解决视频编码可能出现空白项的问题

DownKyi/Services/Utils.cs

@@ -165,7 +165,10 @@ namespace DownKyi.Services
                 if (videoQualityExist == null)
                 {
                     List<string> videoCodecList = new List<string>();
+                    if (codecName != string.Empty)
+                    {
                         ListHelper.AddUnique(videoCodecList, codecName);
+                    }
 
                     VideoQuality videoQuality = new VideoQuality()
                     {
@@ -178,10 +181,13 @@ namespace DownKyi.Services
                 else
                 {
                     if (!videoQualityList[videoQualityList.IndexOf(videoQualityExist)].VideoCodecList.Exists(t => t.Equals(codecName)))
+                    {
+                        if (codecName != string.Empty)
                         {
                             videoQualityList[videoQualityList.IndexOf(videoQualityExist)].VideoCodecList.Add(codecName);
                         }
                     }
+                }
 
                 // 设置选中的视频编码
                 VideoQuality selectedVideoQuality = videoQualityList.FirstOrDefault(t => t.Quality == video.Id);