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[HELP] Convert 25i to 50fps? - Printable Version

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Convert 25i to 50fps? - DannyHicks - 10.01.2020

Is there a way in Hybrid (or another tool) to deinterlace 25fps video footage to 50fps without quality loss?

(Also is it true that this could cause smoother camera pans in the video?)

RE: Convert 25i to 50fps? - Selur - 10.01.2020

You always lose quality when reencoding (to a none lossless format) and during deinterlacing.
Hybrid and tons of other tools allow to deinterlace 25fps interlaced video to 50fps progressive video by a process called 'bobbing' or 'bob'-deinterlacing.
Bobbing takes each of the interleaved fields (top/bottom) and interpolates each of those to a full frame.
Unlike same frame rate deinterlacing, bobbing (double frame rate deinterlacing) does preserve all the motion data from the input interlaced source, so the bobbed source has potentially smoother camera pans than the otherwise deinterlaced content, but it won't create smoother motion than the interlaced the interlaced source.
Usually the only real way trying to get smoother pans it to create additional interpolated frames and convert to a higher frame rate.

QTGMC is currently the 'best' deinterlaced I know of.
You can create bob deinterlaced output with it and you can create same frame rate output with it.

Cu Selur

Ps.: you probably also need to replace the libmvtools.dll (see: https://forum.selur.net/Thread-HELP-error-loading-module), since the current version which comes with Hybrid might be broken.

PPs.: to get some basic understanding of deinterlacing http://www.100fps.com/ is a good place to start.

RE: Convert 25i to 50fps? - DannyHicks - 13.01.2020

Thanks! I'll try QTGMC!

(10.01.2020, 23:32)Selur Wrote: ...
Usually the only real way trying to get smoother pans it to create additional interpolated frames and convert to a higher frame rate.
...

How could I do this?


EDIT: I just tried QTGMC, but I got this error. 

[Image: PGsRMft.png]

RE: Convert 25i to 50fps? - Selur - 13.01.2020

Does the Vapoursynth Preview work or does is throw an error?
Also make sure to update to the latest version.

Cu Selur

RE: Convert 25i to 50fps? - DannyHicks - 14.01.2020

(13.01.2020, 19:18)Selur Wrote: Does the Vapoursynth Preview work or does is throw an error?
Also make sure to update to the latest version.

Cu Selur

I downloaded the latest build of Hybrid before doing this. 

This is the error I get when I go to the Vapoursynth Preview:

Failed to evaluate the script:
Python exception: LibavSMASHSource: Function does not take argument(s) named stream_index

Traceback (most recent call last):
  File "src\cython\vapoursynth.pyx", line 1946, in vapoursynth.vpy_evaluateScript
  File "src\cython\vapoursynth.pyx", line 1947, in vapoursynth.vpy_evaluateScript
  File "C:\Users\<username>\AppData\Local\Temp\tempPreviewVapoursynthFile19_15_43_438.vpy", line 26, in <module>
    clip = core.lsmas.LibavSMASHSource(source="H:/Series/<something>/Dutch/DVD - Seizoen 3/RIP/3x14 Witheet.mp4",stream_index=0)
  File "src\cython\vapoursynth.pyx", line 1825, in vapoursynth.Function.__call__
vapoursynth.Error: LibavSMASHSource: Function does not take argument(s) named stream_index


RE: Convert 25i to 50fps? - Selur - 14.01.2020

strange:
a. 'stream_index' should only be used if the source has multiple video tracks. (no clue why that is the case with your source)
b. instead of 'stream_index', 'track' needs to be used.
-> I'll create a new dev version which used 'track', will send you a link via PM once I'm finshed

Cu Selur