处理 切换段落有杂音问题。

BFRecordScreenKit/Classes/RecordScreen/Controller/BFRecordScreenController.swift

@@ -1548,6 +1548,8 @@ public class BFRecordScreenController: BFBaseViewController {
                 movie?.startProcessing()
                 movieIsProcessing = true
             }
+            //add by ak 切换段落时会有一小段原素材的声音播放时先把视频原音量设置为0
+            assetPlayer?.volume = 0
             assetPlayer?.play()
         } else {
             // 处理图片音频播放