I appreciate ur reply. It took a whole day for me to experiment the ways to send metadata in vod stream in real-time. It turned out that a simple modification in the code would do the trick.
Replacing below code
did the help to my purpose.
I thought streamInstance.sendDirect() is kind of much better way of injecting metadata to streams, as streamInstance.send() failed in case of transcoded streams in my early project. It seems i have to use streamInstance.send() to send metadata to all the clients,those are playing an vod stream.
Hope my whole day effort will be useful to some ppl looking for the same