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How to synchronize multiple H200 STB for multicast stream

Brian Shun
  • Updated

Introduction

This article outlines the necessary setup requirements for synchronizing the video playback of multiple H200 STBs for multicast streams. It is especially helpful for applications such as video walls, where several STBs need to play the same video content in synchronization.

 

A. STB settings

To synchronize your H200 STBs, please follow the requirements below:

1. All STBs have to be upgraded to 25.6.2510.7R or later.

2. Please set the ini options as below:

player.target_buffer_duration_ms=720
player.udp.buffer_for_playback_ms=400
player.udp.buffer_for_playback_after_rebuffer_ms=280
player.dejitter_buf_size=200

Please reboot your STB after completing the setup.

You can now fine-tune the settings according to your experience and results to find the sweet spot for your solution.

 

Note: These settings apply exclusively to SRT and UDP streams within the browser environment. They do not affect AC3 audio streams.
 

B. Setting up Webpage to play a multicast stream

Please follow the instructions on the page below for the basic setup of your webpage:

Video frame under Webpage User interface

To synchronize multiple H200 STB for multicast stream, you have to disable av sync on the STB

(Example: multicast address 233.22.133.118 with port 8110) 

You can simply adjust the "player.setSource" content by adding "?disable_av_sync=true" to disable av sync.

player.setSource("udp://233.22.133.118:8110?disable_av_sync=true");

You can tune your STBs to the above stream at different time. 

Here is a sample page for about example: Sample_Page_Mul_H200.html

Alternatively, you can use API to set the H200 STB to play your multicast channel with av sync disabled.

var player = ENABLE.player.getInstance(0)
player.setSource("udp://233.22.133.118:8110?&disable_av_sync=true");

 

C. Special note

Based on the configuration described above, it is anticipated that there will still be a small time lag of several hundred milliseconds among different STBs. For optimal results in video wall applications, it is highly recommended to connect all participating STBs to the same Ethernet switch to minimize network jitter.

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