[HELP] Advice requested to convert 25 fps to 23.976

[Oldermediaformats]

I have a PAL DVD of John Woo's Bullet in the Head that I extracted in MakeMKV and want to take the MPEG-2 file for the feature film and convert it from 25 to 23.976 fps. The 25 is a CFR. Hybrid initially deciphered it as a telecine and then changed the input scan type to TFF. I am pretty sure that the entire transfer is interlaced.

There are probably a couple ways I could go about the conversion. Within Vapoursynth, I could select TFF as the input scan and under QTGMC check "Bob". For the Preset, I could choose Placebo for best quality. (I have a really fast computer and don't mind waiting anyway.) Then under the Reduction sub-tab under Frame tab, check sRestore. I wonder if I should also check "bob before"?

The alternative would be to treat it as a telecine (since it was transferred from celluloid) and execute a TIVTC with Mode 2 selected and 23.976 as the target frame rate.

After the conversion, I want to resize it from 720x576 to 1280x720.

But first things first. Your suggestions are most welcome.

[Selur]

I am pretty sure that the entire transfer is interlaced.

then let Hybrid know by overwriting the scan type to 'tff' or 'bff'.

For the Preset, I could choose Placebo for best quality.

Note that best quality does not necessarily mean least lossy.
read: https://forum.videohelp.com/threads/4041...commend-it

I wonder if I should also check "bob before"?

No.

The alternative would be to treat it as a telecine (since it was transferred from celluloid) and execute a TIVTC with Mode 2 selected and 23.976 as the target frame rate.

mode 2 will crash,... see: https://github.com/dubhater/vapoursynth-tivtc/issues/4
using mode 7 instead should work, but I would prefer using sRestore

Cu Selur

[Oldermediaformats]

And should I apply sRestore to the PAL video files regardless if they're interlaced or progressive encodes?
I haven't been using TDecimate at all.

[Selur]

When using sRestore Hybrid will always deinterlace before applying it.
Whether sRestore should be applied or not depends on your content.
If you got a PAL source that was created from an NTSC source via speed up, sRestore should not be used, you should then simply undo the speedup.
If you got a PAL source that was created form an NTSC source by adding additional frames, sRestore is the tool to use.

Cu Selur

[Oldermediaformats]

If I have a film source that originated in an NTSC country but has been re-encoded to 25 fps on a PAL DVD, should I use the Speed Change tab at all in Hybrid? So, let's say I want to reclaim the movie's original runtime, which has subsequently been shortened due to 4% PAL speedup: Should I check "Change speed" and then select 23.976 fps from the dropdown? Would the audio sync be alright following this change?

How about "Scale output framerate"? I know that option either duplicates or eliminates frames from the source.

Should either of these filters in Speed Change replace what I can do in sRestore in terms of framerate conversions?

[Selur]

You should only use the speed adjustment settings if the PAL version was created by speeding up the playback.
If this if the case 'change speed', which only changes the fps should be used for the video and you would additionally need to reencode and adjust the audio speed, since the playback time would change.

Cu Selur

[Oldermediaformats]

You should only use the speed adjustment settings if the PAL version was created by speeding up the playback.

...you would additionally need to reencode and adjust the audio speed, since the playback time would change.

First part: Oh, that makes sense.

Second part: And where would I do that in Hybrid? Do you have a guide?

[Selur]

No guide,...
"Audio->Base->Audio Encoding Options->Filtering->Speed change" "decimals from 25 to 23.976

[Oldermediaformats]

Oh, thank you so much!

Now I'm wondering: If I click on the (De-)Interlace/Telecine tab, check Overwrite input scan type to: and then pick "top field first" from the pull down, and have QTGMC VS do my processing, if I'll actually need to use sRestore at all? Because you're right: a majority of my video sources have been sped up by 4% from their native frame rates and so I will need to select Change speed from the other tab.

Or maybe I should include sRestore in my workflow (with Mode: 2) selected?  


Great help here! I  Hybrid.

[Selur]

If your content is interlaced (not field shifted or progressive), you should use QTGMC+Bob which would give you 50fps unique frames,.. then you have to decide what you are aiming for,... 29.97fps interlaced 23.976 progressive or 60 fps progressive,... If you really have unique frames and not blends, using sRestore would probably be the wrong approach.