win-dshow: Add 'deactivate when not showing' option

Useful for two purposes:

1.) When many devices are hooked up to the system and used in separate
scenes, but only one device active at once is desired

2.) Allows users who are dependent on outputting audio to desktop to
disable that audio (via disabling that device) when the device isn't
being displayed

plugins/win-dshow/data/locale/en-US.ini

@@ -31,6 +31,7 @@ Buffering.Disable="Disable"
 Activate="Activate"
 Deactivate="Deactivate"
 FlipVertically="Flip Vertically"
+DeactivateWhenNotShowing="Deactivate when not showing"
 
 # encoder text
 Bitrate="Bitrate"

plugins/win-dshow/win-dshow.cpp

@@ -43,6 +43,7 @@ using namespace DShow;
 #define AUDIO_DEVICE_ID   "audio_device_id"
 #define COLOR_SPACE       "color_space"
 #define COLOR_RANGE       "color_range"
+#define DEACTIVATE_WNS    "deactivate_when_not_showing"
 
 #define TEXT_INPUT_NAME     obs_module_text("VideoCaptureDevice")
 #define TEXT_DEVICE         obs_module_text("Device")
@@ -74,6 +75,7 @@ using namespace DShow;
 #define TEXT_COLOR_RANGE    obs_module_text("ColorRange")
 #define TEXT_RANGE_PARTIAL  obs_module_text("ColorRange.Partial")
 #define TEXT_RANGE_FULL     obs_module_text("ColorRange.Full")
+#define TEXT_DWNS           obs_module_text("DeactivateWhenNotShowing")
 
 enum ResType {
 	ResType_Preferred,
@@ -160,6 +162,7 @@ static DWORD CALLBACK DShowThread(LPVOID ptr);
 struct DShowInput {
 	obs_source_t *source;
 	Device       device;
+	bool         deactivateWhenNotShowing = false;
 	bool         deviceHasAudio = false;
 	bool         flip = false;
 	bool         active = false;
@@ -747,6 +750,7 @@ static DStr GetVideoFormatName(VideoFormat format);
 bool DShowInput::UpdateVideoConfig(obs_data_t *settings)
 {
 	string video_device_id = obs_data_get_string(settings, VIDEO_DEVICE_ID);
+	deactivateWhenNotShowing = obs_data_get_bool(settings, DEACTIVATE_WNS);
 	flip = obs_data_get_bool(settings, FLIP_IMAGE);
 
 	DeviceId id;
@@ -1742,6 +1746,8 @@ static obs_properties_t *GetDShowProperties(void *obj)
 	obs_properties_add_button(ppts, "xbar_config", TEXT_CONFIG_XBAR,
 			CrossbarConfigClicked);
 
+	obs_properties_add_bool(ppts, DEACTIVATE_WNS, TEXT_DWNS);
+
 	/* ------------------------------------- */
 	/* video settings */
 
@@ -1838,6 +1844,22 @@ void DShowModuleLogCallback(LogType type, const wchar_t *msg, void *param)
 	UNUSED_PARAMETER(param);
 }
 
+static void HideDShowInput(void *data)
+{
+	DShowInput *input = reinterpret_cast<DShowInput*>(data);
+
+	if (input->deactivateWhenNotShowing && input->active)
+		input->QueueAction(Action::Deactivate);
+}
+
+static void ShowDShowInput(void *data)
+{
+	DShowInput *input = reinterpret_cast<DShowInput*>(data);
+
+	if (input->deactivateWhenNotShowing && input->active)
+		input->QueueAction(Action::Activate);
+}
+
 void RegisterDShowSource()
 {
 	SetLogCallback(DShowModuleLogCallback, nullptr);
@@ -1849,6 +1871,8 @@ void RegisterDShowSource()
 	                       OBS_SOURCE_AUDIO |
 	                       OBS_SOURCE_ASYNC |
 	                       OBS_SOURCE_DO_NOT_DUPLICATE;
+	info.show            = ShowDShowInput;
+	info.hide            = HideDShowInput;
 	info.get_name        = GetDShowInputName;
 	info.create          = CreateDShowInput;
 	info.destroy         = DestroyDShowInput;