[mythtv-users] Firewire fleeting on SA3250HD

[Allan Wilson]

On 7/24/06, John P Poet <jppoet at gmail.com> wrote:
>
> On 7/24/06, Allan Wilson <allanwilson at gmail.com> wrote:
> > On 7/22/06, John P Poet <jppoet at gmail.com> wrote:
> >
> > >
> >  I have been struggling to get *reliable" firewire communication
> > between my computer and my SA3250HD cable box.  I got it working last
> > night, and scheduled a half dozen shows to record on different
> > channels, throughout the night.  They all recorded just beautifully.
> >
> > Today I noticed a recording start up, and the SA3250HD trying to
> > change channels but it went to the wrong one.  I stopped the recording
> > and changed the channel myself.  Then I tried to capture via
> > test-mpeg2 but got a zero length file.  After about 30 minutes of
> > randomly trying things, I got the firewire to work again.... for a
> > while.  A few hours later it was out of sync, again.
> >
> > If I use 1394commander to reset the bus, and use plugctl to prime the
> > bus, and get the channel changed to a good one, and use test-mpeg2, I
> > can get eventually get a valid video stream.  Once test-mpeg2 is
> > working, I can start myth backup and it will work -- for a while.
> >
> > I have not been able to figure out the sequence of events needed to
> > get the 1394 bus resynchronized when it looses it.  Sometimes just
> > resetting the bus is enough.  Other times it seems like various
> > combinations of plugctl and test-mpeg2 are necessary.
> >
> > I get the impression that people with Motorola boxes have a bit more
> > success with this, than those of us with Scientific Atlanta boxes.
> >
> > The very first time I ever successfully captured video via firewire,
> > It was after I followed Allan's directions here:
> >
> > http://www.gossamer-threads.com/lists/mythtv/users/209409#209409
> >
> > Unfortunately, those instructions do not work every time.
> >
> > Since I cannot remember where I got it, I am attaching the version of
> > sa3250ch.c that works (most of the time) for me.
> >
> > John
> >
> >
> >  _______________________________________________
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> > mythtv-users at mythtv.org
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> >
> >
> >
> >
> >
> > Just an idea but could you be changing to an encrypted channel that
> causes
> > you to loose your connection to the cable box. I had to create a new
> listing
> > and tie that listing to my firewire tuner so that firewire would only
> pickup
> > recording and change to channels it could get to. Just an idea
> >
> > Allan
>
>
> Yeah, I did the new lineup from the beginning.  Only channels above
> 100 show up via the firewire.
>
> For kicks I tried tuning HBO and grabbing data via test-mpeg2, but got
> a zero byte file.  As soon as I switched to a "valid" channel,
> test-mpeg2 was able to grab data again.
>
> I still do not have a reliable recipe to get data via the firewire.
>
> I do seem to need to get the firewire synchronized *after* starting
> mythbackend.  If I have it working, *then* start mythbackend, it
> looses the sync.  So, I start mythbackend, then proceed to beat on it
> with various techniques until test-mpeg2 produces some data -- at that
> point myth will work fine until I restart mythbackend or try to use
> live tv.
>
> John
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>

For what it is worth, I have to do the same thing. Start the backend and get
the firewire going but once I have it going over my SA3250HD then it usually
works fine for weeks at a time. If you need any details that I may be able
to provide ask away and I will pass on what I can. I will throw this out
there though, I had lots of problems with firewire to begin with and through
persistance and help of people on this list I was able to get it to work
reliably and it was worth all the effort. So keep at it and let me know what
I can do to help

Allan
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