Wowza Community

HLS Transcoding >30 seconds behind?

I’ve got Wowza Streaming Engine running in EC2 with transrate transcoding enabled.

I’m publishing over RTMP and trying to consume over HTTP/HLS on iOS devices. My setup is described here: Stream names removed, everything breaks

I’m seeing the HLS stream delayed by about 30 seconds. Is there a way for me to improve this transcoding rate? 30 seconds is really far behind for a live stream, especially since we want viewers to be able to interact. Is there a way to improve this in AWS, maybe through CUDA or something?

HTTP streaming sends chunks to the client. The client needs 3 chunks cached before it starts playing.

By default Wowza is set to send 3, 10 second chunks in each packet sent to the client. You can modify this behavior by editing the Application.xml file.

This guide explains how to control how the Cupertino (iOS device) segmenter segments an incoming live stream:

How to configure Apple HTTP Live Streaming packetization (cupertinostreaming)

Chunks must start on a key frame. So it is best to use a key frame interval that is factor of the cupertinoChunkDurationTarget setting.

Try 2 second key frame frequency and cupertinoChunkDurationTarget “2000” (2 seconds)

Regards,

Salvadore