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• avfilter/f_ebur128 : add all sample rates support

  4 mars 2021, par Paul B Mahol

  avfilter/f_ebur128 : add all sample rates support
  The magic constants come from the unofficial "ITU-R BS.1770-1 filter
  
  specifications"¹ by Raiden (libebur128) which relies on "Parameter
  
  Quantization in Direct-Form Recursive Audio Filters"² by Brian
  
  Neunaber.
  The constants seem to include a quantization bias, for example :
  
   Vb is supposed to be exactly √Vh in a high shelf filter
  
   the Pre-filter Gain should likely be 4dB
  
   Pre Q and RLB Q are respectively very close to √½ and ½
  Those are not adjusted to prevent the values from drifting away from
  
  the official specifications.
  An alternative to this approach would be to requantize on the fly as
  
  proposed by pbelkner³, where the 48kHz code path would use the exact
  
  specifications constants while derivating constants for other
  
  frequencies.
  [1] : https://www.scribd.com/document/49991813/ITU-R-BS-1770-1-filters
  
  [2] : https://www.scribd.com/document/6531763/Direct-Form-Filter-Parameter-Quantization
  
  [3] : https://hydrogenaud.io/index.php?topic=86116.msg740092#msg740092
  

  • [DH] libavfilter/f_ebur128.c

• mp4 Vj Animation video lagging hi res video

  21 février 2020, par Ryan Stone

  I am trying to get a video to play inside a video tag at the top left hand corner of my page, it loads ok, the resolution is good and it seems to be looping but it is lagging very much, definatly not achieving 60fps it is in mp4 format and the resolution on the original mp4 is 1920x1080 it is a hi resolution vj free loop called GlassVein, you can see it if you search on youtube. On right clicking properties it comes up with the following inforamtion ;

  Bitrate:127kbs
  Data rate:11270kbps
  Total bitrate:11398kbs
  Audio sample rate is : 44khz
  filetype is:VLC media file(.mp4)
  (but i do not want or need the audio)

  & it also says 30fps, but I’m not sure i believe this as it runs smooth as butter on vlc media player no lagging, just smooth loop animation

  I have searched on :https://trac.ffmpeg.org/wiki/Encode/AAC for encoding information but it is complete gobbldygook to me, I don’t understand a word its saying

  My code is so far as follows ;

      <video src="GlassVeinColorful.mp4" autoplay="1" preload="auto" class="Vid" width="640" height="360" loop="1" viewport="" faststart="faststart" mpeg4="mpeg4" 320x240="320x240" 1080="1080" 128k="128k">  
  
      </video>

  Does anyone know why this is lagging so much, or what I could do about it.
  it is a quality animation and I don’t really want to loose an of its resolution or crispness.. the -s section was originally set to 1920x1080 as this is what the original file is but i have changed it to try and render it quicker...

  Any helpful sites, articles or answers would be great..

  2020 Update

  The Solution to this problem was to convert the Video to WebM, then use Javascript & a Html5 Canvas Element to render the Video to the page instead of using the video tag to embed the video.

  Html

  <section>
  
          <video src="Imgs/Vid/PurpGlassVein.webm" type="video/webm" width="684" height="auto" muted="muted" loop="loop" autoplay="autoplay">
  
                 <source>
  
                 <source>
  
                 <source>
  
          </source></source></source></video>
  
          <canvas style="filter:opacity(0);"></canvas>
  
  </section>

  Css

  video{
  
     display:none !important;
  
     visibility:hidden;
  
  }

  Javascript

      const Canv = document.querySelector("canvas");
  
      const Video = document.querySelector("video");
  
      const Ctx = Canv.getContext("2d");
  
  
  
      Video.addEventListener('play',()=>{
  
        function step() {
  
          Ctx.drawImage(Video, 0, 0, Canv.width, Canv.height)
  
          requestAnimationFrame(step)
  
        }
  
        requestAnimationFrame(step);
  
      })
  
  
  
      Canv.animate({
  
          filter: ['opacity(0) blur(5.28px)','opacity(1) blur(8.20px)']
  
      },{
  
          duration: 7288,
  
          fill: 'forwards',
  
          easing: 'ease-in',
  
          iterations: 1,
  
          delay: 728
  
      })

  I’ve Also Used the Vanilla Javascript .animate() API to fade the element into the page when the page loads. But one Caveat is that both the Canvas and the off-screen Video Tag must match the original videos resolution otherwise it starts to lag again, however you can use Css to scale it down via transform:scale(0.5) ; which doesn’t seem to effect performance at all.

  runs smooth as butter, and doesn’t loose any of the high resolution image.
  Added a slight blur 0.34px onto it aswell to smooth it even more.

  Possibly could of still used ffmpeg to get a better[Smaller File Size] WebM Output file but thats something I’ll have to look into at a later date.

• How do I stop ffmpeg from spamming itself when I auto restart ?

