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Old 16th May 2018, 17:32   #3091  |  Link
manolito
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Join Date: Sep 2003
Location: Berlin, Germany
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Quote:
Originally Posted by manolito View Post
A1: Using DGDecode
Pulldown flags are honored, A2D sees the source as 29.97 and uses hard FPS conversion. Chapter points are correct

A2: Using DSS2Mod with LAVFilters
MediaInfo recognizes the frame rate as 23.976, DSS2 removes the pulldown flags, and A2D will either use PAL speedup or 23.976 -> 25 pulldown. In both cases the chapter points are off (by about 4% with PAL speedup, much worse when using 23.976 -> 25 pulldown).
Realizing once again that NTSC is still a strange beast to me...
What is the "most correct" way to handle a progressive (film) NTSC clip which is encoded at 23.976fps with 3:2 pulldown flags?

In AVStoDVD the different source filters depend on the MediaInfo information. When DGIndex/DGDecode is used then the "Honor Pulldown Flags" option is set. AviSynth sees a 29.97fps clip which looks "interlaced" due to the repeated fields. For fps conversion to PAL framerate A2D uses the selected "hard" conversion method (default is MCJMFPS).

Is this a good way to do it? Or shouldn't DGIndex use the "Force Film" option instead to serve the 23.976 clip without the repeated fields to AviSynth?

//EDIT//
I had falsely assumed that AVStoDVD actively edits DGIndex.ini to make sure that "Honor Pulldown Flags" is set. This is not true, A2D does not touch the "Field Operation" setting. A user can change this setting to "Force Film" before starting AVStoDVD, and this will make sure that only the encoded frames without the repeated fields will be served to AviSynth.
//END EDIT//


The other method using DSS2Mod and LAVFilters also raises a few questions. In this case MediaInfo reports 23.976fps and 3:2 pulldown for the source clip. A2D adds the "fps=23.976" to the DSS2Mod source filter command. Does this command return the correct frames? Without the "fps=23.976" DSS2Mod would return a rate of 29.97 (like DGIndex with "Honor Pulldown Flags"). Is forcing 23.976 in the source filter command the equivalent of removing the pulldown flags? I have my doubts... I am afraid that DSS2Mod first decodes to 29.97 and afterwards just drops frames to reach the specified frame rate of 23.976.

BTW DirectShowSource and FFmpegSource behave the same way as DSS2Mod.


Whatever, I am mighty glad to live in PAL land where I do not have to deal with those things...


Cheers
manolito

Last edited by manolito; 16th May 2018 at 18:21.
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