Need help trying to change fps from 24 and 23.98 to 23.976....

[Questmark]

I am using Vegas 5 to edit some avi files- I'm using huffyuv. However, not all of my files are the same framerate. Most are 23.976. One is 23.98. And one is 24.00. I would like for them all to be 23.976, as I would imagine once I get these into Vegas they're all going to need to be the same fps. I was planning on using VDubMod to change the framerate for the video, but I don't see how I can change the framerate for the audio to match. Also, if I do it with VDubMod, it'll have to reencode it, right? (No "directstream" or "fast recompress" if I'm changing the fps, right?) If I can, I'd like to just simply use AviSynth so I don't have to have a colorspace change for the video. Can all this be done with a simple line command or two??

As for the audio, I've been hunting for a tutorial, but the issue is that BeSweet, which is generally recommended, seems to only have preset settings for changing the framerate, and my odd fps (24 and 23.98 ) aren't part of its settings. I'm really stumped on this. Is there a different program I can use??

Basically, I can't find a tutorial on this-- either for audio or video-- that really does what I want it to do, and I'm not even sure if I really need to change them anyways. I've made my share of DVDs, and done some NLE with Vegas, but changing the fps is completely new to me. Will it make that big of a difference for such a minimal change in fps when editing between these videos? I'm building a movie, so there's going to be intercut, and there are going to be crossfades, so it seems like they're going to be interchangeable, for both the audio and the video. I pre-rendered a section I'd been working on in Vegas, which changed the fps from 24 to 23.976, and there definitely seemed to be some "ghosting" going on some sort.

How do I get all these videos to agree?!?!

Thanks.

[redwudz]

Audio doesn't have 'framerate' anyway, just length. If the re-encode messes up the length, you could adjust that. If instead, you were to encode them separately to MPEG-2 for DVD, then you wouldn't have to worry about the difference, the encoder would correct it. Then drop all three into your authoring program and let it do the 'joining'. Less chance of sync error that way than joining the AVIs to one. That may not work for what you want to do, but that's the way I usually do it.

[manono]

...BeSweet, which is generally recommended, seems to only have preset settings for changing the framerate

You don't have to use the Presets. You can also fill in before and after (Change Framerate From xx.xxx To yy.yyy). It doesn't always work, though, and you may end up doing the time change on a WAV Editor, on the way to reencoding to whatever the destination format is (AC3, I guess)

[Questmark]

Re: audio and framerate-- I guess my presumption is that if I change the framerate for the video the audio will be out of sync, as it was timed to a longer or shorter video, and that I'll need some sort of audio-"changing" program to make it keep in sync with the newly altered video. Just shortening the audio won't work I think, because it would then be the right length, but not match the actual actions in the video. It would get progressively more out of sync as the video continued, because it would be set to a different pace.

Re: re-encoding to MPEG2-- I do eventually want to make a DVD, but right now I'm doing some editing in Vegas. That's why I have them in an avi using huffyuv. I guess I don't understand how changing the vids to mpeg2's will solve the fps problem from the purposes of my editing. Plus, to get them to be an mpeg2, I have to re-encode them, which will affect quality a lot. I once tried editing with a divx or xvid vid, and it was was basically total cr*p once it got out of Vegas, so now I just put them in with huffyuv. If I was just editing each vid seperately, I might just run them through Vegas, each at their own individual fps rate, and then encode them as mpeg2's separately, as you suggested, thereby perhaps solving the problem, but I doing some "cut and paste" type work, with crossfades and whatnot, so a lot of the video and audio is going to sort of be "intermingled." That's why I figured I needed to get them all to the same fps before I put them in the NLE.

I could maybe see what you're talking about if I just wanted to make a DVD with the vids, but since I want to edit them, I don't think that'll really solve the problem, right?? I dunno, maybe I'm not making sense....

[manono]

I guess I don't understand how changing the vids to mpeg2's will solve the fps problem from the purposes of my editing.

