[mythtv-users] searching dialog then player abort after BE migration

Mike Perkins mikep at randomtraveller.org.uk
Fri Jan 6 12:48:00 UTC 2012


On 06/01/12 03:12, Matt Garman wrote:
> On Thu, Jan 05, 2012 at 07:12:59PM -0600, Matt Garman wrote:
>> On Thu, Jan 05, 2012 at 03:03:26PM +0000, Mike Perkins wrote:
>>> On 05/01/12 03:24, Matt Garman wrote:
>>>>
>>>> I followed the suggestions on this page:
>>>>
>>>>       http://www.mythtv.org/wiki/Repairing_the_Seektable
>>>>
>>>> Basically, optimize_mythdb.pl (on both the FE and BE databases),
>>>> mythcommflag, and mythtranscode.  None of these fixed the
>>>> problematic videos; the problem still exists.
>>>>
>>> optimize_mythdb.pl is only ever going to work on the box that has the mysql
>>> database.
>>>
>>>> But it is intermittent: some recordings are OK, some are
>>>> problematic.  In fact, two shows can be recorded at the same time
>>>> (HDHomeRun w/OTA) with one just fine and one being problematic.  Or,
>>>> a single show can be recorded at any random time, and there seems to
>>>> be a 50/50 chance that it will have the problem.  In other words, I
>>>> can't see any pattern to the problem: not isolated to a particular
>>>> time, channel, or TV show.
>>>
>>> Time, channel, TV show, no. But did you check to see which *tuner*
>>> was used for the good/bad recordings? As things stand, you can
>>> only do this by looking at the backend logs.
>>
>> I will study the logs.
>>
>> In the meantime, what kind of tuner issue would cause this problem?
>> It seems highly unlikely that the tuner would suddenly develop a
>> problem: it's a HDHomeRun, which means I didn't physically touch it
>> at all.  It's worked without issue for a long time now.  Seems
>> unlikely that it would develop problems right when I split my
>> combined FE+BE out to two separate machines.
>>
>> Is it possible that I mis-configured the HDHomeRun when setting up
>> the new BE?  What kidn of configuration problem would lead to this?
>>
>> Also: the videos play just fine, start to finish, as long as we
>> don't try to search.  So they are being recorded correctly.  And
>> since they are recorded correctly, I don't understand why
>> mythcommflag --rebuild doesn't fix the seek table.  Is it possible
>> there is some other issue at work?
>>
>> Also: my wife noticed another quirk: some videos that we initially
>> thought were OK are only OK until you seek forward or backwards a
>> few time.  Then the seeking functionality starts degrading: first
>> the amount of seek starts getting random, then seeking forward makes
>> the video go backward and vice-versa!
>
> I compared tuner information in the logs to player performance.  All
> recordings *except 1* from "cardid 1, sourceid 1" had the seek
> problem.
>
> Two other tuners showed up: "cardid 3, sourceid 1" and "cardid 4,
> sourceid 1".  I don't know why I don't see a cardid 2.  Anyway, all
> of the recordings from this tuner either worked perfectly, or were
> ultra-small files that had no playback at all!
>
> If anything, the problem seems to be getting worse.
>
> For the files that were full-size, but didn't play back correctly
> with Myth's internal player: I was able to play them just fine in
> mplayer, complete with search back and forward.
>
> So, now, in summary, after the BE migration, very few recordings
> (say 10%) are viable in MythTV.  The rest are either tiny files and
> have no data, or have bad seek behavior (but play fine in an
> external player).
>
A couple of points I can mention here, but I must warn you I don't own an HDHR. 
I can only tell you what I've gleaned from this list over the years.

Firstly, an HDHR consists of two tuners in the same box. One of these may have 
different signal sensitivity than the other, causing variations in reception.

Secondly, when you set the HDHR up originally, if you didn't say otherwise, each 
physical tuner will have generated *two* tuner entries in the database. This 
allows *one* tuner to record *two* programs simultaneously, provided they are on 
the same multiplex.

Lastly, there are numerous reports on the list about the quality - or otherwise 
- of HDHR power supplies, causing the receiver to appear to fail. The symptoms 
you describe appear to confirm this. It seems you can get the PSU changed out by 
the maufacturer at little or no cost: another HDHR user can probably better 
advise you.

-- 

Mike Perkins



More information about the mythtv-users mailing list