Android RTSP request does not send audio SETUP command
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I have a RTSP server which sends out a H.264/L16 live stream. It plays out fine on VLC. However, when played using VideoView or MediaPlayer in Android it only sends the SETUP request once for video before sending the PLAY request. Therefore, only video no sound. A L16 encoded audio file (exactly the same format as the stream which is 8000 sample rate) plays out fine by the default Android media player. There is no error except the usual "Couldn't open file on client side, trying server side". I download the Android source code hoping to find the part where it sends the SETUP request but failed.

Any help is appreciated. Thanks in advance.