Bad NTSC to PAL converstion - jerkiness. How to fix?

[PTRACER]

I bought some old programmes recorded off American TV and they have been converted to PAL. However, they are very jerky regardless of what DVD player they are played on.

How can I get rid of the jerkiness so the video plays smoothly again?

[manono]

How can I get rid of the jerkiness so the video plays smoothly again?

You probably can't, as the damage probably can't be undone. But, if you'd like to upload a short 10 second piece of the video, a section showing movement, we can have a look at it.

[PTRACER]

Many thanks, I will do so this evening.

[PTRACER]

Apologies for the use of free webhosts, I have uploaded it to several just in case:

http://www.megaupload.com/?d=JDJ8CXFV
http://www.filefactory.com/file/3b4580/
http://www.savefile.com/files/1035591

On a computer, it's relatively hard to notice the jerkiness unless you look at the cars closely. However, on a standard DVD player, it is very much noticeable.

Please tell me if you have trouble downloading it.

[redwudz]

I'm probably missing something, but played back on VD Mod one frame at a time, I don't see a problem. It seems smooth with no jumps or jerkiness.

[JohnnyMalaria]

I watched it on humble WMP and scan see the jerkiness.

How did you do the conversion?

To me, it looks like it has been done the cheap and not so cheerful way. i.e., dropping every 6th frame to make 30 frames per second (approx.) fit into 25. Hence, it seems to jerk about 5 times a second (most noticeable when the cars are heading up to/out of the first curve).

It's similar to when 24fps films are converted for NTSC television on the cheap (drives me nuts!)

[PTRACER]

I watched it on humble WMP and scan see the jerkiness.

How did you do the conversion?

Ripped with DVD Decrypter and "demuxed" straight to M2V. Then split the file using a file splitter.

To me, it looks like it has been done the cheap and not so cheerful way. i.e., dropping every 6th frame to make 30 frames per second (approx.) fit into 25. Hence, it seems to jerk about 5 times a second (most noticeable when the cars are heading up to/out of the first curve).

Is there any way of fixing that?

[jagabo]

You will probably be better off leaving (or getting) it as NTSC and letting your DVD player and TV display it as PAL60.

[PTRACER]

You will probably be better off leaving (or getting) it as NTSC and letting your DVD player and TV display it as PAL60.

So in other words, convert it back to NTSC?

[JohnnyMalaria]

No point trying to convert it back if the conversion was done the way I indicated - frames have been tossed out. Reversing it in a similar way will make it look even worse.

Presumably, you don't have access to the original NTSC source anymore(?)

[manono]

Yep, the dumbass that made it just pulled out every 6th frame, yet still kept it interlaced. I think it's been resized stupidly as well, as there are interlacing artifacts in the fields. Trying to fix it involves some AviSynth filters to recreate the missing frames. Not worth it, in my opinion.

And you paid for this junk? Frankly, I wouldn't watch it even if it wasn't already ruined. It looks to me like some YouTube garbage blown up to DVD resolution.

[Soopafresh]

Does this look any better ?

http://www.savefile.com/files/1035852

[JohnnyMalaria]

I think it looks worse. Did you reverse the field order?

With the original file, when I play it using GraphEdit it doesn't look as bad. In terms of picture quality, I think it's pretty decent - certainly not YouTube quality(!)

Perhaps I've been staring at this monitor for too long today

[manono]

Does this look any better ?

A little bit. Been fooling around with MVTools? Did you try and get it back to NTSC 29.97fps?

I was wrong before when I said he had pulled out every 6th frame. He pulled out every 6th field, which is different and better. Had he pulled out every 6th frame, it would play even more jerky. What he did is a legitimate way to convert NTSC to PAL, although there's no real good way to do an interlaced conversion like that, especially when there's a lot of movement, like a lot of interlaced sports footage.

[Soopafresh]

Yep. MVtools-motion blur.


JohnnyMalaria - You're probably right. I might have reversed the field order. Not much of an interlacing fan, but I understand how important it is in fast moving sports shots.

[Alex_ander]

Did you try and get it back to NTSC 29.97fps?

