Add SLAudio renderer for Steam Link

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;
+}