implemented gapless playback for WAV files (KidVid)

src/common/SoundSDL2.cxx

@@ -401,39 +401,44 @@ void SoundSDL2::callback(void* udata, uInt8* stream, int len)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool SoundSDL2::playWav(const string& fileName, uInt32 position, uInt32 length)
+bool SoundSDL2::playWav(const string& fileName, const uInt32 position,
+                        const uInt32 length)
 {
-  uInt32 wavLength{0};
-
-  // Stop any playing WAVs
-  stopWav();
-
   // Load WAV file
-  auto* result = SDL_LoadWAV(fileName.c_str(), &myWavSpec, &myWavBuffer, &wavLength);
+  if(fileName != myWavFilename || myWavBuffer == nullptr)
-  if(result == nullptr || position > wavLength)
+  {
+    if(myWavBuffer)
+    {
+      SDL_FreeWAV(myWavBuffer);
+      myWavBuffer = nullptr;
+    }
+    if(SDL_LoadWAV(fileName.c_str(), &myWavSpec, &myWavBuffer, &myWavLength) == nullptr)
       return false;
-
-  length = length
-    ? std::min(length, wavLength - position)
-    : wavLength;
-
     // Set the callback function
     myWavSpec.callback = wavCallback;
     myWavSpec.userdata = nullptr;
+  }
+  if(position > myWavLength)
+    return false;
 
+  myWavFilename = fileName;
+
+  myWavLen = length
+    ? std::min(length, myWavLength - position)
+    : myWavLength;
   myWavPos = myWavBuffer + position;
-  myWavLen = length;
 
   // Open audio device
+  if(!myWavDevice)
+  {
     const char* device = myDeviceId ? myDevices.at(myDeviceId).first.c_str() : nullptr;
 
     myWavDevice = SDL_OpenAudioDevice(device, 0, &myWavSpec, nullptr, 0);
     if(!myWavDevice)
       return false;
-
     // Play audio
     SDL_PauseAudioDevice(myWavDevice, 0);
-
+  }
   return true;
 }
 
@@ -443,9 +448,10 @@ void SoundSDL2::stopWav()
   if(myWavBuffer)
   {
     // Clean up
+    myWavLen = 0;
     SDL_CloseAudioDevice(myWavDevice);
+    myWavDevice = 0;
     SDL_FreeWAV(myWavBuffer);
-
     myWavBuffer = nullptr;
   }
 }

src/common/SoundSDL2.hxx

@@ -116,8 +116,8 @@ class SoundSDL2 : public Sound
 
       @return  True, if the WAV file can be played
     */
-    bool playWav(const string& fileName, uInt32 position = 0,
+    bool playWav(const string& fileName, const uInt32 position = 0,
-                 uInt32 length = 0) override;
+                 const uInt32 length = 0) override;
 
     /**
       Stop any currently playing WAV file.
@@ -186,6 +186,8 @@ class SoundSDL2 : public Sound
     AudioSettings& myAudioSettings;
 
     // WAV file sound variables
+    string myWavFilename{EmptyString};
+    uInt32 myWavLength{0};
     SDL_AudioDeviceID myWavDevice{0};
     uInt8* myWavBuffer{nullptr};
 

src/emucore/KidVid.cxx

@@ -68,7 +68,7 @@ void KidVid::update()
   {
     // Continue playing song after state load
     const uInt8 temp = ourSongPositions[mySongPointer - 1] & 0x7f;
-    const uInt32 songLength = ourSongStart[temp + 1] - ourSongStart[temp];
+    const uInt32 songLength = ourSongStart[temp + 1] - ourSongStart[temp] - (262 * ClickFrames);
 
     // Play the remaining WAV file
     const string& fileName = myOSystem.baseDir().getPath() + ((temp < 10) ? "KVSHARED.WAV" : getFileName());
@@ -140,6 +140,10 @@ void KidVid::update()
   {
     setPin(DigitalPin::Four, (ourData[myIdx >> 3] << (myIdx & 0x07)) & 0x80);
 
