[mythtv-users] Strange time counter issue with recent NBC OTA recordings

[Jim Stichnoth]

On Sun, Dec 8, 2013 at 2:30 PM, Tom Dexter <digitalaudiorock at gmail.com>wrote:

> On Sun, Dec 8, 2013 at 2:11 PM, Jim Stichnoth <stichnot at gmail.com> wrote:
> > On Sun, Dec 8, 2013 at 9:58 AM, Tom Dexter <digitalaudiorock at gmail.com>
> > wrote:
> >>
> >> On Sat, Dec 7, 2013 at 12:48 PM, Jim Stichnoth <stichnot at gmail.com>
> wrote:
> >>
> >> > It would be enlightening if you could dump the recording markup with
> >> > "mythutil --getmarkup markup.xml --chanid <chanid> --starttime
> >> > <starttime>"
> >> > and post/attach the resulting markup.xml file.
> >> >
> >> > Jim
> >>
> >> I sent that as an attachment.  Apparently it's awaiting list moderator
> >> approval because of the size of the attachment.
> >
> >
> > Pretty sure there is no moderation. :)  Try a pastebin.com link, or feel
> > free to email me directly.
> >
> > Jim
>
> Ah....ok.  Here it is.
>
> http://pastebin.com/x6CiDUhH
>

Offhand I don't see any problems with the markup/seektable.  Here are some
interesting bits:

      <mark frame="0" type="33" data="3539156"/>
The recording is 3539.156 seconds long, i.e. 59 minutes.

      <mark frame="0" type="34" data="89908"/>
The recording contains 89908 frames.

      <mark frame="1" type="12"/>
The recording is identified as 16:9 aspect ratio.

      <mark frame="1" type="30" data="1920"/>
      <mark frame="1" type="31" data="1080"/>
      <mark frame="1" type="32" data="29970"/>
The recording is identified as 1920x1080 at 29.97, i.e. 1080i.

The interesting bit is that frames/framerate = 89908/29.97 = 3000s = 50
minute length, which is what 0.25 incorrectly reports.

The bulk of the file is seektable data, e.g.:
      <seek frame="15" type="9" data="1050920"/>
      <seek frame="15" type="33" data="501"/>
This says that frame 15 is a keyframe (only keyframes are listed here) and
that it is 1050920 bytes and 501ms from the start of the file.

Looking at the differences from one seektable entry to the next, it seems
that the framerate is quickly and mostly randomly bouncing between 24fps
and 30fps.  This is most likely due to insertion of the repeat_pict flag
which tells the player to show the frame for an extra half frame interval.

All in all, it looks in order and is exactly what the 0.27 recorder and
player (including mythcommflag --rebuild) changes were designed to handle.

In rereading the thread, it seems that at this point you're saying that
with this rebuilt seektable, during playback it always shows a length of 52
minutes, right?  I have no explanation for that.  It would be very helpful
to get a copy of the 6GB recording file to try to reproduce the issue.
 (Given your gmail account, you could probably upload it using Google Drive
and share it as you like, if you have the time/capacity/patience.)

Jim
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