feat(ddprobe): allow to manually specify gpu preference (#3521)

src/config.cpp

@@ -436,6 +436,7 @@ namespace config {
     {},  // capture
     {},  // encoder
     {},  // adapter_name
+    -1,  // gpu_preference
     {},  // output_name
 
     {
@@ -1088,6 +1089,7 @@ namespace config {
     string_f(vars, "capture", video.capture);
     string_f(vars, "encoder", video.encoder);
     string_f(vars, "adapter_name", video.adapter_name);
+    int_f(vars, "gpu_preference", video.gpu_preference);
     string_f(vars, "output_name", video.output_name);
 
     generic_f(vars, "dd_configuration_option", video.dd.configuration_option, dd::config_option_from_view);

src/config.h

@@ -77,6 +77,7 @@ namespace config {
     std::string capture;
     std::string encoder;
     std::string adapter_name;
+    int gpu_preference;
     std::string output_name;
 
     struct dd_t {

src/platform/windows/display_base.cpp

@@ -386,12 +386,7 @@ namespace platf::dxgi {
       // would have been raised first if it wasn't.
       if (result == S_OK || result == E_ACCESSDENIED) {
         // We found a working GPU preference, so set ourselves to use that.
-        if (set_gpu_preference_on_self(i)) {
-          return true;
-        }
-        else {
-          return false;
-        }
+        return set_gpu_preference_on_self(i);
       }
     }
 
@@ -418,16 +413,25 @@ namespace platf::dxgi {
       return true;
     }
 
-    // Try probing with different GPU preferences and verify_frame_capture flag
-    if (validate_and_test_gpu_preference(display_name, true)) {
-      set_gpu_preference = true;
-      return true;
+    // If the GPU preference was manually specified, we can skip the probe.
+    if (config::video.gpu_preference >= 0) {
+      if (set_gpu_preference_on_self(config::video.gpu_preference)) {
+        set_gpu_preference = true;
+        return true;
+      }
     }
+    else {
+      // Try probing with different GPU preferences and verify_frame_capture flag
+      if (validate_and_test_gpu_preference(display_name, true)) {
+        set_gpu_preference = true;
+        return true;
+      }
 
-    // If no valid configuration was found, try again with verify_frame_capture == false
-    if (validate_and_test_gpu_preference(display_name, false)) {
-      set_gpu_preference = true;
-      return true;
+      // If no valid configuration was found, try again with verify_frame_capture == false
+      if (validate_and_test_gpu_preference(display_name, false)) {
+        set_gpu_preference = true;
+        return true;
+      }
     }
 
     // If neither worked, return false