NOMNOM 2: The Video Machine – The Programming Behind the Project

Credit: This project was developed together with Mint. Thank you :))

For my ICM final, I worked on an improved version of my mid-term pcomp project.

This time the computational challenges were even greater.
Here is the outcome after long weeks of intensive coding –

NomNom: The Video Machine

NOMNOM’s github repository can be found here –

Synching the videos

As a conclusion from the mid-term project, we wanted to give users that ability to play cohesive music. In order to that, we knew that we have to find a way to make sure that all the videos are being played in sync (automatically).

There are many ways to make sure the media is being played synchronously, but none of them deal with videos. To workaround that, we repurposed 2 functions from the p5.js sound library — Phrase and Part.
We used these functions to handle our playback as a loop that includes bars. We can call any callback function at any point on the loop, and therefore, we can actually use them to time our play and stop functions (and many others), based on the user action.

function setup() {

  // setting up serial communication
  serial = new p5.SerialPort();
  serial.on('connected', serverConnected);
  serial.on('open', portOpen);
  serial.on('data', serialEvent);
  serial.on('error', serialError);

  // creating a new 'part' object (
  allVideosPart = new p5.Part();

  // adding general phrase ( to the 'part'
  var generalSequence = [1,0,0,0, 0,0,0,0, 1,0,0,0, 0,0,0,0, 1,0,0,0, 0,0,0,0, 1,0,0,0, 0,0,0,0];
  generalPhrase = new p5.Phrase('general', countSteps, generalSequence);

  for (var i = 0; i<16; i++){
    allVideosPart.addPhrase(new p5.Phrase(i, videoSteps, [0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0]));

  // console.log(allVideosPart);


We initiate the Part, a Phrase per video, and a general Phrase that will be used as a clock, on the setup function.

The ‘countSteps’ callback function is being used to store the current step on a global variable, and the ‘videoSteps’ callback function is being used to play and stop video at the right time.

First success with the beat-sync feature – 

Improving the UI

We really wanted to make it easier for users to understand what is going on on the screen, and to provide a better sense of control on the videos.

In order to achieve that, we used the NexusUI JS library and added 4 graphical elements, each of which indicates a different property of the video (number of repetitions, volume, speed, and trim), on every video.

The graphical elements are shown to the user only when the video is being played.

Also, we add a grayscale CSS filter on videos that are not being played. This way, it is easier for the user to focus on the videos that are being played and making sounds.

Built to perform

While designing the technical architecture for the project, I faced many limitations, mostly because of the slow nature of the ASCII serial communication protocol. Therefore, I had to develop a very efficient internal communication protocol to compensate for the delay we had when pressing the buttons on the box. That was the only way to achieve fast responding controller, that will change the video states on the screen immediately.

This was the first time I was required to write efficient code (and not just for the fun of it). After 2 weeks of re-writing the code, and reducing few milliseconds every time, I came up with the following lines:

Reading data from controller (Arduino side) –

for (uint8_t n = 0; n < numKeys; n++) {
  if (trellis.justPressed(n)) {
   LEDstatus[n] = 3; 

    if (LEDstatus[n] == 3) {
        if (blinkTime >= 4) {
          if (trellis.isLED(n)) {
            } else {

    if (trellis.justReleased(n)) {
      if (buttonPress[n] > 8) {
        LEDstatus[n] = 1;
        oldStatus[n] = 1;
        buttonPress[n] = 0;
      } else {
        buttonPress[n] = 0;
        if (oldStatus[n] == 1) {
          LEDstatus[n] = 0;
          oldStatus[n] = 0;
        } else {
          LEDstatus[n] = 1;
          oldStatus[n] = 1;

Parsing the data on the browser (JavaScript side) – 

function parseData(data){

  // parsing the data by ','
  var newStatus = data.split(",");

  // turning strings into integers
  for (var x=0; x CONTINUE
    if ((newStatus[i] !== 3) && (newStatus[i] === videos[i].status)){
      var vidID = i+1;
      vidID = "#video" + vidID;
      $(vidID).css('border-color', "rgba(177,15,46,0)");
    else {

      // getting the relevant phrase
      var phraseIndex = i;
      var updatedPhrase = allVideosPart.getPhrase(phraseIndex);

      if (newStatus[i] === 3){

        if (videos[i].originStep === null) {
          videos[i].originStep = currentStep;

        changeColor(i, 1);

        videos[i].volume = vol;
        videos[i].cut = cut;
        videos[i].speed = speed;
        videos[i].steps = newStatus[16];

