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[HELP] Converting 25p to 25i using Low Pass Filter in ffmpeg - Printable Version

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Converting 25p to 25i using Low Pass Filter in ffmpeg - jan2ooo - 22.03.2021

Hey.

Regarding FFMPEGs "interlace" Filter I would like to create an 25i prores422hq file from an 25p source with correct metadata (Interlaced, TFF). No frame interpolation, one frame should result in two fields. But I don't know how to handle the parameters Huh 

Frame (25p): (1), (2), (3), (4), ...
Frame (25i Fields): (11), (22), (33), (44), ...

Thank you!


RE: Converting 25p to 25i using Low Pass Filter in ffmpeg - Selur - 22.03.2021

you probably want something like:
ffmpeg -i "F:\TestClips&Co\files\test.avi" -vcodec prores_ks -profile:v 3 -vf tinterlace=4 -flags +ildct+ilme -vtag apch -f mov "E:\Output\test.mov"
where:
-vf tinterlace=4
converts the content to tff interlaced (see: https://www.ffmpeg.org/ffmpeg-all.html#tinterlace)
( '-vf interlace=scan=tff' should also work; see: https://www.ffmpeg.org/ffmpeg-all.html#interlace)
and
-flags +ildct+ilme
makes sure the output is flagged as interlaced (see: https://www.ffmpeg.org/ffmpeg-all.html#toc-Codec-Options)

Cu Selur


RE: Converting 25p to 25i using Low Pass Filter in ffmpeg - jan2ooo - 22.03.2021

Thank you! Buw how to setup the flag (complex_filter, cvlpf)? A simple copy/paste of

ffmpeg -i "F:\TestClips&Co\files\test.avi" -vcodec prores_ks -profile:v 3 -vf tinterlace=4 -flags +ildct+ilme -vtag apch -f mov "E:\Output\test.mov"

will result in a 12,5fps Quicktime with separate odd and even fields in one frame.

https://ibb.co/hMqrk04


RE: Converting 25p to 25i using Low Pass Filter in ffmpeg - Selur - 22.03.2021

Quote:will result in a 12,5fps Quicktime with separate odd and even fields in one frame.
oh, I overlooked that you wanted 25i. Smile
try adding "-r 25"

Quote:Buw how to setup the flag (complex_filter, cvlpf)?
Assuming you are referring to tinterlace:
-vf tinterlace=mode=4:flags=cvlpf

Cu Selur

Ps.: if that doesn't work you probably have to 1st convert 25p to 50p and then convert it to 25i.


RE: Converting 25p to 25i using Low Pass Filter in ffmpeg - jan2ooo - 22.03.2021

Quote:try adding "-r 25"
Sorry, where? I am a ffmpeg noob Angel


RE: Converting 25p to 25i using Low Pass Filter in ffmpeg - Selur - 22.03.2021

Quote:I am a ffmpeg noob
somewhere behind the input


RE: Converting 25p to 25i using Low Pass Filter in ffmpeg - jan2ooo - 26.03.2021

Quote:if that doesn't work you probably have to 1st convert 25p to 50p and then convert it to 25i.
Sorry, I was off for three days. I will try your suggestions asap. Thanks a lot!