fix(video): allow encoder probing when there are no devices at all (#3594)

src/display_device.cpp

@@ -810,19 +810,15 @@ namespace display_device {
     });
   }
 
-  bool is_any_device_active() {
+  EnumeratedDeviceList enumerate_devices() {
     std::lock_guard lock {DD_DATA.mutex};
     if (!DD_DATA.sm_instance) {
-      // Platform is not supported, assume success.
-      return true;
+      // Platform is not supported.
+      return {};
     }
 
     return DD_DATA.sm_instance->execute([](auto &settings_iface) {
-      const auto devices {settings_iface.enumAvailableDevices()};
-      // If at least one device has additional info, it is active.
-      return std::any_of(std::begin(devices), std::end(devices), [](const auto &device) {
-        return static_cast<bool>(device.m_info);
-      });
+      return settings_iface.enumAvailableDevices();
     });
   }
 

src/display_device.h

@@ -121,14 +121,14 @@ namespace display_device {
   [[nodiscard]] bool reset_persistence();
 
   /**
-   * @brief Check if any of the display devices is currently active.
-   * @return True if at least one device is active.
+   * @brief Enumerate the available devices.
+   * @return A list of devices.
    *
    * @examples
-   * const auto result = is_any_device_active();
+   * const auto devices = enumerate_devices();
    * @examples_end
    */
-  [[nodiscard]] bool is_any_device_active();
+  [[nodiscard]] EnumeratedDeviceList enumerate_devices();
 
   /**
    * @brief A tag structure indicating that configuration parsing has failed.

src/video.cpp

@@ -40,6 +40,37 @@ using namespace std::literals;
 
 namespace video {
 
+  namespace {
+    /**
+     * @brief Check if we can allow probing for the encoders.
+     * @return True if there should be no issues with the probing, false if we should prevent it.
+     */
+    bool allow_encoder_probing() {
+      const auto devices {display_device::enumerate_devices()};
+
+      // If there are no devices, then either the API is not working correctly or OS does not support the lib.
+      // Either way we should not block the probing in this case as we can't tell what's wrong.
+      if (devices.empty()) {
+        return true;
+      }
+
+      // Since Windows 11 24H2, it is possible that there will be no active devices present
+      // for some reason (probably a bug). Trying to probe encoders in such a state locks/breaks the DXGI
+      // and also the display device for Windows. So we must have at least 1 active device.
+      const bool at_least_one_device_is_active = std::any_of(std::begin(devices), std::end(devices), [](const auto &device) {
+        // If device has additional info, it is active.
+        return static_cast<bool>(device.m_info);
+      });
+
+      if (at_least_one_device_is_active) {
+        return true;
+      }
+
+      BOOST_LOG(error) << "No display devices are active at the moment! Cannot probe the encoders.";
+      return false;
+    }
+  }  // namespace
+
   void free_ctx(AVCodecContext *ctx) {
     avcodec_free_context(&ctx);
   }
@@ -2550,8 +2581,8 @@ namespace video {
   }
 
   int probe_encoders() {
-    if (!display_device::is_any_device_active()) {
-      BOOST_LOG(error) << "No display devices are active at the moment! Cannot probe encoders as this could break Sunshine.";
+    if (!allow_encoder_probing()) {
+      // Error already logged
       return -1;
     }