[opendtv] Re: HDMI capture

Yea, sort of as I suggested, its reported to be CGMS-A in the 608 in the 708.

 

Technical detail:  708 defines a packet structure which include ‘compatibility 
bytes’ to carry 608.  So the 708 data stream includes ‘native’ 708 and also 
(optionally) ‘compatibility’ 608.  CEA-608 has long had a definition for CGMS-A 
(actually, the bits are as I said below… two bits for CGMS, two for 
Macrovision, one for the “analog source bit” (long story), and one for the 
Broadcast Flag (which was added when we thought the BF would take effect).

 

608 isn’t a sub or super-set of 708.  But, 708 defines how to carry 608 
/inside/ 708 packets… 

 

 

From: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] On 
Behalf Of Ron Economos
Sent: Tuesday, May 27, 2008 8:07 PM
To: opendtv@xxxxxxxxxxxxx
Subject: [opendtv] Re: HDMI capture

 

This post from an engineer at KNTV seems to indicate it was an XDS issue.

http://tech.groups.yahoo.com/group/HDTV-in-SFbay/message/25315

Ron

John Willkie wrote: 

Adam;

CGMS in the XDS data of a CEA-708 (CEA-608 subset) data stream?

While I don't have contemporary streams from NBC-operated TV stations, in the 
ones I have (a few months old) I find analog captons on KNSD and analog and 
digital captions on KNBC (no caption service descriptor on either.) 

It would be interesting if this comes down to NBC's lack of adherence to ATSC 
standards.  (A/65 at 6.9.2 states (in part) 

"This descriptor shall appear as a descriptor in the descriptor() field for 
each EIT event that has one or more closed captioning services during some 
portion of the event" 

combined with how MCE deals with the ambiguity caused by just this point of 
non-compliance.

The CBS streams I have do have the caption_service_descriptor.

I'd parse the streams farther, but I've been held up the last three days while 
I attempt to install the Windows 2008 Server SDK ... 

Perhaps it's a MS conspiracy to keep me from installing the latest help files 
and samples.

Come to think of it, I did get a web site hit a few weeks back from Microsoft 
corp -- somebody was looking for an ATSC transport stream validator.

John Willkie

-----Original Message----- 
From: Adam Goldberg 
Sent: May 25, 2008 1:01 PM 
To: opendtv@xxxxxxxxxxxxx 
Subject: [opendtv] Re: HDMI capture 




John,

 

It clearly wasn’t just the BF, if as you say, it’s generally broadcast.  My 
best guess has to do with the CGMS-A being set to copy never.  Or, more likely, 
both bytes set to ‘111 1111’, which would yield Macrovision turned on, Copy 
Never, Broadcast Flag and Analog Source.  Either of the first two could yield a 
refusal to record reasonably.

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