audio: Handle non-power-of-two spec.samples when unsupported

Fixes #3685

src/audio/SDL_audio.c

@@ -1413,6 +1413,19 @@ open_audio_device(const char *devname, int iscapture,
         }
     }
 
+    /* For backends that require a power-of-two value for spec.samples, take the
+     * value we got from 'desired' and round up to the nearest value
+     */
+    if (!current_audio.impl.SupportsNonPow2Samples && device->spec.samples > 0) {
+        device->spec.samples -= 1;
+        device->spec.samples |= device->spec.samples >> 1;
+        device->spec.samples |= device->spec.samples >> 2;
+        device->spec.samples |= device->spec.samples >> 4;
+        device->spec.samples |= device->spec.samples >> 8;
+        device->spec.samples |= device->spec.samples >> 16;
+        device->spec.samples += 1;
+    }
+
     if (current_audio.impl.OpenDevice(device, devname) < 0) {
         close_audio_device(device);
         return 0;

src/audio/SDL_sysaudio.h

@@ -88,6 +88,7 @@ typedef struct SDL_AudioDriverImpl
     SDL_bool OnlyHasDefaultOutputDevice;
     SDL_bool OnlyHasDefaultCaptureDevice;
     SDL_bool AllowsArbitraryDeviceNames;
+    SDL_bool SupportsNonPow2Samples;
 } SDL_AudioDriverImpl;
 
 

src/audio/alsa/SDL_alsa_audio.c

@@ -1009,6 +1009,7 @@ ALSA_Init(SDL_AudioDriverImpl * impl)
     impl->FlushCapture = ALSA_FlushCapture;
 
     impl->HasCaptureSupport = SDL_TRUE;
+    impl->SupportsNonPow2Samples = SDL_TRUE;
 
     return SDL_TRUE;   /* this audio target is available. */
 }

src/audio/coreaudio/SDL_coreaudio.m

@@ -1173,6 +1173,7 @@ COREAUDIO_Init(SDL_AudioDriverImpl * impl)
 
     impl->ProvidesOwnCallbackThread = SDL_TRUE;
     impl->HasCaptureSupport = SDL_TRUE;
+    impl->SupportsNonPow2Samples = SDL_TRUE;
 
     return SDL_TRUE;   /* this audio target is available. */
 }

src/audio/directsound/SDL_directsound.c

@@ -668,6 +668,7 @@ DSOUND_Init(SDL_AudioDriverImpl * impl)
     impl->GetDefaultAudioInfo = DSOUND_GetDefaultAudioInfo;
 
     impl->HasCaptureSupport = SDL_TRUE;
+    impl->SupportsNonPow2Samples = SDL_TRUE;
 
     return SDL_TRUE;   /* this audio target is available. */
 }

src/audio/disk/SDL_diskaudio.c

@@ -195,6 +195,7 @@ DISKAUDIO_Init(SDL_AudioDriverImpl * impl)
 
     impl->AllowsArbitraryDeviceNames = SDL_TRUE;
     impl->HasCaptureSupport = SDL_TRUE;
+    impl->SupportsNonPow2Samples = SDL_TRUE;
 
     return SDL_TRUE;   /* this audio target is available. */
 }

src/audio/pipewire/SDL_pipewire.c

@@ -1417,6 +1417,7 @@ PIPEWIRE_Init(SDL_AudioDriverImpl *impl)
 
     impl->HasCaptureSupport         = SDL_TRUE;
     impl->ProvidesOwnCallbackThread = SDL_TRUE;
+    impl->SupportsNonPow2Samples    = SDL_TRUE;
 
     return SDL_TRUE;
 }

src/audio/pulseaudio/SDL_pulseaudio.c

@@ -945,6 +945,7 @@ PULSEAUDIO_Init(SDL_AudioDriverImpl * impl)
     impl->GetDefaultAudioInfo = PULSEAUDIO_GetDefaultAudioInfo;
 
     impl->HasCaptureSupport = SDL_TRUE;
+    impl->SupportsNonPow2Samples = SDL_TRUE;
 
     return SDL_TRUE;   /* this audio target is available. */
 }

src/audio/wasapi/SDL_wasapi.c

@@ -617,6 +617,7 @@ WASAPI_Init(SDL_AudioDriverImpl * impl)
     impl->Deinitialize = WASAPI_Deinitialize;
     impl->GetDefaultAudioInfo = WASAPI_GetDefaultAudioInfo;
     impl->HasCaptureSupport = SDL_TRUE;
+    impl->SupportsNonPow2Samples = SDL_TRUE;
 
     return SDL_TRUE;   /* this audio target is available. */
 }