Wowza Community

Wowza nDVR doubts

Hi,

I had set nDVR for a live IPCam stream up to 4 hours limit. Now the problem is that, the player buffers every 3-4 seconds and playing. I had confirmed its not an issue with bandwidth since i am a having a very good bandwidth here. How can i reduce this buffering . Buffering after playing at-least 20 sec playback is okay. This keeps buffering every 3-4 seconds. I am using JW player enterprise edition. How can i tweak this?

Also one more doubt, Is there any impact when i play small video files on VOD rather than a big single file. I asked this because some of my recordings are very big as 5+GB and some are just 200+MB.

Will the recorded file splits when the camera is disconnected?

The regular buffering you describe is probably a bandwidth/bitrate issue. Throughput from Wowza to the client varies with many factors. Otherwise, it is possibly the result of odd key frame frequency.

Actual bandwidth from Wowza to a desktop client playing nDVR (or HLS) using JW Player (or smoothstreaming with Silverlight), can be calculated by looking at .ts chunks being downloaded in the browser’s console (Network tab in Chrome).

Size * 8 / Time = bandwidth

To calculate a stream’s bitrate, get the duration from packetization messages in the Wowza access log for a corresponding chunk. You can also get a general idea of Wowza to client throughput using the BWCheck tool

Size * 8 / duration = bitrate

The Time data is time between request and completed response. Latency is time between the request and the first byte of response.

Also, try making the key frame frequency (key frame interval(gop)/fps) 2 seconds. Try 48gop and 24fps, or 30gop and 15fps, to get a 2 second key frame frequency.

Richard