CEA-608 as byte triplets as defined in SMPTE S334-1 Annex A.
The second and third byte of the byte triplet is the raw CEA608 data, the first byte is a bitfield: The top/7th bit is 0 for the second field, 1 for the first field, bit 6 and 5 are 0 and bits 4 to 0 are a 5 bit unsigned integer that represents the line offset relative to the base-line of the original image format (line 9 for 525-line field 1, line 272 for 525-line field 2, line 5 for 625-line field 1 and line 318 for 625-line field 2).