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• How to effectively turn high resolution images into a video with ffmpeg ?

  5 septembre 2022, par Sprout Coder
  

  • I have 24 frames (frame-%d.png)

  


  • I want to turn them into a video that will be 1 second long

  


  • That means that each frame should play for 1/24 seconds

  


  


  I'm trying to figure out the correct settings in order to achieve that :

  


  await new Promise((resolve) => {
  ffmpeg()
    .on('end', () => {
      setTimeout(() => {
        console.log('done')
        resolve()
      }, 100)
    })
    .on('error', (err) => {
      throw new Error(err)
    })
    .input('/my-huge-frames/frame-%d.png')
    .inputFPS(1/24)
    .output('/my-huge-video.mp4')
    .outputFPS(24)
    .noAudio()
    .run()


  


  

  1. Are my inputFPS(1/24) & outputFPS(24) correct ?

  


  2. Each frame-%d.png is huge : 32400PX x 32400PX ( 720Mb). Will ffmpeg be able to generate such a video, and if so, will the video be playable ? If not, what is the maximum resolution each frame-%d.png should have instead ?

  


  3. Since the process will be quite heavy, I believe using the command line could be more appropriate. In that case, what is the equivalent of the above Js code in the command line (as in ffmpeg -framerate etc...) ?

  


  


• Streaming audio from C++ [closed]

  27 août 2022, par Oliver Hawker

  I have a C++ audio application that generates audio, which I intend to stream over a network using RTSP and FFmpeg (or it's libs directly). Fundamentally, the audio is not coming from a file or device but is generated internally by the application.

  


  So far, I have looked at the following approaches :

  


  


  1. Spin up an FFmpeg process inside my application using FFmpeg-kit, and pipe data in to it using a named pipe
— Written in objective C, so I'd need a wrapper around it to call from C++.
— Feels like an awful lot of overhead for something so simple, I am dubious that it's necessary.

     


  


  2. Leverage libavformat etc. directly.
— I can imagine that the pipeline would look like a regular encode pipeline using raw frames, which I can sort-of see how it would work, but I'm struggling to mix this example with something that also transmits over RTSP.

     


  


  3. Make something myself that transmits raw samples over UDP
— Bandwidth-heavy and probably unnecessary

     


  


  


  Does anybody know of a tutorial, starting point, reference implementation or other project I could look at for some guidance ? Any solution I have come up with seems ridiculously heavyweight for something so simple.

  


  Thanks all.

  


• AWS Lambda tmp disk limit with ffmpeg

  21 avril 2022, par Almaju

  I am using AWS Lambda to render videos using ffmpeg. It is a basic function that downloads external clips, merges those, then uploads the result to S3.

  


  This function needs to be able to scale quickly because I need to generate a lot of videos in a short time period.

  


  The problem is that I reach the /tmp disk limit of 512MB because the same lambda environment is reused by the different requests. I have increased that memory limit to temporarily solve the problem but it does not feel scalable.

  


  I have looked into EFS but the requirement to use a VPC and a NAT to have internet access sounds really heavy for my simple needs.

  


  Is there a way to output the result of ffmpeg directly in S3 (thus not needing the temporary folder) ? Or perhaps force to respawn a clean lambda environment if the memory is about to be full ?