        // making the video border blink
        var vidID = i+1;
        vidID = "#video" + vidID;
        if (newStatus[20] === 2) {
          if (($(vidID).css('border-color')) === "rgba(177, 15, 46, 0)"){
            $(vidID).css('border-color', "rgba(255,255,255,0.9)");
          else {
            $(vidID).css('border-color', "rgba(177, 15, 46, 0)");

        // clearing the sequence
        for (var n=0; n<32; n++){
          updatedPhrase.sequence[n] = 0;

        // applying steps changes, if any
        var stepNum = videos[i].originStep;
        for (var m=0; m 31) {
            stepNum = stepNum - 32;


      else if (newStatus[i] === 1) {
        videos[i].status = 1;
        changeColor(i, videos[i].status);
        var vidID = i+1;
        vidID = "#video" + vidID;
        $(vidID).css('border-color', "rgba(177,15,46,0)");

      else if (newStatus[i] === 0) {
        videos[i].status = 0;
        changeColor(i, videos[i].status);
        var vidID = i+1;
        vidID = "#video" + vidID;
        $(vidID).css('border-color', "rgba(177,15,46,0)");

        // clearing the sequence
        for (var n=0; n<32; n++){
          updatedPhrase.sequence[n] = 0;

        videos[i].originStep = null;


When I review this code now, it all seems so simple (LOL!), but this is one of the pieces of code I'm most proud of.

After looong hours of coding, we are very happy we what we achieved 🙂

Final Project Proposal – The SoundSystem


Ever since popular music has been broadcasted by radio stations (somewhere between 1920’s and 1930’s), and consumed by listeners all over the world, artists were recording most of their music as 3-5 minutes songs.

This convention was born out of a technical limitation – The Phonograph, an early version of the record players we use today, could only play 12” vinyl records. Moreover, when an artist recorded a new album, or a new single, the only way to ship it to the local or national radio station was by sending it using the US Post Office services. The biggest box one could send at that time, for a reasonable price, was a box that could only hold only a 12” record. As you can probably guess, a 12” vinyl record can hold a tune no longer than 5 minutes.

A century ago, music production, consumption, and distribution processes have gone completely digital. Even though most of the music we listen to today is basically bits of data that can be manipulated, we still consume it in the 3-5 minutes linear format. Unlike other mediums, such as text or video, which in many cases are being consumed in a non-linear form, audio is still being consumed in short linear sprints.

I believe that in the age of data, we can do more than that.


The inspiration for the problem, and for the first steps of the solution, can to me from watching and interacting with The Infinite Jukebox project, build by Paul Lamere. Lamere posted a blog post, that tell about the process of making this project.

The Infinite Jukebox - user interface
The Infinite Jukebox – user interface

snapshot-111212-1004-am snapshot-111212-1005-am


Project proposal – The SoundSystem

I would want to build a system that will liberate music creators from composing their musical ideas into 3-5 minute songs.
Instead, artists will be able to focus and record their musical idea, and the system will generate an infinite, interactive, and dynamic piece of music, “conducted” by the artist.

Since I won’t be able to build the entire project for the ICM course final, I plan to build the first part of this project. The specifications of this part are highlighted in the text.

This how I would imagine the interaction (at least of the prototype)

Recording and analysing the recorded sound:

  • Artist will record a short snippet of audio.
  • The system will identify the tempo of the recorded snippet (beat detection).
  • The system will analyse the recorded snippet to get frequency data, timbre, etc. (and maybe in order to identify notes and / or chords?).
  • The system will suggest a rhythmic tempo to go along with the snippet.
  • The system will play the recorded snippet as in infinite loop, along with the rhythmic tempo.
  • The system will try to find new ‘loop opportunities’ within the snippet, in order to play the loop in a none linear way.
  • The artist will be able to record more musical snippets.
  • The artist will be able to choose which parts will be played constantly (background sounds), and which parts will be played periodically.
  • The system will suggest new and interesting combinations of the recording snippets, and play these combinations infinitely.

The listener interacts with the played tune:

  • Since the tune can be played infinitely, some controls will be given to listener. Each and every artist will be able to configure these controls differently. For example, one can decide that the controls will include 2 knobs, one of them changes the tune from ‘dark’ to ‘bright’, and the other changes the tune from ‘calm’ to ‘noisy’. The artist will decide what will happen when each one of these knobs is being turned.
  • For the ICM final, a generic user interface will be provided to the listener. The interface will include a visual representation of the played tune, and will allow the listener to change the rhythmic tempo.

Applying machine learning algorithms:

  • The system will try to generate new music, based on the recorded snippets, and earlier decisions by the same user. This new music will stretch the length of the recorded tune.

