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• 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.

• Video Encode different parts of video using different bitrates

  8 février 2015, par khateeb

  If I’ve a video like : video-lectures

  

  And I need to encode the slides with high bitrate (as it’s the most important to the user) and encode the rest of the view with low bitrate.

  1. Select the part to encode with high bitratre.
     

  2. Separately Encoding the different parts with different bitrates.

  

  3. Combine the different parts into one video.

  The purpose is to reduce the total file-size to be published online, hence reduce the bandwidth needed.
  I need to do that using ffmpeg.
  I’ll use that approach in encoding video-lectures recorded with still camera (180 degree view like the images above), since I know which regions are more useful to students (board and slides) than other regions.