If you don't want to mess with the audio, then you can apply different kinds of pulldown when done encoding for MPEG-2. That is, for the 23.976fps ones, use DGPulldown at default 23.976->29.97fps settings. For a 24fps ones, tick the custom box and fill in 24->29.97fps. For the 23.98 ones, tick Custom and fill in 23.98->29.97fps. That way the videos will all stay the same length as originally, and the audios won't have to be stretched.

That won't work if you have to work with AVIs with 2 different framerates in Vegas, though. You might have to change the audio after all.

[Questmark]

Re: BeSweet-- I see the setting mentioned for special framerates. Now I feel a little dumb. But frankly, I'm having a helluva time using this program. And I can't seem to find any basic tutorials for using it. It also seems to want to automatically change my format to an ac3. Right now I have it in a PCM Wav, which I'm very happy to have it in. I don't really feel any need to change it, but I can't seem to figure that out with this program. Are there other programs that might do what I want and still give me my uncompressed wav file? Or should I start over with an MP3 again (which I'd converted to a PCM Wav) and put that in BeSweet??

I mean, I'm happy to futz with the audio if need be, but I don't feel any compunction to leave the Wav format I'm in.

[manono]

This guide's old, but it should at least help you configure BeSweet to do what you want. By the way, when changing the audio length, it's probably better to convert to a stretched WAV first, and then later convert from WAV to whatever:

https://forum.videohelp.com/viewtopic.php?t=129419

Step 3 of this guide might help:

https://forum.videohelp.com/viewtopic.php?t=234240

[Questmark]

Huzzah!! Now, I have a new wav file at 23.976 fps. Thank you thank you thank you

.... Of course, it's also about 2 secs longer.

Which brings me to my next question, which you seemed to be pointing towards in your last post-- how do I stretch or shrink this wav file?? Or will it, conceivably, fit the new length of the video once I change the video's framerate to 23.946 as well??

Re: which-- getting the video fps to change-- can I do this with AviSynth in VDubMod?? I tried taking my original avi, disabling the audio, brining up the avisynth script editor, and telling it to "AssumeFPS (23.976)". Then I used "direct stream processing"-- my thinking being I could then take the new video with the correct fps, and then run it back through VDubMod with the new appropriate length audio, and then interleave the two of them. However, I'm getting this absolutely huge file coming out, something like 15 gigs for 20-25 mins, so obviously something is wrong. I'm not using huffyuv either, since I'm just direct processing it from an xvid.

Does this make any sense? Obviously I'm doing something wrong here. Is there a better way to change the fps?? If I can, I'd prefer to not have to re-encode my video, but I can't seem to figure it out with AviSynth so far. UGH.

[manono]

Hi-

how do I stretch or shrink this wav file??

You've already done that, haven't you, when you converted it to 23.976fps? Stretching audio means to change the length, whether you make it shorter or longer. You should be able to just convert it to AC3 audio for the DVD now. Or maybe I don't understand the question.

...fit the new length of the video once I change the video's framerate to 23.946 as well??

I take it you mean 23.976fps. And yes, if you stretched the audio correctly (I use HeadAC3he to determine the audio's exact length before and after, although you can't use it to stretch), then after changing the video length as well, everything should synch up. That's the idea, anyway. I use my AviSynth script opened in VDubMod and File->File Information to get the exact length of the video.

...can I do this with AviSynth in VDubMod??

Using AssumeFPS(23.976) or AssumeFPS(24000/1001) in AviSynth will also adjust the length of the video. Don't use ConvertFPS or ChangeFPS. Since you're going for DVD, I'm not exactly sure what you'd use VDubMod for, except to check out the script and make sure it's OK. Maybe you're going back to the beginning to make a new HuffYUV AVI.

http://www.avisynth.org.ru/docs/english/corefilters/fps.htm

Then I used "direct stream processing"--

It doesn't work like that. You can't open an AviSynth script and Direct Stream Process. You'll have to reencode, choosing a codec and settings. You can, however, open the AVI in VDubMod, Direct Stream Process, and change the AVI's framerate by going Video->Frame Rate->Change To xx.xxx.

