Changing AVI from 29fps to 25fps

[Ric76]

Hi all,

I'm really new to all this editing so need some help. I have got some AVI files which are running at 29fps but my DVD player will only play AVI files running a 25fps, is there anyway to change the frame rate on my 29fps AVI's to 25fps so they play on my DVD Player.

I did find a program call "AVI Frame Rate Changer 1.10" via google and gave it ago, even though it changed the frame rate but the audio was out of sync

How do I change the frame rate and keep the audio in sync?

Cheers

[manono]

You reencode using an AviSynth script:

ConvertFPS(25)

and make a blended, blurry mess out of it. Either that or change the framerate while direct streaming it using VDub(Mod) and make a jerky playing mess out of it because you're pulling out unique frames. Using VDubMod, open the AVI and set Video to Direct Stream Copy. Go Video->Frame Rate->Frame Rate Conversion->Convert To FPS:->25. OK back to the main screen and File-Save As. VDub does it in a similar, if not identical (not sure), way.

And if these are movies, then the chances are very good that they're not supposed to be 29.97fps but 23.976fps, and you may or may not (probably not) be able to reencode then to get the correct framerate and also make them 25fps without messing up playback all that much.

Or buy a better player. They're supposed to be able to play AVIs at all framerates.

Edited later because I left out a step.

[jman98]

Or buy a better player. They're supposed to be able to play AVIs at all framerates.

Indeed. Even in the USA where it can sometimes be difficult to find DVD players that can convert PAL DVDs to NTSC, I'm not aware of any DVD players that support Divx/Xvid playback that won't play 25 fps videos. Are you really sure this conversion is necessary? It seems really unusual to have to do this in PAL land.

[Ric76]

All AVI files with a frame rate of 29 play black and white on my DVD player, if they are set at 25 or 23fps then its fine, plays in colour. I did look for an update to my player but its only a cheap one and I can't afford to buy a new one.

Its only some of the movies I get in AVi format which are set at 29fps, most are set at 25 or 23. I did try the Vdub way of settin the frame rate at 25fps but it makes the audio out of sync, thats the biggest issue I'm having here. I can figure out how to change the frame rate its just getting the audio to stay in sync which is giving me the headache.

[jagabo]

Fast dirty method with VirtualDub:

1) File -> Open AVI File.
2) Video -> Frame Rate... in Frame Rate Conversion section enable Convert To FPS and set 23.976 or 25.
3) Video -> Compression... select compression codec and settings (Xvid, target quantizer 3?)
4) File -> Save as AVI.

The result will be a little jerky.

[manono]

I did try the Vdub way of settin the frame rate at 25fps but it makes the audio out of sync

No you didn't, not following the explicit directions both jagabo and I gave you. You shouldn't need to reencode, though. Direct Stream Copy should be enough.

[jagabo]

You can't decimate without reencoding (unless it's an all keyframe codec like MJPEG).

[jman98]

All AVI files with a frame rate of 29 play black and white on my DVD player, if they are set at 25 or 23fps then its fine, plays in colour. I did look for an update to my player but its only a cheap one and I can't afford to buy a new one.

Based on this, I'm guessing that the real problem is that your DVD player is sending out an NTSC or PAL-60 signal for 29.97 fps video and your TV is barfing on it. Wow. You have no idea how rare that is in PAL land.

Anyway, check your DVD player set up and see if you can change the video output from ANY or MULTI to PAL. If you can do that, it should fix your problem without having to re-encode or change frame rates.

[manono]

You can't decimate without reencoding (unless it's an all keyframe codec like MJPEG).

Try it. I wondered about that as well, but I took a regular XviD AVI with 1 B-Frame and Direct Stream Copied it while changing the framerate and, except for the introduced jerkiness, it played fine. Maybe if they have different original settings you'll get the decoding blockiness errors, but I didn't have the problem.

If by "can't", you mean that VDubMod will refuse to Direct Stream Copy it while at the same time decimating it, that's not correct.

Edit: Now I see the problem. Before I was just looking for correct video decoding, and that's OK, same length and all with no obvious decoding errors. But the audio goes in and out of synch for some reason. It lags the video until there's a big jerk in the video when they realign again briefly. You were right again (as usual) - it'll have to be reencoded.

[Ric76]

Thanks, I have been doing the Vdub bit wrong, lol

1) File -> Open AVI File.
2) Video -> Frame Rate... in Frame Rate Conversion section enable Convert To FPS and set 23.976 or 25.
3) File -> Save as AVI.

It works great, alittle jerky but very watchable.

I will check the settings of my DVD player but never really knew what I was looking for.

[jagabo]

You're right, VirtualDub will direct stream copy and change the frame rate. It cuts off the ends of GOPs to do so. So, for example, if a GOP in a 30 fps video is 300 frames it will cut 60 of them off to make them 24 fps. The remaining can now be played at 24 fps without losing sync (except the small sync error during the GOP which probably won't be noticeable).

[Ric76]

Thank you for all your help, the converstions works and I managed to correct my DVD settings do I don't need to convert all of them, theres just a couple of AVI films which wont play correctly on my DVD player or my PC so I've decided to reconvert them as I tried it on 1 and it sorted the problem out.

Thank you once again, I've really learnt some great things from you guys