SVCD at 23.97fps (FILM). Is it possible?

[djethan]

When backing up a DVD to an SVCD using DVD2SVCD, often the resulting mpeg2 will be 23.97fps. Discs with this framerate don't play right in my standalond (Apex AD-1500), the video jumps every second or so. The thing I don't understand is that the same player plays DVDs at the same framerate with no problems.

Is there any special way to set up an SVCD at 23.97fps so it plays correctly? I'm thinking there might be some kind of header info that tells the player the right framerate or something. Anybody know anything about this? I'd rather not change the framerate of a disc for quality reasons.

[poopyhead]

you need to use 3:2 pulldown to make the 23.976 fps encoded movie play as 29.97 fps in your dvd player...

i believe there's a proggie called pulldown.exe that adds the pulldown flags to an already made .mpg

[fantomlord]

you need to use 3:2 pulldown to make the 23.976 fps encoded movie play as 29.97 fps in your dvd player...

i believe there's a proggie called pulldown.exe that adds the pulldown flags to an already made .mpg

that is correct
check the tools section[/url]

[Executioner]

If you're using DVD2SVCD, this should be done for you automatically. Are you changing the default settings?

[djethan]

Thanks all. Yes, I figured out about pulldown.exe, so that solves the immediate issue. But I am still curious about SVCDs at 23.97. The SVCD specification includes this option (as per the official spec on this site). Is there a special way to compile the disc so that it tells the player the framerate or something?

The odd thing is that my standalone DVD player will play DVDs (mpeg2 files) at 23.97, but not SVCDs (also Mpeg2) at the same fps. 23.97 encodes faster, and is the original fps of film to begin with so all the movies you copy start that way. For these reasons, I'd like to figure out how to make it work right.

I'm sure one of you geniuses knows something.

[adam]

23.976fps actually is not supported in either the SVCD or DVD specs, but the 3:2 pulldown effectively gives you an output fps of 29.97fps so you do comply with the specs only if you have this flag inserted in your stream.

Stored at ~24, played back at 29.97fps. The ntsc standard only requires PLAYBACK fps of 29.97fps, so there you go.

Different dvd players have different ways of handling the real time telecine (what the 3:2 pulldown tells the dvd player to do.) Some dvd players will recognize when your material is encoded in ntscfilm and it will automatically telecine it regardless of whether there is a 3:2 pulldown flag present, this is what all vcd compatible dvd players are supposed to do when playing vcds. Most dvd players will not telecine the video unless the flag is present for both dvds and svcds. If your dvds get telecined but your svcds don't, well I suppose this is just something in the firmware.

Its a non-issue though. Always include the 3:2 pulldown flag with ntscfilm encoded material, regardless of whether you are making a SVCD or DVD. I have never ever heard of a dvd player which cannot properly perform the telecine with the flags present and if you include the flag then your SVCD still conforms to spec. Even if your dvd player will autotelecine these anyway and the 3:2 pulldown flag just becomes redundant, it still doesnt hurt anything so always use it.

[adam]

djethan: there are even more important reasons for encoding in ntscfilm.

By encoding at 23.976fps and letting the additional %20 of your frames (added to get 29.97fps) be generated during playback, you now have
%20 more bitrate to work with. This results in roughly %20 better quality, or you could lower your bitrate and get a file that is %20 smaller but still the same quality.

Also, by preserving the original progressive frames you skip the interlacing process. Of course it will still get interlaced upon playback but since you are only encoding progressive frames you do not have to worry about field order, interlacing artifacts, or the fact that not all encoders can handle interlaced material as well as progressive material.