[FFmpeg-user] Creat mosaic without loose quality

[Marco De Angelis]

Hello, I'm pretty new to video processing and I came across this usuful tool.
Using the info I found on the following page I created a mosaic using four mp4 files (original frame rate is 60 fps).
Create a mosaic out of several input videos – FFmpeg


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Create a mosaic out of several input videos – FFmpeg


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The output looks fine but has only 25 fps instead of 60.I'd like to have an output with the same video quality and frame rate of original.
I tryed to add option -crf 0 but it seems doesn't work.

-c:v libx264 -crf 0 output.mp4
What could be the correct settings?
Best regards