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• Get frame from video bytes

  8 septembre 2019, par Kelly Flet

  I’m extracting a frame from a video using ffmpeg and golang. If I have a video in bytes instead of saved on disk as an .mp4, how do I tell ffmpeg to read from those bytes without having to write the file to disk, as that is much slower ?

  I have this working reading from a file, but I’m not sure how to read from bytes.

  I’ve looked at the ffmpeg documentation here but only see output examples instead of input examples.

  func ExtractImage(fileBytes []byte){
  
  
  
      // command line args, path, and command
  
      command = "ffmpeg"
  
      frameExtractionTime := "0:00:05.000"
  
      vframes := "1"
  
      qv := "2"
  
      output := "/home/ubuntu/media/video-to-image/output-" + time.Now().Format(time.Kitchen) + ".jpg"
  
  
  
      // TODO: use fileBytes instead of videoPath
  
      // create the command
  
      cmd := exec.Command(command,
  
          "-ss", frameExtractionTime,
  
          "-i", videoPath,
  
          "-vframes", vframes,
  
          "-q:v", qv,
  
          output)
  
  
  
      // run the command and don't wait for it to finish. waiting exec is run
  
      // ignore errors for examples-sake
  
      _ = cmd.Start()
  
      _ = cmd.Wait()
  
  }

• What are all the command `options` to execute with ?

  25 janvier 2023, par Phil Lucks

  I'd like to be able to compress the video in a way to help improve upload times.

  


  In reading the docs for FFMpeg Kit, using React Native, there is a basic execute command string of '-i file1.mp4 -c:v mpeg4 file2.mp4'... I can guess at what some of this means, in terms of input & output file names based on the ffMPEG docs, however, some of these options I am not sure of.

  


  Like why is there a -i flag prefix ? Is this "input" ?
Why is there -c:v ? Is this "convert video" ?
What if I want to reduce frame rate, or change size of video ?

  


  The TS def is just a string...

  


  Is there a good place to understand what the official docs options map to the strings ? I think

  


• Can you call out to FFMPEG in a Firebase Cloud Function

  27 juillet 2024, par Dave Parks

  Per the Firebase Cloud Functions documentation, you can leverage ImageMagick from within a cloud function : https://firebase.google.com/docs/functions/use-cases

  



  Is it possible do something similar but call out to FFMPEG instead of ImageMagick ? While thumbnailing images is great, I'd also like the capability to append incoming images to a video file stored out on Firebase Storage.