config: add min_fps setting

docs/source/about/advanced_usage.rst

@@ -378,6 +378,26 @@ dwmflush
 
       dwmflush = enabled
 
+min_fps_target
+^^^^^^^^^^^^^^
+
+**Description**
+   The minimum FPS Sunshine will attempt to maintain. Increasing this value slightly may help when streaming
+   mostly static content.
+
+   .. Warning:: Higher values will consume more bandwidth.
+
+**Default**
+   ``10``
+
+**Range**
+   ``1-240``
+
+**Example**
+   .. code-block:: text
+
+      min_fps_target = 10
+
 Audio
 -----
 

src/config.cpp

@@ -314,7 +314,8 @@ video_t video {
 
   0, // hevc_mode
 
-  1, // min_threads
+  10, // min_fps_target
+  1,  // min_threads
   {
     "superfast"s,   // preset
     "zerolatency"s, // tune
@@ -886,6 +887,7 @@ void apply_config(std::unordered_map<std::string, std::string> &&vars) {
   string_f(vars, "adapter_name", video.adapter_name);
   string_f(vars, "output_name", video.output_name);
   bool_f(vars, "dwmflush", video.dwmflush);
+  int_between_f(vars, "min_fps_target", video.min_fps_target, { 1, 240 });
 
   path_f(vars, "pkey", nvhttp.pkey);
   path_f(vars, "cert", nvhttp.cert);

src/config.h

@@ -15,6 +15,7 @@ struct video_t {
 
   int hevc_mode;
 
+  int min_fps_target;     // Minimum fps target, determines minimum frame time
   int min_threads; // Minimum number of threads/slices for CPU encoding
   struct {
     std::string sw_preset;

src/video.cpp

@@ -1281,6 +1281,10 @@ void encode_run(
   const encoder_t &encoder,
   void *channel_data) {
 
+  // set minimum frame time
+  auto minimum_frame_time = std::chrono::milliseconds(1000 / config::video.min_fps_target);
+  BOOST_LOG(info) << "Minimum frame time set to "sv << minimum_frame_time.count() << "ms, based on min fps target of "sv << config::video.min_fps_target << "."sv;
+
   auto session = make_session(disp.get(), encoder, config, disp->width, disp->height, std::move(hwdevice));
   if(!session) {
     return;
@@ -1311,9 +1315,9 @@ void encode_run(
       idr_events->pop();
     }
 
-    // Encode at a minimum of 10 FPS to avoid image quality issues with static content
+    // Encode at a minimum of FPS to avoid image quality issues with static content
     if(!frame->key_frame || images->peek()) {
-      if(auto img = images->pop(100ms)) {
+      if(auto img = images->pop(minimum_frame_time)) {
         if(session->device->convert(*img)) {
           BOOST_LOG(error) << "Could not convert image"sv;
           return;

src_assets/common/assets/web/config.html

@@ -502,6 +502,22 @@ <h1 class="my-4">Configuration</h1>
           Disable if you encounter any VSync-related issues.
         </div>
       </div>
+      <!--min_fps_target-->
+      <div class="mb-3">
+        <label for="qp" class="form-label">Minimum FPS Target</label>
+        <input
+          type="number"
+          class="form-control"
+          id="min_fps_target"
+          placeholder="10"
+          v-model="config.min_fps_target"
+        />
+        <div class="form-text">
+          The minimum FPS Sunshine will attempt to maintain.<br />
+          Increasing this value slightly may help when streaming mostly static content.<br />
+          Higher values will consume more bandwidth.<br />
+        </div>
+      </div>
       <div class="mb-3" class="config-page" v-if="platform === 'linux'">
         <label for="output_name" class="form-label">Monitor number</label>
         <input
@@ -547,7 +563,7 @@ <h1 class="my-4">Configuration</h1>
           Quantization Parameter<br />
           Some devices may not support Constant Bit Rate.<br />
           For those devices, QP is used instead.<br />
-          Higher value means more compression, but less quality<br />
+          Higher value means more compression, but less quality.<br />
         </div>
       </div>
       <!-- Min Threads -->
@@ -914,6 +930,7 @@ <h1 class="my-4">Configuration</h1>
     "dwmflush": "enabled",
     "encoder": "",
     "fps": "[10,30,60,90,120]",
+    "min_fps_target": 10,
     "gamepad": "x360",
     "hevc_mode": 0,
     "key_rightalt_to_key_win": "disabled",