Filter
Top Products
2004 Jan 26 21
Philips Semiconductors Product specification
MPEG-2 video and MPEG-audio/AC-3
audio encoder with multiplexer
SAA6752HS
7.3.8.3 Internal Closed Caption user data insertion
compliant to ATSC/NTSC standard
Automatic insertion of Closed Caption data into the user
data 2 area on picture header level compliant to the ATSC
and EIA-708 standard can be selected via the I
2
C-bus.
Closed Caption data, which is delivered from the video
input processor (e.g. SAA7114) and captured in the video
front-end will be inserted into the user data 2 area (picture
header level) of the video stream. Preconditions are
appropriate settings of the video input processor and the
VBI data extractor in the video front-end. The Closed
Caption user data will be written for both fields. If no valid
Closed Caption data for field 2 is available these data will
be marked as invalid in the stream. At SIF mode only
field 1 Closed Captions can be inserted from the video
input signal and dummy values (80H 80H) will be inserted
for field 2.
If extended data services (XDS data, line 21 field 2) are
inserted, the insertion will be transparent. No modification
of the CGMS-A copy information will be done.
In accordance to EIA-708 the Closed Caption data will
appear in the stream in transport order. If B-frames are
present the user data is re-ordered in the same way as the
video frames.
Advanced TV Closed Captioning (ATVCC) channel packet
data (cc_type 10 or 11) is not supported, because the
input signal of the encoder is an analog video signal, which
can carry only NTSC Closed Captions, but not ATV Closed
Captions.
No additional user data on picture header level can be
inserted if internal Closed Caption user data insertion
compliant to the ATSC/NTSC standard is active.
7.3.8.4 Internal Closed Caption user data insertion
compliant to DVD standard
Automatic insertion of Closed Caption data into the user
data area on GOP header level compliant to the DVD
standard can be selected via I
2
C-bus.
Closed Caption data, which is delivered from the video
input processor (e.g. SAA7114) and captured in the video
front-end will be inserted into the user data 1 area (GOP
header level) of the video stream. Preconditions are
appropriate settings of the video input processor and the
VBI data extractor in the video front-end. The Closed
Caption user data will be written for both fields. If no valid
Closed Caption data for field 2 is available these data will
be marked as invalid in the stream.
If extended data services (XDS data, line 21 field 2) are
inserted, the insertion will be transparent. No modification
of the CGMS-A copy information will be done.
The Closed Caption data will be inserted for each field of
the GOP in display order. At SIF mode only field 1 Closed
Captions can be inserted from the video input signal and
dummy values (80H 80H) will be inserted for field 2.
The user data is delayed by one GOP period. The first
GOP in the stream carries dummy data marked as invalid.
No additional user data on GOP header level can be
inserted if internal Closed Caption user data insertion
compliant to the DVD standard is active.
The amount of user data depends on the GOP size:
5 bytes header and 3 bytes/field are required. With the
maximum GOP size of 19 this results in
5+19× 2 × 3 = 119 bytes, which is more than the
available array of 64 bytes for GOP user data. Therefore
the 64 byte array for picture user data is also used for GOP
user data, if GOP sizes larger than 9 are selected. Then all
128 bytes, which are available for user data insertion on
GOP and picture header level will be used for the insertion
of CC data on GOP level. In this case no additional user
data insertion on picture header level is possible.
7.3.9 MOTION ADAPTIVE NOISE REDUCTION
The gain and adaptivity can be controlled to optimize
encoding efficiency in case of noisy input sequences, i.e.
off-air reception.