Change Framerate from 29.970 to 23.976 or vice-versa

[randywest]

How can I convert an Mpeg file of 320 x 240 that has a 23.976 to 29.970 or vice-versa? Is it possible? If it is can we do it without having synch problem?

[adam]

23.976fps is converted to 29.97fps through a process called a telecine, and the reverse is done through a process called an Inverse telecine.

TMPGenc can perform a telecine by setting the output framerate to 29.97fps and enabling the 3:2 pulldown filter on the advanced tab. There is almost no reason to ever do this. VCDs, SVCDs, and DVDs support an internal framerate of 23.976fps. This means you encode it at 23.976fps (much higher quality-do a forum search on ntscfilm) and it is played back at 29.97fps. This is how the vast majority of commercial DVDs are made.

TMPGenc can perform an inverse telecine by setting output to 23.976fps and enabling the Inverse telecine filter on the advanced tab.

Audio sync is a non-issue when doing a proper telecine. A telecine creates new frames from existing fields, so the runtime doesn't change there are just more frames every second.

[randywest]

Thanks Bro.

[thor300]

Standard DVD does not support 23.976 fps. You have to use 3:2 pulldown, and its supported only with MPeg2.

[randywest]

How do I keep the 320 x 240 ratio? I don't want to choose 352 x 240 VCD.

[thor300]

You have to chose 352x240 to keep the aspect ratio. But if you insist on changing it, then click Load - extra - unlock.mcf. Then something like arrange settings - center. VCD does support 23.976 frame rate, so no need to change it in your case.

[FOO]

You have to chose 352x240 to keep the aspect ratio

Not exactly . You have to do 352 because 340 isn't DVD legal

[thor300]

He can arrange it to center setting to keep the video at 320x240, and encode at 352x240, thats what i wrote, or tried to write . But, then he lose aspect ratio.

[KBeee]

How do I keep the 320 x 240 ratio? I don't want to choose 352 x 240 VCD.

In TMPGEnc (settings/advanced/video arrange method)you can keep the aspect ratio if you use the "centre (custom size)" option and set 320X240 as the custom size

[macleod]

the guide in my signature should give you most of the information you need.

[adam]

Standard DVD does not support 23.976 fps. You have to use 3:2 pulldown, and its supported only with MPeg2.

That's why I said that VCDs, SVCDs, and DVDs support 23.976fps internally.

[thor300]

There is almost no reason to ever do this. VCDs, SVCDs, and DVDs support an internal framerate of 23.976fps.

Sorry adam, thats the lines that made me misunderstand then, i thought you said you dont need to use 3:2 pulldown for DVD and SVCD, and i have only heard about VCD being able to play 23,976fps without pulldown.

[jtommyj]

I found that in my experience, Main Concept is the best at framerate conversions such as PAL 25 FPS to NTSC 29.97 FPS VCD conversions.

It seems to be less jumpy and keeps the audio in synch very well. I'm pretty sure it could be the same for your conversion.

[thor300]

jtommyj, find it hard to believe that framerate conversion is better than 3:2 pulldown/inverse telecine. When going from Pal to Ntsc and vice-versa its needed, sure, but pulldown/inverse telecine is lossless. I think you have a point anyway about the jumpiness, so maybe its worth a try. And thanx for the advice about Mainconcept, i havent tried that as i only have trial version. Am very satisfied with AviSynths ConvertFPS() in blend mode so far, but maybe i'll give it a shot with Mainconcept next time.

[jtommyj]

Not saying it is better than 3:2 pulldown, just another option.
For me it is simpler to just put a PAL 25 FPS in Main Concept and let it do the work to 29.97 NTSC VCD, which is different from 23.97 to 29.97. I also adjust the audio at that point to 48K so I can get around 6.5 hours of VCD's on a single DVD using TMPGEnc DVD Author, or I let DVD Author convert the audio for me.

Tom