UI: Fix AutoRemux not working when FFmpeg output configured

When the Advanced Output configuration is set to use custom FFmpeg
output, automatic remuxing is disabled. Unfortunately this check will
also take place even if Simple Output is used (as the value is set in
the configuration data, but is not "active").

This check ensures that the check for custom FFmpeg output is only
applied when Advanced Output is enabled.

UI/window-basic-main.cpp

@@ -7122,17 +7122,31 @@ void OBSBasic::StreamingStop(int code, QString last_error)
 
 void OBSBasic::AutoRemux(QString input, bool no_show)
 {
-	bool autoRemux = config_get_bool(Config(), "Video", "AutoRemux");
+	auto config = Config();
+
+	bool autoRemux = config_get_bool(config, "Video", "AutoRemux");
 
 	if (!autoRemux)
 		return;
 
-	const char *recType = config_get_string(Config(), "AdvOut", "RecType");
+	bool isSimpleMode = false;
 
-	bool ffmpegOutput = astrcmpi(recType, "FFmpeg") == 0;
+	const char *mode = config_get_string(config, "Output", "Mode");
+	if (!mode) {
+		isSimpleMode = true;
+	} else {
+		isSimpleMode = strcmp(mode, "Simple") == 0;
+	}
 
-	if (ffmpegOutput)
-		return;
+	if (!isSimpleMode) {
+		const char *recType =
+			config_get_string(config, "AdvOut", "RecType");
+
+		bool ffmpegOutput = astrcmpi(recType, "FFmpeg") == 0;
+
+		if (ffmpegOutput)
+			return;
+	}
 
 	if (input.isEmpty())
 		return;