From 762fe929332e3c18f8849b2bd5af5cd64d248364 Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Fri, 31 Aug 2018 00:09:31 -0400
Subject: [PATCH] Allow streaming with no audio device. Fixes #52

---
 app/streaming/audio.cpp   | 56 ++++++++++++++++++++++++++++++++++++++-
 app/streaming/session.cpp | 12 +++++++--
 app/streaming/session.hpp |  3 +++
 3 files changed, 68 insertions(+), 3 deletions(-)

diff --git a/app/streaming/audio.cpp b/app/streaming/audio.cpp
index 325eb1b6..dd2958ab 100644
--- a/app/streaming/audio.cpp
+++ b/app/streaming/audio.cpp
@@ -70,6 +70,60 @@ Exit:
     return ret;
 }
 
+bool Session::testAudio(int audioConfiguration)
+{
+    SDL_AudioSpec want, have;
+    SDL_AudioDeviceID dev;
+    bool ret;
+
+    if (SDL_InitSubSystem(SDL_INIT_AUDIO) != 0) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "Audio test - SDL_InitSubSystem(SDL_INIT_AUDIO) failed: %s",
+                     SDL_GetError());
+        return false;
+    }
+
+    SDL_zero(want);
+    want.freq = 48000;
+    want.format = AUDIO_S16;
+    want.samples = SAMPLES_PER_FRAME;
+
+    switch (audioConfiguration) {
+    case AUDIO_CONFIGURATION_STEREO:
+        want.channels = 2;
+        break;
+    case AUDIO_CONFIGURATION_51_SURROUND:
+        want.channels = 6;
+        break;
+    default:
+        SDL_assert(false);
+        ret = false;
+        goto Exit;
+    }
+
+    // Test audio device for functionality
+    dev = SDL_OpenAudioDevice(NULL, 0, &want, &have, 0);
+    if (dev == 0) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "Audio test - Failed to open audio device: %s",
+                     SDL_GetError());
+        ret = false;
+        goto Exit;
+    }
+
+    SDL_CloseAudioDevice(dev);
+
+    SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                "Audio test - Successful with %d channels",
+                want.channels);
+
+    ret = true;
+
+Exit:
+    SDL_QuitSubSystem(SDL_INIT_AUDIO);
+    return ret;
+}
+
 int Session::sdlAudioInit(int /* audioConfiguration */,
                           POPUS_MULTISTREAM_CONFIGURATION opusConfig,
                           void* /* arContext */, int /* arFlags */)
@@ -82,7 +136,7 @@ int Session::sdlAudioInit(int /* audioConfiguration */,
         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                      "SDL_InitSubSystem(SDL_INIT_AUDIO) failed: %s",
                      SDL_GetError());
-        return AUDIO_CONFIGURATION_STEREO;
+        return -1;
     }
 
     SDL_zero(want);
diff --git a/app/streaming/session.cpp b/app/streaming/session.cpp
index dbee8173..6c1cd69d 100644
--- a/app/streaming/session.cpp
+++ b/app/streaming/session.cpp
@@ -275,7 +275,8 @@ Session::Session(NvComputer* computer, NvApp& app)
       m_Window(nullptr),
       m_VideoDecoder(nullptr),
       m_DecoderLock(0),
-      m_NeedsIdr(false)
+      m_NeedsIdr(false),
+      m_AudioDisabled(false)
 {
     qDebug() << "Server GPU:" << m_Computer->gpuModel;
 
@@ -472,6 +473,12 @@ bool Session::validateLaunch()
         }
     }
 
+    // Test that audio hardware is functional
+    m_AudioDisabled = !testAudio(m_StreamConfig.audioConfiguration);
+    if (m_AudioDisabled) {
+        emitLaunchWarning("Failed to open audio device. Audio will be unavailable during this session.");
+    }
+
     if (m_Preferences.videoDecoderSelection == StreamingPreferences::VDS_FORCE_HARDWARE &&
             !isHardwareDecodeAvailable(m_Preferences.videoDecoderSelection,
                                        m_StreamConfig.supportsHevc ? VIDEO_FORMAT_H265 : VIDEO_FORMAT_H264,
@@ -688,7 +695,8 @@ void Session::exec()
     }
 
     int err = LiStartConnection(&hostInfo, &m_StreamConfig, &k_ConnCallbacks,
-                                &m_VideoCallbacks, &k_AudioCallbacks,
+                                &m_VideoCallbacks,
+                                m_AudioDisabled ? nullptr : &k_AudioCallbacks,
                                 NULL, 0, NULL, 0);
     if (err != 0) {
         // We already displayed an error dialog in the stage failure
diff --git a/app/streaming/session.hpp b/app/streaming/session.hpp
index 2cc623bf..8f07baf9 100644
--- a/app/streaming/session.hpp
+++ b/app/streaming/session.hpp
@@ -49,6 +49,8 @@ private:
 
     int sdlDetermineAudioConfiguration();
 
+    bool testAudio(int audioConfiguration);
+
     void getWindowDimensions(bool fullScreen,
                              int& x, int& y,
                              int& width, int& height);
@@ -107,6 +109,7 @@ private:
     IVideoDecoder* m_VideoDecoder;
     SDL_SpinLock m_DecoderLock;
     bool m_NeedsIdr;
+    bool m_AudioDisabled;
 
     int m_ActiveVideoFormat;
     int m_ActiveVideoWidth;