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• A *hot* Piwik Community Meetup 2015 !

  10 août 2015, par André Bräkling — Community

  Last weekend I arrived in Germany to attend the Piwik Community Meetup 2015 and now I am in Poland.

  The meetup was HOT in every sense ! Berlin temperatures reached 35 degrees (celsius), as I finally meet in person several long-time, dedicated Piwik community contributors.

  

  Meetup preparation in Berlin, photo by M. Zawadziński, licensed under CC-BY-SA 4.0

  Pictures from the meetup preparation sessions
  

  In the first leg of my trip I was in Berlin to meet Piwik community members to prepare for the 2015 annual Piwik community meetup. These are my notes taken during the meeting at the request of one of my colleagues. I also relayed live on Framasphère, Twitter and IRC.

  

  Community discussion at the meetup, photo by D.Czajka, licensed under CC-BY-SA 4.0

  More pictures from the Piwik meetup
  

  This was harder than I expected, as I took notes with my laptop, pictures with my phone, wrote live to social media (using the Android Diaspora Native Web App), and used my laptop to relay on IRC. Going forward this requires better preparation, I was glad I had a few links and pictures ready before hand but it really requires intense focus to achieve this. I am glad presenters were patient when I requested repeating some of the ideas they shared. I am also a bit disappointed not much happened in IRC.

  Two day preparation sessions

  The discussions and session we had during the two days prior to the meetup are available here.

  We gathered in rented apartments in Berlin, this reminded me very much of similar community gatherings and perhaps of BarCamp and, at a much smaller scale, UDS sessions.

  

  Piwik Pizza !, photo by F. Rodríguez, licensed under CC-BY-SA 4.0

  A list of ideas of topics was initially submitted, we then proceeded to have scheduled sessions for open discussion. Several people shared their concern there was no possible remote participation which led to making public the Trello boards used/linked here.

  Note : The Trello links below still have action items and notes that are pending bug report / feature requests filing which should happen over the coming weeks. Most importantly, many action items will need identifying leads for different community team including Translations and Documentation, and better coordination of coming community engagement.

  Monday sessions consisted of the following subjects :

  • What are Piwik values & how to communicate them ? (see below for details)
  • How to encourage and recognize new external contributors ?
  • How could we double the Piwik userbase ?
  • How Community can organise help resources

  On Tuesday we met again to discuss the following subjects :

  • Piwik Long Term support (LTS)
  • How do Piwik.org (project) and Piwik PRO (company) sit together / are organized ? – An important part of this session was about having better communication channels and improving the new team page (bug #8520 and bug #8519, respectively)
  • Improving usability of Piwik e.g. for new users – this last session was not held has we ran out of time and prepared to go to the meetup venue.

  Some more details about individual preparation sessions

  What are Piwik values & how to communicate them ?

  The main subjects in this session were important changes proposed in the project mission and values. This was edited directly on on the wiki page on GitHub, some of the changes can be seen by comparing revisions.

  Piwik mission statement (bug #7376)

  “To create the leading Free and open source analytics platform, and to support global organisations and communities to keep full control over their data.”

  Our values

  • Openness
  • Freedom
  • Transparency
  • Data ownership
  • Privacy
  • Kaizen (改善) : continuous improvement

  This was also presented by Matthieu Aubry at the meetup and is published in the Roadmap page. Bringing more visibility and perhaps having a top page for Mission and Values was also brought up.

  Meetup agenda and notes

  The official agenda is available here.

  Many Piwik PRO employees stayed in Berlin for the meetup, and we had good participation although less than last year in Munich as my colleagues told me. Some were consultants, others staff from public organizations, universities, etc. In retrospect considering the very hot weather and summer holidays the attendance was good. I was very happy to arrive at the beautiful Kulturbrauerei and enter the air-conditioned Soda Club. T-Shirts were waiting for all attendees and free drinks (non-alcohol !) were welcome

• Recording voice using HTML5 and processing it with ffmpeg

  22 mars 2015, par user3789242

  I need to use ffmpeg in my javascript/HTML5 project which allows the user to select the format he wants the audio to open with.I don’t know anything about ffmpeg and I’ve been doing lots of research I don’t know how to use it in my project. I found an example https://github.com/sopel39/audioconverter.js but the problem how can I install the ffmpeg.js which is 8 mg to m project. please if someone can help me I’ll be very thankfull
  here is my full code :

  the javascript page :

  // variables
  
  var leftchannel = [];
  
  var rightchannel = [];
  
  var recorder = null;
  
  var recording = false;
  
  var recordingLength = 0;
  
  var volume = null;
  
  var audioInput = null;
  
  var sampleRate = 44100;
  
  var audioContext = null;
  
  var context = null;
  
  var outputString;
  
