[mythtv-users] Incorrect length in OSD for MPG videos
level42 at sympatico.ca
Sat Jun 2 17:51:44 UTC 2007
Trying to track done the source of the problem, I have several MPEG movies
recorded from DVB that mythtv reports the incorrect length in the OSD. This
is the cause whether from "view recordings" or after I move them to
mythvideo (and use mythtranscode to re-generate position map). As yes I
have a good position map.
Mythtv determines the length from the frame number of the last key frame in
the position map (from recordedseek for recordings; or filemarkup for
videos). Here an example:
Video length is actually 2:14:53, but mythtv reports it as 1:48:26. Have
confirm that the actual mythtv play time is 2:14, but the OSD reports on
1:48. The entry in the position map (recordedseek or filemarkup) is 195006
which is 195006/29.97 = 6506 seconds or 108 minutes (1:48). To determine
the the position in the recording/video, mythtv counts the frames played,
multiplies by the frame rate. This seems to all make sense, but I can not
explain/understand why the discrepancy between the actual play time and the
calculated run time. Doesn't matter if the video is played from "view
recordings" or from mythvideo, same results.
When mythtv reads the mpeg, it does note in the log that it is 6506 seconds
long and that it's frame rate is 29.97. I presume this comes from the mpeg
file header, as other video player software show the same thing.
When I play in other software, they report the play time correctly.
It almost seems like the actual frame rate in the file is 23.97 and mythtv
is automatically compensating for this, but not telling me in the log
messages and still counts the frames as if they were 29.97/sec. The 23.97
would make some sense to save bandwidth on DVB transmission.
Any suggestions where to look to fix this problem or as to the cause of the
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