+  #ifdef DEBUG_BUILD
+    cerr << (DigitalPin::Four, (ourData[myIdx >> 3] << (myIdx & 0x07)) & 0x80 ? "X" : ".");
+  #endif
+
     // increase to next bit
     ++myIdx;
     --myBlockIdx;
@@ -172,7 +176,7 @@ void KidVid::update()
     if(mySongPlaying)
     {
       mySongLength = myOSystem.sound().wavSize();
-      myTapeBusy = (mySongLength > 262 * ClickFrames) || !myBeep;
+      myTapeBusy = (mySongLength > 262 * TapeFrames) || !myBeep;
       // Check for end of played sample
       if(mySongLength == 0)
       {
@@ -188,7 +192,7 @@ void KidVid::update()
     if(mySongLength)
     {
       --mySongLength;
-      myTapeBusy = (mySongLength > ClickFrames);
+      myTapeBusy = (mySongLength > TapeFrames);
     }
   }
 }
@@ -259,6 +263,7 @@ void KidVid::openSampleFiles()
     44 + 38 + 42 + 62
   };
 
+#ifdef SOUND_SUPPORT
   if(!myFilesFound)
   {
     int i = myGame == Game::Smurfs ? myTape - 1 : myTape + 2;
@@ -274,6 +279,7 @@ void KidVid::openSampleFiles()
            << "found file: " << "KVSHARED.WAV" << endl;
   #endif
 
+#endif
     mySongLength = 0;
     mySongPointer = firstSongPointer[i];
   }
@@ -288,7 +294,7 @@ void KidVid::setNextSong()
     myBeep = (ourSongPositions[mySongPointer] & 0x80) == 0;
 
     const uInt8 temp = ourSongPositions[mySongPointer] & 0x7f;
-    mySongLength = ourSongStart[temp + 1] - ourSongStart[temp];
+    mySongLength = ourSongStart[temp + 1] - ourSongStart[temp] - (262 * ClickFrames);
 
     // Play the WAV file
     const string& fileName = (temp < 10) ? "KVSHARED.WAV" : getFileName();
@@ -309,7 +315,7 @@ void KidVid::setNextSong()
   {
     myBeep = true;
     myTapeBusy = true;
-    mySongLength = 80;   /* delay needed for Harmony without tape */
+    mySongLength = TapeFrames + 32;   /* delay needed for Harmony without tape */
   }
 }
 
@@ -438,14 +444,14 @@ const std::array<uInt32, KidVid::SongStartSize> KidVid::ourSongStart = {
   3059116,
 
 /* kvs1 */
-  44,          /* Harmony into 1 */
+  44,          /* Harmony intro 1 */
-  164685,      /* falling notes (into 2) */
+  164685,      /* falling notes (intro 2) */
   395182,      /* instructions */
   750335,      /* high notes are high */
   962016,      /* my hat's off to you */
   1204273,     /* 1 2 3 do re mi */
   1538258,     /* Harmony */
-  1801683,     /* concratulations (all of the Smurfs voted) */
+  1801683,     /* congratulations (all of the Smurfs voted) */
   2086276,     /* line or space */
   2399093,     /* hooray */
   2589606,     /* hear yeeh */

src/emucore/KidVid.hxx

@@ -111,7 +111,8 @@ class KidVid : public Controller
       NumBlockBits  = NumBlocks * 8,  // number of bits / block
       SongPosSize   = 44 + 38 + 42 + 62 + 80 + 62,
       SongStartSize = 104,
-      ClickFrames = 48                // eliminate click noise at song end
+      TapeFrames    = 60,
+      ClickFrames   = 3               // eliminate click noise at song end
     ;
 
     // Whether the KidVid device is enabled (only for games that it

src/emucore/Sound.hxx

@@ -114,8 +114,8 @@ class Sound
 
       @return  True, if the WAV file can be played
     */
-    virtual bool playWav(const string& fileName, uInt32 position = 0,
+    virtual bool playWav(const string& fileName, const uInt32 position = 0,
-                         uInt32 length = 0) { return false; }
+                         const uInt32 length = 0) { return false; }
 
     /**
       Stop any currently playing WAV file.