[mythtv] 6100 series STB boxes - FOUND THE PROBLEM!

Joe Borne joe.borne at gmail.com
Fri Oct 19 13:10:04 UTC 2007


> On 10/18/07, Joe Borne <joe.borne at gmail.com> wrote:
> >
> >
> > Kelly Campbell wrote:
> > > > Encrypted 5C channels is one problem, but it's a pain to even get
> the
> > > > non-encrypted channels to work consistently. I'm not sure this is
> > > > actually a problem with the motorola's or if it's a linux
> driver/libs
> > > > issue. I've never tried capturing on MacOS or windows.
> > > >
> > > > I've been able to get my firewire working mostly consistently by
> > > > building from svn for myth, libraw1394, libiec61883, and libavc1394.
> > > > They recently made a new release of libraw1394 which included a
> > > > segfault bugfix.
> > > >
> > > > For me this is what I've found is required to get a stable
> connection:
> > > >
> > > > 1. The motorola box has to be powered off (power cable unplugged,
> > > > firewire is still live even if the) and then plugged back in with
> the
> > > > linux system online and firewire connected.
> > > >
> > > > 2. I have to run firewire_tester -B -n <node> until it's stable.
> > > >
> > > > 3. configure mythtv to connect in broadcast mode.
> > > >
> > > > Once in a while it will lose stability for some reason, and just
> > > > running firewire_tester -B -n once or twice will usually fix it. If
> > > > not I have to reset the stb power.
> > > >
> > > > Hope that helps.
> > > >
> > > > -Kelly
> > > >
> > > > On 10/17/07, Steven Adeff <adeffs.mythtv at gmail.com> wrote:
> > > >
> > > >> On 10/17/07, Joe Borne < joe.borne at gmail.com> wrote:
> > > >>
> > > >>> I have a very cooperative cable company (Insight) who is willing
> to
> > > help
> > > >>> resolve the issues some users have with tuning in HD channels on
> the
> > > >>> Motorola set top boxes. They feel that I should be able to watch
> > > every
> > > >>> channel I pay for out of the firewire ports on the back,
> > > unencrypted. They
> > > >>> would like to work with us as testers.
> > > >>>
> > > >>> Who is currently working on the code used to communicate with
> these
> > > Motorola
> > > >>> STBs? I'd like to get them involved so we can work this out. I'm
> > > running the
> > > >>> current SVN.
> > > >>>
> > > >> all they have to do is turn off 5C in the Motorola software.
> Normally
> > > >> this signal is sent by the cable company in the channel/show's
> > > digital
> > > >> stream to the cablebox and is passed through from the network but
> it
> > > >> can be intercepted/changed/ignored at any step along that process.
> > > >>
> > > >> --
> > > >> Steve
> > > >> Before you ask, read the FAQ!
> > > >> http://www.mythtv.org/wiki/index.php/Frequently_Asked_Questions
> > > >> then search the Wiki, and this list,
> > > >> http://www.gossamer-threads.com/lists/mythtv/
> > > >> Mailinglist etiquette -
> > > >> http://www.mythtv.org/wiki/index.php/Mailing_List_etiquette
> > > >> _______________________________________________
> > > >> mythtv-dev mailing list
> > > >> mythtv-dev at mythtv.org
> > > >> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-dev
> > > >>
> > > >>
> > > > _______________________________________________
> > > > mythtv-dev mailing list
> > > > mythtv-dev at mythtv.org
> > > > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-dev
> > > >
> > > if you're paying for the channels why would they be 5C encrypted on
> the
> > > firewire port?
> >
> >
> >
> > The problem I am seeing is the same as Kelly is indicating. I have
> several
> > channels that will not tune in despite  NOT being 5C encrypted. I have
> > checked them by doing the following:
> >
> > 1. Powering off the STB with the power button while tuned to the channel
> > that refuses to work.
> > 2. Hitting "setup" on the front of the STB within 2 seconds of power
> off.
> > 3. Checking the setup screen that appears for the "5C" or "%C" flag. (I
> > don't remember the exact line, but it was pretty obvious to me.)
> >
> > I came across a thread in a silicondust forum via google that discussed
> a
> > similar problem for folks using a digital tuner card on QAM channels.
> They
> > reported almost 100% success if they unchecked a checkbox for
> "unencrypted
> > channels only" under the mythtv backend setup >> 4. Input connections
> menu.
> >
> >
> >
> http://www.silicondust.com/forum/viewtopic.php?p=24438&sid=3695300530c53326eb14ab4affba59d4
> >
> > Apparently, some channels can carry a 5C flag even if not encrypted and
> > Myth picks up on this and doesn't even try to tune them. I did wonder if
> > this could be a similar issue, but that seems illogical as the STB does
> > change to the channel but the signal never locks. Unless the two are
> > unrelated, and what's happening is that the STB changes channels, but
> then
> > Myth never really attempts to lock on the signal. I don't know enough
> about
> > the firewire connection to even speculate. (Are channels transmitted
> through
> > the firewire on different frequencies, or are they all just raw MPEG2
> feeds
> > of whatever channel the STB is on?)
> >
> > I'm going to attempt Kelly's solution and compile libraw1394,
> libiec61883,
> > and libavc1394 from source.
> >
> > I'll post the results.
> >
> >
> > Thanks
> >
> > Joe
> >
>
> Update: Compiling the libraw, libie and libavc from source has not fixed
> the
> problem. I took some time and mapped out which channels do and do not work
> using 6200ch and test-mpeg2. (With many, many, MANY restarts of
> mythbackend
> and running "firewire_tester -n 0 -p 0 -B -r 5" in between. Interestingly,
> if firewire-tester cannot fix a broken connection, a restart of
> mythbackend
> seems to help.)
>
> Does anyone know how to query out the Motorola's configuration through the
> firewire connection? It sure would be nice to be able to look at the
> config
> for each channel in a flat file so I can compare and find what's
> different.
> Otherwise I have to wait til I get home and do the power off/setup button
> trick on every channel in question.
>
> Also, just out of curiosity, what's the difference between the internal
> channel changer code MythTV uses for the Motorola and 6200ch?
>
>
> Thanks
>
> Joe



