Captions

Caption Control Codes
Data Channel 1  Data Channel 2  Mnemonic    Command Description
~~~~~~~~~~~~~~  ~~~~~~~~~~~~~~  ~~~~~~~~    ~~~~~~~~~~~~~~~~~~~
0x14 0x20       0x1C 0x20       RCL         Resume caption loading
0x14 0x21       0x1C 0x21       BS          Backspace
0x14 0x22       0x1C 0x22       AOF         Reserved (formerly Alarm Off)
0x14 0x23       0x1C 0x23       AON         Reserved (formerly Alarm On)
0x14 0x24       0x1C 0x24       DER         Delete to End of Row
0x14 0x25       0x1C 0x25       RU2         Roll-Up Captions-2 Rows
0x14 0x26       0x1C 0x26       RU3         Roll-Up Captions-3 Rows
0x14 0x27       0x1C 0x27       RU4         Roll-Up Captions-4 Rows
0x14 0x28       0x1C 0x28       FON         Flash On
0x14 0x29       0x1C 0x29       RDC         Resume Direct Captioning
0x14 0x2A       0x1C 0x2A       TR          Text Restart
0x14 0x2B       0x1C 0x2B       RTD         Resume Text Display
0x14 0x2C       0x1C 0x2C       EDM         Erase Displayed Memory
0x14 0x2D       0x1C 0x2D       CR          Carriage Return
0x14 0x2E       0x1C 0x2E       ENM         Erase Non-Displayed Memory
0x14 0x2F       0x1C 0x2F       EOC         End of Caption (Flip Memories)
0x17 0x21       0x1F 0x21       TO1         Tab Offset 1 Column
0x17 0x22       0x1F 0x22       TO2         Tab Offset 2 Columns
0x17 0x23       0x1F 0x23       TO3         Tab Offset 3 Columns

0xFC 0x80 0x80 = Field 1 filler (CC1, CC2)
0xFD 0x80 0x80 = Field 2 filler (CC3, CC4)

0xFD = 11111100
MMMMMVCC
M = marker bits, must be all 1s
V = CC Valid, must be 1
C = CC Type: 0=field 1, 1=field 2, 2=DTVCC data, 3=DTVCC start

DID	SDID	Content
0x41	0x05	Active Format Description (AFD)
0x41	0x07	SCTE-104 (SCTE-35 over SDI)
0x41	0x08	OP47 (teletext in SMPTE-2031)
0x43	0x01	(unsupported, no samples) OP47 over VANC multi-packet
0x43	0x02	OP47 (teletext over SDI VANC)
0x43	0x03	(unsupported, no samples) OP47 over WSS packet
0x5F	0xDF	ARIB captions
0x5F	0xFE	ARIB audio
0x60	0x60	timecode
0x61	0x01	708 captions (including 708-wrapped 608)
0x61	0x02	608 captions
0x61	0x03	teletext
0x64	0x64	timecode
0x64	0x7F	Vertical Interval Timecode (VITC)