[mythtv-users] SA4200HD via 1394, mixed SD and HD

[Ed Brandon]

I have two 4250HD STB's from Cablevision here in NY and I have had pretty
good success recording HD and SD over firewire. I tried channel changing
channels over firewire when first setup however the results were chaotic so
I still use a IR blaster. Myth lets me watch any HD content on my SD TV
without any problem, it just letterboxes it which is fine for me.
 
The main problem I have is certain channels (mainly Discovery HD Theatre,
YESHD and all of the SD STARZ and Encore Channels simply can't be viewed
through MythTV over firewire. Oddly enough YES in SD, the discovery channel
and STARZHD can be viewed. Cablevision says they do not put any 5C
encryption on the firewire ports and my other 200 channels seem to work fine
although I never watch most of them. I also have looked at the diag menu on
the cable box and it looks clean. I have heard cable networks themselves
will put encryption on by themselves but why would STARZ let me watch there
HD channel freely and not their SD lineups? I've called Cablevision about it
and they were actually surprised I have gotten firewire capturing working
since they have been unable to do it using Windows MC and they are trying to
figure out how to get it to work.
 
Most of my firewire resets are now tied to switching to these channels which
makes me unplug the firewire cable from my Myth box and power cycle the STB
and them plug the firewire cable back into the Mythbox. I haven't had any
luck with firewire bus resets being able to bring things back to life by
itself.

  _____  

From: mythtv-users-bounces at mythtv.org
[mailto:mythtv-users-bounces at mythtv.org] On Behalf Of fuzzie1300
Sent: Saturday, March 08, 2008 9:25 AM
To: Discussion about mythtv
Subject: Re: [mythtv-users] SA4200HD via 1394, mixed SD and HD



I got the STB shortly before SA4200 support was added to MythTV SVN, and
by the time I got my cables all sorted out it was working.  Initially I
had some stability problems:  every week or so, a firewire recording would
fail, and I would have to power-cycle the STB as well as re-start the
backend to get things working again.


I have the SA4250 and have similar problems.  




This was all taken care of after enabling BusReset in
"libs/libmythtv/linuxfirewiredevice.cpp" (back when this was not enabled
by default), and in subsequent SVNs this has been very reliable without
changes.  Thanks to whomever fixed that!


as I am on mythdora 4, does the firewire_tester  reset command do same?  I
haven't had any luck with firewire tester testing or resetting (I do have
firewire tester svn from around December ).




I have two remaining problems.  The first, I don't know how to debug:
I've only run into it twice.  The backend claims to have recorded a show,
yet the file simply does not exist.  There were no unusual messages in the
mythbackend log, just notations that the recording was started & stopped
at the expected times.  I've recently upgraded to SVN r16382, and will
post again if I ever see this specific behavior.


I have a file, but it's 0 bytes (I think  this is a symptom of it just not
working as above? )




On the SA4200HD, no matter how fast you enter the channel numbers, channel
changes are slow.  This is due to the box itself, not MythtTV.  What can
be a problem is the fact that MythtTV begins streaming before the channel
change finishes.

What I wind up with then is a file that has a brief section of HD
material, followed by the SD stream that I'm trying to record.  Since I
cannot display HD material, I get a "Failed to Reinit Video" message and
cannot watch that program.

Occasionally I get "lucky" and will be able to sneak a "fast forward"
command in before MythTV finishes the screen init, and I can then watch
the SD programming, but without sound.  I'm apparently skipping past
something in the stream that is required to detect or set up the audio
tracks.


With HD recordings in order view to them on my SD tv, I have to view the
recording on vnc and cut out the first few seconds before the channel change
and then let the transcoder do it's thing to SD size.  If I don't cut out
the first few seconds from the SD channel, transcoding fails.  Lastly, with
the transcoded file, sometimes I get audio, sometimes I don't.




What I've settled on is this change to
"libs/libmythtv/firewiredevice.cpp":

in function FirewireDevice::SetChannel, ~line 222, I added a 3 second
sleep after the channel change, just before the function returns.

It may be that a shorter sleep duration would work.



Again, not being on svn, I can't do this.  Hopefully this could be in the
next release or some other method to improve it.







-- 
This message has been scanned for viruses and 
dangerous content by  <http://www.mailscanner.info/> MailScanner, and is 
believed to be clean. 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mythtv.org/pipermail/mythtv-users/attachments/20080308/86799e02/attachment.htm