Sur d’autres sites (4186)

• Handling an arbitrary number of start and stop time pairings to cut a movie file down

  9 juin 2019, par Kieran

  I am writing a function that takes a list of tuples and a file path string as arguments and outputs a cut down video that only includes the frames that fall inside the start/stop pairings provided.

  I’m getting stuck because I am not sure whether the .trim() method of the ’infile’ object is altering the existing object or or creating a new one or doing something else entirely.

  the list of start/stop frame pairings can be arbitrarily long, every example I have found has been for a specific number of start and stop pairings and I can’t find anything describing what data structure needs to be passed back to ffmpeg.concat().

  My code is displayed below :

  import ffmpeg
  
  
  
  frameStamps = [(50,75),(120,700),(1250,1500)]
  
  videoFilePath = 'C:/Users/Kieran/Videos/testMovie.mp4'
  
  outputFolder = 'C:/Users/Kieran/Videos/'
  
  
  
  def slice_video(frameStamps, videoFilePath, outputFolder):
  
  
  
      originalFile = ffmpeg.input(videoFilePath)
  
  
  
      for stamp in frameStamps:
  
          ffmpeg.concat(originalFile.trim(start_frame=stamp[0], end_frame=stamp[1]))
  
  
  
  
  
      ffmpeg.output(outputFolder + 'testoutput.mp4')
  
      ffmpeg.run() 
  
  
  
  slice_video(frameStamps, videoFilePath, outputFolder)

  Now I am able to get the following when I individually print out originalFile.trim() which are getting recognised in the console as "FilterableStream" objects

  trim(end_frame=75, start_frame=50)[None] <29b4fb0736ec>
  
  trim(end_frame=700, start_frame=120)[None] <c66c4e1a48f5>
  
  trim(end_frame=1500, start_frame=1250)[None] &lt;13e0697a5288>  
  
  </c66c4e1a48f5>

  and I have tried passing them back as a list, dictionary and tuple and haven’t been able to get it working

  Output Errors :

    File "C:/Users/Kieran/Example.py", line 21, in slice_video
  
  ffmpeg.output(outputFolder + 'testoutput.mp4')
  
  
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\ffmpeg\_ffmpeg.py", line 94, in output
  
  return OutputNode(streams, output.__name__, kwargs=kwargs).stream()
  
  
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\ffmpeg\nodes.py", line 282, in __init__
  
  kwargs=kwargs
  
  
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\ffmpeg\nodes.py", line 170, in __init__
  
  self.__check_input_len(stream_map, min_inputs, max_inputs)
  
  
  
    File "C:\ProgramData\Anaconda3\lib\site-packages\ffmpeg\nodes.py", line 149, in __check_input_len
  
  raise ValueError('Expected at least {} input stream(s); got {}'.format(min_inputs, len(stream_map)))
  
  
  
  ValueError: Expected at least 1 input stream(s); got 0

• How to convert a javascript animation to video on the server-side using nodejs ?

  13 mai 2019, par user9964622

  I have a app where a user can create animations , I want to be able to convert these animations to video on server side, so user can save and share them eg YouTube, etc

  Here is what I have so far , animation created using create js and ffmpegserver.js.

  ffmpegserver.js.

  This is a simple node server and library that sends canvas frames to the server and uses FFmpeg to compress the video. It can be used standalone or with CCapture.js

  Test3.html

      
  
  
  
  
  
  
  
  <code class="echappe-js">&lt;body onload=&quot;init();&quot;&gt;
  
          
  Simple Tween Demo
      
  
  
  
  
  &lt;script src=&quot;http://localhost:8081/ffmpegserver/CCapture.js&quot;&gt;&lt;/script&gt;
  
  &lt;script src=&quot;http://localhost:8081/ffmpegserver/ffmpegserver.js&quot;&gt;&lt;/script&gt;
  
  &lt;script src=&quot;https://code.createjs.com/1.0.0/createjs.min.js&quot;&gt;&lt;/script&gt;
  
  &lt;script src=&quot;https://cdnjs.cloudflare.com/ajax/libs/tween.js/17.2.0/Tween.js&quot;&gt;&lt;/script&gt;
  
  &lt;script src='http://stackoverflow.com/feeds/tag/test3.js'&gt;&lt;/script&gt;
  
  

  Test3.js

  /* eslint-disable eol-last */
  
  /* eslint-disable no-undef */
  
  /* eslint-disable quotes */
  
  var canvas, stage;
  
      function init() {
  
          var framesPerSecond = 60;
  
          var numFrames = framesPerSecond * 5; // a 5 second 60fps video
  
          var frameNum = 0;
  
