[mythtv-users] Problem with 1080i h264 video - video appears to be twice as long as it should.

Manuel McLure manuel at mclure.org
Thu Jun 4 03:42:07 UTC 2009

On Wed, Jun 3, 2009 at 6:51 PM, Manuel McLure <manuel at mclure.org> wrote:
> Well, I'm afraid there is still a bit of a problem even with the new
> patch in place. It's almost perfect, except that MythTV stops playing
> the show (for a 1/2 hour show) about a minute or two early. If I then
> restart the show and use 30-second skips to the end, I can watch a
> little more of the show. Still, it's much better than it was. I'm
> going to see if applying the fixes in
> http://svn.mythtv.org/trac/ticket/6243 improves the situation.

Just to follow up on my previous post in case one of the h264 gurus is
reading this, I did some experimenting. I went to near the end of the
file, and played from there, bringing up the OSD so I could see what
MythTV seemed to think the file position was. It counted up apparently
fine, but when it reached 0:28:55 of 0:29:56 the "End of Recording"
dialog popped up. So it appears that MythTV is getting the right
length, but somehow it's hitting some sort of "end of file" marker. I
looked in the recordedseek table for that recording and found 53832
entries which if multiplied by 29.97 fps gives exactly 0:29:56, so it
would appear that the lengths are correct. The last recorded offset
was 1788083228 for a file length of 1789042028 bytes - also very

And some more very interesting information: if I use my 20622SVN
backend built on Gentoo with the mythtv-fixes-glvdpau20549.patch and
the 24_newfix_h264_frame_counting.patch applied, but use Jean-Yves'
latest stable Ubuntu frontend package on my desktop (which I believe
does not have the h264 patches in place) the video plays to
completion. Very bizarre. It's almost like the patch is correctly
creating the seek table, but incorrectly playing the video.
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

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