How to encode audio to different fps?

[mrjust]

I have a movie which is 23.976 fps that i encoded with 3:2 pulldown playback!
Now do i need to encode the audio to 29.97 or leave as is?

What if i have a movie that is 25 fps and encode to 29.97 fps do i need to encode the audio from 25 to 29.97?

Because i usually have sync issues!

[tomlee59]

The fps aren't the issue per se, but sometimes is a hint. If going from PAL to NTSC (or vice-versa), the most common hack is to speed up/slow down as necessary to map 25fps PAL into 23.97 NTSC film. The 4% difference can cause sync problems if in subsequent conversions this factor isn't taken into account. So, if you are noticing a 5-minute sync error at the end of a 2 hour movie, then this is likely the source of the problem. It's all about duration, not fps directly.

If your sync error is much smaller than that (say, only a half-dozen seconds or so by the end of a typical film), then you've got other problems. If you can't uncover (or fix) the underlying root cause, you can still fix things up with a good audio editor. The simplest sync errors are ones that are either fixed or grow linearly with time. A tool such as Audacity can insert/delete sections to correct fixed offsets, and also can speed up/slow down the track to correct the constant-drift sync error.

[jagabo]

The whole point of pulldown when displaying 23.976 fps at 29.97 fps is to avoid changes in the running time. You don't have to change the audio at all.

Pulldown can also be used to display 25 fps PAL sources at 29.97 fps. Doing so also avoids changing the running time.

As tomlee59 mentioned, most commercial PAL/NTSC conversions involve slowing 25 fps down to 23.976 fps (then applying pulldown), or speeding up 23.976 fps to 25 fps. These do cause changes in the running time and hence adjusting the audio.

[mrjust]

So basically for all my 23.976 media i have to add an 3:2 pulldown and encode that way i dont have to change the audio time?

What about 25 fps?
Do i encode as 25fps then add an 3:2 pulldown with DGpulldown so i dont have to change the audio time?

[jagabo]

So basically for all my 23.976 media i have to add an 3:2 pulldown and encode that way i dont have to change the audio time?

Yes.

What about 25 fps?
Do i encode as 25fps then add an 3:2 pulldown with DGpulldown so i dont have to change the audio time?

Yes. (Technically it's 3:2:3:2:2 pulldown.) Just select the 25 to 29.97 fps option.

[mrjust]

Thanks Jagabo

Since i have TMPGenc Xpress 4.0 and my video is 25 fps all i need to do is encode it at 25 fps then Use Dgpulldown (25fps to 29.97)?

Thanks Again

One more question, what about for 23.976 fps? Do i have to encode at a different FPS or add a pulldown? thanks

[manono]

Since i have TMPGenc Xpress 4.0 and my video is 25 fps all i need to do is encode it at 25 fps then Use Dgpulldown (25fps to 29.97)?

Yes, you'll have to do it after encoding at 25fps since you can't do that type of pulldown within TMPGEnc. I assume you've also converted to an NTSC compliant resolution.

[mrjust]

16th Mar 2010 06:01
manono
Re: How to encode audio to different fps?

Yes, you'll have to do it after encoding at 25fps since you can't do that type of pulldown within TMPGEnc. I assume you've also converted to an NTSC compliant resolution.

Actually you can add a 3:2 pulldown in TMPGenc Xpress 4, by compliant resolutin do you mean (720 x 420) ?
I dont think i did that
I dont believe that if you encode at 25 fps Pal it wont allow you to an NTSC resolution of 720 x 420 ? would it?
Im at work but ill check as soon as i get Home

[manono]

Actually you can add a 3:2 pulldown in TMPGenc Xpress 4

Of course you can do 23.976->29.97 (3:2) pulldown within TMPGEnc. I said you couldn't do 25->29.97fps (3:2:3:2:2) pulldown. You'll have to use DGPulldown on the encoded 25fps video afterwards.

by compliant resolutin do you mean (720 x 420) ?

Unless that's a typo and you meant to write 720x480, then no. You should make it an NTSC DVD compliant resolution, one such as 720x480. I do this using AviSynth scripts. I have no idea how to do it within TMPGEnc. You're the one using it so I expect you should know how to do it. Otherwise, why are you using it at all?

I dont believe that if you encode at 25 fps Pal it wont allow you to an NTSC resolution of 720 x 420 ? would it?

I believe if you turn off the wizards or templates or whatever you call them in TMPGEnc, you can do whatever you want. I don't (and won't) use that program for MPEG-2 encoding, so someone else may have to give you the gory details. If you want a better and faster (and absolutely free) encoder to use, I might recommend HCEnc. Of course, you'll have to learn some AviSynth to use it.

Here's the FulciLives guide that explains how to change the settings to allow 720x480 encoding at 25fps when using TMPGEnc:

https://forum.videohelp.com/threads/241000-How-to-convert-a-PAL-DVD-to-a-NTSC-DVD-using...GEnc-Plus-2-5x

[mrjust]

Unless that's a typo and you meant to write 720x480, then no. You should make it an NTSC DVD compliant resolution, one such as 720x480. I do this using AviSynth scripts. I have no idea how to do it within TMPGEnc. You're the one using it so I expect you should know how to do it. Otherwise, why are you using it at all?

yes that was a typo i meant 720x480.
Actually yes TMPGenc does allow you to change the resolution to 720x480 while encoding 25pal fps!

I actually encoded an .avi which had FPS as 25 PAL with TMPGenc with resolution 720x480 and then i added the 3:2 pulldown with DGPULLDOWN and i loved it Thank you guys.

I havent watched the video but will come and update and let you know if its error free