[mythtv-users] Commercial skips about 5-15 seconds early

[Kevin Kuphal]

Bruce Markey wrote:

> Chris Pinkham wrote:
>
>>> I'm having an issue recently.  My commercial detection seems to 
>>> detect perfectly (duration wise) but the commercial skips about 5-15 
>>> seconds early.  So I miss 5-15 seconds prior to each break and see 
>>> about 5-15 seconds of the last commercial.  The clocks on both 
>>> machines are synced up to each other.  My system is made up of 
>>> master backend, slave backend, and remote frontend.
>>>
>>> Any suggestions appreciated.
>>
>>
>>
>> Can you look at the frame numbers for the commercial markers in
>> recordedmarkup and see if they match up to the proper frame numbers
>> where commercials start/end when you look at them in the editor?
>>
>> If the frame numbers match up (so commercial detection is correct),
>> you can put some debug statements into
>> NuppelVideoPlayer::AutoCommercialSkip() to see if this is being
>> triggered early for some reason or if frame numbers look off in
>> there for some reason.
>
>
> Chris, this problem has existed for a long time with software encoding
> but I hadn't ever wanted to bother you with it. If a file is damaged
> by a pegged CPU, temporary loss of signal or any other reason that
> might cause a significant number of dropped frames, the commercial
> markers will be off by the same amount for the remainder of the show.
> I assume that this is because the frame numbers are sequential and
> don't count the dropped frames while something else is assuming the
> frame number should be time * framerate.

To confirm part of this, I am using 2 software capture cards in the 
master backend and a single PVR-150 in slave backend.  It only seems 
that this started recently when I am capturing 3 shows.  The slave 
backend has no local disk so it is writing over the network to the 
master.  The master is indeed close to CPU bound with 2 simultaneous 
recordings + commflagging.  The shows that exhibit this typically have 
portions in them when I watch them were the video lags behind the audio 
(dropping frames) but eventually catches up. 

Kevin