Wowza Community

Live Video Synchronization for multiple HLS Clients

Let me apologize first, if this has been discussed in detail, and I just simply missed the thread. Also, I am new to streaming video, and this forum, so please address accordingly.

I am attempting to stream live video to several televisions in a large room. We take the live video, encode is using a Teradek Cube, and stream using HLS from Wowaz. Each client has an android tv set top box, and receives the signal using either VLC, MX Player, and we have tried Chrome - all work fine. We are streaming video, with no audio. The problem is none of the video clients are in sync. When standing in the room, each TV is off by seconds. People complain that it is distracting. I understand why this is, but I am looking for a solution to try to get these as close to synchronized as possible. My first though is to switch to multicast, but I am not sure the network will support that. Is there a way, to sync all the clients, receiving the HLS stream from Wowaz?

Thank you in advance.

Hi,

A http protocol, such as HLS, isn’t really the right approach for this particular application. The HLS packetizing parameters could be adjusted so that there is a shorter delay in the stream starting. However, it is still not going to be perfect.

You are likely better off using a more realtime protocol such as RTMP or RTSP. RTMP requires a flash player, so that won’t go for Android,

but RTSP should work, as the native player should support it. A url for rtsp would take the following form:

 rtsp://[wowza-ip-address]:1935/live/mystream

Daren

Daren, Great! Thank you.

Switching to rtsp did bring the displays closer in sync - thank you again for your reply. However, it also introduced choppiness. Are there other adjustments that should be made when using rtsp? I understand there are several variables to consider, I lowered the bit rate, and lowered the output resolution, but neither seemed to have an effect.

Can I increase a buffer space in VLC to help with this? Or does having a buffer disrupt the synchronization?