TVP5146 and TVP5150A VBI Raw Data Mode

The TI family of video decoders offers a VBI raw data mode for use in systems where VBI data slicing and processing is handled in the digital backend receiver instead of the video decoder. In this mode of operation, the decoders are configured to output raw 2x oversampled luma data on the ITU-R BT.656 output during the defined VBLK (vertical blanking) interval. The raw, unsliced A/D video data is transmitted during the active video portion of the line with chroma samples being replaced with the luma samples. The default VBLK interval for Field 1 is defined as lines 1 through 20 for 525-line video formats and lines 623 through 23 for 625-line video formats. This interval may be adjusted to include additional lines. Support for NTSC line 21 closed caption data, for example, requires extension of the VBLK interval to include line 21.