Instruction manual

HDE-3000 - 79 -
The VANC Area
The vertical ancillary space is specified for the 1080 formats in SMPTE274M and for the
720 formats in SMPTE296M. SMPTE334M specifies the VANC area as follows: “data may
be located in any lines in the area from the second line after the line specified for switching
to the last line before active video”. The “line specified for switching” is defined by SMPTE
RP168 and summarized in the following table.
Format RP168 switch lines second line after the line specified for switching
720 P 7 9
1080 I 7 and 569(6) 9 and 571(8)
1080 PsF 7 and 569(6) 9 and 571(8)
1080 P 7 9
NOTE! For 1080 I and 1080 PsF: line 569 = field 2 line 6, and line 571 = field 2 line 8
The “last line before active video” is specified for the 1080 formats in SMPTE274M and
for the 720 formats in SMPTE296M. The following table lists the VANC area definitions for
each video format.
field 1 VANC area field 2 VANC area
Format first line last line first line last line
720 P 9 25 - -
1080 I 9 20 571(8) 583(20)
1080 PsF 9 20 571(8) 583(20)
1080 P 9 41 - -
Ancillary data packets to be encoded into the VANC area are encoded contiguously
starting at the beginning of the VANC area (see SMPTE291M section 4). Several types of
data packets may be encoded into the VANC area. The following is a list of the types of
ancillary packets that may be encoded into the VANC area.
Caption data (SMPTE334M)
MPEG2 recoding info (SMPTE353M)
Camera position metadata (SMPTE315M)
Ancillary timecode (SMPTE RP188)
DTV program description (SMPTE RP207)
VBI data (SMPTE RP208)
VANC key length value data (SMPTE RP214)
Film transfer info (SMPTE RP215)
Because the VANC area may contain several types of data packets, and they are
packed contiguously in the order that they are encoded, there is no guarantee that any
particular data packets will always be encoded on any particular video line. However, all of
these data packets will always be encoded within the VANC area (space permitting), and
the first data packet encoded will always be at the beginning of the VANC area.