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• Revision 67258 : Report de la correction du pattern des archives

  29 octobre 2012, par eric@… — Log

  Report de la correction du pattern des archives

• Align media file size with exFAT cluster size

  2 avril 2021, par Crissov

  Some multimedia container formats with embedded metadata tags (e.g. ID3v2 for MP3) support to allocate some free space inside the file to improve editing speeds for metadata tag updates, because not the whole file needs to be rewritten to disk for minor changes. In MOV and MP4 files, the boxes / atoms free and skip are used for this, as far as I know.

  


  In order to use disk space efficiently, how can I use FFmpeg, MP4Box or some other commonly available software to increase the allocated free space within dozens of 100+ MB video files in a way that the resulting total file sizes are exact multiples of the partition’s allocation unit size, e.g. 128 KiB by default for a 1-terabyte exFAT drive ?

  


• How to create a video file webm from chunks by media recorder api using ffmpeg

  17 octobre 2020, par Caio Nakai

  I'm trying to create a webm video file from blobs generated by MediaRecorderAPI in a NodeJS server using FFMPEG. I'm able to create the .webm file but it's not playable, I ran this command $ ffmpeg.exe -v error -i lel.webm -f null - >error.log 2>&1 to generate an error log, the error log file contains this :

  


  


  [null @ 000002ce7501de40] Application provided invalid, non monotonically increasing dts to muxer in stream 0 : 1 >= 1

  


  [h264 @ 000002ce74a727c0] Invalid NAL unit size (804 > 74).

  


  [h264 @ 000002ce74a727c0] Error splitting the input into NAL units.

  


  Error while decoding stream #0:0 : Invalid data found when processing input

  


  


  This is my web server code

  


  const app = require("express")();
const http = require("http").createServer(app);
const io = require("socket.io")(http);
const fs = require("fs");
const child_process = require("child_process");

app.get("/", (req, res) => {
  res.sendFile(__dirname + "/index.html");
});

io.on("connection", (socket) => {
  console.log("a user connected");

  const ffmpeg = child_process.spawn("ffmpeg", [
    "-i",
    "-",
    "-vcodec",
    "copy",
    "-f",
    "flv",
    "rtmpUrl.webm",
  ]);

  ffmpeg.on("close", (code, signal) => {
    console.log(
      "FFmpeg child process closed, code " + code + ", signal " + signal
    );
  });

  ffmpeg.stdin.on("error", (e) => {
    console.log("FFmpeg STDIN Error", e);
  });

  ffmpeg.stderr.on("data", (data) => {
    console.log("FFmpeg STDERR:", data.toString());
  });

  socket.on("message", (msg) => {
    console.log("Writing blob! ");
    ffmpeg.stdin.write(msg);
  });

  socket.on("stop", () => {
    console.log("Stop recording..");
    ffmpeg.kill("SIGINT");
  });
});

http.listen(3000, () => {
  console.log("listening on *:3000");
});



  


  And this is my client code, using HTML, JS :

  


  &#xA;&#xA;  &#xA;    &#xA;    &#xA;    &#xA;  &#xA;  <code class="echappe-js">&lt;script src='http://stackoverflow.com/socket.io/socket.io.js'&gt;&lt;/script&gt;&#xA;  &lt;script&gt;&amp;#xA;    const socket = io();&amp;#xA;    let mediaRecorder = null;&amp;#xA;    const startRecording = (someStream) =&gt; {&amp;#xA;      const mediaStream = new MediaStream();&amp;#xA;      const videoTrack = someStream.getVideoTracks()[0];&amp;#xA;      const audioTrack = someStream.getAudioTracks()[0];&amp;#xA;      console.log(&quot;Video trac &quot;, videoTrack);&amp;#xA;      console.log(&quot;audio trac &quot;, audioTrack);&amp;#xA;      mediaStream.addTrack(videoTrack);&amp;#xA;      mediaStream.addTrack(audioTrack);&amp;#xA;&amp;#xA;      const recorderOptions = {&amp;#xA;        mimeType: &quot;video/webm;codecs=h264&quot;,&amp;#xA;        videoBitsPerSecond: 3 * 1024 * 1024,&amp;#xA;      };&amp;#xA;&amp;#xA;      mediaRecorder = new MediaRecorder(mediaStream, recorderOptions);&amp;#xA;      mediaRecorder.start(1000); // 1000 - the number of milliseconds to record into each Blob&amp;#xA;      mediaRecorder.ondataavailable = (event) =&gt; {&amp;#xA;        console.debug(&quot;Got blob data:&quot;, event.data);&amp;#xA;        if (event.data &amp;amp;&amp;amp; event.data.size &gt; 0) {&amp;#xA;          socket.emit(&quot;message&quot;, event.data);&amp;#xA;        }&amp;#xA;      };&amp;#xA;    };&amp;#xA;&amp;#xA;    const getVideoStream = async () =&gt; {&amp;#xA;      try {&amp;#xA;        const stream = await navigator.mediaDevices.getUserMedia({&amp;#xA;          video: true,&amp;#xA;          audio: true,&amp;#xA;        });&amp;#xA;        startRecording(stream);&amp;#xA;        myVideo.srcObject = stream;&amp;#xA;      } catch (e) {&amp;#xA;        console.error(&quot;navigator.getUserMedia error:&quot;, e);&amp;#xA;      }&amp;#xA;    };&amp;#xA;&amp;#xA;    const stopRecording = () =&gt; {&amp;#xA;      mediaRecorder.stop();&amp;#xA;      socket.emit(&quot;stop&quot;);&amp;#xA;    };&amp;#xA;  &lt;/script&gt;&#xA;  &#xA;    
  hello world
  &#xA;
  start rec
  &#xA;
  stop rec
  &#xA;&#xA;    &#xA;    &lt;script&gt;&amp;#xA;      const myVideo = document.getElementById(&quot;myvideo&quot;);&amp;#xA;      myVideo.muted = true;&amp;#xA;    &lt;/script&gt;&#xA;  &#xA;&#xA;&#xA;
  

  


  Any help is appreciated !