  
  
  
  
  
  
  if (!navigator.getUserMedia)
  
  navigator.getUserMedia = navigator.getUserMedia ||
  
                           navigator.webkitGetUserMedia ||
  
                           navigator.mozGetUserMedia || 
  
                           navigator.msGetUserMedia;
  
  
  
  if (navigator.getUserMedia){
  
  navigator.getUserMedia({audio:true}, success, function(e) {
  
  alert('Error capturing audio.');
  
  });
  
  } else alert('getUserMedia not supported in this browser.');
  
  
  
  
  
  
  
  function getVal(value)
  
    {
  
  
  
  // if R is pressed, we start recording
  
  if ( value == "record"){
  
      recording = true;
  
      // reset the buffers for the new recording
  
      leftchannel.length = rightchannel.length = 0;
  
      recordingLength = 0;
  
      document.getElementById('output').innerHTML="Recording now...";
  
  
  
   // if S is pressed, we stop the recording and package the WAV file
  
   } else if ( value == "stop" ){
  
  
  
      // we stop recording
  
      recording = false;
  
      document.getElementById('output').innerHTML="Building wav file...";
  
  
  
      // we flat the left and right channels down
  
      var leftBuffer = mergeBuffers ( leftchannel, recordingLength );
  
      var rightBuffer = mergeBuffers ( rightchannel, recordingLength );
  
      // we interleave both channels together
  
      var interleaved = interleave ( leftBuffer, rightBuffer );
  
  
  
  
  
  
  
      var buffer = new ArrayBuffer(44 + interleaved.length * 2);
  
      var view = new DataView(buffer);
  
  
  
      // RIFF chunk descriptor
  
      writeUTFBytes(view, 0, 'RIFF');
  
      view.setUint32(4, 44 + interleaved.length * 2, true);
  
      writeUTFBytes(view, 8, 'WAVE');
  
      // FMT sub-chunk
  
      writeUTFBytes(view, 12, 'fmt ');
  
      view.setUint32(16, 16, true);
  
      view.setUint16(20, 1, true);
  
      // stereo (2 channels)
  
      view.setUint16(22, 2, true);
  
      view.setUint32(24, sampleRate, true);
  
      view.setUint32(28, sampleRate * 4, true);
  
      view.setUint16(32, 4, true);
  
      view.setUint16(34, 16, true);
  
      // data sub-chunk
  
      writeUTFBytes(view, 36, 'data');
  
      view.setUint32(40, interleaved.length * 2, true);
  
  
  
  
  
      var lng = interleaved.length;
  
      var index = 44;
  
      var volume = 1;
  
      for (var i = 0; i < lng; i++){
  
          view.setInt16(index, interleaved[i] * (0x7FFF * volume), true);
  
          index += 2;
  
      }
  
  
  
      var blob = new Blob ( [ view ], { type : 'audio/wav' } );
  
  
  
      // let's save it locally
  
  
  
      document.getElementById('output').innerHTML='Handing off the file now...';
  
      var url = (window.URL || window.webkitURL).createObjectURL(blob);
  
  
  
      var li = document.createElement('li');
  
      var au = document.createElement('audio');
  
      var hf = document.createElement('a');
  
  
  
      au.controls = true;
  
      au.src = url;
  
      hf.href = url;
  
      hf.download = 'audio_recording_' + new Date().getTime() + '.wav';
  
      hf.innerHTML = hf.download;
  
      li.appendChild(au);
  
      li.appendChild(hf);
  
      recordingList.appendChild(li);
  
  
  
  }
  
  }
  
  
  
  
  
  function success(e){
  
  
  
  audioContext = window.AudioContext || window.webkitAudioContext;
  
  context = new audioContext();
  
  
  
  
  
  volume = context.createGain();
  
  
  
  // creates an audio node from the microphone incoming stream(source)
  
  source = context.createMediaStreamSource(e);
  
  
  
  // connect the stream(source) to the gain node
  
  source.connect(volume);
  
  
  
  var bufferSize = 2048;
  
  
  
  recorder = context.createScriptProcessor(bufferSize, 2, 2);
  
  
  
  //node for the visualizer
  
  analyser = context.createAnalyser();
  
  analyser.smoothingTimeConstant = 0.3;
  
  analyser.fftSize = 512;
  
  
  
  splitter = context.createChannelSplitter();
  
  //when recording happens
  
  recorder.onaudioprocess = function(e){
  
  
  
      if (!recording) return;
  
      var left = e.inputBuffer.getChannelData (0);
  
      var right = e.inputBuffer.getChannelData (1);
  
