[mythtv-users] 6100 series STB boxes - CONCLUSION

[Jerry Rubinow]

On 10/22/07, Joe Borne <joe.borne at gmail.com> wrote:
> As many of you know, I have been working with insight Digital cable here in
> Northern KY to determine why some MythTV users cannot view certain digital
> channels via the firewire connection despite the channels NOT being 5C
> encrypted.
>
> 1. Apparently, this CCI bit is enforced at the STB box. It does NOT prevent
> you from watching these channels via a digital tuner card (pchd5000 etc).
> unfortunately, my limited knowledge of that card prevented me from tuning in
> the channels I wanted. The mythTV scanner only managed to find 10 of my 100
> or so digital channels, and none of the critical 6 I want to get back in HD.
>
> So, if anyone has a better guide on how to fine-tune for channels than what
> I have found on the pchd5000 forums or the mythtv wiki, please contact me.
> Is there a way to use the information from Schedules Direct to help find
> these channels?
>
> 2. Content is still pushed out clean through the HDMI/DVI and Component (NOT
> composite, critical difference there) outputs. I still feel the best
> solution to ALL of these 5c/CCI problems is the creation of a converter that
> can connect one of these STB outputs to a MythTV input.

A year ago I was struggling with many of these same issues.  Here's my
attempt at a an explanation in a nutshell of how these various things
interact.  Hopefully this will be useful.

Let's consider two channels, channel X and channel Y.  Channel X is an
OTA channel carried by your cable/fios provider.  Channel Y is a
digital channel (something like USA or TNT) carried by your cable/fios
provider.

If you look at the raw signals on the coax, before they enter the set
top box, they are all encoded in QAM (usually QAM-256, but this can
vary by provider).  Channel X will typically be unencrypted (and in
fact the FCC requires this, but do the providers listen?).  Channel Y
will typically be encrypted (although this can vary by provider).  A
card that can receive QAM signals, such as a pchdtv, Avermedia A180 or
HDHomerun, can receive any channel like channel X that is encoded in
QAM in an unencrypted form.  If the channel is encrypted, it cannot be
picked up from the QAM stream.

Once the signals hit the set top box, the STB has the algorithms to
decrypt all the encrypted channels.  However, as you noted, even if
the channel has no encryption before it hits the box, it also looks at
each channel to see the setting of the CCI bits.  If CCI is 0, it
passes the channel through to firewire unencrypted.  If CCI is not 0,
it encrypts the stream for that channel before passing it through to
the firewire.  Only hardware/software which knows the algorithms and
has the proper keys can unencrypt that stream at this point.  As far
as I know, this protection (5C/DTCP) has not been broken so there is not going
to be any way for Myth to decrypt the stream.

Sometime the cable/fios company is confused and turns on the CCI bits
when they shouldn't be, so that even channels you can receive through
a QAM tuner cannot be received through firewire.  We've both
experienced this firsthand.

My solution is to use a QAM tuner for all the unencrypted stuff, a
PVR-500 to get the s-video from the STB for the digital CCI=1/2/3
channels, and a firewire connection to change channels on the STB.

Like I said, what is encrypted varies widely by provider.  Some people
can get ESPN-HD, TNT-HD, Discovery-HD, etc in the clear (I can't), and
some people can get the non-HD digital channels in the clear (I
can't).

As far as hardware that takes the uncompressed component/DVI/HDMI
output of the STB and compresses it to MPEG on the fly, there's
nothing available that does this that isn't really expensive.  And
there's too much bandwidth to store it uncompressed.

Note also that 5C (or DTCP) protection is what is going on through the
firewire.  The encryption of QAM signals is some other unknown form of
encryption.

For a better explanation of the various forms of encryption, go here:

http://www.avsforum.com/avs-vb/showthread.php?t=843982

And scroll down to post #15, by stranger89.

-Jerry