Avisynth PAL to NTSC Conversion method for best picture quality?

[VideoFanatic]

I have a short 720 x 576 interlaced video here. This is my script which works fine. I can use the same script but with the numbers changed to convert NTSC to PAL and the PAL conversion looks practically identical to the NTSC original. However the reverse is not true. When using the same script to convert PAL to NTSC I notice that the picture quality is noticeably lower and the framerate looks blurry & weird. Is there any way to get a better quality PAL to NTSC conversion with regards to the picture quality and framerate?

McTemporalDenoise(settings="medium", interlaced=true) 

AssumeTFF()
QTGMC(Preset="Super Fast")
Lanczos4Resize(720,480) ConvertFPS(59.94)
SeparateFields() SelectEvery(4,0,3) Weave()

[manono]

When using the same script to convert PAL to NTSC I notice that the picture quality is noticeably lower and the framerate looks blurry & weird.

Use 'ChangeFPS(59.94)' rather than 'ConvertFPS(59.94)'.

[VideoFanatic]

That made the framerate look like slow motion.

[manono]

No it didn't.

[VideoFanatic]

Whatever you want to call it, it gives a jerky framerate. I don't know why anyone would want to use that.

[manono]

First you say it plays in slow motion. But it's the exact same length as your source MPG so what you said is clearly wrong. Earlier you said your script made it blurry. And that's because you used ConvertFPS. I explained how to make it sharper. You can't have it both ways, as there's no ideal way to convert interlaced PAL to interlaced NTSC. Yes, there are duplicate fields/frames added to go from a bobbed 50fps to a bobbed 59.94fps. Then you reinterlace it. Me, I'll take the ChangeFPS way any day of the week.

I don't know why anyone would want to use that.

I see nothing at all out of the ordinary. Maybe we're seeing different things. I play the script and it looks fine. Maybe you screwed up the field order.

[jagabo]

Whatever you want to call it, it gives a jerky framerate. I don't know why anyone would want to use that.

Post your resulting file. I suspect you did something wrong.

You could try SmoothFPS2(60000,1001) from this post:
https://forum.videohelp.com/threads/345774-How-to-convert-from-60fps-to-25fps-to-get-co...=1#post2159173

[VideoFanatic]

Here's the resulting file where I used ChangeFPS. This is my script:

McTemporalDenoise(settings="medium", interlaced=true)   

AssumeTFF() 
QTGMC(Preset="Super Fast") 
Lanczos4Resize(720,480) 
ChangeFPS(59.94) 
SeparateFields() SelectEvery(4,0,3) Weave()

When I view the file on my media player connected to my TV, the framerate is jerky.

[jagabo]

You did the conversion correctly. I wonder if there's something odd about the way your media player or TV displays it. To me, ChangeFPS() looks a little better than ConvertFPS() when going from 25i to 30i. It's a little more jerky but you don't get those weird phasing effects caused by blended fields/frames.

By the way, if you're making h.264 video, why don't you leave it 59.94 fps progressive? Can your player not handle it?

Did you try SmoothFPS()? It's the smoothest of all. But you get odd distortions now and then.

[smrpix]

Hi, this conversation is a little over my head (I've never gotten QTGMC to work) but I'm trying to learn something here.

Everybody is taking into account that the source tape comes from an NTSC broadcast converted to PAL by Sky before you ever got your hands on it, right? Is a "good" conversion back to NTSC really possible?

[VideoFanatic]

You did the conversion correctly. I wonder if there's something odd about the way your media player or TV displays it. To me, ChangeFPS() looks a little better than ConvertFPS() when going from 25i to 30i. It's a little more jerky but you don't get those weird phasing effects caused by blended fields/frames.

By the way, if you're making h.264 video, why don't you leave it 59.94 fps progressive? Can your player not handle it?

Did you try SmoothFPS()? It's the smoothest of all. But you get odd distortions now and then.

SmoothFPS requires some other code doesn't it as I used SmoothFPS(59.94) on it's own and it gave an error message. I'm not sure what else is needed.

You are correct about my media player. For some reason it plays ChangeFPS content with a really jerky framerate. I burned to a Bluray and it was fine although it was still slightly jerky. I still prefer ConvertFPS as ChangeFPS gives me motion sickness when I watch it. The picture quality on both was so similar I couldn't really tell them apart.

[jagabo]

SmoothFPS2() requires MvTools2. 60p Sample attached.