Modifying the system’s decisions:

  • The artist will be able to effect the system’s decisions about the looped tune, and about the new music it generates. For example, the user will be able to decide when a specific part enters, or which algorithmic rules won’t generate new music.

Applying sensors and automations

  • The artist will be able to set rules based on 3rd party data or sensors. For example, the tune can be played differently if it is rainy on the first day of the month, if it is currently Christmas, if it is exactly 5:55am, or if the light in the room was dimmed to certain level. These rules will apply to each tune separately.


  • There should be a new music format that could hold the tune (or the snippets) and the data necessary for playing it correctly. In the same way, a new player should be introduced in order to read the data and to play the tune correctly.
  • This format should allow the artist to update the tune configuration or the musical snippets at any time, after the tune was distributed to the listeners.
  • For the ICM final (and probably for the end product as well), the tune will be played in the web browser.


Controlling video playback features


For the first time in my ITP history, I was able to combine home assignment for ICM with home assignment for Pcomp.

I created a video manipulation interface, that could be controlled by a physical controller.
The entire project was build with Mint for our Physical Computing class mid-term.

The Video Machine - Web Interface
The Video Machine – Web Interface


The Video Machine – Web Interface from Dror Ayalon on Vimeo.


I used the JavaScript video API to do the following manipulations on the video playback:

  • Loop – Playing the video in an infinite loop.
  • Volume – Changing the volume of the sound.
  • Cut – Trimming the length of the video.
  • Speed – Changing the speed of the video playback.
The Video Machine
The Video Machine


Here is the JavaScript code I used for this project –

The Video Machine


The Video Machine is a video controller, powered by an Arduino, that controls the playback of videos presented on a web browser. By pressing a button on the controller, the correlated video is being played on the screen and heard through the speakers.
Videos are being played in an infinite loop.
Only the videos that are being played, are being heard.

I was lucky enough to work on this project with the super talented Mint for our Physical Computing class mid-term.
Working with Mint not only was a great learning experience, but also a lot of fun! I hope I’ll be able to work with her again on our next project (more on that below).

The Video Machine from Dror Ayalon on Vimeo.

Many thanks for Joe Mango, our beloved resident, who assisted a lot with finding the right technologies for the project, and helped us on one critical moment, when suddenly nothing worked.

The Video Machine – Split Screen from Dror Ayalon on Vimeo.

The building process

The process of building The Video Machine went through the following stages:

  • Prototyping – Once we had a broad idea about what we want to make, we wanted to test how hard would it be to build such interaction, and if the interaction feels ‘right’ to us.
  • Understanding the complications The prototyping stage helped us understand what could be the possible complications of this product, and what might be the limitation. We analysed what could be the limitations of the serial communication between the Arduino board and our laptop computer, and what types of video manipulations could be easily achieved using JavaScript.
    Understanding what’s possible helped us shape our final design, and the different features
  • Designing the architecture – Before we started to build the final product, we talked about the technical design of the product under the hood. These decisions basically defined the way the end product would operate, and the way users would interact with it.
  • Picking up the technologies – To apply our technical design, we needed to find the right tools.
    For the video manipulations, we decided to use vanilla JavaScript, because its easy to use video API. The biggest discussion was around the implantation of the buttons, on which the user needs to press in order to play the videos. After some research, and brainstorming with Joe Mango, we decided to use the Adafruit Trellis. That was probably the most important decision we took, and one that made this project possible to make, given the short amount of time we had at that point (four days).
  • Building, and making changes – We started to assemble the project and the write the needed code. While doing that, we changed our technical design a few times, in order to overcome some limitations we learned about along the way. And then came then moment where everything worked smoothly.
The Video Machine - Final product
The Video Machine – Final product

Some code

The entire code can be viewed on our GitHub repository.


The reactions to The Video Machine were amazing. The signals started to arrive on the prototyping stage, when people constantly wanted to check it out.

When we showed the final project to people on the ITP floor, it appeared that everyone wants to put a hand on our box.

The Video Machine
The Video Machine

People were experimenting, listening, looking, clicking, laughing, some of them even lined up to use our product.

The Video Machine
The Video Machine

Further work

I hope that Mint and I will be able to continue to work on this project for our final term.
I cannot wait to see the second version of The Video Machine.
I believe that the goals for the next version would be:

  • To add more functionality, that will allow better and easier video/sound manipulation.
  • To make playing very easy for people with no knowledge of music or playing live music. Beat sync could be a good start. The product should allow anyone to create nice tunes.
  • To find a new way to interact with the content, using the controller. This new interaction needs to be somethings that allows some kind of manipulation to the video or the sound, that is not possible (or less convenient) using the current and typical controller interface.
  • To improve the content so all videos will be very useful for as many types of music as possible.
  • To improve the web interface to make it adjustable for different screen sizes.
The Video Machine - Controller
The Video Machine – Controller

The ITP GitHub Hall of Fame

To practice my web APIs skills, I got some data from the GitHub API, and used it to create a list of the most starred (== popular) ITP related repositories.

