[mythtv-users] Myth problem or HDPVR probmem?
kbass at kenbass.com
Mon Feb 14 22:13:56 UTC 2011
On 2/14/2011 4:02 PM, Michael T. Dean wrote:
> And, critically, that if they're /not/ in good working order, that the
> drivers will report an error.
> The drivers /are not/ reporting an error--therefore, MythTV does not
> report (or assume) an error.
I mentioned this in a previous thread and got no response. Why is MythTV
calling SetInputAndFormat() for NTSC and ATSC on an HD-PVR type device?
That is a bug. That is never a valid case. And if you look at the logs
that people have posted there are lots of 'error messages' such as
1) 'SetInputAndFormat() failed',
2) 'Error: Start encoding failed'
3) 'eno: Resource temporarily unavailable (11)'
The MythTV code appears to be ignoring those errors and continuing on.
When trying to watch live TV, mythtv is 'smart' enough to print an error
about either timeouts or no available tuners, etc. Why can't it be
smarter when starting a recording?
> You're only assuming that the lack of data to write is an error. For
> users whose digital channels disappear at times of the day, recording a
> show that comes at the beginning of the broadcast period may, in fact,
> include a period of no data.
I think we can probably assume that for a non-tunable 'frame capture
device' like the HD-PVR, lack of data is an error.
> I don't know about others, but I'm leary of having MythTV just assume
> there are problems and react... How long do you wait until you say it's
> a problem? If you decide there's a problem, what do you do? Switch
> this recording to a new input, then mark the current input as
> unavailable and reschedule? How long does the input get marked as
> unavailable? Do you want to continuously poll the recorder, trying to
> start recordings on it until one succeeds? Do you, instead, want to
> mark the input as unavailable until the user notices the log message or
> missed recordings and investigates and fixes the STB/capture
I'm leary of MythTV producing 0 byte recordings that I find out about
only after it is too late to watch the show.
I'm not sure the scenario has to be so complicated. There is a good bit
of evidence from multiple users of the HD-PVR, that
within the first 30-60 seconds of recording you will encounter the
SetInputAndFormat() failed error message. At a minimum, the recording
should be aborted and allowed to reschedule.
There is no reason the current code should be printing error messages
for an hour and transitioning to a 'Recorded' state.
The better solution would be to abort and immediately reschedule on
another tuner. Its better to miss the first minute of a recording than
the whole show.
> And these are only a few of the decisions you'd have to make to
> implement a "MythTV is smarter than V4L/DVB and all hardware "
> functionality. I vote that if someone can make a case that it is an
> error, the drivers be fixed to notice--and report--the error properly.
> MythTV is an application, not a hardware interface layer.
The whole MythTV is an application, not a hardware interface layer is a
cop out. Without hardware and working around the quirks, MythTV is
useless. Being an application purist does not solve real world problems.
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