Hi, manono.
Is there any special procedure in MVTools for interpolating the dropped frame exactly in its old place? This could solve the problem.
I recently tried to restore a progressive NTSC => PAL video with dropped frames by framerate conversion to 50 with MVFlowFps and interlacing, this improved motion noticeably but left it far from perfect (it couldn't be) at fast panning.

[manono]

Hello Alex_ander-

No, because I've never had to use it. However, if the pattern is the same throughout, as this one seems to be, I see no reason why you can't smart bob it, exclude 3 of the bobbed fields out of every 5, and then use the other 2 to create the new one in between, before then reinterlacing it. That would be for an interlaced source like this one. Something similar could perhaps be attempted with a progressive source.

Easy to say, but maybe harder to do.

[PTRACER]

And you paid for this junk? Frankly, I wouldn't watch it even if it wasn't already ruined. It looks to me like some YouTube garbage blown up to DVD resolution.

Yeah, £2.50 including postage and it's not Youtube garbage at all. The quality of it is incredibly good, definitely recorded off the TV, it's just the jerky motion which is ruining it. The resolution is PAL, 704x576.

As for the source, it wasn't recorded in America, it was recorded off of Japanese TV. He then copied it and sold it to one person, who also copied it and sold it to another person, who then copied it and sold it to me. I can probably track the source if I turn myself into a private investigator, but it's going to cost me time and money.

I'd rather try and "fix" this first, if possible.

[PTRACER]

No, because I've never had to use it. However, if the pattern is the same throughout, as this one seems to be, I see no reason why you can't smart bob it, exclude 3 of the bobbed fields out of every 5, and then use the other 2 to create the new one in between, before then reinterlacing it. That would be for an interlaced source like this one. Something similar could perhaps be attempted with a progressive source.

Easy to say, but maybe harder to do.

And how do I do that? Is there some kind of AVISynth script that can do it?

[jagabo]

With MVTools, and off the top of my yead, something like this:

function smoothfps(clip source, float fps) {
fp=fps*100
backward_vec = source.MVAnalyse(isb = true, truemotion=true, pel=2, idx=1)
# we use explicit idx for more fast processing
forward_vec = source.MVAnalyse(isb = false, truemotion=true, pel=2, idx=1)
cropped = source.crop(4,4,-4,-4) # by half of block size 8
backward_vec2 = cropped.MVAnalyse(isb = true, truemotion=true, pel=2, idx=2)
forward_vec2 = cropped.MVAnalyse(isb = false, truemotion=true, pel=2, idx=2)
return source.MVFlowFps2(backward_vec,forward_vec,backwar d_vec2,forward_vec2,num=int(fp),den=100, idx=1,idx2=2)
}

MPEG2Source("file.d2v")
LeakKernelBob(order=0)
SelectEvery(5, 0, 2, 3) #last three numbers will depend on which field was dropped
SmoothFPS(59.94)
LanczosResize(720, 480)
SeparateFields()
SelectEvery(4, 0, 3)
Weave()

Unfortunately, I don't think the drop pattern is regular enough for this to work.

[PTRACER]

Looking better, but still a very pronounced jerk motion.

[jagabo]

I modified the post several times so make sure you got the latest one. And note that the result is 29.97 fps interlaced NTSC.

Using the script as it is now I found that the resulting video slipped in and out of smoothness several times. That is what I meant by the drop pattern not being regular enough. The only way you'll get perfect results is to split the file into segments (a new segment at every break in the pattern), encode them separately, and finally join them all together. Based upon the short sample you provided you have hundreds or thousands of segments.

There are a few other issues too: LeakKernelBob() isn't perfect. Sometimes bits of interlaced material will come through. SmoothFPS() can generate odd artifacts at times, especially with blurry material and complex motions.

It will likely be faster, easier, and better to track down the original NTSC material.

[PTRACER]

It will likely be faster, easier, and better to track down the original NTSC material.

Thanks, I am attempting to do so.

[PTRACER]

Nope, the person I bought it from doesn't want to give up the information.

Looks like I'll have to try and fix what I've got.

[PTRACER]

Using the script as it is now I found that the resulting video slipped in and out of smoothness several times. That is what I meant by the drop pattern not being regular enough. The only way you'll get perfect results is to split the file into segments (a new segment at every break in the pattern), encode them separately, and finally join them all together. Based upon the short sample you provided you have hundreds or thousands of segments.

