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• Create time lapse video from other video

  27 janvier 2017, par Orlando

  Using avconv (or even ffmpeg, so I can use as a reference), how can I create a time lapse video by taking only anchor/reference frames from another video ? Most information I find is on how to create a time lapse video by combining images, and I’d like to do it by extracting frames from a video. Say, if a video is 30 seconds long at 30 FPS, I’d like to take 60 out of those 900 frames (900/60 = every 15 seconds) to produce a 2 second video.

• Sync Video Multitrack Recording (with video.js and FFMpeg ?) [closed]

  28 avril 2020, par finnk

  I am writing a web application that gives the ability to record multiple videos and merge them into a single split-screen video. The videos have to be synchronous with each other, so if the user had already recorded a video, it will playback on the next recording. So the captured video(s) play(s) while recording.
Right now, I implemented it by using video.js and videojs-record. 
I merge the videos server-side using FFmpeg( client-side would be much better, but I didn't figure out how to achieve this)

  



  When I start the record, the playback of each recorded video begins as well. 
This approach produces, of course, a small latency between the videos.

  



  Any suggestions on how to sync the recordings ?

  



  Do you know ay better other libraries ?

  



  Thank you & Best regards,

  


• Merging 3 separate commands into one that re-encodes a video, extracts a thumbnail, delete original and rename new video in subdirectories

  16 janvier 2017, par Ali Samii

  I am trying to execute a find bash command to process hundreds of video files that are all named video-original.mp4 but are in subdirectories of a parent directory.

  Here’s an example of the directory structure :

  videos
  
  ├── 01a
  
  │   └── video-original.mp4
  
  ├── 01b
  
  │   └── video-original.mp4
  
  ├── 02a
  
  │   └── video-original.mp4
  
  ├── 02b
  
  │   └── video-original.mp4
  
  ├── 03a
  
  │   └── video-original.mp4
  
  └── 03b
  
      └── video-original.mp4

  I am using the following command :

  find ./ -name 'video-original.mp4' -exec bash -c 'ffmpeg -i "$0" -f mp4 -vcodec libx264 -preset veryslow -profile:v high -acodec aac -movflags faststart video.mp4 -hide_banner' {} \;

  The problem I am having is that it is saving the file video.mp4 in the parent videos directory, instead of in the subdirectory next to the original video-original.mp4

  Afterwards, I want to delete the file video-original.mp4. Currently, my process entails waiting for all the videos to be reencoded, and then once complete, issuing a separate command to delete the file video-original.mp4 :

  find ./ -name 'video-original.mp4' -exec bash -c 'rm -rf "$0"' {} \;

  And my final step would be to extract a screenshot of the new video.mp4 at 10 seconds and save it as thumbnail.jpg. Again, I am currently doing that as a separate step that I execute after the previous two steps are completed.

  find ./ -name 'video.mp4' -exec bash -c 'ffmpeg -i "$0" -ss 00:00:10 -vframes 1 thumbnail.jpg' {} \;

  What I would like to do is combine these three steps into a single command so the end result will be :

  videos
  
  ├── 01a
  
  │   ├── thumbnail.jpg
  
  │   └── video.mp4
  
  ├── 01b
  
  │   ├── thumbnail.jpg
  
  │   └── video.mp4
  
  ├── 02a
  
  │   ├── thumbnail.jpg
  
  │   └── video.mp4
  
  ├── 02b
  
  │   ├── thumbnail.jpg
  
  │   └── video.mp4
  
  ├── 03a
  
  │   ├── thumbnail.jpg
  
  │   └── video.mp4
  
  └── 03b
  
      ├── thumbnail.jpg
  
      └── video.mp4

  Finally, it would be great to save that as a bash script and include it in my path in /usr/local/bin or ~/bin as an executable so I could just issue the command reencode and it would run. Would be even better if the input file could have any video file, for example, random_name.mp4 or random_name.mov or random_name.webm, basically any video file (but skipping video.mp4 at the encoding step).