[opendtv] Re: Speaking of MPEG-4 ...
- From: "John Willkie" <johnwillkie@xxxxxxxxxxxxx>
- To: <opendtv@xxxxxxxxxxxxx>
- Date: Tue, 16 Sep 2008 09:11:26 -0700
No normative reference to CEA-608 is a major change, and "allowed" is quite
different than "required." But, sometimes it seems that I'm one of the few
people that knows that CEA-608 captions are required to be passed on by DTV
stations.
John Willkie
_____
De: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] En
nombre de Ron Economos
Enviado el: Tuesday, September 16, 2008 3:02 AM
Para: opendtv@xxxxxxxxxxxxx
Asunto: [opendtv] Re: Speaking of MPEG-4 ...
I'm not sure what you mean by "no analog captions". Seems like
EIA-608 fields in EIA-708 user_data_registered_itu_t_t35 packets
are still allowed.
Also, stream_type 0x1B isn't exactly "new". It was added to H.222.0
in 2004.
Ron
John Willkie wrote:
Correction: stream_type 27/ 0x1B.
John Willkie
_____
De: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] En
nombre de John Willkie
Enviado el: Monday, September 15, 2008 1:54 PM
Para: opendtv@xxxxxxxxxxxxx
Asunto: [opendtv] Speaking of MPEG-4 ...
The ATSC today announced the publication of ATSC Standard A/72, in two parts
(part 1 <http://www.atsc.org/standards/a_72_part_1.pdf> ) and (part 2
<http://www.atsc.org/standards/a_72_part_2.pdf> ) providing for the carriage
of AVC (MPEG-4, part 10) video within ATSC A/53 transport streams. I
suspect that the first real use of AVC will not be in A/53 transport
streams, in no small part due to the inability of legacy digital receivers
to deal with AVC (for the most part.) For what that use will be, you will
have to stay tuned.
But, note that there is now a new stream_type for AVC (28 / 0x1B) , and how
this information is conveyed in PSIP.
A few highlights: finally support for still pictures, and NO ANALOG
CAPTIONS, just digital ones.
There is a press release. If you'd like a copy, and it isn't available from
the ATSC web site, send me an email and I'll forward it to you. I tend to
not read press releases on this type of stuff.
I'll have support for AVC to my PSIP generator, EtherGuide Emissary, and
test the changes, before the day is out. (Turn on a dime, and give nine
cents change.)
John Willkie
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