I used the static 32 bit Windows version from here. It took me a few goes to find out how this can be done, but eventually I got something working.įirst of all, make sure you have downloaded a build of FFmpeg. I recently needed to cut a few sections out of a pre-existing MP4 file to make it a bit shorter. You can use it to perform all kinds of amazing manipulations on video (and audio) files, if only you can work out the correct command line arguments. no, you can't do that with a simple trim/rewrap.FFmpeg is a remarkably versatile tool. If you want to cut precisely here to precisely there. if say, you have a 30 minute file and you just want to eliminate the last 12 minutes or so. Which can be a second or more away from where you'd rather cut. Which means, you can only 'cut' on complete I-frames. both! The computer has to decompress & store an I-frame in RAM, then call up the next "frame" dataset, and compute it from the stored I-frame it's already decompressed. For those in-between 'frames', called p & b frames, there's only a dataset stored of a) the pixels that have changed after the last I-frame or b) the pixels that will change before the next I-frame. used to be 9-15 apart, then 9-30, and now, with partial I-frames on some drones, up to 120 frames in between actual complete frames. H.264 is encoded as complete or I-frames that are complete but compressed, and in-between those. H.264 files are tricky to do this as only between every 9-30 frames can you actually 'cut' with only a re-wrap. Search with something like "cutting and re-wrapping video files without re-encoding", and you'll get results for a number of different apps, YouTube vids on doing it, that sort of thing. There are some apps out there, some free, some paid, that can do trimming & re-wrapping.
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