[mythtv] TWC / Brighthouse SA3250 and firewire support

Bryan Mayland bmayland at leoninedev.com
Thu Feb 10 17:26:00 UTC 2005


> I have been wanting to use the firewire port on the SA3250 to capture
> video/ change channels for a while now, so I am stoked to see support
> for this in cvs and the upcoming .17 version. I have a couple of
> questions b4 I take the plunge and swap out my cable box (my 3250
> doesn't have the firewire).

    I have BrightHouse Tampa and fought for serveral months to actually 
get a firewire box last year.  I can share my experiences, although they 
are not MythTV specific

>
> 1. What kind of system resources (cpu/ram) does this use in
> comparison to the PVR250?

    Straight capture from firewire used about as much CPU time as a `cat 
/dev/video` on my PVR-250.  That is, less than 5% on a P4 2.4B.

> 2. Has anyone been able to change channels on the 3250 via firewire.?
> I see the code for the dct6200 in contrib, but nothing for the 3250.
> The 3250 will not work with my IR blaster.


    No, the port is unidirectional only by all accounts, even though it 
does say it has "AVC Tuner Capability".

> 3. I also saw mention that the video output (except analog/HD) is
> encrypted. Is this true?

    Yup.  There is no way to decrypt it either unless you have a 5C 
certified firewire card (hint: they don't exist).

> 4. Not soo important (and maybe stupid), but will this enable me to
> record/view HD content through myth? I don't have a hdtv set. I have
> a standard 27" tv and do a lot of my viewing on the backend with a lcd
> monitor. 

    ^^^ This I don't know, but I do knw this vvvv

Analog channels (almost all of the ones between 2-125) don't come out 
the firewire port.  Some Digital channels don't come out the firewire 
port.  The digital channels that do come out the port are all encrypted 
and tagged with 5C "once" meaning that if device on the other side could 
decrypt it, it can not pass it on (which means that a firewire VCR in 
the middle won't forward you the unencrypted signal).  Even network HD 
channels are encrypted.  I've called BrightHouse and complained that the 
HD channels are public broadcast and should not be encrypted but nobody 
there really cares.  I got bounced around a bit and finally gave up.  
Every once in a while, there would be a show on Discovery HD that would 
be unencrypted, I don't know why though.

    Long story short, most the channels I want are analog, so no 
firewire anyway, and the ones I do want (HD ones) are encrypted so I 
can't view them. 

    Actually, now I just turned on my box and it has a big red message 
that says "NOT AUTHORIZED FOR USE".  Nice.

If you have any other questions, I'd be happy to answer them
Bry


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