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• MJPEG Stream works in Firefox but not in Chrome

  11 décembre 2019, par Maoration

  We have a system that contains cameras and we want to stream them to multiple clients.
  Behind the scenes on the server we get connections from cameras, we keep everything related to that camera in a CameraContainer, which also includes a mpegtsToMjpegStream that extends Duplex (both Readable and Writable Stream).

  after a camera connects, we open an ffmpeg process to work on the incoming mpegts stream, and output an MJPEG stream :

        '-map', '0:v', '-c:v', 'mjpeg','-f', 'mjpeg', `-`,

  ** we are doing this because we are also mapping to other outputs, like writing files.

  ---

  On the ’serving’ side, we are currently testing a simple API to GET an mjpeg stream with a camera id :

    async getCameraStream(@Param('cameraId') cameraId: string, @Res() res): Promise<any> {
  
  const cameraContainer = this.cameraBridgeService.getCameraContainer(cameraId);
  
  if (!cameraContainer) {
  
    throw new Error(`Camera with id: ${cameraId} was not found`);
  
  }
  
  
  
  if (!cameraContainer.mpegtsToMjpegStream) {
  
    throw new Error('ERROR: mpegtsToMjpegStream stream does not exist on this camera container');
  
  }
  
  
  
  const writable = new Writable({
  
    write: (chunk, encoding, callback) => {
  
      res.write(`Content-Type: image/jpeg\r\nContent-Length: ${chunk.length}\r\n\r\n`);
  
      res.write(chunk);
  
      res.write('\r\n--ffmpeg_streamer\r\n');
  
      callback();
  
    },
  
  });
  
  
  
  res.set('Content-Type', 'multipart/x-mixed-replace;boundary=ffmpeg_streamer');
  
  res.write('--ffmpeg_streamer\r\n');
  
  
  
  cameraContainer.mpegtsToMjpegStream.pipe(writable, { end: false });
  
  
  
  res.once('close', () => {
  
    if (cameraContainer.mpegtsToMjpegStream &amp;&amp; writable) {
  
      cameraContainer.mpegtsToMjpegStream.unpipe(writable);
  
    }
  
    res.destroy();
  
  });
  
  </any>

  ---

  The problem is this code works very nicely when accessing the stream with Firefox- after 1-2 seconds we get a stable, high quality, low latency stream.
  With Chrome however, the same code does not behave- the video output is corrupted, disappears into a black screen all the time, and we have to keep refreshing the page constantly just to view a few seconds of the stream until it disappears again.

  Any suggestions as to why this happens and how can I fix it ?

• Three.js video texture displays green on Chrome mobile, wrong encoding ?

  19 mai 2015, par beeb

  I am trying to make a video texture "skybox" that works on mobile browsers with Three.js. So far, I’ve been able to implement this and it works great on desktop browsers. The problem is, when viewing the animation in Chrome mobile (42.0.2311.111 on Android 5.0.2), the video appears all green with a few artifacts. I tried with mp4 (encoded with ffmpeg libx264) and ogv (ffmpeg libtheora) videos and they both fail to work (mp4 is green as stated, and ogv doesn’t display at all - black). Is the encoding the problem or webgl ? The strange thing is that my method is the same as this method : http://jeromeetienne.github.io/threex.videotexture/examples/videotexture.html
  But my Chrome mobile browser can play this example fine, so I’m guessing the encoding must be the problem ?

  Here are the command lines I used to generate the videos :

  ffmpeg -framerate 30 -i %05d.png -c:v libtheora -qscale:v 8 -r 30 outputfile.ogv
  
  ffmpeg -framerate 30 -i %05d.png -c:v libx264 -qscale:v 8 -r 30 outputfile.mp4

  Here’s the full code, even though I don’t think the problem originates from this : https://jsfiddle.net/rufn75ef/ (you have to hit the play button, autoplay doesn’t work on mobile so I disabled it for this example)

  video = document.createElement('video');
  
  video.crossOrigin = "Anonymous";
  
  var canPlayMp4 = document.createElement('video').canPlayType('video/mp4') !== '' ? true : false;
  
  var canPlayOgg = document.createElement('video').canPlayType('video/ogg') !== '' ? true : false;
  
  if (canPlayMp4) {
  
      video.src = 'vid.mp4';
  
  } else if (canPlayOgg) {
  
      video.src = 'vid.ogv';
  
  } else {
  
      alert('Your browser can\'t play video, please view this site in a modern desktop browser.');
  
  }
  
  video.muted = true;
  
  video.loop = true;
  
  
  
  video.width = 358;
  
  video.height = 264;
  
  
  
  video.load(); //do after source change
  
  
  
  videoTexture = new THREE.Texture(video);
  
  videoTexture.minFilter = THREE.NearestFilter;
  
  videoTexture.magFilter = THREE.NearestFilter;

  If you are able to test, do you experience the same problem ? How should I encode my videos using ffmpeg to maximize mobile compatibility ?

  Thanks in advance

• Revision 3213 : des items de langue et un logo par défaut

  9 avril 2010, par kent1 — Log

  des items de langue et un logo par défaut