Use SDL_QueueAudio() instead callbacks on filling sound buffer

Fixes some issues when sound buffer get exhausted before refilling.

libmve/movie_sound.cpp

@@ -21,15 +21,6 @@
 
 namespace D3 {
 
-void MovieSoundDevice::SDLAudioCallback(void *userdata, unsigned char *stream, int len) {
-  auto device = static_cast<MovieSoundDevice *>(userdata);
-  for (int i = 0; i < len; i += 2) {
-    int16_t sample = device->m_sound_buffer->front();
-    device->m_sound_buffer->pop_front();
-    memcpy(&stream[i], &sample, 2);
-  }
-}
-
 MovieSoundDevice::MovieSoundDevice(int sample_rate, uint16_t sample_size, uint8_t channels, uint32_t buf_size,
                                    bool is_compressed) {
   SDL_AudioFormat format = (sample_size == 2) ? AUDIO_S16LSB : AUDIO_U8;
@@ -37,8 +28,8 @@ MovieSoundDevice::MovieSoundDevice(int sample_rate, uint16_t sample_size, uint8_
   spec.freq = sample_rate;
   spec.format = format;
   spec.channels = channels;
-  spec.size = 4096;
-  spec.callback = &MovieSoundDevice::SDLAudioCallback;
+  spec.size = buf_size;
+  spec.callback = nullptr;
   spec.userdata = this;
 
   m_device_id = SDL_OpenAudioDevice(nullptr, 0, &spec, nullptr, 0);
@@ -48,16 +39,20 @@ MovieSoundDevice::MovieSoundDevice(int sample_rate, uint16_t sample_size, uint8_
 MovieSoundDevice::~MovieSoundDevice() {
   if (m_device_id > 0) {
     SDL_CloseAudioDevice(m_device_id);
+    m_device_id = 0;
   }
-  m_sound_buffer.reset();
 }
 
+void MovieSoundDevice::FillBuffer(char *stream, int len) const {
+  SDL_QueueAudio(m_device_id, stream, len);
+};
+
 void MovieSoundDevice::Play() { SDL_PauseAudioDevice(m_device_id, 0); }
 
 void MovieSoundDevice::Stop() { SDL_PauseAudioDevice(m_device_id, 1); }
 
-void MovieSoundDevice::Lock() { SDL_LockAudioDevice(m_device_id); };
+void MovieSoundDevice::Lock() { SDL_LockAudioDevice(m_device_id); }
 
-void MovieSoundDevice::Unlock() { SDL_UnlockAudioDevice(m_device_id); };
+void MovieSoundDevice::Unlock() { SDL_UnlockAudioDevice(m_device_id); }
 
 } // namespace D3

libmve/movie_sound.h

@@ -49,19 +49,17 @@ public:
   [[nodiscard]] bool IsInitialized() const { return m_device_id > 0; }
 
   /**
-   * Callback for filling SDL audio buffer
-   * @param userdata pointer to instance of this class
-   * @param stream stream that will be filled on callback
-   * @param len length of stream
+   * Fill internal audio stream to be played
+   * @param stream source buffer
+   * @param len length of source buffer
    */
-  void static SDLAudioCallback(void *userdata, unsigned char *stream, int len);
+  void FillBuffer(char *stream, int len) const;
 
   void Play() override;
   void Stop() override;
   void Lock() override;
   void Unlock() override;
 
-  using ISoundDevice::GetBuffer;
   using ISoundDevice::IsCompressed;
 
 };

libmve/mve_audio.cpp

@@ -16,8 +16,7 @@
  */
 
 #include <algorithm>
-#include <deque>
-#include <memory>
+#include <cstring>
 
 #include "byteswap.h"
 
@@ -62,26 +61,23 @@ static int16_t getWord(unsigned char **fin) {
   return value;
 }
 
-void mveaudio_process(std::unique_ptr<std::deque<int16_t>> &buffer, unsigned char *data, bool is_compressed) {
+void mveaudio_process(char *buffer, unsigned char *data, bool is_compressed) {
   if (is_compressed) {
     int nCurOffsets[2];
 
     data += 4;
-    int swath = getWord(&data) / 2;
+    int samples = getWord(&data) / 2;
+    // Fill predictors
     nCurOffsets[0] = getWord(&data);
     nCurOffsets[1] = getWord(&data);
-    buffer->push_back((int16_t)std::clamp(nCurOffsets[0], -32768, 32767));
-    buffer->push_back((int16_t)std::clamp(nCurOffsets[1], -32768, 32767));
 