[J. Baker]

This isn't rocket science. Open them in VirtualDub and use the "Convert to fps:" option. Audio will still be insync. Oh and use the lagarith codec so you don't loose quality.

[manono]

Audio will still be insync.

That's correct, the audio will still be in synch. And he will have removed a frame every 40 seconds or so. He may find that to be a satisfactory solution. It's certainly an easy one. Me, I don't purposely make my videos play jerky.

Oh and use the lagarith codec so you don't loose quality.

He's got that one covered, as he's already using HuffYUV.

[Questmark]

I'm happy to just try changing the fps in VDubMod (although I didn't know it could do that), but in all the tutorials about changing the fps they use BeSweet and whatnot. I was just following their examples. Both manono and J.Baker have suggested this though, so I'll give it a try. Is there any difference between the sort of output I'll get from this vs. using an AviSynth script in VDubMod with the 'AssumeFPS(xx.xxx)' ?

Obviously, I don't want a "jerky" playback-- I simply want all of my video to be at the same fps when I edit it in Vegas. Is there a way to change the fps and have it stay smooth??

As for the DVD-- I'm not really there yet. Eventually, I'm going to make one, but I'm not there yet. All of this is just so I can get the vids into Vegas and have them work when I start editing them together.

Finally though, it seems like I'm getting three slightly different options--

1) Use VDubMod, direct stream process, and change the fps
2) Use VDubMod, use full processing mode, use Huffyuv or Lagarith, and change the fps
3) Use AviSynth with VDubMod, put in my "Assume FPS (xx.xxx)' command, and then run it through the full processing mode.

Are there any benefits to one over the other? I can't use fast recompress in VDubMod can I, if I want to change the fps?? And does any of these options make the playback _not_ jerky?? I can't imagine the change will be much between 24 and 23.976 fps, will it??

[manono]

1) Use VDubMod, direct stream process, and change the fps

Using J. Baker's ConvertFPS, VDubMod either adds or removes frames in order to achieve both the desired FPS and keep it the same length. This introduces stutters/jerks into the playback (admittedly not very many, given the very slight adjustments in the framerate you're making). The original unchanged audio can be used. Using my Change To xx.xxx, it either speeds up or slows down the video to achieve the desired framerate. The video stays smooth playing, but the audio has to be stretched to match.

2) Use VDubMod, use full processing mode, use Huffyuv or Lagarith, and change the fps

Why would you do that? Unless creating the Lagarith or HuffYUV all over again? Still a silly idea if you know how to use AviSynth for the job.

3) Use AviSynth with VDubMod, put in my "Assume FPS (xx.xxx)' command, and then run it through the full processing mode.

Doing the frameserving and all the filtering in AviSynth, including adding AssumeFPS(23.976) to the script, does require encoding (or reencoding), but also allows you to use Fast Recompress in VDubMod, as opposed to having to use Full Processing.

[Questmark]

Thanks for the help so far.

Well, I tried the "convert fps", but I found it was a bit "jerky" so I left that alone. I also found that I still needed to run the sound through BeSweet and change its "fps" to get it line up with the newly converted video.

I can't find much of a difference though between using "direct stream copy" and "change fps" with VDubMod, versus using Avisynth with "Assumefps" and fast recompress. This is because in either version, in the end I want a huffyuv for editing in Vegas-- thus, I'm going to need to take the VDubMod "cahnge fps" version and then re-encode it with huffyuv and the altered-length audio after I fix the frameragte, OR I'm going to need to fast recompress it using huffyuv with Avisynth.

In the end, I'm just choosing Avisynth. Is there anything better about doing it one way versus the other?? I hope to get back with an answer to how it goes.....

[manono]

I can't find much of a difference though between using "direct stream copy" and "change fps" with VDubMod, versus using Avisynth with "Assumefps" and fast recompress.

Direct Stream Copy should be faster, I guess, but if the videos are short, I don't guess that's a factor. Since you're going from lossless to lossless, I don't think there should be any differences other than the framerate. I don't know if there would be any possible colorpace changes. I don't think so, as you're not using Full Processing, which would force a change to RGB24 (and you may be in RGB24 already).