Duplicate frame removing

[Maximilian Goof]

I mostly deal with PAL SD 25fps content. I want to increase the frame rate to 48/50/60 fps and for best results I want to remove the duplicate frames first (essentially restore the original 24fps footage). For this purpose, I tried Shutter Encoder (GUI version of ffmpeg), but hit a rock. This program requires reencoding for removing of duplicate frames, which is highly inefficient. With maximum quality and 2-pass encoding the rendering speed is ridiculously slow (about 5 frames/second). Can you recommend another app that can do the same job without having to change formats, codecs, bitrates, etc.?

[jagabo]

Use a lossless codec for your dup-free intermediate.

[Maximilian Goof]

Use a lossless codec for your dup-free intermediate.

I tried this but at least in this edition of ffmpeg there is not support for duplicate frame removing for lossless codecs.
Here is screenshot of the ffmpeg window when I choose HEVC (see the bottom right field under Advanced Features)

[Attachment 83902 - Click to enlarge]
Here is the same window when I choose Uncompressed or FFVI (watch the same place)

[Attachment 83903 - Click to enlarge]
I tried another GUI ffmpeg (clever ffmpeg). In that version there are two framerate options: fix framerate and change framerate (see at right)

[Attachment 83904 - Click to enlarge]
I am not pretty sure what those two do. Change framerate is probably only conversion but fix framerate is for corrupted video streams and probably do more than simply framerate conversion. Both functions are without reencoding and are pretty fast but there is nowhere information if in those there is included detection and removing of duplicate frames or not. Any advice?

[jagabo]

Try switching x265 to qp encoding, set the qp to 1 (near lossless), and force the preset to ultrafast. Or, if the program lets you pass custom parameters to x265 force the preset to ultrafast and pass "--lossless" to x265.