-    for (int i = 0; i < swath; i++) {
-      nCurOffsets[i & 1] += audio_exp_table[data[i]];
-      buffer->push_back((int16_t)std::clamp(nCurOffsets[i & 1], -32768, 32767));
+    for (int i = 0; i < samples; i++) {
+      nCurOffsets[i & 1] = std::clamp(nCurOffsets[i & 1] + audio_exp_table[data[i]], -32768, 32767);
+      memcpy(buffer + i * 2, &nCurOffsets[i & 1], 2);
     }
   } else {
     data += 2;
     int samples = getWord(&data);
-    for (int i = 0; i < samples; i++) {
-      buffer->push_back(getWord(&data));
-    }
+    memcpy(buffer, &data, samples * 2);
   }
 }

libmve/mve_audio.h

@@ -24,6 +24,6 @@
  * @param data input data
  * @param is_compress true if input data is compressed
  */
-void mveaudio_process(std::unique_ptr<std::deque<int16_t>> &buffer, unsigned char *data, bool is_compressed = true);
+void mveaudio_process(char *buffer, unsigned char *data, bool is_compressed = true);
 
 #endif /* INCLUDED_MVE_AUDIO_H */

libmve/mveplay.cpp

@@ -184,7 +184,7 @@ static int create_audiobuf_handler(unsigned char major, unsigned char minor, uns
     is_compressed = true;
   }
 
-  snd_ds = std::make_unique<D3::MovieSoundDevice>(sample_rate, sample_size, channels, desired_buffer, is_compressed);
+  snd_ds = std::make_unique<D3::MovieSoundDevice>(sample_rate, sample_size, channels, 4096, is_compressed);
 #endif
 
   return 1;
@@ -204,18 +204,17 @@ static int audio_data_handler(unsigned char major, unsigned char minor, unsigned
   static const int selected_chan = 1;
   if (snd_ds->IsInitialized()) {
     int chan = get_ushort(data + 2);
+    int size = get_ushort(data + 4);
     if (chan & selected_chan) {
+      void *buf = malloc(size);
       if (major == MVE_OPCODE_AUDIOFRAMEDATA) {
-        snd_ds->Lock();
-        mveaudio_process(snd_ds->GetBuffer(), data, snd_ds->IsCompressed());
-        snd_ds->Unlock();
+        mveaudio_process((char *)buf, data, snd_ds->IsCompressed());
       } else {
         // SILENCE, MORTALS!
-        int nsamp = get_ushort(data + 4);
-        snd_ds->Lock();
-        snd_ds->GetBuffer()->insert(snd_ds->GetBuffer()->end(), nsamp, 0);
-        snd_ds->Unlock();
+        memset(data, 0, size);
       }
+      snd_ds->FillBuffer((char *)buf, size);
+      free(buf);
     }
   }
 #endif

libmve/sound_interface.h

@@ -20,19 +20,15 @@
 #define LIBMVE_SOUND_INTERFACE_H_
 
 #include <cstdint>
-#include <deque>
-#include <memory>
 
 namespace D3 {
 
 /// Abstract class for sound device.
 class ISoundDevice {
 protected:
-  std::unique_ptr<std::deque<int16_t>> m_sound_buffer;
   bool m_is_compressed = false;
 
 public:
-  ISoundDevice() { this->m_sound_buffer = std::make_unique<std::deque<int16_t>>(); };
   /// Play stream
   virtual void Play() {};
   /// Stop stream
@@ -42,8 +38,6 @@ public:
   /// Unlock buffer
   virtual void Unlock() {};
 
-  /// Get access to sound buffer
-  std::unique_ptr<std::deque<int16_t>> &GetBuffer() { return m_sound_buffer; }
   /// Check if encoded sound is compressed
   [[nodiscard]] bool IsCompressed() const { return m_is_compressed; };