I've been having intermittent problems recording from my motoroloa DCT-6200 over firewire that would result in 0-length files (displayed as size "B" in mythweb). I am posting this in case someone else finds this solution useful. My symptons were as follows:

1. If the first recording on the dct-6200 after a back-end restart worked, then all subsequent recordings would be OK.

2. If the first recording after a back-end restart failed, then all subsequent recordings from the dct-6200 would fail. When this would happen, I would do repeated restarts until I could finally get a good recording. Sometimes it would take 3-4 restarts in a row and/or a power-cycle of the dct-6200 box to get things working. What a pain!

This weekend I was doing some tweaking of my system and noticed that I had two "sources" associated with my hidef channel lineup. In the database they had a source ID of 3 & 4. SourceID 3 was linked to my DCT-6200 tuner; source ID 4 was unused. I then did the following from myth setup:

1. Unlinked the source from the dct-6200 tuner.

2. deleted sources 3 & 4.

3. Created a new source for the hidef channel linup.

4. Linked it back to the dct-6200.

Subsequent to this I've restarted the backend 4 times over a period of 2 days and shows always record properly from the dct-6200 tuner.

Marc

Thanks Marc, I've seen the "B" recordings too after a failed record and this will be interesting to try next time it happens. Have you tried to make a failed recording? (I can do this by tuning to a channel with very spotty reception.)

cenvee703, my failure would always happen after a restart of the backend. EIther it would fail on the first and all subsequent recordings or it would work on the first and all subsequent recordings. I've tried 4 restarts over a 2-day period and in all instances it has worked. ie: No 0-length recordings.

Marc

I resolved my identical issue by doing the following:

1) mythtv-setup: change to point-to-point at 400mbps
2) following this: http://www.mythtv.org/wiki/index.php/Firewire_Priming at the mythtv wiki, I added the following to /etc/init.d/mythtv-backend near the top:


which sets the point to point connections on node 0 input 0 to 1.

has worked like a charm ever since.

Misosoup777, are you saying that the problem you had was identifcal to mine or ceenvee703's? Also, which vesion of knoppmyth do you have installed? Just curious.


Marc

Essentially identical. Zero length recordings, solved by restarts and/or cable box reboots. Generally worked ok after a restart that got a successful recording.

A tweaked version of R5D1...

So I am doing something similiar, but setting it up for "broadcast" rather than "peer-to-peer", as there were several posts indicating that "broadcast" was the way to go. The exact commands I issue are:



The plug# is either 0 or 1, depending on what the box decided to do on it's last reset. It sounds like you are configured for peer-to-peer in the setup and using "plugctl" to tell the box to accept 1 p2p connection while I'm configed for broadcast and telling the box to accept 1 broadcast connection.

Does anyone know if there are any pros/cons with peer-to-peer vs. broadcast? It looks like Misosoup777 & I have both achieved a high level of reliability using these two different options...

Marc

Sad news. On my 8th backend stop/start, I once again starting having 0-length files. I tried switching to p2p instead of broadcast -- problem persisted. It took several power-cycles of the dct-6200 to finally get recordings working again. Looks like I don't have a solution after all...

A quick update. I found a posting by ed3120 at http://mysettopbox.tv/phpBB2/viewtopic.php?t=11826 that talks about the program firewire_tester -- it really solves the problem! There is a more recent version of this program at the myttv SVN download site -- http://svn.mythtv.org/svn/trunk/mythtv/contrib

Download the program "firewire_tester.c". Compile it using the following command:


Assuming you are using broadcast mode on node 0 to talk to the DCT-6200 box, use the following command to get things working properly:


Replace "-n 0" with the nodenumber you get from plugreport if you're not on node 0. It will put things into working order!

The only thing that bugs me is that the "-static" should not be necessary. Looks like there are multiple versions of some library in the distribution, and the version that it compiles with is not the same one that is in memory when firewire_tester executes, so doing a static link is required.

Marc

Added to the next release.

That's great, thanks!

Marc

Despite all my success to date with point to point, it suddenly decided to stop working 2 days ago. Nothing that I did would bring it back. So I switched to the "tester" method and it seems to be working again.

go figure.