Some fixes to the latest SDL sound code. Sounds seem to keep better

sync with the video updates in this version.


git-svn-id: svn://svn.code.sf.net/p/stella/code/trunk@116 8b62c5a3-ac7e-4cc8-8f21-d9a121418aba

stella/src/ui/sdl/SoundSDL.cxx

@@ -13,15 +13,15 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: SoundSDL.cxx,v 1.1 2002-10-11 13:07:00 stephena Exp $
+// $Id: SoundSDL.cxx,v 1.2 2002-10-12 15:24:49 stephena Exp $
 //============================================================================
 
 #include <SDL.h>
 
 #include "SoundSDL.hxx"
 
-static uInt8 currentVolume;
+static uInt8 _myCurrentVolume;
-static MediaSource* _mediaSource;
+static MediaSource* _myMediaSource;
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 SoundSDL::SoundSDL(bool activate)
@@ -64,8 +64,8 @@ SoundSDL::SoundSDL(bool activate)
   mySampleRate = obtained.freq;
 
   // Take care of the static stuff ...
-  currentVolume = 0;
+  _myCurrentVolume = 0;
-  _mediaSource = (MediaSource*) NULL;
+  _myMediaSource = (MediaSource*) NULL;
 
   SDL_PauseAudio(0);
 }
@@ -73,6 +73,7 @@ SoundSDL::SoundSDL(bool activate)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 SoundSDL::~SoundSDL()
 {
+  close();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -105,8 +106,6 @@ void SoundSDL::mute(bool state)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void SoundSDL::close()
 {
-  SDL_PauseAudio(0);
-
   if(myIsInitializedFlag)
     SDL_CloseAudio();
 
@@ -120,28 +119,26 @@ void SoundSDL::setSoundVolume(uInt32 percent)
     return;
 
   if((percent >= 0) && (percent <= 100))
-    currentVolume = (int) (((float) percent / 100.0) * (float) SDL_MIX_MAXVOLUME);
+    _myCurrentVolume = (int) (((float) percent / 100.0) * (float) SDL_MIX_MAXVOLUME);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void SoundSDL::updateSound(MediaSource& mediaSource)
+void SoundSDL::setMediaSource(MediaSource& mediaSource)
 {
-  // this is a HUGE HACK and will disappear soon
+  _myMediaSource = &mediaSource;
-  _mediaSource = &mediaSource;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void SoundSDL::fillAudio(void* udata, uInt8* stream, Int32 len)
 {  
-  if(!_mediaSource)
+  if(!_myMediaSource)
-    return;
-
-  uInt32 samples = _mediaSource->numberOfAudioSamples();
-  if(samples == 0)
     return;
 
+  // Dequeue samples as long as full fragments are available
+  if(_myMediaSource->numberOfAudioSamples() >= (uInt32) len)
+  {
     uInt8 buffer[len];
-  _mediaSource->dequeueAudioSamples(buffer, len);
+    _myMediaSource->dequeueAudioSamples(buffer, (uInt32)len);
-
+    SDL_MixAudio(stream, buffer, len, _myCurrentVolume);
-  SDL_MixAudio(stream, buffer, len, currentVolume);
+  }
 }

stella/src/ui/sdl/SoundSDL.hxx

@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: SoundSDL.hxx,v 1.1 2002-10-11 13:07:01 stephena Exp $
+// $Id: SoundSDL.hxx,v 1.2 2002-10-12 15:24:49 stephena Exp $
 //============================================================================
 
 #ifndef SOUNDSDL_HXX
@@ -28,7 +28,7 @@
   This class implements the sound API for SDL.
 
   @author  Stephen Anthony
-  @version $Id: SoundSDL.hxx,v 1.1 2002-10-11 13:07:01 stephena Exp $
+  @version $Id: SoundSDL.hxx,v 1.2 2002-10-12 15:24:49 stephena Exp $
 */
 class SoundSDL
 {
@@ -52,9 +52,9 @@ class SoundSDL
     uInt32 getSampleRate() const;
 
     /**
-      Return true iff the sound device was successfully initlaized.
+      Return true iff the sound device was successfully initialized.
 
-      @return true iff the sound device was successfully initlaized.
+      @return true iff the sound device was successfully initialized
     */
     bool isSuccessfullyInitialized() const;
 
@@ -67,25 +67,27 @@ class SoundSDL
     void setSoundVolume(uInt32 volume);
 
     /**
-      Update the sound device using the audio sample from the specified
+      Notifies this class of the MediaSource object where sample data
-      media source.
+      may be obtained.  The SDL sound api is thread-based, so the SDL
+      audio callback directly queries the MediaSource when it requires
+      more audio samples.
 
-      @param mediaSource The media source to get audio samples from.
+      @param mediaSource The MediaSource where sample data is obtained
     */
-    void updateSound(MediaSource& mediaSource);
+    void setMediaSource(MediaSource& mediaSource);
 
     /**
-      Closes the soudn device
+      Set the mute state of the sound object.
-    */
-    void close();
 
-    /**
+      @param state Mutes sound if true, unmute if false
-      Set the mute state of the sound object
-
-      @param state Mutes sound iff true
     */
     void mute(bool state);
 
+    /**
+      Closes the sound device
+    */
+    void close();
+
   private:
     // Indicates if the sound device was successfully initialized
     bool myIsInitializedFlag;
@@ -99,12 +101,11 @@ class SoundSDL
     // Indicates if the sound is currently muted
     bool myIsMuted;
 
-  /**
-    Some stuff which is required to be static since the SDL audio
-    callback is a C-style function.
-  */
   private:
-
+    /**
+      The callback used by the SDL sound API.  It obtains samples
+      from the MediaSource as it needs them.
+    */
     static void fillAudio(void* udata, uInt8* stream, Int32 len);
 
 };

stella/src/ui/sdl/mainSDL.cxx

@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: mainSDL.cxx,v 1.30 2002-10-11 13:07:01 stephena Exp $
+// $Id: mainSDL.cxx,v 1.31 2002-10-12 15:24:49 stephena Exp $
 //============================================================================
 
 #include <fstream>
@@ -587,7 +587,7 @@ void togglePause()
     thePauseIndicator = true;
   }
 
-  // Pause the console
+  // Pause the console and the audio
   theConsole->mediaSource().pause(thePauseIndicator);
 
   // Show a different palette depending on pause state
@@ -1573,6 +1573,10 @@ int main(int argc, char* argv[])
   theConsole = new Console(image, size, filename, 
       theEvent, propertiesSet, sound.getSampleRate());
 
+  // Let the sound object know about the MediaSource.
+  // The sound object takes care of getting samples from the MediaSource.  
+  sound.setMediaSource(theConsole->mediaSource());
+
   // Free the image since we don't need it any longer
   delete[] image;
 
@@ -1625,7 +1629,6 @@ int main(int argc, char* argv[])
 
       startTime = getTicks();
       theConsole->mediaSource().update();
-      sound.updateSound(theConsole->mediaSource());
       updateDisplay(theConsole->mediaSource());
       handleEvents();
 
@@ -1665,7 +1668,6 @@ int main(int argc, char* argv[])
       if(!thePauseIndicator)
       {
         theConsole->mediaSource().update();
-        sound.updateSound(theConsole->mediaSource());
       }
       updateDisplay(theConsole->mediaSource());
       handleEvents();