10–10 • Appendix B. Captioning Commands
TES9 Software User Manual (Iss. 04)
This command starts the periodic insertion of a Program Descriptor packet, as described in
section 6.9 (Core Descriptors), of the ATSC document A/65B.
The parameters are outlined in
After this command is received, the specified packet is inserted on a cyclic basis, with the
specified time interval between successive insertions. The packet is inserted until the time
specified by the duration expires. If a duration with no colon is specified, then it is assumed to be
in minutes. If a duration of -1 is specified, then the packet is inserted forever. If the {interval} or
{duration} parameters are not specified, then the default for the omitted parameter is used
(interval = 60 fields, duration = forever).
Example
The following command inserts the Stuffing Program Descriptor with a length of zero bytes. The
packet is inserted every 10 video fields, and is inserted forever.
<CTRL-A> N_PD 8000 I=10 D=-1 <CR>
Stop Encoding Program Descriptor
Format: <CTRL-A> N_PD {tag} <CR>
This command stops the periodic insertion of a Program Descriptor packet. The parameter {tag}
is a 2-digit hex value specifying the Descriptor Tag for the Program Descriptor to be stopped.
Note
— In order to use this command to insert the Redistribution Control Program
Descriptor (Program Descriptor using a tag with a value of 0xAA), the optional
Redistribution Control feature must be purchased. If this feature has not been purchased,
then the Redistribution Control button on the Caption Stream Configuration menu will be
greyed out.
Table 10.8 Start Encoding Program Descriptor
Parameter
Description
{tag and data}
ASCII-encoded hex values for the Descriptor Tag
and data (beginning with the Descriptor Tag) to be
inserted, each byte being defined by 2 hex digits.
This parameter consists only of hex digits, and must
contain no spaces.
{interval}
time interval, in fields, between each insertion of the
packet. The maximum allowable interval is 32767
{duration}
length of time for which the packet is to be inserted,
in the format “mmm:ss”, allowing times up to 999
minutes, 59 seconds
