Converting 1080/25i to 1080/50i

[simon744]

Assuming the frames are already progressive and you want to double the frame rate, a full script might look like:

LWlibavVideoSource("filename.ext")
InterFrame(cores=4) # defaults to double frame rate
AssumeTFF()
SeparateFields()
SelectEvery(4,0,3)
Weave()

or:

LWlibavVideoSource("filename.ext")
FrameRateConverter() # defaults to double frame rate
AssumeTFF()
SeparateFields()
SelectEvery(4,0,3)
Weave()

or:

LWlibavVideoSource("filename.ext")
z_ConvertFormat(pixel_type="RGBPS", colorspace_op="709:709:709:l=>rgb:709:709:f")
Rife(gpu_thread=1, model=6, sc=true, sc_threshold=0.12) # defaults to double frame rate
z_ConvertFormat(pixel_type="YUV420P8", colorspace_op="rgb:709:709:f=>709:709:709:l")
AssumeTFF()
SeparateFields()
SelectEvery(4,0,3)
Weave()

The first two have lots of variables you can use to tune the results, bias toward blending or distortion, speed vs. quality, etc. The last one usually gives the best quality.

But why would you want interlaced video when you can just leave your video at 50p or 60p and have smooth motion with no interlace artifacts, reduced resolution, and worse encoding?

And as I mentioned before, motion interpolation like this often creates very ugly artifacts. I don't really recommend it.

Thanks a lot and sorry for the late reply! I was feeling too unwell during the whole week to test the script and get back to you.

To be honest, this is more of an experiment than just trying to ruin a perfectly good looking video. More specifically, what am trying to achieve here is what the encoder of the video I have sent you has achieved...namely, making an interlaced stream appear as though if it were de-interlaced. It's clear there's no de-interlacing or motion interpolation involved, as the MediaInfo clearly states:

Frame rate mode                : Variable
Frame rate                     : 59.940 FPS
Original frame rate            : 29.970 (30000/1001) FPS

And then:

Scan type                      : Interlaced
Scan type, store method        : Separated fields
Scan order                     : Top Field First

It probably has to do with the "Separated Fields" part that not only adds that metadata to the MediaInfo log but also "forces" players like VLC to recognize the frame/field rate as 59.940.

[simon744]

And as I mentioned before, motion interpolation like this often creates very ugly artifacts. I don't really recommend it.

That's what I tried to suggest to OP in post #5 https://forum.videohelp.com/threads/411010-Converting-1080-25i-to-1080-50i?p=2703524&v...=1#post2703524

I failed to understand he has no knowledge on the matter, so your detailed explanation should convince him now. Thanks.

Well, that's only partially true. I actually do know quite a bit about video, though, admittedly not as much about interlaced content. But....as I already have said: TRYING TO LEARN!

[_Al_]

Yes, as long as your player or device handles those videos, there is nothing to fix. I was particularly interested how to load those videos into Avisynth/Vapoursynth because as everything was as default, it would load wrong. So jagabo explanation was important.
For example MPC-HC was playing it ok or mpv or mpvnet players also (pressing key "D" to activate deinterlace)

[simon744]

Yes, as long as your player or device handles those videos, there is nothing to fix. I was particularly interested how to load those videos into Avisynth/Vapoursynth because as everything was as default, it would load wrong. So jagabo explanation was important.
For example MPC-HC was playing it ok or mpv or mpvnet players also (pressing key "D" to activate deinterlace)

How is there nothing to fix if I'm looking to make a change to it?

[_Al_]

I have no idea what you want, and guessing others also. You said, you are learning, that is why I said what I said to share what I got.

[simon744]

I have no idea what you want, and guessing others also. You said, you are learning, that is why I said what I said to share what I got.

I wasn't trying to be rude. I appreciate your help very much. I don't know what made you think otherwise. I was simply saying there is perhaps something to "fix" since am looking to make a change to the video.

[poisondeathray]

The sample posted was an example of a desired output video, not input video, correct? _Al_ (and probably many people) assumed it was an input video

What your options are could might be different for each input source. Mediainfo does not indicate what the actual content is, only how it was encoded and/or flagged. So you've really posted not much important information about what you're actually starting with - and many assumptions are being made

[simon744]

The sample posted was an example of a desired output video, not input video, correct?

Yeah. I've posted samples/MediaInfo logs for both.

[_Al_]

Why not to just posted one video at a time and what problem you have with it. Done. You could potentially save weeks of ping-pong gaming.

You can just post 10 second of a video if you cut it losslessly.

There is no such a thing as different frame rate for interlace video, like 29.97i and 59.94i (25i and 50i). There is only one frame rate where label 29.97i or 59.94i could be used.

Interlace video could have only 29.97fps or 25fps.
Fields have temporal resolution 59.94 or 50 if things are right, But fps is 29.97 or 25 only.
That was mentioned in post #2 right away, but not sure if you registered that. You did not respond to most important input in this thread.

[poisondeathray]

The sample posted was an example of a desired output video, not input video, correct?

Yeah. I've posted samples/MediaInfo logs for both.

I only see the "after" sample in post #9. Where is the "before" sample, or what YOU are starting with ?

I don't have the before, and am not sure if the metadata would be preserved if I were to try cutting the video myself, so am sending a link to the file:

https://5qwt55-my.sharepoint.com/:v:/g/personal/dream66_5qwt55_onmicrosoft_com/EerRVaJ...43I8A?e=Oe3QY8

P.S. I don't do torrents from the scene or something haha, this file's from Sharemania where people post backhauls of awards shows, performances, etc.

[simon744]

Guess I could've simply asked how to re-encode interlaced video as one with separated fields as that pretty much seems to be what I actually need.

[poisondeathray]

Guess I could've simply asked how to re-encode interlaced video as one with separated fields as that pretty much seems to be what I actually need.

Probably not

Whether or not a source encoded with separated fields, interleaved fields, or MBAFF does not affect "smoothness" - it does not change the actual underlying content

eg. You start with a 25p content source. That is 25 samples taken per second from the camera. If you encode that interlaced as a separated fields, it doesn't add more unique samples. It's still 25 samples /s just encoded in a different manner. Each field is still taken from the same moment in time. You don't magically now have 50 unique moments in time per second. Conversely, true interlaced content aka. "25i content" has 50 samples per second - the motion is smoother to begin with. That's what some of the assumptions were about motion interpolation and generating new inbetween frames. But it's not clear what you have , or what you are starting with

Similarly, if you start with some "25i" source with interleaved fields, regardless of content, and encode it with interlaced separated fields - it does NOT change the content. It's only a different way of storing the same information. The underlying information is not changed.

A common mistake is how people interpret mediainfo - Mediainfo does not analyse the file for actual content - It just reports how a file was encoded, metadata, flagging . It does not give you them most critical information - that information about content.