Add audio decoding support

Makefile

@@ -28,6 +28,7 @@ SOURCES = \
     gamepad.cpp              \
     connectionlistener.cpp   \
     viddec.cpp               \
+    auddec.cpp               \
 
 # Build rules generated by macros from common.mk:
 

auddec.cpp

@@ -0,0 +1,143 @@
+#include "moonlight.hpp"
+
+#define MAX_CHANNEL_COUNT 6
+#define FRAME_SIZE 240
+
+typedef struct decoded_sample_entry {
+    struct decoded_sample_entry *next;
+    int sampleLength;
+    short sampleBuffer[1];
+} decoded_sample_entry_t;
+
+#define MAX_QUEUE_LENGTH 14
+#define QUEUE_PRUNING_LENGTH 7
+
+static int s_OpusChannelCount;
+static decoded_sample_entry_t* s_SampleQueueHead;
+static decoded_sample_entry_t* s_SampleQueueTail;
+static int s_SampleQueueLength;
+static pthread_mutex_t s_SampleQueueLock;
+
+static void ReapSampleQueue() {
+    decoded_sample_entry_t *entry;
+    
+    while (s_SampleQueueHead) {
+        entry = s_SampleQueueHead->next;
+        free(s_SampleQueueHead);
+        s_SampleQueueHead = entry;
+    }
+    
+    s_SampleQueueTail = NULL;
+    
+    s_SampleQueueLength = 0;
+}
+
+static void AudioPlayerSampleCallback(void* samples, uint32_t buffer_size, void* data) {
+    unsigned char* buffer = (unsigned char *)samples;
+    int offset = 0;
+    
+    pthread_mutex_lock(&s_SampleQueueLock);
+
+    while (s_SampleQueueHead && s_SampleQueueHead->sampleLength <= buffer_size - offset) {
+        decoded_sample_entry_t* lastEnt;
+        
+        memcpy(&buffer[offset], s_SampleQueueHead->sampleBuffer, s_SampleQueueHead->sampleLength);
+        offset += s_SampleQueueHead->sampleLength;
+        
+        lastEnt = s_SampleQueueHead;
+        s_SampleQueueHead = s_SampleQueueHead->next;
+        free(lastEnt);
+        s_SampleQueueLength--;
+        
+        // Remove another sample if we're in pruning mode
+        if (s_SampleQueueLength > QUEUE_PRUNING_LENGTH) {
+            lastEnt = s_SampleQueueHead;
+            s_SampleQueueHead = s_SampleQueueHead->next;
+            free(lastEnt);
+            s_SampleQueueLength--;
+        }
+    }
+    
+    if (!s_SampleQueueHead) {
+        s_SampleQueueTail = NULL;
+    }
+    
+    pthread_mutex_unlock(&s_SampleQueueLock);
+    
+    // Zero the remaining portion of the sample buffer to reduce noise when underflowing
+    if (buffer_size != offset) {
+        memset(&buffer[offset], 0, buffer_size - offset);
+    }
+}
+
+void MoonlightInstance::AudDecInit(int audioConfiguration, POPUS_MULTISTREAM_CONFIGURATION opusConfig) {
+    int rc;
+    
+    pthread_mutex_init(&s_SampleQueueLock, NULL);
+    
+    s_OpusChannelCount = opusConfig->channelCount;
+    g_Instance->m_OpusDecoder = opus_multistream_decoder_create(opusConfig->sampleRate,
+                                                                opusConfig->channelCount,
+                                                                opusConfig->streams,
+                                                                opusConfig->coupledStreams,
+                                                                opusConfig->mapping,
+                                                                &rc);
+                                                                
+    pp::AudioConfig audioConfig = pp::AudioConfig(g_Instance, PP_AUDIOSAMPLERATE_48000, FRAME_SIZE * 3);
+    
+    g_Instance->m_AudioPlayer = pp::Audio(g_Instance, audioConfig, AudioPlayerSampleCallback, NULL);
+    
+    // Start playback now
+    g_Instance->m_AudioPlayer.StartPlayback();
+}
+
+void MoonlightInstance::AudDecCleanup(void) {    
+    pthread_mutex_destroy(&s_SampleQueueLock);
+    
+    if (g_Instance->m_OpusDecoder) {
+        opus_multistream_decoder_destroy(g_Instance->m_OpusDecoder);
+    }
+    
+    ReapSampleQueue();
+}
+
+void MoonlightInstance::AudDecDecodeAndPlaySample(char* sampleData, int sampleLength) {
+    decoded_sample_entry_t* entry = (decoded_sample_entry_t*)malloc(sizeof(decoded_sample_entry_t) +
+                                                                    (s_OpusChannelCount * FRAME_SIZE * sizeof(short)));
+    if (entry) {
+        int decodeLen = opus_multistream_decode(g_Instance->m_OpusDecoder, (unsigned char *)sampleData, sampleLength,
+                                                entry->sampleBuffer, FRAME_SIZE, 0);
+        if (decodeLen > 0) {
+            entry->sampleLength = decodeLen * s_OpusChannelCount * sizeof(short);
+            entry->next = NULL;
+            
+            pthread_mutex_lock(&s_SampleQueueLock);
+            
+            if (s_SampleQueueLength == MAX_QUEUE_LENGTH) {
+                printf("Reaped sample queue\n");
+                ReapSampleQueue();
+            }
+            
+            if (!s_SampleQueueTail) {
+                s_SampleQueueHead = s_SampleQueueTail = entry;
+            }
+            else {
+                s_SampleQueueTail->next = entry;
+                s_SampleQueueTail = entry;
+            }
+            
+            s_SampleQueueLength++;
+            
+            pthread_mutex_unlock(&s_SampleQueueLock);
+        }
+        else {
+            free(entry);
+        }
+    }
+}
+
+AUDIO_RENDERER_CALLBACKS MoonlightInstance::s_ArCallbacks = {
+    MoonlightInstance::AudDecInit,
+    MoonlightInstance::AudDecCleanup,
+    MoonlightInstance::AudDecDecodeAndPlaySample
+};