See it here.

The ITP GitHub Hall of Fame
The ITP GitHub Hall of Fame

The expected (unpleasant) surprise

The process of making this page wasn’t smooth at all. In fact, this project cannot be further away from my original intentions. Here’s the truth:

  • I decided to let users enter a word (as an input), and to use this word to form a Haiku poem from three different poems.
  • I found poetry.db, which at first glance looked like the perfect source for my project.
  • I started to work on the logic that will form new Haiku poems out of the text I’ll get from poetry.db.
  • The logic was partially ready, and I was eager to test it on real data.
  • Oh no! My browser is shouting at me that I have a cross origin request error, and it is blocking my request to the API. I’m starting an endless search to find a solution, while going over countless Stackverflow threads, that appeared to be somewhat useless in my poor situation.
  • Aha! Apparently, JSONP should be JS’s workaround for this problem. My project could be saved!
  • Oh no! poetry.db’s server does not support JSONP. My options are:
    • To setup a web server and to hope for the best.
    • To try to find a new project that has better chances of success. — Chosen.
  • A new project! This time I’ll go for an API that was build by great developers, for the average developer, something that is a ‘one size fits all’, and I can assume that is stable and well maintain – GitHub’s API!

Some conclusions

GitHub’s API is well structured, fast, and reliable. I will surely recommend it to everyone.

Eventually, this process taught me (again), that when I deal with web APIs, the hustle is just part of the game. I’m sure that if I had some more time (a few extra days) I could have found a solution for the poetry.db API, and I could have completed my original project.

The cross-origin problem is a problem I face often, and I hope that we will be able to talk about it in class. I really feel that mastering the logic behind the cross-origin workaround is critical for web development.

(if you got to this point, feel free to scroll up and click that ‘See it here’ link again).

Domino Blueprint

For this week’s assignment, I created a sequential domino scene, as a homage for a game I used to play a lot when was younger. I still think that it is a brilliant game.

Take a look – click here

Or watch the video –

Domino Blueprint from Dror Ayalon on Vimeo.

This piece required many lines of code, but it was somewhat expected :\

btw – I’m officially in ♥ with object constructors.

Canvas Duel

The purpose of this app is to run some user testing, and investigate how people will find the experience of drawing (or designing) with a machine that tries to complete the next step in the drawing for them.

Currently, the app handles a single user. This is the first step towards implementing this concept – Currently, user can draw on a canvas, and hit the ‘space’ key to apply his/her own changes.

You can try it out yourself here.

The code can be found here.

The ‘Loopster’ failure


This week I tried to to build a project that originally simple to me. I wanted to build Loopster – a web app that will allow users to record short samples of music, save them, and use loop them to create a musical piece. I wanted Loopster to allow users to share their loops publicly, and to use loops by other users. Sort of the GitHub for music making.

So the goals were:

  • To build a web application that will allow users to record live stream (basically an analog stream).The recording could be done using the laptop microphone or the laptop input jack.
  • To allow users to trim their loops (or to try to detect the beats and to do it automatically).
  • To allow users to put some loops, which were created by them or by others, on a sequencer, and to enjoy them all together.

Bottom line:  Almost none of than happened.


I decided to use Web Audio API to implement the main functionality of the app. The Web Audio APIs are a little complicated, and it took my about 1-2 hours to be able to record sound through the laptop microphone.

Anything beyond that, just failed to work.
I spent another 8-10 hours trying to gain some progress on this project, but nothing seems to work anywhere near my expectations.

Eventually, the only thing that this app can do, is to open the laptop microphone, and play what it goes through it (which cause an immediate feedback..).


