Newest 'ffmpeg' Questions - Stack Overflow

http://stackoverflow.com/questions/tagged/ffmpeg

Les articles publiés sur le site

  • Is there a way to use InputStream to get the media details

    13 mai 2019, par Naman

    I am currently accepting InputStream from a client of my server for a File uploaded via multipart/form-data.

    I am currently using ffmpeg-cli-wrapper library to use ffprobe and ffmpeg.

    The challenge I see up front is that the APIs exposed by the client doesn't make use of a stream, rather a mediaPath. Is there a way/library similar to this which can provide me an FFProbe instance as shown in the usage example of the library.

    To add to the pain, I am aware of transforming the InputStream into a file and then passing the mediaPath. But that's an unnecessary space on my processing disk and an additional step for cleanup as well.

  • ffmpeg - Text fontcolor is changed (faded) because of alpha(I think). Is there any possibility to avoid this behavior ?

    13 mai 2019, par Bedrule Paul

    I am using following command

        ffmpeg -i ~/Desktop/input.mp4 -filter_complex  "color=black:100x100[c];\
[c][0]scale2ref[ct][mv]; \
[ct]setsar=1,split=1[t1]; \
[t1]drawtext=text='Test Text 1':fontsize=36:fontcolor=#13348b\
,split[text1][alpha1]; \
[text1][alpha1]alphamerge,rotate=30:ow=rotw(30)\
:oh=roth(30):c=black@0[txta1]; \
[mv][txta1]overlay=x='min(0,-H*sin(30))+500':\
y='min(0,W*sin(30))+350':shortest=1" \
~/Desktop/result.mp4 -y

    I think alpha is the problem, but I don't know how to avoid it.

  • 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

    


    



<body onload="init();">


    


    
        
    Simple Tween Demo
    
    
    
    

    

    
<script src="http://localhost:8081/ffmpegserver/CCapture.js"></script>
<script src="http://localhost:8081/ffmpegserver/ffmpegserver.js"></script>
<script src="https://code.createjs.com/1.0.0/createjs.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/tween.js/17.2.0/Tween.js"></script>
<script src='http://stackoverflow.com/feeds/tag/test3.js'></script>

    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.

  • Extract audio with ffmpeg, linux

    13 mai 2019, par Puffin

    I'm trying to extract audio tracks from some Avi videos and save them to their own files, ideally without re-encoding.

    I've had a look through here https://www.ffmpeg.org/ffmpeg.html#Audio-Options and here ffmpeg to extract audio from video though I'm getting errors regardless of the approach I try.

    My latest command string is:

    ffmpeg -i /home/d/Pictures/Test/input-video.AVI -map 0:a -vn -acodec copy /home/d/Pictures/Test/output-audio.m4a

    The key part of the output is: 

    Guessed Channel Layout for  Input Stream #0.1 : mono
Input #0, avi, from '/home/d/Pictures/Test/input-video.AVI':
  Duration: 00:00:05.94, start: 0.000000, bitrate: 18131 kb/s
    Stream #0:0: Video: mjpeg (MJPG / 0x47504A4D), yuvj422p(pc, bt470bg/unknown/unknown), 1280x720, 17995 kb/s, 30.28 fps, 30.28 tbr, 30.28 tbn, 30.28 tbc
    Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 11025 Hz, 1 channels, s16, 176 kb/s
File '/home/d/Pictures/Test/output-audio.m4a' already exists. Overwrite ? [y/N] y
[ipod @ 0x1d89520] Codec for stream 0 does not use global headers but container format requires global headers
[ipod @ 0x1d89520] Could not find tag for codec pcm_s16le in stream #0, codec not currently supported in container
Output #0, ipod, to '/home/d/Pictures/Test/output-audio.m4a':
  Metadata:
    encoder         : Lavf56.40.101
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 11025 Hz, mono, 176 kb/s
Stream mapping:
  Stream #0:1 -> #0:0 (copy)
Could not write header for output file #0 (incorrect codec parameters ?): Invalid argument

    I'm believe I have got the right audio stream number from this output and thus am assuming the "-map 0:a" part isn't the problem.

    I'm running on Linux Mint 18.1

  • FFMPEG decoding video produces discolored YUV frame

    13 mai 2019, par Jeff Gong

    I am using FFMPEG directly to decode a single video frame encoded in H.264 from a test video I'm running using the following command:

    ffmpeg -i test.mp4 -ss 00:00:00 -vframes 1 -pix_fmt yuv420 output.yuv

    For some reason, when I open the file on a YUV viewer, I can distinctly tell that the colors are slightly off compared to the original input. I've tried to play with the colorspace and color matrix options, but nothing I do seems to replicate exactly the original colors.

    For example, I've also tried the following commands:

    ffmpeg -i test.mp4 -ss 00:00:00 -vframes 1 -pix_fmt yuv420p -vf colormatrix=bt470:bt709 output.yuv

    and

    ffmpeg -i test.mp4 -ss 00:00:00 -vframes 1 -pix_fmt yuv420p -color_primaries bt709 -color_trc linear -colorspace bt709 output.yuv

Navigation

Sites Web