Mailing List Archive: MythTV: Users

SA4200HD via 1394, mixed SD and HD

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mark at mark

Mar 7, 2008, 9:57 AM

Post #1 of 6 (1246 views)
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SA4200HD via 1394, mixed SD and HD

This is just an informational post detailing some of the small problems
I've had with using a SA4200HD STB with a firewire connection with MythTV,
as well as the resolutions.

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.

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!

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.

The other problem is a bit peculiar to my setup - I have a combo FE/BE
that is only capable of Standard Def. output. My two recording sources
are a PVR-250 and the STB via firewire. Until I get an HDTV and upgrade
my frontend, I am using "mencoder" to halve the horizontal and vertical
resolution of the HD recording. This gives me a file that I can watch on
my SDTV (and it looks better than watching broadcast, with no overscan),
as well as archive to DVD.

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.

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.

Hopefully this info will be useful to the 5 other people who have a
similar setup :)

Cheers,
-=Mark
_______________________________________________
mythtv-users mailing list
mythtv-users [at] mythtv
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

fuzzie1300 at optonline

Mar 8, 2008, 6:24 AM

Post #2 of 6 (1186 views)
Permalink

Re: SA4200HD via 1394, mixed SD and HD [In reply to]

>
> 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.

fuzzie1300 at optonline

Mar 8, 2008, 6:26 AM

Post #3 of 6 (1190 views)
Permalink

Re: SA4200HD via 1394, mixed SD and HD [In reply to]

What's also interesting to note that sometimes I don't reset anything, other
than maybe a reboot or just turning off SA4250, all of a sudden firewire
starts working ok after not working for several weeks.

bigeb at ebnet

Mar 8, 2008, 11:28 AM

Post #4 of 6 (1184 views)
Permalink

Re: SA4200HD via 1394, mixed SD and HD [In reply to]

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
[mailto:mythtv-users-bounces [at] mythtv] 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.

mark at mark

Mar 8, 2008, 12:18 PM

Post #5 of 6 (1184 views)
Permalink

Re: SA4200HD via 1394, mixed SD and HD [In reply to]

fuzziel300 wrote:

> What's also interesting to note that sometimes I don't reset anything, other
> than maybe a reboot or just turning off SA4250, all of a sudden firewire
> starts working ok after not working for several weeks.

This is how it used to fail for me - the channel change would work, but
mythbackend never received a stream - I would see "Warning: No Input in
XXmsec..." a few times, and then it would give up. Now, instead of giving
up on the recording, it will reset the firewire bus and begin streaming
again. I still sometimes see the "No Input" messages, but then I get the
normal "Buffered packets 2000 (8000 KB)" which indicates the stream in
progress.

I'm not sure if this will work for you, but before BusReset did its magic,
this was my method, which had about a 75% rate of success.

1) halt the backend

2) remove 1394 cable from back of STB

3) power-cycle the STB (just power off/on on front panel)

4) when STB is booted, plug in 1394 cable

4) reboot backend

Also note that my STB had two 1394 ports, and one of them (the inboard
port) was more reliable, in that it had a slightly higher chance of
responding to the reboot.

You say you are not running SVN. That's fine... but are you installing
from packages, or from source? If you're installing from source then you
can at least check linuxfirewiredevice.cpp to see how it handles the
BusReset function.

FWIW the version I was running previously (which was the first SVN I
installed that didn't need the BusReset tweaking) was from October 2007.

Cheers
-=Mark
_______________________________________________
mythtv-users mailing list
mythtv-users [at] mythtv
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

fuzzie1300 at optonline

Mar 8, 2008, 2:38 PM

Post #6 of 6 (1176 views)
Permalink

Re: SA4200HD via 1394, mixed SD and HD [In reply to]

On Sat, Mar 8, 2008 at 3:18 PM, Mark Staudinger <mark [at] mark>
wrote:

> fuzziel300 wrote:
>
> > What's also interesting to note that sometimes I don't reset anything,
> other
> > than maybe a reboot or just turning off SA4250, all of a sudden firewire
> > starts working ok after not working for several weeks.
>
> This is how it used to fail for me - the channel change would work, but
> mythbackend never received a stream - I would see "Warning: No Input in
> XXmsec..." a few times, and then it would give up. Now, instead of giving
> up on the recording, it will reset the firewire bus and begin streaming
> again. I still sometimes see the "No Input" messages, but then I get the
> normal "Buffered packets 2000 (8000 KB)" which indicates the stream in
> progress.
>
> I'm not sure if this will work for you, but before BusReset did its magic,
> this was my method, which had about a 75% rate of success.
>
> 1) halt the backend
>
> 2) remove 1394 cable from back of STB
>
> 3) power-cycle the STB (just power off/on on front panel)
>
> 4) when STB is booted, plug in 1394 cable
>
> 4) reboot backend
>
> Also note that my STB had two 1394 ports, and one of them (the inboard
> port) was more reliable, in that it had a slightly higher chance of
> responding to the reboot.
>
> You say you are not running SVN. That's fine... but are you installing
> from packages, or from source? If you're installing from source then you
> can at least check linuxfirewiredevice.cpp to see how it handles the
> BusReset function.
>
> FWIW the version I was running previously (which was the first SVN I
> installed that didn't need the BusReset tweaking) was from October 2007.
>
> Cheers
> -=Mark
>

Thanks, when I am not afraid of throwing out my back I will try this exact
method.

Here's something interesting that just happened. I am in Cablevision land
on the NJ side. I see it tried to record at 4:30pm on channel 720 HD "Hard
water 505 World Championships", which has a 0 byte file. Earlier today it
recorded Hard Water no problem. It's now recording Channel 48 SD "Grendel"
through firewire. I started to play Grendel back and it works fine.

I install from packages ...MythDora. I have the 169 build (svn 14921) from
atrpms.net from November 20th.

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