This is the (complicated) code for this (simple) interaction:
For some reason, WordPress took my html code too literaly

var AudioContext = window.AudioContext || window.webkitAudioContext; //cross browser compatibility
var myAudio = new AudioContext();
var record;

// get user's audio as an inputPoint
navigator.getUserMedia = (navigator.getUserMedia ||
                          navigator.webkitGetUserMedia ||
                          navigator.mozGetUserMedia ||

// audio nodes
var gain = myAudio.createGain();
gain.gain.value = 0;

// connecting the nodes
if (navigator.getUserMedia) {
   console.log('getUserMedia supported.');
   navigator.getUserMedia (
         audio: true,

      // Success callback

      // Error callback
      function(err) {
         console.log('The following gUM error occured: ' + err);
} else {
   console.log('getUserMedia not supported on your browser!');

function showButtons(){

function play(stream) {
  var source = myAudio.createMediaStreamSource(stream);

// start recording
function recordInput(stream){
  record = new MediaRecorder(stream);

function buttonEvents() {
  console.log('callback worked');
    gain.gain.value = 0.5;
    console.log('click on play');

    gain.gain.value = 0;
    console.log('click on stop');

// stop recording
$(window).keypress(function(key) {
  if ((key.keyCode === 32) && (record.state == 'recording')){
    console.log('Space pressed -- stopping recording process');
    // record.exportWAV( doneEncoding );

You can try to use it using this link, but Chrome (and I’m sure that this is relevant to any other browser) doesn’t allow any web app to open the microphone if the app’s files are not being served using a secured connection.


If you still want to see it happening, you can go to the project page on GitHub, download the files, and open index.html on your beloved browser.

Learning (at least trying to..)

Ok, some lessons from this unpleasant experience:

  • I chose the wrong tools. Web Audio API is definitely a wonderful API, but learning it was not the purpose of this project. P5.js, for example, could do most of the things I wanted to do. Also, using P5.js could get be pretty fast to the stage where I can experiment with the app and test the overall experience, the design of the interaction, and so on, which to me, are way more interesting.
  • I must find ideas that I’m more passionate about. The idea behind Loopster is nice, but not nice enough. A ‘nice enough’ idea would have got me to get rid of all the complications and to build it as fast as possible.
    On the Loopster case, the only passion I found was in learning new API or to experiment with new tools. But to me, the tools are not the story.

I hope I’ll do better next time :\

Device motion and orientation data

In continue to my previous post, I decided to take the first step in building my next project (more about it soon).

I  followed the Web API instructions about how to detect device’s movement (using the device accelerometer sensor) and orientation (using the device orientation sensor), and experimented with getting and presenting the this data.

You can see the end result here.

I wrote the following code for the task (This code gets the device movement and orientation data, and appends it to the DOM’s body) –

And this is the result (the changes in the blue numbers occur because I rotated my phone, while the most of the changes in the red numbers cause because the Web API library is still in beta, and doesn’t deal well enough with the device accelerometer) –

Apparently, my Macbook Pro also has an accelerometer, to protect its hard-drive while moving the laptop –

Try it yourself.

Here’s the entire code on GitHub.

ICM (+pcomp) Synthesis Workshop

A few days ago we had an ICM synthesis workshop. I must say that I had very low expectations from the workshop, which ended-up being one of the most inspiring and enjoyable activities I’ve been part of since I started ITP. I truly feel that this workshop was a milestone in my personal ITP growth.

First experience with changing digital objects using physical sensors

I was lucky enough to work with talented Scott Reitherman. We picked-up one of Scott’s early P5.js drawings, and manipulated it using a potentiometer.

The following video shows the final outcome, but doesn’t show exactly what’s happening (lesson learned about documentation videos).

Scott’s P5 drawing is being manipulated with a physical potentiometer: The jitters’ speed is changing when I rotate the knob.

My personal conclusion from the workshop

  • Doing is more inspiring than reading – Sounds trivial right? Not to everyone. I tend to read a lot and cover a vast range of topics using only my eyes. For some reason, this workshop made me realize finally  (or maybe reminded me after so many years of learning and having almost zero time for experiments) what is the difference between reading and doing, and how inspiring doing can be.
    Working on this tiny project, made me think of so many applications that could be interesting and challenging to make.
    Maybe it is because I just read “Sketching User Experiences: The Workbook” by Saul Greenberg, Bill Buxton from the pcomp class reading list, which reminded me how useful sketching could be, but I decided that from now on I’ll try to focus on sketching and making more than on anything else. To me, this is a very motivating and uplifting conclusion.
  • Focus on projects – From on, I’ll try to be more focused on projects, that will include subjects that were covered in different classes, more than on simply learning. Sounds vague, but maybe this is how it should be.
  • P5 is not ready – P5.js doesn’t seem too stable when dealing with serial  inputs. It doesn’t handle buffers very well, and tend to stop being responsive after 5-10 seconds of interaction.
    This limitation didn’t take anything from my first ‘sensor + digital visualization’ experience, but led me to the conclusion that I will not be able to use P5 on any of my final projects, if stability is something I’m looking for (I do).