[mythtv-users] Firewire stops working -- and how to record twice?

[Brad Templeton]

I recenty caved and got a Comcast Motorola DCH3200 HD set top box
with firewire/1394.   I want myth to be able to record HD cable
channels and this seems to be the only way to do it, short of the
more experimental wintv component recorder.

Like many I have had problems getting this to work, and I hope for
some help here, but I also am interested in thoughts on work-arounds
for dealing with a time when you have an unreliable system.

Anyway...  I can get recording from the STB to work on a freshly
booted system.   I prime the box and use broacast mode as suggested
since p2p mode shows some failures.  I am able to suck out mpegs,
change the channel with 6200ch and record programs in mythtv.

However, sooner or later something will make it fail.  I don't know
exactly what causes the failures but after it fails, it seems impossible
to bring it back.  I've tried all the various priming scripts, such
as the two on the wiki, and manual playing with the pcrs and mcrs on
the firewire bus.  (In failed state the pcr[0] channel seems to be set
to 0 instead of 63, but setting it back to 63 doesn't help.

In failed state all firewire-tester attempts fail, all test-mpeg2 fetches
come back null.

My firewire controller is the Agere Systems FW323 (rev 61), which is
on motherboard in my aopen xcube.  I'm running an older gutsy system
with 2.6.20 -- I will upgrade soon, but I will need to get the latest
trunk mythtv to build in order to do that and work with the new firewire
drivers.  The mythtv is from an old trunk, rev 15102 from 12 months ago.


So what fixes it?  Reboot of the linux box.   Reboot of the STB or
unplug/plug of the 1394 cable does not fix it.   firewire bus reset
from firewire-tester does not fix it.

However, even in the broken state, 6200ch changes channels like a charm,
so the firewire bus itself is working and the nodes are up.

Obviously that's not an acceptable way to fix things!

Here's what plugreport looks like now:

    Node 0 GUID 0x002374fffe4343ac
    ------------------------------
    oMPR n_plugs=1, data_rate=2, bcast_channel=0
    oPCR[0] online=1, bcast_connection=0, n_p2p_connections=1
            channel=63, data_rate=1, overhead_id=0, payload=376
    iMPR n_plugs=0, data_rate=2


Is the Agere FW323 the culprit?  The working 6200ch seems to say no.
Should I try to get an actual 6200 -- they have those, but they have
not got HDMI which means a different cabling of the audio and no 5.1
audio as I am out of ports for that other than over HDMI.

Any other suggestions?

-=--------------------------------------------------------


Part 2: What to do when you're not robust

If you have a tuner which is not robust, you don't want to lose shows.
Is there a good way to convince Mythtv to record the same show twice at
the same time, on two different tuners?   Other than applying lots of
overrides, that is?   I find that if I create two "record on this channel"
schedules it still wants to record on only one of them.   So I need to
create two manual overrides or I won't get two recordings.

Of course, another nice thing would be if myth noticed a tuner is failing
or has failed, and is not building a file, and started up another tuner
until it got some success.  Right now it will retry at different time slots,
but with the same tuner.

In this case, when I ask it to record Battlestar in HD from SciFi HD, which
is obviously going to be the 1st priority, I could get it to also record
it using an analog tuner card from regular analog cable Scifi Channel.

Or, since channel change works, I could also have the wintv-pvr-150 record
the NTSC signal from the cable box's svideo port.   Turns out that a
recording of that port from an HD signal is still better than an analog
recording of the SD channel.   Alas, Myth will not know that the analog
port and the firewire port are recording from the very same tuner, so this
is risky.

But in the end the goal is to say, "I really want this show, and this tuner
is flaky, so record it twice for me."   Any way to do that?  I guess if Myth
could understand that the HD version is different from the SD version, and
also different from an SD recording of the HD version (which is even tougher
since they look like the same channel to it.)