1，描边相素* 系数 2， 文字清空时同时清空背景色

BFRecordScreenKit/Classes/RecordScreen/Controller/BFRecordScreenController.swift

@@ -540,6 +540,7 @@ public class BFRecordScreenController: BFBaseViewController {
 
         } else {
             subtitleLabel.text = ""
+            subtitleLabel.backgroundColor = UIColor.clear
         }
     }
 
@@ -549,7 +550,7 @@ public class BFRecordScreenController: BFBaseViewController {
         if settingModel.subtitleIsShow {
             // 设置样式
             subtitleLabel.strokeColor = settingModel.strokeColor
-            subtitleLabel.strokeWidth = settingModel.strokeWidth
+            subtitleLabel.strokeWidth = settingModel.strokeWidth * 375 / 1080
             subtitleLabel.font = UIFont.boldSystemFont(ofSize: CGFloat(settingModel.subtitleSize) * 375 / 1080)
             subtitleLabel.textColor = settingModel.fontColor
 
@@ -733,6 +734,7 @@ public class BFRecordScreenController: BFBaseViewController {
 
         // 清空字幕UI
         subtitleLabel.text = ""
+        subtitleLabel.backgroundColor = UIColor.clear
     }
 
     @objc func deleteRecorded() {