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• What ffmpeg filters can I use to achieve shrinking a video and keeping original aspect ratio ?

  3 août 2020, par sivano

  I am trying to do some specific video editing with ffmpeg and am lacking the correct terminology to describe it (and thus read online how to achieve it). Can someone help describe this using standard (ffmpeg/video editing) terminology ?

  


  The below describes it verbosely, and you can see it visually at the end (this was done manually for one image).

  


  I have a video with aspect ratio 1280x720. At some point in the video, I want to shrink the video diagonally (i.e. maintaining aspect ratio) so that it only takes up half the original width (i.e. 640) and then pad what is left with black. The purpose of this is to then overlay some other image on the left hand of the modified video.

  


  Before


  


  After


  


  Thank you

  


• What is the recommended settings for video editing using ffmpeg ?

  19 août 2020, par Moustafa Mahmoud

  I am quite new for using FFmpeg, and I am using FFmpeg in screen recording. I checked the online documentation in this link ffmpeg documentation "Capturing your Desktop / Screen Recording", but I didn't find sufficient information.

  


  I have a 4k laptop with invidia GPU, and I am using the below command to screencast the video (4k, 60 f/s), and audio from my laptop.

  


  ffmpeg -video_size 3840x2160 \
 -framerate 60 \
 -f x11grab -i :1 -f pulse -ac 2 -i default \
 -c:v libx264 \
 -crf 0 \
 -qp 0 \
 -preset ultrafast videoname.mp4


  


  I have some problems in these settings as following :

  


  

  1. The output video is too large, and I need to reduce the size without touch the quality at all.

  


  2. The output video seems to be not a row video, and it takes too much time in video editing decoding and encoding. I am not sure if there is a recommended setting for video editing. As I did some search and found the above is advised, but in practice perspective, it is not efficient.

  


  


  Below is my Linux distro information :

  


  Distributor ID: Ubuntu
Description   : Ubuntu 20.04.1 LTS
Release       : 20.04
Codename      : focal


  


• Nodejs - Using ffmpeg with video thumbnails

  8 mars 2016, par RunningFromShia

  I am pretty much lost within the concept of ffmpeg and nodejs. ffmpeg is supposed to do important conversion work, that I get, but every time I try to implement a nodejs package with ffmpeg it just fails. I will give an example :

  using this for example in my app :
  https://www.npmjs.com/package/video-thumb

  my app.js :

  var express = require('express');
  
  var app = express();    
  
  
  
  var thumbler = require('video-thumb');
  
  
  
  thumbler.extract('http://www.w3schools.com/html/mov_bbb.mp4', 'snapshot.png', '00:00:1', '200x125', function(){
  
  
  
      console.log('snapshot saved to snapshot.png (200x125) with a frame at 00:00:1');
  
  
  
  });
  
  
  
  var port = process.env.PORT || 1337;
  
  
  
  app.listen(port);  

  Basically, I’ve tried a couple of nodejs packages that turn a snapshot out of a given video, and then save it to my server. each attempt failed. they all use ffmpeg. the above is just one of them.

  Now, I put a ffmpeg.exe in my root folder, I am just not sure where it’s supposed to be or how to use it with node. Needless to say, the above example doesn’t do anything. Tutorials online only show how to convert a certain video to a certain format in windows using ffmpeg, there is nothing about nodejs.
  I’d like some guidance here, thank you for your time.