How to convert 4k 60 FPS to real 1080i (29.970)with Avisynth?

[frank_zappa]

hello guys good afternoon, a favor if I want to create a 1080i from this video 4k (60 FPS), but be really a 1080i at 29.970, how could I create it in avisynth someone will have some example please, first time I try this. The point is to use the output file to create a real 1080i bluray.
Is interpolation necessary?

thanks for your help

this is the original source :

Vídeo
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L5.2
Format settings                          : CABAC / 3 Ref Frames
Format settings, CABAC                   : Sí
Format settings, RefFrames               : 3 fotogramas
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 3 h 9 min
Source duration                          : 3 h 9 min
Bit rate mode                            : Variable
Bit rate                                 : 35,0 Mb/s
Width                                    : 3 840 píxeles
Height                                   : 2 160 píxeles
Display aspect ratio                     : 16:9
Frame rate mode                          : Variable
Frame rate                               : 59,940 (59940/1000) FPS
Minimum frame rate                       : 59,940 FPS
Maximum frame rate                       : 60,000 FPS
Original frame rate                      : 59,940 (60000/1001) FPS
Standard                                 : NTSC
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progresivo
Bits/(Pixel*Frame)                       : 0.070
Stream size                              : 46,2 GiB (99%)
Source stream size                       : 46,2 GiB (99%)
Encoded date                             : UTC 2017-11-09 13:42:29
Tagged date                              : UTC 2017-11-09 13:53:24
Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

[LigH.de]

Should be quite straightforward... ???Resize (not too sharp) to 1080p; AssumeFrameBased; AssumeTFF; SeparateFields; SelectEvery(4, 0, 3); Weave. Possibly AssumeFPS(30000,1001): I believe Select does not reduce the frame rate. Encode interlaced (TFF).

The only point where I am not really sure is if the new fields should slightly bob by half a line height.

[LMotlow]

Spline36Resize(1920,1080)
AssumeTFF()
SeparateFields()
SelectEvery(4,0,3)
Weave()
AssumeFPS("NTSC_video")

[_Al_]

It would be interesting how it is going to be comparable to HD 60p to DVD, because a certain degree of low pass was needed in that case, or special resize, or both. To avoid horizontal line flickering in the footage.

[frank_zappa]

Spline36Resize(1920,1080)
AssumeTFF()
SeparateFields()
SelectEvery(4,0,3)
Weave()
AssumeFPS("NTSC_video")

I took a screenshot, maybe you can confirm if it would work, in the image has the info

thanks so much

https://forum.videohelp.com/images/imgfiles/RTRbOwq.jpg

by chance you will have at hand some method to do the inverse but in a real way with interpolation, etc.

let say to go from 23.976 or 29.970 = 60 FPS, so that it has greater fluidity, starting from a DVD NTSC or PAL for example to perform an upscale.

I tried a lot of scripts that are on the net, interframe, etc. but nothing really looks good... do you know any effective methods?

[jagabo]

Of course it will work. Just be sure to encode it interlaced, top field first.

[frank_zappa]

Of course it will work. Just be sure to encode it interlaced, top field first.

where I can encode it like this? I thought I'd put it in the virtualdub or simple x264 launcher,

How does the final script look, please?, and with which program I encode it.

thanks so much

[jagabo]

You need to add a source filter to the start of the script. If your source is mp4 try LSmashVideoSource(). Otherwise try LWlibavVideoSource(). Both are part of the LSMash plugin for AviSynth.

I use the x264 command line encoder where the option is "--tff" (for top field first video, --bff for bottom field first). I haven't used Simple x264 launcher -- I don't know if it supports interlaced encoding via the UI. But it appears to support custom encoding options. You probably want to enter --tff there.

[frank_zappa]

You need to add a source filter to the start of the script. If your source is mp4 try LSmashVideoSource(). Otherwise try LWlibavVideoSource(). Both are part of the LSMash plugin for AviSynth.

I use the x264 command line encoder where the option is "--fff" (for top field first video, --bff for bottom field first). I haven't used Simple x264 launcher -- I don't know if it supports interlaced encoding via the UI. But it appears to support custom encoding options. You probably want to enter --tff there.

thanks so much for your help i ll try right now

[LigH.de]

^ correction: "--tff"

VirtualDub-FilterMod supports x264 as internal encoder, and is able to output MP4. That could be a simple solution. Other advanced AviSynth based converters with technical focus and support for the x264 CLI encoder are StaxRip x64 and MeGUI.

[pandy]

My personal advice is - don't go over HP@L4.0 and force BD compatibility - even less capable HW decoders should work fine with such settings.

[jagabo]

^ correction: "--tff"

Fixed the typo.

[frank_zappa]

^ correction: "--tff"

Fixed the typo.

Thanks so much