Missing playback frames using Force Film?

[ScottZ]

Something caught my eye when I started playing around with Force Film in 140rc6 and wanted to make sure it was maybe my misunderstanding.

I have a short 23.976->29.97 NTSC vob I'm experimenting with and DGIndex is showing 98% Film progressive.

In turning on Force Film and doing a preview I get:
2179 - Coded #
2162 - Playback #

I thought for sure the numbers should have matched.
So I took a look in Parse d2v and it indeed shows 2179 frames.

But what looked odd is the last GOP section was missing from the playback # and it accounted for the 17 frames not being played.


2145 [B]: 2145,2145.............2
2146 [P]: 2146,2146.............2
[GOP]
2147 [B]: 2147,2147.............2
2148 [B]: 2148,2148.............2
2149 [I]: 2149,2149.............2
2150 [B]: 2150,2150.............2
2151 [B]: 2151,2151.............2
2152 [P]: 2152,2152.............2
2153 [B]: 2153,2153.............2
2154 [B]: 2154,2154.............2
2155 [P]: 2155,2155.............2
2156 [B]: 2156,2156.............2
2157 [B]: 2157,2157.............2
2158 [P]: 2158,2158.............2
2159 [B]: 2159,2159.............2
2160 [B]: 2160,2160.............2
2161 [P]: 2161,2161.............2
[GOP]
2162 [B]: 2162,2162.............2
2163 [B]: 2163,2163.............2
2164 [I]: 2164,2164.............2
2165 [B]: 2165,2165.............2
2166 [B]: 2166,2166.............2
2167 [P]: 2167,2167.............2
2168 [B]: 2168,2168.............2
2169 [B]: 2169,2169.............2
2170 [P]: 2170,2170.............2
2171 [B]: 2171,2171.............2
2172 [B]: 2172,2172.............2
2173 [P]: 2173,2173.............2
2174 [B]: 2174,2174.............2
2175 [B]: 2175,2175.............2
2176 [P]: 2176,2176.............2
2177 [B]: 2177,2177.............2
2178 [P]: 2178,2178.............2
[EOF]


So I ran two vobs together (This one and the next chapter) as a test.

17610 - Coded #
17590 - Playback #

End of the Parse d2v looks like:


17603 [B]: 17603,17603..........0 *
17604 [P]: 17604,17604..........1 *
[GOP]
17605 [B]: 17605,17605..........2 *
17606 [B]: 17606,17606..........3 *
17607 [I]: 17607,17607..........0 *
17608 [P]: 17608,17608..........1 *
17609 [P]: 17609,17609..........2 *
[EOF]


So now I'm not sure where the additonal 3 frames off came from.

I opened up Virtual Dub just to compare numbers and it indeed is showing the shorter playback frame count.

Am I missing something here?

Thanks!

[Guest]

It is due to the frame decimation performed by FF and it's a coincidence that it is 17 frames.

I've explained elsewhere that FF sometimes has to insert or delete frames to maintain 23.976 fps, depending on the distribution of pulldown flags in the source. You have 2% of your source that does not have pulldown flags, so those sections have to be decimated to maintain 23.976 fps (those sections have no pulldown to ignore, so the only way to reduce their frame rate is to remove frames).

I have on my private bug list the need to fix the fact that Parse D2V does not show the frame insertion/decimation effects of FF. Thanks for exposing it to the world. :)

[ScottZ]

EDIT - Took this post out as it was a mistake

[Guest]

How can it be the same VOB if one has 2179 frames and the other has 737 frames? And in your combined case, you have a frame count from the combined run showing less frames than just the first VOB!

[ScottZ]

My question exactly... thought it was due to changes between 130 and 140.

VOB is 35MB if you want to try it?

I'm trying it again to make sure.

[Guest]

>My question exactly... thought it was due to changes between 130 and 140.

You think 1.4.0 loses thousands of frames and no-one noticed it? :)

Please upload the VOB to my ftp server and tell me the filename. I'll look at it right away.

[ScottZ]

CRAP! Your right (of course) my fault.

[Guest]

Please explain the error. Did you have a range set or something? Thank you.

[ScottZ]

You think 1.4.0 loses thousands of frames and no-one noticed it?

No.. I'm just learning this and don't know any better.

[Guest]

OK, no problem. I'm happy to help if you have any other questions. Thank you for your interest in DGMPGDec and welcome to the forum!