On android 4.4 avformat_open_input failed found invalid data where processing input?

[yt7589]

On Android 4.4 it was OK for audio call. But for video call the logcat show these errors: QCMediaPlayer mediaplayer not present avformat_open_input failed, err:invalid data found when processing input avformat_open_input failed, err:invalid data found when processing input

I had debug the programm found that: in NgnAVSession.handleMediaUpdate method: NgnMediaType _newMediaType = NgnMediaType.ConvertFromNative(newMediaType);

change the newMediaType from NgnMediaType.AudioVideo to NgnMediaType.Audio. It seemed that the native code did this. How to fix this problem?

the video window couldn't display but the audio part was OK.

What should I do to use the audio call on android 4.4 or above version?