  15 décembre 2019, par billy61300

  const fs = require("fs");
  
  const express = require("express");
  
  const app = express();
  
  const path = require("path");
  
  const ffmpeg = require("fluent-ffmpeg");
  
  const md5 = require("md5");
  
  const readline = require("readline");
  
  const formidable = require("formidable");
  
  
  
  const dir = "Custom/Dir";
  
  const thumb = __dirname + "/thumb";
  
  const ph = __dirname + "/placeholder";
  
  
  
  app.use("/serve", express.static(dir));
  
  app.use("/thumb", express.static(thumb));
  
  app.use("/ph", express.static(ph));
  
  
  
  const list = [];
  
  const listThumb = [];
  
  
  
  process.on("uncaughtException", (err) => {
  
      console.log("Caught Exception: " + err);
  
  });
  
  
  
  let passwords = fs.readFileSync("passwords.txt").toString().split("\n");
  
  
  
  app.get("/", (req, res) => {
  
      res.sendFile(__dirname + "/index.html")
  
  });
  
  
  
  app.get("/upload", (req, res) => {
  
      res.sendFile(__dirname + "/upload.html");
  
  });
  
  
  
  app.post("/uploadFile", (req, res) => {
  
      let form = new formidable.IncomingForm();
  
      form.parse(req, (err, fields, files) => {
  
          if (passwords.includes(md5(fields.password))) {
  
              fs.readFile(files.filetoupload.path, (err, data) => {
  
                  let newPath = dir + "/" + files.filetoupload.name;
  
                  if (!fs.existsSync(newPath)) {
  
                      fs.writeFile(newPath, data, (err) => {
  
                          res.writeHead(200, {"Content-Type": "text/html"});
  
                          res.write("<h1>File Uploaded</h1>");
  
                          res.end();
  
                      });
  
                  } else {
  
                      res.writeHead(200, {"Content-Type": "text/html"});
  
                      res.write("<h1>File already exists. Upload with a different name please.</h1>");
  
                      res.end();
  
                  }
  
              });
  
          }
  
      });
  
  });
  
  
  
  fs.readdir(dir, (err, files) => {
  
      if (err) {
  
          throw err;
  
      } else {
  
          let i = 0;
  
          files.forEach((file) => {
  
              list[i] = path.basename(file);
  
              if (!fs.existsSync(__dirname + "\\thumb\\" + list[i] + ".png")) {
  
                  console.log("Generating: " + list[i] + ".png");
  
                  let proc = new ffmpeg({source: dir + "/" + file, nolog: true});
  
                  proc.setFfmpegPath(__dirname + "\\ffmpeg.exe");
  
                  proc.screenshots({
  
                      timestamps: [0.0],
  
                      filename: list[i] + ".png",
  
                      folder: __dirname + "\\thumb\\",
  
                      size: "100x100"
  
                  });
  
              }
  
              i++;
  
          });
  
          let serveDoc = "";
  
          for (let j = 0; j &lt; list.length; j++) {
  
              if (path.extname(list[j]).toLowerCase() !== ".jpg" &amp;&amp; path.extname(list[j]).toLowerCase() !== ".jpeg" &amp;&amp; path.extname(list[j]).toLowerCase() !== ".png") {
  
                  if (path.extname(list[j]).toLowerCase() == ".mp3" || path.extname(list[j]).toLowerCase() == ".wav") {
  
                      serveDoc += "<a href="http://stackoverflow.com/feeds/tag/address&#034; + list[j] + &#034;">" + "<img width='100' height='100' src="http://stackoverflow.com/feeds/tag/address" />" + "</a> ";;
  
                  }/* else if (path.extname(list[j]).toLowerCase() == ".webm") {
  
                      serveDoc += "<a href="http://stackoverflow.com/feeds/tag/address&#034; + list[j] + &#034;">" + "<img width='100' height='100' src="http://stackoverflow.com/feeds/tag/address" />" + "</a> ";;
  
                  }*/ else {
  
                      serveDoc += "<a href="http://stackoverflow.com/feeds/tag/address&#034; + list[j] + &#034;">" + "<img width='100' height='100' src="http://stackoverflow.com/feeds/tag/address&#034; + list[j] + &#034;.png" />" + "</a> ";
  
                  }
  
              } else {
  
                  serveDoc += "<a href="http://stackoverflow.com/feeds/tag/address&#034; + list[j] + &#034;">" + "<img width='100' height='100' src="http://stackoverflow.com/feeds/tag/address&#034; + list[j] + &#034;" />" + "</a> ";
  
              }
  
          }
  
          serveDoc += "";
  
          fs.writeFile("index.html", serveDoc, (err) => {
  
              if (err) throw err;
  
          });
  
      }
  
  });
  
  
  
  setTimeout(() => {
  
      process.exit(0);
  
  }, 1000 * 60 * 30);
  
  
  
  app.listen(80, (err) => {
  
      if (err) {
  
          throw err;
  
      } else {
  
          console.log("Listening on port 80.");
  
      }
  
  });

  Issue is that the program needs to be restarted every X minutes so that the list of media will update on it’s own. However, upon a restart, ffmpeg goes crazy and starts to spam a batch window under it’s name repeatedly over and over again without stopping. The only way out of it is to restart my computer.

  I’ve tried to use PM2, Forever, Supervisor. Nodemon afaik won’t auto restart.