[mythtv-users] Firewire No Input in XXX msec

Peter Bennett pgbennett at comcast.net
Thu Nov 3 22:05:42 UTC 2011

I have this problem with my firewire setup. I am using a Scientific
Atlanta 3250HD set top box and a BYTECC firewire card. I have two
tuners, the firewire and a DVB USB stick.

Every so often (about every 5th recording), the firewire recording
fails. Normally 1 minute after starting a program, the following
messages appear in the log:
2011-11-02 22:28:26.416 LFireDev(00169204EBAE0000), Warning: No Input in
50 msec...
2011-11-02 22:28:26.500 LFireDev(00169204EBAE0000), Warning: No Input in
100 msec...
2011-11-02 22:28:26.584 LFireDev(00169204EBAE0000), Warning: No Input in
150 msec...
2011-11-02 22:28:26.667 LFireDev(00169204EBAE0000), Warning: No Input in
200 msec...
2011-11-02 22:28:26.750 LFireDev(00169204EBAE0000), Warning: No Input in
250 msec...
2011-11-02 22:28:26.833 LFireDev(00169204EBAE0000), Warning: No Input in
300 msec...
2011-11-02 22:28:26.917 LFireDev(00169204EBAE0000), Warning: No Input in
350 msec...
And so on. Every 25 messages or so it tries a bus reset.
If you do nothing, this continues for the entire duration of the program
(30 minutes, 60 minutes,etc.) you are trying to record, creating many
megabytes of logs with this message.
I get just a few seconds of the start of the program recorded.
The bus reset was not helping and it was nullifying the "plugctl -n 1
"oPCR[0].n_p2p_connections=1", n_2p2_connections was set to 0, so I
disabled bus reset in the backend.

If you restart the backend, the recording resumes and runs perfectly to
the end of the program.

I have created a shell script that scans the log every 30 seconds and
restarts the backend when it sees these messages. This is in fact
working very well but this is really a kludge. I get the rest of the
program recorded in a separate file. It also interrupts other recordings
that are being done at the same time on the DVB stick, and they get
separated into 2 files.

It should be possible to program the system so that when it encounters
this error, it closes the firewire connection and opens it again (or
whatever the equivalent firewire action happens on killing the backend
and starting it again), and then continue recording with just a second
or so interruption. Anybody have any ideas how to do this?

I have exchanged the set top box at the cable company.  I originally had
a Cisco RNG-150 and then exchanged it for the Scientific Atlanta 3250.
This did not make a difference.

I have added a line "firewire_tester -p -n 1" to my channel change
script. I am not sure if this will help, a subsequent recording failed
with "No Input in XXX msec" at 29 minutes into the program.

So far the problem occurs most often 1 minute into the program, but has
also occurred 29 minutes in, and 59 minutes in. It also happens when
watching live TV if you get to the end of a program and it is trying to
continue on to the next program. I get a "Program Switch Buffer Error"
or something like that and the backend is displaying the "No Input in
xxx msec" messages.


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