[mythtv] Ticket #7984: Commercial break detection on H264 progressive recordings off by 2

[Manuel McLure]

On Sat, Feb 27, 2010 at 8:19 AM, Chris Pinkham <cpinkham at bc2va.org> wrote:
> The commercial flagger works on a frame-count basis, it does not work
> on timestamps, and the frame numbers that the flagger uses come directly
> from the decoder, so either the decoder is providing incorrect frame
> counts during flagging or the ones provided during flagging do not match
> up with the ones provided during playback.  Is this current trunk or is
> this 0.22-fixes?  I ask because we recently went through a libavcodec sync
> that may have had bearing on this.

This is 0.22-fixes SVN revision 23069. Interestingly enough, this used
to work fine on 0.21-fixes.

> I may not be the right person to fix this since it doesn't appear to be
> a commercial flagger issue, but if you want to email me privately with
> a link to a download of the first 15 minutes or so, that should easily
> be enough to take a look at the issue.

I'm sending you a link in a separate email.

>> mysql> select * from recordedmarkup where chanid = 1647 and starttime
>> = '2010-02-26 19:30:00';
>> +--------+---------------------+-------+------+---------+
>> | chanid | starttime           | mark  | type | data    |
>> +--------+---------------------+-------+------+---------+
>> |   1647 | 2010-02-26 19:30:00 |     0 |    4 |    NULL |
>> |   1647 | 2010-02-26 19:30:00 | 10272 |    4 |    NULL |
>> |   1647 | 2010-02-26 19:30:00 | 23715 |    4 |    NULL |
>> |   1647 | 2010-02-26 19:30:00 | 34225 |    4 |    NULL |
>> |   1647 | 2010-02-26 19:30:00 |    82 |    5 |    NULL |
>> |   1647 | 2010-02-26 19:30:00 | 15941 |    5 |    NULL |
>> |   1647 | 2010-02-26 19:30:00 | 26576 |    5 |    NULL |
>> |   1647 | 2010-02-26 19:30:00 | 37081 |    5 |    NULL |
>> +--------+---------------------+-------+------+---------+
>
> (non-flagging items deleted from above)
>
> The 'mark' in these rows is the frame number of the commercial start
> or end flag.  If your theme provides the frame number in the cutlist
> editor, can you see if these line up with the frame numbers you see
> from the database query above?

Can you suggest a theme that does this? I tested with a few of overall
and OSD themes and was unable to find one that gave me frame numbers.
However, if I divide the frame numbers by 60 * 30 (for 30 fps video)
they match up pretty close to the locations MythTV is skipping to.
-- 
Manuel A. McLure WW1FA <manuel at mclure.org> <http://www.mclure.org>
...for in Ulthar, according to an ancient and significant law,
no man may kill a cat.                       -- H.P. Lovecraft