  
  
          var progressElem = document.getElementById("progress");
  
          var progressNode = document.createTextNode("");
  
          progressElem.appendChild(progressNode);
  
  
  
          function onProgress(progress) {
  
            progressNode.nodeValue = (progress * 100).toFixed(1) + "%";
  
          }
  
  
  
          function showVideoLink(url, size) {
  
            size = size ? (" [size: " + (size / 1024 / 1024).toFixed(1) + "meg]") : " [unknown size]";
  
            var a = document.createElement("a");
  
            a.href = url;
  
            var filename = url;
  
            var slashNdx = filename.lastIndexOf("/");
  
            if (slashNdx >= 0) {
  
              filename = filename.substr(slashNdx + 1);
  
            }
  
            a.download = filename;
  
            a.appendChild(document.createTextNode("Download"));
  
            var container = document.getElementById("container").insertBefore(a, progressElem);
  
  
  
          }
  
  
  
          var capturer = new CCapture( {
  
            format: 'ffmpegserver',
  
            //workersPath: "3rdparty/",
  
            //format: 'gif',
  
            //verbose: true,
  
            framerate: framesPerSecond,
  
            onProgress: onProgress,
  
            //extension: ".mp4",
  
            //codec: "libx264",
  
          } );
  
          capturer.start();
  
  
  
  
  
          canvas = document.getElementById("testCanvas");
  
          stage = new createjs.Stage(canvas);
  
          var ball = new createjs.Shape();
  
          ball.graphics.setStrokeStyle(5, 'round', 'round');
  
          // eslint-disable-next-line quotes
  
          ball.graphics.beginStroke('#000000');
  
          ball.graphics.beginFill("#FF0000").drawCircle(0, 0, 50);
  
          ball.graphics.setStrokeStyle(1, 'round', 'round');
  
          ball.graphics.beginStroke('#000000');
  
          ball.graphics.moveTo(0, 0);
  
          ball.graphics.lineTo(0, 50);
  
          ball.graphics.endStroke();
  
          ball.x = 200;
  
          ball.y = -50;
  
          createjs.Tween.get(ball, {loop: -1})
  
              .to({x: ball.x, y: canvas.height - 55, rotation: -360}, 1500, createjs.Ease.bounceOut)
  
              .wait(1000)
  
              .to({x: canvas.width - 55, rotation: 360}, 2500, createjs.Ease.bounceOut)
  
              .wait(1000)
  
              .to({scaleX: 2, scaleY: 2}, 2500, createjs.Ease.quadOut)
  
              .wait(1000)
  
          stage.addChild(ball);
  
          createjs.Ticker.addEventListener("tick", stage);
  
  
  
  
  
          function render() {
  
              requestAnimationFrame(render);
  
              capturer.capture( canvas );
  
  
  
              ++frameNum;
  
              if (frameNum < numFrames) {
  
              progressNode.nodeValue = "rendered frame# " + frameNum + " of " + numFrames;
  
              } else if (frameNum === numFrames) {
  
              capturer.stop();
  
              capturer.save(showVideoLink);
  
              }
  
          }
  
  
  
          render();
  
  }

  Everything works fine, you can test it yourself if you want by cloning the repo.

  Right now animation rendering happens in client side, I would like this animation rendering to happen in the backend side

  What do I need to change to make this animation rendering in backend server side using Nodejs ? any help or suggestions will be appreciated.

• Audio conversion and filter application using ffmpeg with 1 command

  1er juillet 2019, par user2773013

  I have an mp3 file I need to convert to wav, and apply loudnorm filter afterwards. So far i’ve been doing it with 2 commands.

  ffmpeg -i input.mp3 output.wav

  and

  ffmpeg -y -nostdin -i output.wav -filter_complex "[0:0]FILTER PARAMETER" -map_metadata 0 -map_metadata:s:a:0 0:s:a:0 -map_chapters 0 -map [norm0] -c:a pcm_s16le -ar 1500 -c:s copy out2.wav   

  Is there anyway to use 1 command instead of 2 ? I tried converting straight from mp3 to out2.wav by changing output.wav to input.mp3, but when the resulting file is compared with diff, they are different compared to the 2 step process.

  I’m fairly new to ffmpeg, and have spent hours on the documentation without really knowing how to accomplish what i’m trying to do.