main.cpp

@@ -53,7 +53,7 @@ void* MoonlightInstance::ConnectionThreadFunc(void* context) {
                             &s_StreamConfig,
                             &MoonlightInstance::s_ClCallbacks,
                             &MoonlightInstance::s_DrCallbacks,
-                            NULL,
+                            &MoonlightInstance::s_ArCallbacks,
                             NULL, 0, 4);
     if (err != 0) {
         pp::Var response("Starting connection failed");

moonlight.hpp

@@ -4,6 +4,7 @@
 #include "ppapi/cpp/mouse_lock.h"
 #include "ppapi/cpp/graphics_3d.h"
 #include "ppapi/cpp/video_decoder.h"
+#include "ppapi/cpp/audio.h"
 
 #include "ppapi/c/ppb_gamepad.h"
 #include "ppapi/c/pp_input_event.h"
@@ -22,6 +23,8 @@
 
 #include <Limelight.h>
 
+#include <opus_multistream.h>
+
 struct Shader {
   Shader() : program(0), texcoord_scale_location(0) {}
   ~Shader() {}
@@ -36,6 +39,7 @@ class MoonlightInstance : public pp::Instance, public pp::MouseLock {
             pp::Instance(instance),
             pp::MouseLock(this),
             m_IsPainting(false),
+            m_OpusDecoder(NULL),
             m_CallbackFactory(this),
             m_MouseLocked(false),
             m_KeyModifiers(0) {            
@@ -90,9 +94,14 @@ class MoonlightInstance : public pp::Instance, public pp::MouseLock {
         static void VidDecCleanup(void);
         static int VidDecSubmitDecodeUnit(PDECODE_UNIT decodeUnit);
         
+        static void AudDecInit(int audioConfiguration, POPUS_MULTISTREAM_CONFIGURATION opusConfig);
+        static void AudDecCleanup(void);
+        static void AudDecDecodeAndPlaySample(char* sampleData, int sampleLength);
+        
     private:
         static CONNECTION_LISTENER_CALLBACKS s_ClCallbacks;
         static DECODER_RENDERER_CALLBACKS s_DrCallbacks;
+        static AUDIO_RENDERER_CALLBACKS s_ArCallbacks;
     
         pp::Graphics3D m_Graphics3D;
         pp::VideoDecoder* m_VideoDecoder;
@@ -103,6 +112,9 @@ class MoonlightInstance : public pp::Instance, public pp::MouseLock {
         std::queue<PP_VideoPicture> m_PendingPictureQueue;
         bool m_IsPainting;
         
+        OpusMSDecoder* m_OpusDecoder;
+        pp::Audio m_AudioPlayer;
+        
         double m_LastPadTimestamps[4];
         const PPB_Gamepad* m_GamepadApi;
         pp::CompletionCallbackFactory<MoonlightInstance> m_CallbackFactory;