Is there any tool that can manipulate / transcode h264 or h265 video streams throwing away approximately half of the frames, without performing a full re-encode?
I'm thinking it would be theoretically possible to preserve motion vectors and such computed data, preserve all I-frames, and just throw away approximately half of the B- and P-frames (possibly adjusting the remaining ones.) The result does not need to be CFR.
Is there a way to do this with ffmpeg? (or any other tool)