  
  
      leftchannel.push (new Float32Array (left));
  
      rightchannel.push (new Float32Array (right));
  
      recordingLength += bufferSize;
  
  
  
      // get the average for the first channel
  
      var array =  new Uint8Array(analyser.frequencyBinCount);
  
      analyser.getByteFrequencyData(array);
  
  
  
      var c=document.getElementById("myCanvas");
  
      var ctx = c.getContext("2d");
  
      // clear the current state
  
      ctx.clearRect(0, 0, 1000, 325);
  
      var gradient = ctx.createLinearGradient(0,0,0,300);
  
      gradient.addColorStop(1,'#000000');
  
      gradient.addColorStop(0.75,'#ff0000');
  
      gradient.addColorStop(0.25,'#ffff00');
  
      gradient.addColorStop(0,'#ffffff');
  
      // set the fill style
  
      ctx.fillStyle=gradient;
  
      drawSpectrum(array);
  
      function drawSpectrum(array) {
  
          for ( var i = 0; i < (array.length); i++ ){
  
                  var value = array[i];
  
                  ctx.fillRect(i*5,325-value,3,325);
  
              } 
  
  
  
      }
  
  }
  
  
  
  function getAverageVolume(array) {
  
      var values = 0;
  
      var average;
  
  
  
      var length = array.length;
  
  
  
      // get all the frequency amplitudes
  
      for (var i = 0; i < length; i++) {
  
          values += array[i];
  
      }
  
  
  
      average = values / length;
  
      return average;
  
  }
  
  
  
      // we connect the recorder(node to destination(speakers))
  
      volume.connect(splitter);
  
      splitter.connect(analyser, 0, 0);
  
  
  
      analyser.connect(recorder);
  
      recorder.connect(context.destination);
  
  
  
  }
  
  
  
  
  
  
  
  
  
  function mergeBuffers(channelBuffer, recordingLength){
  
  var result = new Float32Array(recordingLength);
  
  var offset = 0;
  
  var lng = channelBuffer.length;
  
  for (var i = 0; i < lng; i++){
  
  var buffer = channelBuffer[i];
  
  result.set(buffer, offset);
  
  offset += buffer.length;
  
  }
  
      return result;
  
     }
  
  
  
  function interleave(leftChannel, rightChannel){
  
  var length = leftChannel.length + rightChannel.length;
  
  var result = new Float32Array(length);
  
  
  
  var inputIndex = 0;
  
  
  
  for (var index = 0; index < length; ){
  
   result[index++] = leftChannel[inputIndex];
  
   result[index++] = rightChannel[inputIndex];
  
   inputIndex++;
  
  }
  
  return result;
  
  }
  
  
  
  
  
  function writeUTFBytes(view, offset, string){ 
  
  var lng = string.length;
  
  for (var i = 0; i < lng; i++){
  
  
  
  view.setUint8(offset + i, string.charCodeAt(i));
  
  }
  
  }

  and here is the html code :

      
  
      
  
      
  
      <code class="echappe-js">&lt;script src=&quot;http://stackoverflow.com/feeds/tag/js/functions.js&quot;&gt;&lt;/script&gt;
      
  
      
  
  
  
  

• Sorenson Video 3 For Posterity

  12 août 2010, par Multimedia Mike — Software Museum

  On a recent dumpster dive, I procured a complete, never-been-opened copy of Sorenson Video 3 Professional Edition Compressor for Windows. And because I’m me, I thought it would be interesting to document it here :

  
  

  
  

  Not opened until now, anyway :

  
  
  

  I chuckled at the thought that I might open the user manual and find the complete data stream format listed therein. As expected, the guide offers a broad overview of video compression concepts (lossy vs. lossless, inter/intraframes, that kind of thing) and goes on to describe general guidelines for compressing different types of data. Then there is the feature reference. There are standard features and professional features (the latter includes things like bidirectional prediction, masking, and watermarking).

  I was hoping to figure out how to encode some video with this software. But I think I need full Quicktime Pro in order to do that. If you’re interested, here’s the user manual in PDF format : Sorenson Video 3 User Guide (626 Kbytes). Here’s an interesting claim from the chapter on audio compression :

  Most movies are made up of two parts, video and audio. Historically, the video portion of a digital movie was so large that the audio was only a minor piece of the puzzle. However, with Sorenson Video’s excellent compression capabilities it is possible to create a file where audio is the largest portion.

  I know it’s possible to do that, but is it really recommended ? I’m sure I have some samples in my vast repository where this is the case but it still doesn’t strike me as optimal for network delivery.