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• Async function doesn't pop off a second time

  9 août 2020, par Chris

  I'm creating a button to record a canvas using FFMPEG. Here's the code that finalizes the download process.

  


  const recordButton = document.querySelector("#record")
recordButton.addEventListener('click', function () {
function startRecording() {
const { createFFmpeg } = FFmpeg;
const ffmpeg = createFFmpeg({
  log: true
});

var transcode = async (webcamData) => {
  var name = `record${id}.webm`;
  await ffmpeg.load();
  await ffmpeg.write(name, webcamData);
  await ffmpeg.transcode(name, `output${id}.mp4`);
  var data = ffmpeg.read(`output${id}.mp4`);

  var video = document.getElementById('output-video');
  video.src = URL.createObjectURL(new Blob([data.buffer], { type: 'video/mp4' }));
  dl.href = video.src;
}

fn().then(async ({ url, blob }) => {
  transcode(new Uint8Array(await (blob).arrayBuffer()));
})

...

id += 1}


  


  The problem arises with the transcode variable. While the button works initially, every other attempt (on a single page load) fails just the async function. I'm not well versed enough in the function to know why it would only work once. That said, I do know it is the only bit of code that does not fire off upon second attempt.

  


  It could be a few things. This is borrowed code, and I've repurposed it for multiple uses. I may have messed up the declarations. It may be an async issue. I tried to use available values to rig up a secondary, similar function, but that would defeat the purpose of the first.

  


  I tried clearing and appending the DOM elements affected, but that doesn't do anything.

  


• Node.js ffmpeg creating a mp4 video from 2 or more jpg images

  9 mai 2020, par programmerRaj

  I am making a video animator that first generates .jpg images from an html canvas tag and then use the images as frames for the video. I am using ffmpeg to do the video generating.

  



  It works when only using 1 image

  



  const ffmpeg = require('fluent-ffmpeg');
ffmpeg.setFfmpegPath("C://Program Files/ffmpeg/bin/ffmpeg.exe");

var command = ffmpeg();

command
    .input("./test.jpg")
    .save("./test.mp4")
    .outputFPS(1)
    .on('end', () => {
        console.log("done");
    });


  



  I got it to make a mp4 video that is 1 second long with this code, but this is only with one image/frame.

  



  What I'm trying to do (2+ images)

  



  const ffmpeg = require('fluent-ffmpeg');
ffmpeg.setFfmpegPath("C://Program Files/ffmpeg/bin/ffmpeg.exe");

var command = ffmpeg();

command
    .input("./test.jpg")
    .input("./another.jpg")
    .save("./test.mp4")
    .outputFPS(1)
    .frames(2)
    .on('end', () => {
        console.log("done");
    });


  



  This doesn't work as it generates the same video as the first example. Instead of showing one image for the first second and another image for the second second, it generates a one second long video that only has the first image.

  



  Can someone please show how to fix this ?

  


• FFMPEG Hardware Encoding H264

  9 mai 2019, par nameless

  I’m currently trying to use FFMPEG with Hardware/GPU Encoding with the H264 Codec.

  What I do is, I pipe raw data direclty into ffmpeg to output them to a udp stream. Those are my settings :

  var ffmpegArgs = [
  
      '-c:v', 'rawvideo',// input container
  
      '-f', 'rawvideo',
  
      '-pix_fmt', 'rgba', // input pixel format
  
      '-s', '600x600', //input size
  
      '-video_size', '600x600',
  
      '-i', 'pipe:0', // input source
  
      '-f', 'mpegts', // output container format
  
      '-s', '600x600',
  
      '-video_size', '600x600',
  
      '-c:v', 'libx264', // output video codec
  
      '-b:v', '1m', // output bitrate
  
      'udp://239.255.123.46:1234' // output destination
  
  ];

  And in generally it is working, but with really miserable quality and latency. The frames are like 5 seconds behind and then have lots of bugs in them so it takes at least 10 or 15 seconds to see the hole frame (the video is a "live stream" from a canvas).

  However I thought that GPU Encoding might help here, but I don’t get this working. I’m trying to use VAAPI, but no matter which command from ffmpeg I’m trying to use (descirbed here), it’s not working....

  I’m trying to run this on a Intel NUC (this one) on an Ubuntu 16.04.

  Are there any tips on how I can get this running ?