When you are setting up a Wowza based streaming application which need to stream and record more than a thousand cameras, and in the testing stage you need to see how the system works by providing multiple H.264 camera streams. But, when you have only one camera for testing purposes, you cannot overload the camera by taking a thousand streams from it to test the application. And if the camera gives an MPEG-4 stream, Wowza is not going to play since H.264 is the only supported format by it. We did a workaround to overcome this situation in Amazon EC2. We launched a large wowza instance from paid AMI and installed VLC in it. Using VLC we transcoded the MPEG-4 video stream to H.264. Illustration given below
vlc -vvv rtsp://camera.hostname:port/stream-name --sout "#transcode{venc=x264{keyint=60,profile=baseline,level=3.0,nocabac, qpmax=36,qpmin=10,me=hex,merange=24,subme=9,qcomp=0.6},vcodec=x264,vb=128,scale=1, width=640,height=480,acodec=mp4a,channels=1,fps=15,samplerate=4750} :rtp{dst=local.amazon.ip.ofwowzainstance,port-video=10000,port-audio=10002 ,sdp=file:///wowza-installation-dir/content/vlc.sdp}" -R -d
Next we added a username and password to file /usr/local/WowzaMediaServer/conf/admin.password so that we can access the stream manager. Then we had to start wowza server, access the stream manager using the url http://public-dns-name-of.instance:8086/streammanager/
After Login using the username and password mentioned in /usr/local/WowzaMediaServer/conf/admin.password. Click on “start receiving stream” under rtplive.
In the configuration window mentioned Application as rtplive/_definst_ , MediaCaster Type as rtp, and Stream Name as vlc.sdp and clicked “OK” to submit and stream to start. The RSTP url to access the stream was be rtsp://public-dns-name-of.instance:8086/rtplive/vlc.sdp and this give an H.264 stream which is equivalent to a stream from an H.264 camera. The advantage of this setup is you need not overload a single IP camera by taking 1000 streams as this single rtsp output can be used multiple times to simulate a multiple IP-Camera system and feed it as input to the wowza streaming infrastructure we are developing in Amazon EC2.
