Testing Wowza on LAN - is a 10-20 second delay typical?
I'm doing some development tests for a client and we're interested in using Wowza for a live streaming application.
I have deployed Wowza to a local server. This setup is all running on a LAN so there shouldn't be any network latency issues.
I'm running Flash Media Live Encoder on a Macbook Pro laptop (i5 processors, 4GB RAM). I've set my encoding options for H264 (as we're streaming to iOS devices), bitrate is very low at 200kbps for video and 56 kbps for audio, resolution 320x240/15fps. Audio is MP3 mono 44khz. So...everything is quite low (IMO).
When testing a live stream to both iPad and iPhone, the latency is around 10-20 seconds. When the above settings were higher they went way up to over 30 seconds.
My question is...is a delay of 10-20 seconds considered 'normal'? What would be an ideal normal range for latency in terms of live streaming? I'm curious to know what others are experiencing so that we have an optimal setup.
This is considered normal for HTTP Live Streaming. The video is segmented into chunks. You might be able to reduce this a little by reducing the chunk size in wowza (if possible).
With live streaming you should be able to obtain latencies below 1 second. For instance try using VLC to view the stream. You should have a very low latency. With my application I send iOS -> RTP -> Wowza/EC2 -> RTP -> VLC with round trip times around 300 to 500ms. The same could be achieved on iOS if you use RTP to stream into the phone.
Glad you got it working. There's an inherent delay in any of the HTTP delivery methods because of the packetizing process. With RTMP/RTSP, latency can usually be measured in frames, rather than seconds since the server is simply redistributing them. You add a little bit more if you're using an edge/origin setup, but it's often still sub-second.