Is there any way of programming in this alternate pattern into AVISynth?

As you say, it's smooth for a few seconds, then jerky again, then smooth, then jerky. It's like the field order is changing midway part through the video.

[jagabo]

Using the script as it is now I found that the resulting video slipped in and out of smoothness several times.

Is there any way of programming in this alternate pattern into AVISynth?

If the pattern of dropped fields is repeatable you can. But if the video was cut and pasted after conversion there may be no simple pattern.

The SelectEvery() line in the script I posted assumes your video was converted from 30.0 fps to 25.0 fps. Since the original was really 29.97 fps source the script is expected to slip in and out of sync -- every 15 seconds or so. It seemed to do that more often so I think something else is going on. The correction to account for 29.97 fps would be not to drop 1 field out of every 1000. If you can identify a pattern that is repeated throughout the video you can use SelectEvery() to account for it. But I don't know if SelectEvery() will accept enough arguments for a 1000 frame long segment. Something like SelectEvery(1000, 0 2, 3......998, 999).

Another possible approach is to encode with all six variations of the SelectEvery(5, 0, 2, 3) command. That will give you several videos with different smooth/jerky parts. Then go through and cut and paste all the smooth sections into one final video.

I don't think you're going to be able to fix the video unless you're willing to spend dozens, even hundreds of hours on it.

[PTRACER]

So, let's say the clip was perfectly in sync and I was just doing it to 1000 frames for the sake of it, the sequence would be:

SelectEvery(1000,0,2,3,5,7,8,10,12,13,15,17,18.... 995,997,998)

Let's assume it went out of sync exactly every 3 seconds, would I go SelectEvery(1000,0,2,3,5,7,8,10,12,13,15,17,18.... ...etc........70,72,73) and then change the sequence?

[jagabo]

Let's assume it went out of sync exactly every 3 seconds, would I go SelectEvery(1000,0,2,3,5,7,8,10,12,13,15,17,18.... ...etc........70,72,73) and then change the sequence?

SelectEvery(N, .....) selects the indicated frames out of every N frames (it throws away all the others). If your sequence is 75 frames long, N should be 75. Otherwise the above sequence would throw away frames 75 thought 999.

[PTRACER]

FANTASTIC!!!! I've managed to fix it!!! I'll upload the file shortly...

I actually did it very simply, in fact. Only problem is, it's currently in DivX and 60fps. How do I convert that to PAL 25fps, without it jerking about?

Here's the script by the way:

function smoothfps(clip source, float fps) {
fp=fps*100
backward_vec = source.MVAnalyse(isb = true, truemotion=true, pel=2, idx=1)
# we use explicit idx for more fast processing
forward_vec = source.MVAnalyse(isb = false, truemotion=true, pel=2, idx=1)
cropped = source.crop(4,4,-4,-4) # by half of block size 8
backward_vec2 = cropped.MVAnalyse(isb = true, truemotion=true, pel=2, idx=2)
forward_vec2 = cropped.MVAnalyse(isb = false, truemotion=true, pel=2, idx=2)
return source.MVFlowFps2(backward_vec,forward_vec,backward_vec2,forward_vec2,num=int(fp),den=100, idx=1,idx2=2)
}

LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\SmoothDeinterlacer.dll")
MPEG2Source("E:\1981\VIDEO_TS\project.d2v")
SmoothDeinterlace(tff=true)
SmoothFPS(60)
SeparateFields()
SelectEvery(4,0,3)
Weave()

[Alex_ander]

FANTASTIC!!!! I've managed to fix it!!! I'll upload the file shortly...

I actually did it very simply, in fact. Only problem is, it's currently in DivX and 60fps. How do I convert that to PAL 25fps, without it jerking about?

I'd try applying the function one more time to the restored 60, to go from 60 to 100. Then select fields and weave like this:

...........................
LeakKernelDeint(order=1)#0 if your source is BFF or use your fav deinterlacer as you did
SmoothFPS(60)#just to smoothly restore dropped frames as you successfully did
SmoothFPS(100)# to interpolate frame sequence with better time points for PAL
AssumeTFF().SeparateFields()#200 fields/s
SelectEvery(8,0,5)# to use equidistant frames for interlacing
Weave()