From 0bde9325507a392c36b9d82a1716a4930ac9b6c7 Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Thu, 26 Jul 2018 19:26:22 -0700
Subject: [PATCH] Prevent HEVC streaming with the software decoder for
 performance reasons

---
 app/streaming/session.cpp                    | 33 ++++++++++++--------
 app/streaming/video/ffmpeg-renderers/sdl.cpp | 12 ++++++-
 2 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/app/streaming/session.cpp b/app/streaming/session.cpp
index e4bb74cb..f6639583 100644
--- a/app/streaming/session.cpp
+++ b/app/streaming/session.cpp
@@ -310,23 +310,30 @@ bool Session::validateLaunch()
     QStringList warningList;
 
     if (m_StreamConfig.supportsHevc) {
-        if (m_Preferences.videoCodecConfig == StreamingPreferences::VCC_FORCE_HEVC ||
-                m_Preferences.videoCodecConfig == StreamingPreferences::VCC_FORCE_HEVC_HDR) {
-            if (m_Computer->maxLumaPixelsHEVC == 0) {
-                emit displayLaunchWarning("Your host PC GPU doesn't support HEVC. "
-                                          "A GeForce GTX 900-series (Maxwell) or later GPU is required for HEVC streaming.");
-            }
-        }
-        else if (!isHardwareDecodeAvailable(m_Preferences.videoDecoderSelection,
-                                            VIDEO_FORMAT_H265,
-                                            m_StreamConfig.width,
-                                            m_StreamConfig.height,
-                                            m_StreamConfig.fps)) {
+        bool hevcForced = m_Preferences.videoCodecConfig == StreamingPreferences::VCC_FORCE_HEVC ||
+                m_Preferences.videoCodecConfig == StreamingPreferences::VCC_FORCE_HEVC_HDR;
+
+        if (!isHardwareDecodeAvailable(m_Preferences.videoDecoderSelection,
+                                       VIDEO_FORMAT_H265,
+                                       m_StreamConfig.width,
+                                       m_StreamConfig.height,
+                                       m_StreamConfig.fps)) {
             // NOTE: HEVC currently uses only 1 slice regardless of what
             // we provide in CAPABILITY_SLICES_PER_FRAME(), so we should
             // never use it for software decoding (unless common-c starts
             // respecting it for HEVC).
             m_StreamConfig.supportsHevc = false;
+
+            if (hevcForced) {
+                emit displayLaunchWarning("This PC's GPU doesn't support HEVC decoding.");
+            }
+        }
+
+        if (hevcForced) {
+            if (m_Computer->maxLumaPixelsHEVC == 0) {
+                emit displayLaunchWarning("Your host PC GPU doesn't support HEVC. "
+                                          "A GeForce GTX 900-series (Maxwell) or later GPU is required for HEVC streaming.");
+            }
         }
     }
 
@@ -348,7 +355,7 @@ bool Session::validateLaunch()
                                             m_StreamConfig.width,
                                             m_StreamConfig.height,
                                             m_StreamConfig.fps)) {
-            emit displayLaunchWarning("Your client PC GPU doesn't support HEVC Main10 decoding for HDR streaming.");
+            emit displayLaunchWarning("This PC's GPU doesn't support HEVC Main10 decoding for HDR streaming.");
         }
         else {
             // TODO: Also validate display capabilites
diff --git a/app/streaming/video/ffmpeg-renderers/sdl.cpp b/app/streaming/video/ffmpeg-renderers/sdl.cpp
index 69ad5e40..5244172a 100644
--- a/app/streaming/video/ffmpeg-renderers/sdl.cpp
+++ b/app/streaming/video/ffmpeg-renderers/sdl.cpp
@@ -1,5 +1,7 @@
 #include "renderer.h"
 
+#include <Limelight.h>
+
 SdlRenderer::SdlRenderer()
     : m_Renderer(nullptr),
       m_Texture(nullptr)
@@ -25,10 +27,18 @@ bool SdlRenderer::prepareDecoderContext(AVCodecContext*)
 }
 
 bool SdlRenderer::initialize(SDL_Window* window,
-                             int,
+                             int videoFormat,
                              int width,
                              int height)
 {
+    // NOTE: HEVC currently uses only 1 slice regardless of what
+    // we provide in CAPABILITY_SLICES_PER_FRAME(), so we should
+    // never use it for software decoding (unless common-c starts
+    // respecting it for HEVC).
+    if (videoFormat != VIDEO_FORMAT_H264) {
+        return false;
+    }
+
     m_Renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
     if (!m_Renderer) {
         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,