[mythtv-users] Comcast clear QAM

[Steven Adeff]

On Fri, Dec 5, 2008 at 12:20 AM, Yeechang Lee <ylee at pobox.com> wrote:
> Jeff Thurston <jthurston at skyline-ats.com> says:
>> That's odd though, I can get both CBS (KPIX) and FOX (KTVU) in HD
>> either QAM or OTA with my TV through Comcast, no cable-card, just
>> the built-in tuner.  Just can't get it over firewire with the STB
>> into Myth.  If it were CBS & FAX encrypting it, I shouldn't be able
>> to get it at all.
>
> Two similar--but separate--issues here, as I understand it.
>
> * There's 5C, which is encryption of pay cable channels and other
>  (including, in most cases, all non-OTA channels). Encryption is done
>  at the cable company's end and decryption is done by the cable box.
> * Then there's RC, which is a simple flag that indicates whether a
>  broadcast can be copied or not. Yes, this is (a version of) the
>  infamous "broadcast flag" of a few years back. No encryption.

5C is not encryption, it's a flag in the stream. Yes, FOX, CBS, etc
can enable 5C in their broadcast stream which then gets passed on to
the cable box, but that does not mean the stream is itself encrypted
in anyway. If you were to tune to it via a tuner card it would come in
fine.

5C can be used in conjunction with a cable operator's normal channel
encryption, but it is, itself, not encryption, though the 5C signal is
"encrypted". It also doesn't "disable" the firewire port, it just
disables the box from sending a signal over it, the firewire port is
still on, open and active.

I've not heard of RC, so I can't comment on that.

I believe it was ABC in Boston that accidentally had their 5C flag set
for a month or so at one point. I could tune it fine with one of my
three QAM tuner cards, but neither of the two cable boxen I had would
send it out over firewire. I took a few minutes to check the status on
a friends box and low-and-behold!

I believe Comcast that all they do is send the signal on, and from
what I understand they only apply a 5C signal to Comcast generated
content, everything else is set by their source.

Of course, the HD-PVR is the best way to get HD channels out of a cable box...
-- 
Steve
http://www.jobs-khakis-chicks.com/MythTV/
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