Avi:from 29.97 to 25fps. How?

[Instant Martian]

Hi there.
I am authoring a dvd (PAL) starting from a bunch of avi files. Almost all of them are 25fps but two files are 29.970fps, as you can see:



Is there a way to change the framerate 29.970->25 and convert this avi to a PAL DVD compliant .m2v file?

[guns1inger]

If there is meant to be an image there I am not seeing it.

The question is why they they are 29.970 fps.

If they have been telecined then you can Inverse Telecine (IVTC) them with Avisynth, re-encode them at 23.976 fps, then use DGpulldown to get 25 fps playback.

If they were actually shot at 29.970 fps then there is no nice way to get back to 25 fps. In that case you either have to

a) slow everything down, which would be noticeable
b) discard almost 1 in 5 frames, which will be jerky
c) Blend frames, which will be visibly ugly

However I have no idea what your source is, so I cannot say which is applicable.

[Instant Martian]

Hi guns1inger and thanks for replying.
Sorry I edited the post, now you should be able to see the pic.

I think they were 23.976fps so they have been telecined.
I have done this kind of conversion before but starting from VOBs (creating the .d2v file with DGIndex).
Now I am dealing with avi and I don't know exactly how to do.
I'm gonna try to understand the IVTC stuff and let you know.
Thanks for now.

[guns1inger]

Still no image, but it could be my end. The ITVC process will be the same, especially if you use Avisynth. Manono is your man for this stuff. I don't see enough of it to have to do it very often

[Instant Martian]

I have had good help both from you and manono in the past.
Hoping in manono then.

[manono]

Post small 10 second samples - samples with steady movement - for us to have a look.

The pic shows DivX 3.11 with Windows Media Audio. Isn't that an unusual combination?

[Instant Martian]

Here is the sample, I hope it's fine.

http://rapidshare.com/files/251581100/sample.avi.html

[manono]

Yes, it's a good sample. That particular one was just blend deinterlaced to make it 29.97fps with 2 blended frames in every cycle of 5 frames. For that one there's a filter that can pretty much 'fix' it and restore it to 23.976fps so you can then do whatever you like with it:

23976avi.avi

The script I used is:

AVISource("C:\Path\To\Video.avi",audio=false)
Import("C:\Path\To\SRestore.avs")
ConvertToYV12()
SRestore(omode="pp3")
TDecimate()#part of the TIVTC package

http://avisynth.org/mediawiki/Srestore

[Instant Martian]

Thanks!
As guns1inger said, you are the man for this stuff!
But what have I to put into the SRestore script?

[manono]

That's what the link was for - to explain how to use it and the filters needed. OK, here's the complete script I used:

LoadPlugin("D:\AviSynth Stuff\Dlls\MT_MaskTools.dll")
LoadPlugin("D:\AviSynth Stuff\Dlls\TIVTC.dll")
LoadPlugin("D:\AviSynth Stuff\Dlls\Average.dll")
LoadPlugin("D:\AviSynth Stuff\Dlls\RemoveGrain.dll")
AVISource("E:\Test\samplenew.avi",audio=false)
Import("D:\AviSynth Stuff\plugins\SRestore.avs")
ConvertToYV12()
SRestore(omode="pp3")
TDecimate()

Adjust for your names and paths. Make sure you also get the srestore.avsi. I think I renamed the MT_MaskTools from it's original name. You have to be careful to get the most recent RemoveGrain. You have to have a recent TIVTC. Import the SRestore.avsi (I renamed it as .avs) to your script. Test the script out in VDub(Mod) and if something's wrong it should give you an error message pointing to the culprit. Here's the thread about it:

http://forum.doom9.org/showthread.php?t=95924

[Instant Martian]

That's what the link was for - to explain how to use it and the filters needed.

Sorry, I gave a look at the link but it looked a little bit complex to me
I'll try and let you know.

[Instant Martian]

I created this testscript1 script:

LoadPlugin("C:\Programmi\AviSynth 2.5\Dlls\MT_MaskTools.dll")
LoadPlugin("C:\Programmi\AviSynth 2.5\Dlls\TIVTC.dll")
LoadPlugin("C:\Programmi\AviSynth 2.5\Dlls\Average.dll")
LoadPlugin("C:\Programmi\AviSynth 2.5\Dlls\RemoveGrain.dll")
AVISource("sample.avi",audio=false)
Import("SRestore.avs")
ConvertToYV12()
SRestore(omode="pp3")
TDecimate()

When I test it with VirtualDubMod I get this error:

Avisynth open failure:
RemoveGrain: invalid mode 19
(SRestore.avs, line 45)
(D:\...\testscript1.avs, line 8)

[jagabo]

SRestore() requires lots of other filter that you have to download and install:

needed plugins:
- mt_masktools v2.0 (allways)
- TIVTC v1.04 or higher (only for cache>0, not default)
- RemoveGrain (only for double-blend-removal, not default)
- Average (only for double-blend-removal, not default)

[manono]

You've got the wrong RemoveGrain.dll. Here, use this one:

removegrain.zip

[Instant Martian]

It works!
Thank you for your precious help.
And what about the audio? I must end up with a 25fps video so, do you think I am going to have sync issues?

[manono]

The audio? I don't mess with WMA. Someone else will have to help. However, if you change the length of the video, you'll also have to change the length of the audio.

Just because you used SRestore to get that video back to 23.976fps, and just because you're making a PAL DVD, doesn't necessarily mean you have to change the length (or framerate) of the video. It can be encoded at PAL 720x576 resolution but using the 23.976fps framerate. Then when done, to make it compliant for PAL DVD run the M2V through DGPulldown set for 23.976->25. That's up to you though. The audio will still have to be reencoded to make it PAL DVD compliant. To AC3 or MP2 audio, most likely.

[Instant Martian]

It can be encoded at PAL 720x576 resolution but using the 23.976fps framerate. Then when done, to make it compliant for PAL DVD run the M2V through DGPulldown set for 23.976->25.

Yeah, that is exactly what I am going to do, only I have made it only with VOBs by now (and in that case the audio still remains in sync). My doubt was about this method applied to avi.
Ok, I'll try asap and let you know.

[Instant Martian]

After a quick test it seems there are no sync problems.
Many thanks to manono for his help