Add SLAudio renderer for Steam Link

app/streaming/audio/audio.cpp

@@ -5,18 +5,24 @@
 #include "renderers/soundioaudiorenderer.h"
 #endif
 
+#ifdef HAVE_SLAUDIO
+#include "renderers/slaud.h"
+#endif
+
 #include "renderers/sdl.h"
 
 #include <Limelight.h>
 
 IAudioRenderer* Session::createAudioRenderer()
 {
-#ifdef HAVE_SOUNDIO
+#if defined(HAVE_SOUNDIO)
     if (qgetenv("ML_AUDIO") == "SDL") {
         return new SdlAudioRenderer();
     }
 
     return new SoundIoAudioRenderer();
+#elif defined(HAVE_SLAUDIO)
+    return new SLAudioRenderer();
 #else
     return new SdlAudioRenderer();
 #endif

app/streaming/audio/renderers/slaud.cpp

@@ -0,0 +1,58 @@
+#include "slaud.h"
+
+#include <SDL.h>
+
+SLAudioRenderer::SLAudioRenderer()
+    : m_AudioContext(nullptr),
+      m_AudioStream(nullptr)
+{
+}
+
+bool SLAudioRenderer::prepareForPlayback(const OPUS_MULTISTREAM_CONFIGURATION* opusConfig)
+{
+    m_AudioContext = SLAudio_CreateContext();
+    if (m_AudioContext == nullptr) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "SLAudio_CreateContext() failed");
+        return false;
+    }
+
+    m_AudioStream = SLAudio_CreateStream(m_AudioContext,
+                                         opusConfig->sampleRate,
+                                         opusConfig->channelCount,
+                                         SAMPLES_PER_FRAME * sizeof(short) * opusConfig->channelCount,
+                                         1);
+    if (m_AudioStream == nullptr) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "SLAudio_CreateStream() failed");
+        return false;
+    }
+
+    SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                "Using SLAudio renderer");
+
+    return true;
+}
+
+SLAudioRenderer::~SLAudioRenderer()
+{
+    if (m_AudioStream != nullptr) {
+        SLAudio_FreeStream(m_AudioStream);
+    }
+
+    if (m_AudioContext != nullptr) {
+        SLAudio_FreeContext(m_AudioContext);
+    }
+}
+
+bool SLAudioRenderer::submitAudio(short* audioBuffer, int audioSize)
+{
+    void* outputBuffer = SLAudio_BeginFrame(m_AudioStream);
+
+    if (outputBuffer != nullptr) {
+        memcpy(outputBuffer, audioBuffer, audioSize);
+        SLAudio_SubmitFrame(m_AudioStream);
+    }
+
+    return true;
+}

app/streaming/audio/renderers/slaud.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "renderer.h"
+#include <SLAudio.h>
+
+class SLAudioRenderer : public IAudioRenderer
+{
+public:
+    SLAudioRenderer();
+
+    virtual ~SLAudioRenderer();
+
+    virtual bool prepareForPlayback(const OPUS_MULTISTREAM_CONFIGURATION* opusConfig);
+
+    virtual bool submitAudio(short* audioBuffer, int audioSize);
+
+private:
+    CSLAudioContext* m_AudioContext;
+    CSLAudioStream* m_AudioStream;
+};