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• how to pipe ffmpeg to ffmpeg ?

  4 juillet 2022, par imagesck

  How to pipe ffmpeg output frame by frame to ffmpeg ? i dont see any library either nodejs or python that as powerfull as the application directly. so what i need to do is take rawvideo from ffmpeg, then manipulate in middle stage, then push again that buffer to ffmpeg. i got inavlid buffer size after encode 24 frames. is stdin buffer push too fast ?

  


  const { spawn } = require('child_process');
const path = require('path');

const decArgs = [
    '-i', path.join(__dirname + '/public/blackpink.mp4'),
    '-c:v', 'copy',
    '-an',
    '-f', 'rawvideo',
    '-'
];

const decode = spawn('ffmpeg', decArgs);

const encArgs = [
    '-f', 'rawvideo',
    '-video_size', '854x480',
    '-i', '-',
    '-c:v', 'libx264',
    '-preset', 'ultrafast',
    '-crf', '30',
    '-pix_fmt', 'yuv420p',
    '-y',
    path.join(__dirname + '/public/output.mp4')
];

const encode = spawn('ffmpeg', encArgs, {
    stdio: [
        decode.stdout,
        null,
        null
    ]
})

encode.stderr.on('data', data => {
    console.log(data.toString())
})


  


• FFmpeg seeking in Mpeg4 streams

  4 juillet 2012, par Chris Robinson

  I am currently attempting to develop a player that can perform accurate seeking based on an mpeg4 elementary video stream. I'm in the planning stage and trying to decide how to go about things and I'd like some advice before I start.
  Some things to note are :

  • I will have complete control over the encoding of the file.
  • The original content will be I-frame only
  • FFmpeg is the encoding/decoding library
  • Audio can be disregarded for now. I will only be dealing with the video stream.
  • Frame accurate seeking must be implemented

  So, when I'm encoding the content, can I query what type of frame (I, P, B) has been encoded so I can construct an additional index stream for the seeking operation. If not, I can query the GOP after it has been encoded to find the I-frame.

  As for playback, the user needs to be able to type in a specific time and go to that frame (the nearest I-frame will be suitable for now). We can assume that the GOP is closed and the length is fairly short (e.g. 15 frames). My thoughts are to query the index stream that I created during encode and determine the relevant distance into the stream for the requested time.

  I'm not sure how to seek using the FFMpeg library when playing back files.

  Has anyone done anything similar and if so, can you give a brief explanation of how you did it ?

• How to import fluent-ffmpeg in AWS lambda ?

  30 janvier 2020, par Fook

  I’m trying to use fluent-ffmpeg in AWS Lambda, but cannot get it setup correctly. At the top of my index.js :

  import ffmpeg from "fluent-ffmpeg";

  But it is always undefined.

  ffmpeg === undefined.

  I’m using Serverless and have ffmpeg included as a layer.

  serverless.yaml

  functions:
  
    createGifFromVideo:
  
      handler: src/services/createGifFromVideo/index.handler
  
      layers:
  
        - { Ref: FfmpegLambdaLayer }
  
      events:
  
        - sns: arn:aws:sns:us-east-1:${self:custom.accountId}:NewVideoPostContentTopic-${self:provider.stage}
  
  
  
  layers:
  
    ffmpeg:
  
      path: src/layers

  package.json

  {
  
    "name": "createGifFromVideo",
  
    "version": "1.0.0",
  
    "main": "index.js",
  
    "license": "MIT",
  
    "private": true,
  
    "dependencies": {
  
      "fluent-ffmpeg": "^2.1.2"
  
    }
  
  }

  The uploaded lambda seems to be constructed correctly from what I can tell. Webpack builds the file with fluent-ffmpeg merged in and it is linked to the ffmpeg layer.

  I can load other packages. It’s just fluent-ffmpeg that comes back undefined.

  From the docs it mentions passing FFMPEG_PATH and FFPROBE_PATH as environment variables. Are these necessary with a layer ?

  I would be grateful to see a configuration that works.