*******************************************
Interesting update - apparently this has to do with the CCI bit problem!
See below post from the mythtv-users digest and my response at the bottom

*******************************************


Steven Adeff wrote:
> > On 10/12/07, R. G. Newbury <newbury at mandamus.org> wrote:
> >> This link: http://lauren.vortex.com/archive/000310.html
> >>
> >> is an interesting article about cableco's changing the 'do not copy
> byte'.
> >>
> >> Does anyone know of any programs which would allow a user to find the
> >> CCI byte in a digital stream?


<snipped for brevity>

Well  I have not seen any decisions which inpinge on the BetaMax fair
> use doctrine. The DMCA and cases coming from it have focussed on the
> 'circumvention' aspects or on the 'making available' contravention..
>
> Geoff


On an unexpectedly related note...  Apparently, this is the cause of the
problems many MythTV users have been having with tuning in channels on their
set top boxes connected via firewire.

As some of you might know. I am currently working with Insight Digital Cable
in Northern Kentucky to resolve an issue where some of my HD channels that
once worked will now not "tune in" via my firewire connection to my Motorola
DCT 61xx box. I've been contacted by two other users in the area who have
the exact same problem.

Josh at insight has been extremely cooperative. If his attitude is
reflective of the corporation as a whole, it indicates they lean towards
consumer rights versus draconian DRM restrictions (which, if you understand
the FCC regulations, are largely illegal).

Root cause analysis has revealed the following about our situation:

1. We all lost the same channels at the same time.
2. Insight did a channel frequency listings change/update at that time.
3. HD/SD is not a factor.
4. Whether the channel is a "premium" channel (TNTHD, ESPNHD etc) or a
channel that is free OTA (ABC, NBC, CBS etc) is not a factor. I have
examples of both being blocked.
5. The CCI bit on every channel that is blocked is set to 0x02, and on every
channel that works it's set to 0x00.

Josh has confirmed my findings on several pieces of equipment in their labs.
He is going to request they fix this situation. He is in contact with a
technician at the head office and has promised to get back to me in the next
day or two with their response concerning this.
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