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• A 'clean' way to cut an MP4 movie into two sections using FFMPEG ?

  30 août 2020, par Peter in Japan

  I am attempting to use FFMPEG to make a script that can easily split a short MP4 movie with sound into two pieces at a certain point. I've searched through what feels like hundreds of posts to try to find "the" answer, but most of my attempts end up with poor results, broken video files that cause my video play to freeze, and so on. I am attempting to make a script that allows me to easily cut a short anime movie (something grabbed from Twitter or some other short source) and cut it into two sections, so it can be under the 2:20 Twitter time limit, or to cut out some scene I don't want to show my followers.

  


  The issue is that FFMPEG is good at cutting videos into segments, but bad at know where keyframes are, so most videos have two seconds of blank video at the front before some keyframe appears, which looks terrible.

  


  One example I found that works well is below, which cuts any mp4 into a bunch of chunks of n second size (six seconds in the example below). Source and documentation for this is https://moe.vg/3b8eNTs

  


  ffmpeg -i seitokai.mp4 -c:v libx264 -crf 22 -map 0 -segment_time 6 -reset_timestamps 1 -g 30 -sc_threshold 0 -force_key_frames "expr:gte(t,n_forced*1)" -f segment output%03d.mp4

  


  This code works great, at least allowing me to access the "left" side of a video that I want, in this case a six-second segment I want. Can anyone tell me how to accomplish the above, but starting at the 13-second period in said video, so I could get right "right" (not starting from 00:00:00) video cut cleanly ?

  


  Alternately, a single, unified and elegant way to split (re-encode) an MP4 into two segments that forces keyframes from the very beginning of the cut pieces would be wonderful. I can't believe how hard this seems to be.

  


  Thanks in advance for any help you can give ! Greetings from rural Japan !

  


• Capture Image from Serial Camera FFMPEG

  28 mai 2018, par Jomanuel Ponferrada

  I have a serial camera plugged-in on my linux os. I would like to capture image using FFMPEG but the all example are webcam and ip camera. I also visit this link to see the list of devices https://www.ffmpeg.org/ffmpeg-devices.html. But i cant see the serial camera examples. My serial cam location is on /dev/ttyS0.
  In my C++ program i can capture image from my serial camera..

  Tnx for the help in advance :)

• Video Concat using ffmpeg [closed]

  17 juin 2022, par Milan K Jain

  ffmpeg -i url1 -i url2 -i url3 -i url4 -filter_complex "[0:v:0]scale=1920:1080[c1] ; [1:v:0]scale=1920:1080[c2] ; [2:v:0]scale=1920:1080[c3] ; [3:v:0]scale=1920:1080[c4], [c1] [0:a:0] [c2] [1:a:0] [c3] [2:a:0] [c4] [3:a:0] concat=n=4:v=1:a=1 [v] [a]" -map "[v]" -map "[a]" /Users/myname/Downloads/f1-2017-07-12.mp4 -y

  


  In Place of url I want to give link U get from after storing my video in amazon s3 bucket
Someone pls help