Last Updated: May 5, 2022
The following bullets describe what affects synchronization and how to ensure you get the best results:
1. Image playback can be sluggish on HDx10 (HD210, HD210w, HD1010, HD1010w), HDx20 (HD220, HD1020) and LS422 players, especially with larger images at 1080p. For sync on those players, we always recommend using videos. See Optimal content type for synchronization.
2. Video synchronization can be improved when using the BrightWall feature or by enabling the Enhanced Synchronization in master and slave presentations. Enhanced Synchronization can be enabled on the File > Presentation Properties > Interactive tab. Enhanced Synchronization is automatically enabled in BrightWall.
Non-enhanced sync only synchronizes videos at the top and at the end of playback. With enhanced sync, there's communication during playback to keep the videos together.
Enhanced Synchronization is not supported on HDx10 players. For HDx10, we recommend making videos smaller. Shorter videos will synchronize better.
In non-enhanced sync the videos can be up to 1.5 frames out of sync (in the worst case). Enhanced sync is supposed to be frame accurate.
3. If you synchronize images between the BrightSign players, the images should have the same size and format.
4. If you synchronize videos, the videos should have the same resolution and must be encoded at a fixed rate.
Video bitrate should not exceed 25Mbit/s for H.264 (AVC) videos.
Video bitrate should not exceed 80Mbit/s for H.265 (HEVC) videos.
If you use HDx10 models for synchronization, ensure that there is no audio track in the video files.
If you have LS422, HDx20 (HD220, HD1020), HDx22 (HD222, HD1022), XDx30 (XD230, XD1030, XD1230), XDx32 (XD232, XD1032, XD1132) or 4K (4K242, 4K1042, 4K1142) or newer units, then video files could have audio tracks. In the case of a master unit that has video and audio, the slave devices should also have video and audio. Video and audio must be the same length to the ms, otherwise there might be issues. In the case where all the screens are visible from the same location, we usually recommend to drive all the audio from just one of the devices so that you can ensure that you don't get out of phase issues from the different players.
5. We recommend using Class 10 SD cards for playing back synchronize presentations. BrightSign SD cards have been tested and proven to work well for synchronized applications.
Transcend cards are not recommended as they can cause unpredictable playback problems.
You should use same SD cards on all players.
6. You should use same firmware version on all players. The presentations for the players must be created in the same BrightAuthor version. Use the latest BrightAuthor version and firmware version available on the downloads page: http://www.brightsign.biz/downloads/
If it is necessary to use players with different firmware versions (not recommended), make sure the Master (Screen 1 in a BrightWall) has the same or older firmware version as the slave players.
7. Sync over wireless is supported on recent 8.x firmware, but care must be taken to avoid multipath if there are multiple active network connections. Sync traffic should be limited to one network interface, via use of VLANs and/or blocking/filtering PTP multicast.
8. If you want to synchronize content between multiple players that are also using zone synchronization, make sure to use Zone Message commands/events, rather than Link Zones commands/events.
9. In order to ensure that players are properly in sync, they must belong to the same product line. For example, you can synchronize LS422 with LS422, HDx10 with HDx10, HDx20 with HDx20, and so on. And you can't sync HDx10 with HDx20, HDx20 with 4K, etc.
10. Portrait video support has both file/media and output restrictions depending on the model.
See this article for details: https://docs.brightsign.biz/display/DOC/Optimizing+Video+Quality#OptimizingVideoQuality-PortraitVideo
11. Off-board processing by distribution amplifiers/splitters, display/wall processors, and on-display processing (scaling, filtering, smoothing) can introduce additional delays and v-sync discrepancies.