The Link Electronics LEI-599 will accept HD/SD SDI transport streams with embedded closed captions from either VBI (line 21/22) or VANC (SMPTE 334 Caption Data Packet {CDP}) and decode them. The captions will then be "burnt" into the outgoing HD/SD-SDI stream so that the captions now appear during active video. Captions which appear in active video are called "Open" captions. The unit will pass ANC data untouched including audio to the output. The LEI-599 can decode ("Open") the following channels or services; CC1, CC2, CC3, CC4, S1, S2, S3, S4, S5 and S6. The data from the selected decoded captions are also sent out the Ethernet port for "data recovery". This data can be used for monitoring, to make a caption file, or to encode another stream. The VBI and 708 VANC closed captions can be deleted on the output. This can be used to remove unwanted captions from the SDI stream or to make sure that captions will not get double decoded when decoding with this device.
The LEI-599 latency between the open and closed captions has had every effort made to keep it to a minimum. The signal processing starts with the input SDI data being equalized and de-serializes to 20-bit parallel data streams. Any closed caption data in the video data stream will be used to select appropriate characters from a custom on-board character ROM. The characters are then digitally mixed into the visible areas of the video, just as they might appear on a typical caption enabled receiver. The new data stream, with the visible captions, are then re-serialized and re-clocked and output as SDI in the exact same format of the input transport stream. There are no scaling or format conversions used in this device. Essentially, as applied to standards and formats, all outputs follow the input format and standards.
The LEI-599 can also be used to insert a V-chip icon onto the active video. It will read V-chip from Extended Data Services (XDS) for Motion Picture Association (MPA), U.S. TV parental Guideline, Canadian English Language, and Canadian French Language Rating Systems and insert the appropriate V-chip Icon, including U.S. TV flags (FV, D, L, S, and V). The V-chip icon can be set to be inserted all the time, by a timed display, or GPI controlled. The LEI-599 will have one optically isolated GPI input for turning open captions and/or V-chip on/off. The decoder options can be viewed on the front panel 40 character (2-line) LCD display. A front panel navigation switch is used to scroll through the menus and select which of the caption channels that is to be displayed.