)
 static int
 PAUDIO_Init(SDL_AudioDriverImpl * impl)
 {
+    /* !!! FIXME: not right for device enum? */
     int fd = OpenAudioPath(NULL, 0, OPEN_FLAGS, 0);
     if (fd < 0) {
         SDL_SetError("PAUDIO: Couldn't open audio device");
@@ -543,7 +544,8 @@ PAUDIO_Init(SDL_AudioDriverImpl * impl)
     impl->CloseDevice = DSP_CloseDevice;
     impl->OnlyHasDefaultOutputDevice = 1;       /* !!! FIXME: add device enum! */
 
-    return 1;
+    /* !!! FIXME: device enum might make this 1. */
+    return 2;  /* 2 == definitely has an audio device. */
 }
 
 AudioBootStrap PAUDIO_bootstrap = {

src/audio/pulseaudio/SDL_pulseaudio.c

@@ -380,6 +380,7 @@ PULSEAUDIO_Init(SDL_AudioDriverImpl * impl)
     impl->Deinitialize = PULSEAUDIO_Deinitialize;
     impl->OnlyHasDefaultOutputDevice = 1;
 
+    /* !!! FIXME: should test if server is available here, return 2 if so. */
     return 1;
 }
 

src/audio/windib/SDL_dibaudio.c

@@ -327,6 +327,7 @@ WINWAVEOUT_Init(SDL_AudioDriverImpl * impl)
     impl->CloseDevice = WINWAVEOUT_CloseDevice;
     impl->OnlyHasDefaultOutputDevice = 1;       /* !!! FIXME: Is this true? */
 
+    /* !!! FIXME: not right for device enum? */
     return 1;
 }
 

src/audio/windx5/SDL_dx5audio.c

@@ -508,6 +508,7 @@ DSOUND_Init(SDL_AudioDriverImpl * impl)
     impl->Deinitialize = DSOUND_Deinitialize;
     impl->OnlyHasDefaultOutputDevice = 1;       /* !!! FIXME */
 
+    /* !!! FIXME: not right for device enum? */
     return 1;
 }