platform/windows: add DwmFlush() call to improve Windows capture

CMakeLists.txt

@@ -122,6 +122,7 @@ if(WIN32)
 		ws2_32
 		d3d11 dxgi D3DCompiler
 		setupapi
+		dwmapi
 		)
 
 	set_source_files_properties(third-party/ViGEmClient/src/ViGEmClient.cpp PROPERTIES COMPILE_DEFINITIONS "UNICODE=1;ERROR_INVALID_DEVICE_OBJECT_PARAMETER=650")

docs/source/about/advanced_usage.rst

@@ -333,6 +333,26 @@ Example
         3840x1600,
       ]
 
+dwmflush
+^^^^^^^^
+
+Description
+   Invoke DwmFlush() to sync screen capture to the Windows presentation interval.
+
+   .. Caution:: Applies to Windows only. Alleviates visual stuttering during mouse movement.
+      If enabled, this feature will automatically deactivate if the client framerate exceeds
+      the host monitor's current refresh rate.
+
+Default
+   ``enabled``
+
+Examples
+
+   Windows
+      .. code-block:: text
+
+         dwmflush = enabled
+
 Audio
 -----
 

src_assets/common/assets/web/config.html

@@ -37,13 +37,13 @@ <h1 class="my-4">Configuration</h1>
           class="form-select"
           v-model="config.min_log_level"
         >
-          <option :value="0">Verbose</option>
-          <option :value="1">Debug</option>
-          <option :value="2">Info</option>
-          <option :value="3">Warning</option>
-          <option :value="4">Error</option>
-          <option :value="5">Fatal</option>
-          <option :value="6">None</option>
+          <option value="0">Verbose</option>
+          <option value="1">Debug</option>
+          <option value="2">Info</option>
+          <option value="3">Warning</option>
+          <option value="4">Error</option>
+          <option value="5">Fatal</option>
+          <option value="6">None</option>
         </select>
         <div class="form-text">
           The minimum log level printed to standard out
@@ -400,7 +400,18 @@ <h1 class="my-4">Configuration</h1>
           You can select the video card you want to stream:<br />
           The appropriate values can be found using the following command:<br />
           tools\dxgi-info.exe<br />
-          <br />
+        </div>
+      </div>
+      <!--DwmFlush-->
+      <div class="mb-3" v-if="platform === 'windows'">
+        <label for="dwmflush" class="form-label">DwmFlush</label>
+        <select id="dwmflush" class="form-select" v-model="config.dwmflush">
+          <option value="disabled">Disabled</option>
+          <option value="enabled">Enabled</option>
+        </select>
+        <div class="form-text">
+          Improves capture latency/smoothness during mouse movement.<br />
+          Disable if you encounter any VSync-related issues.
         </div>
       </div>
       <div class="mb-3" class="config-page" v-if="platform === 'linux'">
@@ -497,7 +508,7 @@ <h1 class="my-4">Configuration</h1>
       <div class="mb-3">
         <label for="encoder" class="form-label">Force a Specific Encoder</label>
         <select id="encoder" class="form-select" v-model="config.encoder">
-          <option :value="''">Autodetect</option>
+          <option value>Autodetect</option>
           <option value="nvenc">nVidia NVENC</option>
           <option value="amdvce">AMD AMF/VCE</option>
           <option value="vaapi">VA-API</option>
@@ -696,7 +707,7 @@ <h1 class="my-4">Configuration</h1>
         </select>
       </div>
       <div class="mb-3">
-        <label for="amd_coder" class="form-label">AMD AMF Rate Control</label>
+        <label for="amd_coder" class="form-label">AMD AMF Coder</label>
         <select id="amd_coder" class="form-select" v-model="config.amd_coder">
           <option value="auto">auto</option>
           <option value="cabac">cabac</option>
@@ -832,6 +843,7 @@ <h1 class="my-4">Configuration</h1>
             this.config.key_rightalt_to_key_win || "disabled";
           this.config.gamepad = this.config.gamepad || "x360";
           this.config.upnp = this.config.upnp || "disabled";
+          this.config.dwmflush = this.config.dwmflush || "enabled";
           this.config.min_log_level = this.config.min_log_level || 2;
           this.config.origin_pin_allowed =
             this.config.origin_pin_allowed || "pc";
@@ -842,6 +854,7 @@ <h1 class="my-4">Configuration</h1>
           this.config.nv_preset = this.config.nv_preset || "default";
           this.config.nv_rc = this.config.nv_rc || "auto";
           this.config.nv_coder = this.config.nv_coder || "auto";
+          this.config.amd_coder = this.config.amd_coder || "auto"
           this.config.amd_quality = this.config.amd_quality || "default";
           this.config.amd_rc = this.config.amd_rc || "auto";
           this.config.vt_coder = this.config.vt_coder || "auto";

