Download 4.6-E1

ARIB TR-B15
Version 4.6-E1
descriptor has been sent with the broadcasted program, the descriptor needs to be output without any
changes.
[Output operation rule]
•
If the relevant ES needs to be protected from digital copying, and this descriptor is originally
contained in a broadcasted program, the original descriptor must be inserted into the PMT as it was
when its was first transmitted.
(6) Video Decode Control Descriptor
[Purpose]
This descriptor is used when the video decoding must be controlled at the changing point of video
coding methods within the same "service_id". This descriptor also indicates whether the ES is a
static frame image of an MPEG-I.
[Output operation rule]
This descriptor should be inserted to a PMT if the original broadcasted program contains this
descriptor, and the actions specified by this descriptor needs to be perform in the video that
constitutes a partial TS.
[Other notes]
Video Decode Control Descriptor contains the following sets of information that enable reception
control.
1) Seamless video switching when the video format is changed
2) Determination of whether the ES is a static frame image of a MPEG-I.
If the same reception control needs to be performed during broadcast and replay, both of the above sets of
information should be output. A receiver may use the second information set to determine whether the ES
is a static image. Therefore, when a static image needs to be output as a partial TS, Video Decode Control
Descriptor must be inserted to the PMT.
6.2.3 DIT (Discontinuity Information Table)
6.2.3.1 Structure and operation of a DIT
[Purpose]
This table indicates the discontinuity points of a stream that will be output as a partial TS. If there are
some discontinuity points in a partial TS for some reasons, a receiver inserts a DIT to the partial TS.
[Structure]
Table 6-12 shows the structure of a DIT, which consists of a single section. This DIT section is
transmitted through a transport stream packet whose PID value is "0x001E". The table ID for a DIT is
"0x7E".
―2-45―