Comskip goes HD

[-stattik-]

Are the commercials as found aligned in the debug window?
Do the commercials start and stop where the debug bar has placed them?

The commercials as found are not aligned in the debug window.

The commercials do not start and stop where the debug bar places them. They are offset it seems.

[-stattik-]

It's on its way.

It's finished. The clip catches the end of the previous show, then goes to commercials. Then the show starts, goes to commercials and then back to the show before it ends.

[erik]

Thanks, that should help.

Now I have found an interresting problem and I only have to solve it.
According to the MPEG decoder in Comskip a certain mpeg has 1780 frames and according to other tools it has 1970 frames. How come???????????

I hope to have some answers but it will take a couple of days..........

[erik]

I have found the cause.

The recording you made switches between progressive NTSC 29.97 and 24.9... frame rate, but is in average at 25fps.

So comskip is right in frame numbers but how to translate this into seconds?????

And my debugwindow supposes a constant frame rate. So how to navigate over time?

And how does GBPVR do the skipping? Is the mpeg player used "frame number correct"? Or is it internally using time so things get messed up when you supply frame numbers.


Questions Questions Questions Questions
Answers will take more time.

[-stattik-]

Erik,

What application are you using to monitor frame rate? I'd like to check it against my other recordings to see if this unique to this channel or not.

Are the changes in frame rate during commercial breaks or is it more random? If the former, then it could be another way to detect commercials.

[erik]

Many applications I used failed to notice the changes.

However mplayer nice showed in its logging window in realtime the changes during playback.

The changes I saw where very regular, once every couple of seconds, during a normal show, I think it was "Close to home"????

See below


Warning! FPS changed 23.976 -> 29.970 (-5.994000) [4] % 17.0% 55 0
A: 4.8 V: 3.8 A-V: 0.986 ct: 0.182 92/ 85 108% 10% 21.0% 81 0
demux_mpg: 24000/1001fps progressive NTSC content detected, switching framerate.
A: 11.3 V: 9.2 A-V: 2.119 ct: 0.720 221/214 100% 6% 16.8% 208 0
demux_mpg: 30000/1001fps NTSC content detected, switching framerate.
Warning! FPS changed 23.976 -> 29.970 (-5.994000) [4] % 16.7% 209 0
A: 12.2 V: 9.8 A-V: 2.431 ct: 0.778 241/231 100% 6% 18.0% 224 0
demux_mpg: 24000/1001fps progressive NTSC content detected, switching framerate.
A: 18.1 V: 14.6 A-V: 3.455 ct: 1.261 357/347 98% 5% 17.2% 339 0
Too many video packets in the buffer: (1079 in 8391268 bytes).
Maybe you are playing a non-interleaved stream/file or the codec failed?
For AVI files, try to force non-interleaved mode with the -ni option.
a52: CRC check failed!
a52: error at resampling

Too many video packets in the buffer: (1079 in 8391268 bytes).
Maybe you are playing a non-interleaved stream/file or the codec failed?
For AVI files, try to force non-interleaved mode with the -ni option.
A: 18.7 V: 23.0 A-V: -4.300 ct: 1.181 561/551 98% 5% 10.8% 339 0
demux_mpg: 30000/1001fps NTSC content detected, switching framerate.
Warning! FPS changed 23.976 -> 29.970 (-5.994000) [4] 10.8% 339 0
A: 18.2 V: 24.2 A-V: -5.995 ct: 1.066 598/585 98% 5% 10.2% 339 0
demux_mpg: 24000/1001fps progressive NTSC content detected, switching framerate.
A: 18.6 V: 29.7 A-V:-11.126 ct: 0.508 733/719 98% 5% 8.3% 339 0
demux_mpg: 30000/1001fps NTSC content detected, switching framerate.
Warning! FPS changed 23.976 -> 29.970 (-5.994000) [4] 8.3% 339 0
A: 19.0 V: 30.1 A-V:-11.054 ct: 0.473 745/729 98% 5% 8.2% 339 0
demux_mpg: 24000/1001fps progressive NTSC content detected, switching framerate.
A: 18.5 V: 41.5 A-V:-22.972 ct: -0.682 1022/1006 99% 5% 5.9% 339 0
demux_mpg: 30000/1001fps NTSC content detected, switching framerate.
Warning! FPS changed 23.976 -> 29.970 (-5.994000) [4] 5% 5.9% 339 0
A: 18.7 V: 41.6 A-V:-22.966 ct: -0.693 1026/1009 99% 5% 5.9% 339 0
demux_mpg: 24000/1001fps progressive NTSC content detected, switching framerate.
A: 18.4 V: 72.0 A-V:-53.661 ct: -3.754 1761/1743 100% 5% 3.4% 339 0
demux_mpg: 30000/1001fps NTSC content detected, switching framerate.
Warning! FPS changed 23.976 -> 29.970 (-5.994000) [4] 5% 3.4% 339 0
A: 18.3 V: 73.9 A-V:-55.647 ct: -3.946 1817/1799 98% 5% 3.3% 339 0

[-stattik-]

I tested a few more files and I found that the frame rate changes occured once the program started. Usually there would be a few commercials or previews for other shows. I didn't see any frame changes during this time. Once the main program started, so did the frame rate changes. I don't know if will help or not but it is interesting.

[erik]

It will depend on the mpeg player used if these frame rate changes are a problem.
It certainly is a problem for comclean because comclean uses the frame rate to convert the frame number to a time code.
But also other cutting programs are having problems.
Womble seems to be able to use frame numbers but its actually a converted time code so it assumes the whole recording is in 29.97 fsp and everything fails.

Also the debugwindow of comskip can currently not deal with these changes.
The generated frame numbers are correct! I checked on the file you uploaded (thanks again) and all is OK.

Does GBPVR player use the real frame numbers or does it conver the frame numbers back to time and then uses time to skip?????

[-stattik-]

Another interesting finding:

DVR-MS is the only reliable way to record ATSC programming for me.
I then convert it to PS or TS files.
Both types have the same frame rate changes

I went ahead and used the Cyberlink muxer to record a ATSC show.
As usual, the video stuttered which was expected because it's happened in the past as well. The interesting part is that there weren't any frame rate changes. Perhaps the DVR-MS muxer adds the frame rate changes to keep the video smooth because without it, you get the stuttering.

[sub]

What version of Cyberlink mux did you try?