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• ffmpeg throws error while converting wav to flac

  24 août 2017, par user3815252

  I am working on a research project and it requires me to first record audios from browser (using getuserMedia) and save them in a wav format. My code looks like this :

  navigator.mediaDevices.getUserMedia({ audio: true }).then(stream => {
  
          const chunks = [];
  
          const recorder = new MediaRecorder(stream);
  
          recorder.ondataavailable = e => {
  
              chunks.push(e.data);
  
              if (recorder.state == 'inactive') {
  
                  $scope.blob = new Blob(chunks, { type: 'audio/wav' });
  
                  $scope.file = new File([$scope.blob], "myFile.wav", {type: 'audio/wav', lastModified: Date.now()});
  
  
  
                  $scope.blobUrl = URL.createObjectURL($scope.blob);
  
                  createAudioElement($scope.blobUrl);
  
              }
  
          };
  
          recorder.start(1000);
  
          $scope.stop = function() {
  
              recorder.stop();    
  
          };
  
  
  
      }).catch(console.error);

  After saving $scope.file on filesystem, I convert it to flac format using ffmpeg utility ([https://www.ffmpeg.org/).

  Now my problem is the ffmpeg tool sometimes gives me error saying that this file cannot be recognized as wav file. The exact output of ffmpeg tool is :

    ffmpeg-user: Wav to Flac conversion: Invalid data found when processing input
  
  
  
    ffmpeg version 3.3.3 Copyright (c) 2000-2017 the FFmpeg developers 
  
    built with Apple LLVM version 7.0.2 (clang-700.1.81) 
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.3.3 --enable-shared 
  
    --enable-pthreads --enable-gpl --enable-version3 
  
    --enable-hardcoded-tables 
  
    --enable-avresample --cc=clang --host-cflags= --host-ldflags= 
  
    --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl 
  
  
  
    --disable-lzma --enable-vda 
  
    libavutil      55. 58.100 / 55. 58.100 
  
    libavcodec     57. 89.100 / 57. 89.100 
  
    libavformat    57. 71.100 / 57. 71.100 
  
    libavdevice    57.  6.100 / 57.  6.100 
  
    libavfilter     6. 82.100 /  6. 82.100 
  
    libavresample   3.  5.  0 /  3.  5.  0 
  
    libswscale      4.  6.100 /  4.  6.100 
  
    libswresample   2.  7.100 /  2.  7.100 
  
    libpostproc    54.  5.100 / 54.  5.100 

  Does anyone know why am I getting this error ?

• Is ffmpeg able to read ArrayBuffer input from stream

  7 juillet 2017, par jAndy

  I want to accomplish the following tasks :

  • Record Video+Audio from any HTML5 (MediaStream) capable browser
  • Send that data via WebSocket as Blob / ArrayBuffer chunks to a server
  • Broadcast that input stream-data to multiple clients

  As it turns out, this brought me into a world of pain. The first task is fairly simple using the HTML5 MediaStream objects alongside WebSockets.

  // ... for simplicity...
  
  navigator.mediaDevices.getUserMedia({ audio: true, video: true }).then(stream => {
  
      let mediaRecorder = new MediaRecorder( stream );
  
      // ...
  
      mediaRecorder.ondataavailable = e => {
  
          webSocket.send( 'newVideoData', e.data ); // configured for binary data
  
      };
  
  });

  Now, I want to receive those data fragments and stream those via nginx vod module, because I guess I want the output stream in HLS or DASH.
  I could write a little nodejs script as backend, which just receives the binary chunks and write them to a file or stream, and just reference it so nginx vod module could possibly read it and create the m3u8 manifest on the fly ?

  I am wondering now,

  • if ffmpeg is able to read that binary data directly (should be webm format), without a man-in-the-middle script, "somehow" ?
  • If not, do I have to write the data down into a file and pass that as input to ffmpeg or can I (should I) pipe the data to a self spawned ffmpeg instance ? (if so, how ?)
  • Do I actually need the nginx server (probably alongside rtmp module) to deliver the output stream as HLS or could I just use ffmpeg to also create a dynamic manifest ?
  • Is the nginx vod module capable of creating a dynamic hls/dash manifest or must the input data be complete beforehand ?
  • Ultimately, am I on the totally wrong track here ? :P

  Actually I just want to create a little video-live-chat demo, without any plugins or 3rd party encoding software, pure browser.

• Ffmpeg : Bitstream not supported by this decoder

  23 décembre 2018, par John Kim

  I’m trying to create a livestream web app using NodeJS. The code I currently have emits a raw (webm format) binary stream from the webcam on the client using socket IO and the node server receives this raw data. Using fluent-ffmpeg, I want to encode this binary stream into mpegts and send it to an RTMP server in real time, without creating any intermediary files. However when trying to convert the blobs in ffmpeg I get the following error :

  Error while decoding stream #0:1: Invalid data found when processing input
  
  [NULL @ 000001b15e67bd80] Invalid sync code 61f192.
  
  [libvpx @ 000001b15e6c5000] Failed to decode frame: Bitstream not supported by this decoder

  My relevant frontend client code :

  navigator.mediaDevices.getUserMedia(constraints).then(function(stream) {
  
      video_show(stream);//only show locally, not remotely
  
  
  
      socket.emit('config_rtmpDestination',url);
  
      socket.emit('start','start');
  
      var options = {mimeType: 'video/webm;codecs=h264'};
  
  
  
      mediaRecorder = new MediaRecorder(stream, options);
  
      mediaRecorder.start(2000);
  
  
  
      mediaRecorder.onstop = function(e) {
  
          stream.stop();
  
      }
  
  
  
      mediaRecorder.ondataavailable = function(e) {
  
          //var arraybuffer = Uint8Array.from(e.data).buffer;
  
          socket.emit("binarystream", blob);
  
          //chunks.push(e.data);
  
      }
  
  }).catch(function(err) {
  
      console.log('The following error occured: ' + err);
  
      show_output('Local getUserMedia ERROR:'+err);
  
  });

  Relevant NodeJS server code :

  socket.on('binarystream',function(m){
  
      feedStream(m);
  
  });
  
  
  
  socket.on('start',function(m){
  
      ...
  
      var ops=[
  
          '-vcodec', socket._vcodec,'-i','-',
  
          '-c:v', 'libx264', '-preset', 'veryfast', '-tune', 'zerolatency',
  
          '-an', '-bufsize', '1000',
  
          '-f', 'mpegts', socket._rtmpDestination
  
      ];
  
      ffmpeg_process=spawn('ffmpeg', ops);
  
      feedStream=function(data){
  
          ffmpeg_process.stdin.write(data);
  
      }
  
      ...
  
  }