[mythtv] dvb zero length record

[Tom Hughes]

In message <c2e2812f05052000552b21392e at mail.gmail.com>
        Phil Vid <phil.vid at gmail.com> wrote:

> I'd just like to update everyone with my ongoing investigations into
> the zero byte dvb recording phenomenon.
>
> There appear to be 3 distinct causes of the problem:
>
> 1. Blank recording, nothing obvious in the logs case 1. This appears
> to be a keyframe detection problem. The recordings enter the
> ReadFromDMX() loop but silently exit as no keyframe has been detected.
> The obvious symptom of this is the absence of the message 'DVB#x Found
> keyframe' in the log. I will investigate this first as this is the
> cause of 90% of my zero byte recordings.
>
> 2. Blank recording, nothing obvious in the logs case 2. Problem with
> PMT/CAM or not authorised to view. The recording enters the
> ReadFromDMX() loop but silently exits upon receiving scrambled
> packets. Easy to detect with an additional debug line upon exit, after
> fixing case 1 hopefully this case can be remedied with some additional
> resends of the PMT.
>
> 3. DVB#x WARNING - No data received ... This one I'm not sure about at
> all. It doesnt appear to be CAM related, have tested by replaying the
> correct PMT back to the CAM upon receiving this error message.

None of those sounds like my case which was reported in the other
thread that somebody referred you to. Those look like this:

2005-05-09 13:38:03.476 DVB#0 DVB signal 5300 | snr 5000 | ber 619ea4 | unc    0
2005-05-09 13:38:03.479 DVB#0 Status: LOCK.
2005-05-09 13:38:03.481 DVB#0 Multiplex Locked
2005-05-09 13:38:09.999 DVB#0 Timeout Getting PMT
2005-05-09 13:38:10.001 DVB#0 ERROR - Tuning for channel #1 failed.
2005-05-09 13:38:10.104 Changing from None to RecordingOnly
2005-05-09 13:38:10.289 DVB#0 Recorder: Card opened successfully (using PS mode).
2005-05-09 13:38:10.296 DVB#0 Data read from DMX - This is for debugging with transform.c 

I believe I now understand what is causing those ones, and I've been
running with a fix since last Sunday and haven't lost anything yet. I
was only loosing one or two a week though so I want to run it for
another week or two before pronouncing it fixed for sure.

Tom

-- 
Tom Hughes (tom at compton.nu)
http://www.compton.nu/