Closed Caption
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      1. LEIGHTRONIX Knowledge Base
      2. UltraNEXUS-HD
      3. Closed Caption

      Closed Caption Capability of the UltraNEXUS-HD Series Servers

      Information regarding the UltraNEXUS-HD series closed captions functionality. This article applies to UltraNEXUS-HD, UltraNEXUS-HD X2, X5, Flex, Cast, and Blade servers.

      The UltraNEXUS-HD series servers can record and play closed captions per the parameters listed below.

      Please be sure the firmware in your UltraNEXUS-HD server is up to date.

      Recording

      • The UltraNEXUS-HD records caption distribution packets on the SDI input per the CEA-708/SMPTE 334 standards.  
      • The UltraNEXUS-HD will take the SMPTE 334 data and put it into a sidecar file if the data is present in the SDI input signal.
      • Note: the UltraNEXUS-HD Cast does not have record capabilities.

      Playback

      SDI Output

      • The UltraNEXUS-HD plays caption distribution packets on the SDI output per CEA-708/SMPTE 334 standards.

      Composite (CVBS) Output

      • The UltraNEXUS-HD plays line 21 caption data on the CVBS (composite/analog) output.
      • Note: the UltraNEXUS-HD Flex and Cast do not have CVBS output capabilities.

      File Types

      The following four video file types can work with closed caption data embedded in the file.

      • M2T with CEA-708 captions embedded in the H.264 video stream as specified by ATSC A/72 and SCTE 128 standards.
      • MPG with embedded DVD or ATSC A/53 captions.
      • MP4 with embedded captions.
      • MOV with embedded captions.

      Also, the file must not have a video bitrate larger than 10 Mb/s, or the timing of the captions may be off, and some characters may be doubled or duplicated. In some cases, the captions may not play at all.

      Sidecar Files

      You can use your own sidecar caption files to be played with your video files by transferring them to the UltraNEXUS-HD storage with the video files.

      • The UltraNEXUS-HD will automatically detect the sidecar file and automatically play them with the corresponding video file.
      • MCC and SRT sidecar caption files are supported with any of the four video file types listed above.
      • The sidecar file must have the same file name as the video file, excluding the file extension.
      • The sidecar file must reside on the same storage device as the video file.