JSMpeg not playing audio when websocket stream is used

[nikshay-psts]

I am streaming RTSP stream to web browser using ffmpeg with help of a websocket relay in node js as per the example given here https://github.com/phoboslab/jsmpeg

FFMPEG command used:
ffmpeg -rtsp_transport tcp -i rtsp://wowzaec2demo.streamlock.net/vod/mp4:BigBuckBunny_115k.mp4 -f mpegts -c:a mp2 -c:v mpeg1video http://127.0.0.1:5100/stream_from_ffmpeg

The video is playing good, but no audio, if i open the same RTSP URL above in vlc, the video plays along with the audio