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• How to sync DTS with PTS (ffmpeg)

  24 novembre 2017, par Damian

  Just a quick question in regards to video encoding/muxing a video file with ffmpeg. Basically, I have my muxer functioning and I’m trying to have my packets output the correct PTS/DTS.

  This is a portion of my code that encodes my AVFrame, muxing it to an output file :

  int ret;
  
  int got_packet = 0;
  
  
  
  AVPacket pkt = { 0 };
  
  av_init_packet(&pkt);
  
  
  
  pkt.data = NULL;
  
  pkt.size = 0;
  
  
  
  /* encode the image */
  
  ret = avcodec_encode_video2(cc, &pkt, frame, &got_packet);
  
  if (ret < 0)
  
  {
  
      fprintf(stderr, "rasterbench: error encoding video frame: %s\n", av_err2str(ret));
  
      exit(EXIT_FAILURE);
  
  }
  
  
  
  if (got_packet)
  
  {
  
      av_packet_rescale_ts(&pkt, cc->time_base, st->time_base);
  
  
  
      fprintf(stderr, "\npkt.pts     = %ld\n", pkt.pts);
  
      fprintf(stderr,   "pkt.dts     = %ld\n", pkt.dts);
  
      fprintf(stderr, "rasterbench: writing frame\n");
  
  
  
      ret = av_interleaved_write_frame(fmt_ctx, &pkt);
  
      av_packet_unref(&pkt);
  
  }
  
  else
  
  {
  
      ret = 0;
  
  }
  
  
  
  ...

  I’m then getting an output of the following :

  pkt.pts     = 0
  
  pkt.dts     = 0
  
  rasterbench: writing frame
  
  
  
  pkt.pts     = 1502
  
  pkt.dts     = 0
  
  rasterbench: writing frame
  
  
  
  pkt.pts     = 3003
  
  pkt.dts     = 1502
  
  rasterbench: writing frame
  
  
  
  pkt.pts     = 4505
  
  pkt.dts     = 3003
  
  rasterbench: writing frame
  
  
  
  ...

  My goal is to have my PST and DST both with the pattern : 1502, 3003, 4505, 6006, 7508, ...

  But it seems that the first DTS value is repeating once, and thus being off-sync with it’s corresponding PTS value. It’s also worth mentioning that the codec context was configured to have no b-frames, so only i- and p- frames are present here.

  Does anyone with more experience have some insight on this ?

  Addition :

  I ran the following command in terminal to check if my DTS and PTS values were consistent to my print statements :

  /opt/dreamcatcher/bin/ffprobe -show_packets -print_format json mux_test.ts | less

  And I got the following :

  {
  
      "packets": [
  
          {
  
              "codec_type": "video",
  
              "stream_index": 0,
  
              "pts": 0,
  
              "pts_time": "0.000000",
  
              "dts": -1501,
  
              "dts_time": "-0.016678",
  
              "duration": 1501,
  
              "duration_time": "0.016678",
  
              "convergence_duration": "N/A",
  
              "convergence_duration_time": "N/A",
  
              "size": "55409",
  
              "pos": "564",
  
              "flags": "K"
  
          },
  
          {
  
              "codec_type": "video",
  
              "stream_index": 0,
  
              "pts": 1502,
  
              "pts_time": "0.016689",
  
              "dts": 0,
  
              "dts_time": "0.000000",
  
              "duration": 1501,
  
              "duration_time": "0.016678",
  
              "convergence_duration": "N/A",
  
              "convergence_duration_time": "N/A",
  
              "size": "46574",
  
              "pos": "60160",
  
              "flags": "_"
  
          },
  
          {
  
              "codec_type": "video",
  
              "stream_index": 0,
  
              "pts": 3003,
  
              "pts_time": "0.033367",
  
              "dts": 1502,
  
              "dts_time": "0.016689",
  
              "duration": 1501,
  
              "duration_time": "0.016678",
  
              "convergence_duration": "N/A",
  
              "convergence_duration_time": "N/A",
  
              "size": "2544",
  
              "pos": "110356",
  
              "flags": "_"
  
          },
  
  
  
          ...

  Which doesn’t show my first DTS value repeated, but continues to show my DTS one cycle behind my PTS.

• New Piwik Mobile 2.3.0 is released

  25 novembre 2016, par Thomas Steur — Piwik Mobile Releases

  New Piwik Mobile 2.3.0 update is now available for Android 7+ and iOS10+ devices. Read below to learn more, including a special message to Android users.

  What’s new in Piwik Mobile ?

  This new version brings some bug fixes and improvements to our Android and iOS apps :

  • Custom Dimension reports are now shown within the app
  • Segments are now applied in sub-reports #5353
  • User ID is now displayed in visitor profile #5341
  • URL submitted on login are now trimmed #5338
  • iOS : a 64 bit version of the app #5328
  • Android : Remove possibility to disable SSL validation #5354 (read more below)
  • We have updated the underlying framework bringing some performance and compatibility improvements

  Attention to Android users : read more

  We have removed the possibility to disable SSL validation in this update due to a Google Play restriction. We know there are some users depending on this feature and we recommend to not update if you cannot make the SSL certificate valid for your Piwik Analytics domain.

  Download the Apps

  Update now or install either the iOS version or the Android version. Because of the SSL validation change we have made the Android update only available to Android 7+ devices. If you are an Android 6+ user and still want to get the update, you can download Piwik 2.3.0 for Android 6+ from our website.

  If you experience any issues with this version please let us know.

  Sponsor

  The new Piwik Mobile release has been sponsored by InnoCraft, the creators of Piwik.

  

  Happy analytics on the go,

• 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