add an option to select audio device

src/audio/abstract.cpp

@@ -26,6 +26,10 @@ bool TAAudio::setRun(bool run) {
   return running;
 }
 
+std::vector<String> TAAudio::listAudioDevices() {
+  return std::vector<String>();
+}
+
 bool TAAudio::init(TAAudioDesc& request, TAAudioDesc& response) {
   response=request;
   return true;

src/audio/sdl.cpp

@@ -1,4 +1,6 @@
+#include <SDL_audio.h>
 #include <string.h>
+#include <vector>
 #include "../ta-log.h"
 #include "sdl.h"
 
@@ -49,14 +51,40 @@ bool TAAudioSDL::setRun(bool run) {
   return running;
 }
 
+std::vector<String> TAAudioSDL::listAudioDevices() {
+  std::vector<String> ret;
+  if (!audioSysStarted) {
+    if (SDL_Init(SDL_INIT_AUDIO)<0) {
+      logE("could not initialize SDL to list audio devices\n");
+    } else {
+      audioSysStarted=true;
+    }
+  }
+
+  int count=SDL_GetNumAudioDevices(false);
+  if (count<0) return ret;
+
+  for (int i=0; i<count; i++) {
+    const char* devName=SDL_GetAudioDeviceName(i,false);
+    if (devName!=NULL) {
+      ret.push_back(String(devName));
+    }
+  }
+
+  return ret;
+}
+
 bool TAAudioSDL::init(TAAudioDesc& request, TAAudioDesc& response) {
   if (initialized) {
     logE("audio already initialized\n");
     return false;
   }
-  if (SDL_Init(SDL_INIT_AUDIO)<0) {
-    logE("could not initialize SDL\n");
-    return false;
+  if (!audioSysStarted) {
+    if (SDL_Init(SDL_INIT_AUDIO)<0) {
+      logE("could not initialize SDL\n");
+      return false;
+    }
+    audioSysStarted=true;
   }
 
   desc=request;
@@ -69,12 +97,13 @@ bool TAAudioSDL::init(TAAudioDesc& request, TAAudioDesc& response) {
   ac.callback=taSDLProcess;
   ac.userdata=this;
 
-  ai=SDL_OpenAudioDevice(NULL,0,&ac,&ar,SDL_AUDIO_ALLOW_FREQUENCY_CHANGE);
+  ai=SDL_OpenAudioDevice(request.deviceName.empty()?NULL:request.deviceName.c_str(),0,&ac,&ar,SDL_AUDIO_ALLOW_FREQUENCY_CHANGE);
   if (ai==0) {
     logE("could not open audio device: %s\n",SDL_GetError());
     return false;
   }
 
+  desc.deviceName=request.deviceName;
   desc.name="";
   desc.rate=ar.freq;
   desc.inChans=0;

src/audio/sdl.h

@@ -4,6 +4,7 @@
 class TAAudioSDL: public TAAudio {
   SDL_AudioSpec ac, ar;
   SDL_AudioDeviceID ai;
+  bool audioSysStarted;
 
   public:
     void onProcess(unsigned char* buf, int nframes);
@@ -11,5 +12,8 @@ class TAAudioSDL: public TAAudio {
     void* getContext();
     bool quit();
     bool setRun(bool run);
+    std::vector<String> listAudioDevices();
     bool init(TAAudioDesc& request, TAAudioDesc& response);
+    TAAudioSDL():
+      audioSysStarted(false) {}
 };

src/audio/taAudio.h

@@ -31,7 +31,7 @@ enum TAAudioFormat {
 };
 
 struct TAAudioDesc {
-  String name;
+  String name, deviceName;
   double rate;
   unsigned int bufsize, fragments;
   unsigned char inChans, outChans;
@@ -46,40 +46,6 @@ struct TAAudioDesc {
     outFormat(TA_AUDIO_FORMAT_F32) {}
 };
 
-class TAAudio {
-  protected:
-    TAAudioDesc desc;
-    TAAudioFormat outFormat;
-    bool running, initialized;
-    float** inBufs;
-    float** outBufs;
-    void (*audioProcCallback)(void*,float**,float**,int,int,unsigned int);
-    void* audioProcCallbackUser;
-    void (*sampleRateChanged)(SampleRateChangeEvent);
-    void (*bufferSizeChanged)(BufferSizeChangeEvent);
-  public:
-    void setSampleRateChangeCallback(void (*callback)(SampleRateChangeEvent));
-    void setBufferSizeChangeCallback(void (*callback)(BufferSizeChangeEvent));
-
-    void setCallback(void (*callback)(void*,float**,float**,int,int,unsigned int), void* user);
-
-    virtual void* getContext();
-    virtual bool quit();
-    virtual bool setRun(bool run);
-    virtual bool init(TAAudioDesc& request, TAAudioDesc& response);
-
-    TAAudio():
-      outFormat(TA_AUDIO_FORMAT_F32),
-      running(false),
-      initialized(false),
-      inBufs(NULL),
-      outBufs(NULL),
-      audioProcCallback(NULL),
-      sampleRateChanged(NULL),
-      bufferSizeChanged(NULL) {}
-
-    virtual ~TAAudio();
-};
 
 enum TAMidiMessageTypes {
   TA_MIDI_NOTE_OFF=0x80,
@@ -146,7 +112,42 @@ class TAMidiOut {
 class TAMidi {
   std::vector<TAMidiIn*> in;
   std::vector<TAMidiOut*> out;
+};
 
+class TAAudio {
+  protected:
+    TAAudioDesc desc;
+    TAAudioFormat outFormat;
+    bool running, initialized;
+    float** inBufs;
+    float** outBufs;
+    void (*audioProcCallback)(void*,float**,float**,int,int,unsigned int);
+    void* audioProcCallbackUser;
+    void (*sampleRateChanged)(SampleRateChangeEvent);
+    void (*bufferSizeChanged)(BufferSizeChangeEvent);
+  public:
+    TAMidi* midi;
+    void setSampleRateChangeCallback(void (*callback)(SampleRateChangeEvent));
+    void setBufferSizeChangeCallback(void (*callback)(BufferSizeChangeEvent));
 
+    void setCallback(void (*callback)(void*,float**,float**,int,int,unsigned int), void* user);
+
+    virtual void* getContext();
+    virtual bool quit();
+    virtual bool setRun(bool run);
+    virtual std::vector<String> listAudioDevices();
+    virtual bool init(TAAudioDesc& request, TAAudioDesc& response);
+
+    TAAudio():
+      outFormat(TA_AUDIO_FORMAT_F32),
+      running(false),
+      initialized(false),
+      inBufs(NULL),
+      outBufs(NULL),
+      audioProcCallback(NULL),
+      sampleRateChanged(NULL),
+      bufferSizeChanged(NULL) {}
+
+    virtual ~TAAudio();
 };
 #endif