sunshine/config.cpp

@@ -220,9 +220,16 @@ video_t video {
     std::nullopt,
     -1 }, // amd
 
-  {}, // encoder
-  {}, // adapter_name
-  {}, // output_name
+  {
+    0,
+    0,
+    1,
+    -1 }, // vt
+
+  {},  // encoder
+  {},  // adapter_name
+  {},  // output_name
+  true // dwmflush
 };
 
 audio_t audio {};
@@ -722,16 +729,14 @@ void apply_config(std::unordered_map<std::string, std::string> &&vars) {
   }
 
   int_f(vars, "vt_coder", video.vt.coder, vt::coder_from_view);
-  video.vt.allow_sw = 0;
   int_f(vars, "vt_software", video.vt.allow_sw, vt::allow_software_from_view);
-  video.vt.require_sw = 0;
   int_f(vars, "vt_software", video.vt.require_sw, vt::force_software_from_view);
-  video.vt.realtime = 1;
   int_f(vars, "vt_realtime", video.vt.realtime, vt::rt_from_view);
 
   string_f(vars, "encoder", video.encoder);
   string_f(vars, "adapter_name", video.adapter_name);
   string_f(vars, "output_name", video.output_name);
+  bool_f(vars, "dwmflush", video.dwmflush);
 
   path_f(vars, "pkey", nvhttp.pkey);
   path_f(vars, "cert", nvhttp.cert);

sunshine/config.h

@@ -44,6 +44,7 @@ struct video_t {
   std::string encoder;
   std::string adapter_name;
   std::string output_name;
+  bool dwmflush;
 };
 
 struct audio_t {

sunshine/platform/windows/display.h

@@ -8,6 +8,7 @@
 #include <d3d11.h>
 #include <d3d11_4.h>
 #include <d3dcommon.h>
+#include <dwmapi.h>
 #include <dxgi.h>
 #include <dxgi1_2.h>
 
@@ -95,6 +96,7 @@ class duplication_t {
 public:
   dup_t dup;
   bool has_frame {};
+  bool use_dwmflush {};
 
   capture_e next_frame(DXGI_OUTDUPL_FRAME_INFO &frame_info, std::chrono::milliseconds timeout, resource_t::pointer *res_p);
   capture_e reset(dup_t::pointer dup_p = dup_t::pointer());
@@ -172,4 +174,4 @@ class display_vram_t : public display_base_t, public std::enable_shared_from_thi
 };
 } // namespace platf::dxgi
 
-#endif
+#endif

sunshine/platform/windows/display_base.cpp

@@ -2,6 +2,7 @@
 // Created by loki on 1/12/20.
 //
 
+#include <cmath>
 #include <codecvt>
 
 #include "display.h"
@@ -20,6 +21,10 @@ capture_e duplication_t::next_frame(DXGI_OUTDUPL_FRAME_INFO &frame_info, std::ch
     return capture_status;
   }
 
+  if(use_dwmflush) {
+    DwmFlush();
+  }
+
   auto status = dup->AcquireNextFrame(timeout.count(), &frame_info, res_p);
 
   switch(status) {
@@ -213,6 +218,21 @@ int display_base_t::init(int framerate, const std::string &display_name) {
     << "Offset             : "sv << offset_x << 'x' << offset_y << std::endl
     << "Virtual Desktop    : "sv << env_width << 'x' << env_height;
 
+  // Enable DwmFlush() only if the current refresh rate can match the client framerate.
+  auto refresh_rate = framerate;
+  DWM_TIMING_INFO timing_info;
+  timing_info.cbSize = sizeof(timing_info);
+
+  status = DwmGetCompositionTimingInfo(NULL, &timing_info);
+  if(FAILED(status)) {
+    BOOST_LOG(warning) << "Failed to detect active refresh rate.";
+  }
+  else {
+    refresh_rate = std::round((double)timing_info.rateRefresh.uiNumerator / (double)timing_info.rateRefresh.uiDenominator);
+  }
+
+  dup.use_dwmflush = config::video.dwmflush && !(framerate > refresh_rate) ? true : false;
+
   // Bump up thread priority
   {
     const DWORD flags = TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY;