d3 audio waveforms block

## d3 audio waveforms block
d3 audio waveforms block

## index.html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta name="description" content="">
    <meta name="author" content="jm3">
    <title>d3 audio waveforms</title>
    <!-- build:css stylesheets/app.min.css-->
    <link rel="stylesheet" type="text/css" href="http://fonts.googleapis.com/css?family=Roboto:400,100|Raleway:400,200|Amatic+SC">
    <link rel="stylesheet" type="text/css" href="waveform.css">
    <!-- endbuild-->
  </head>
  <body>
    <div class="page">
      <h1>d3 audio waveforms &middot;<a href="http://www.jm3.net/">john manoogian III</a></h1>
      <div class="waveform">
        <h2>divs:</h2>
        <div></div>
        <h2>SVG:</h2>
        <div class="svg">
          <!-- h2 Audio:-->
        </div>
      </div>
      <iframe width="100%" height="166" scrolling="no" frameborder="no" src="https://w.soundcloud.com/player/?url=https%3A//api.soundcloud.com/tracks/141102884&amp;amp;color=ff5500&amp;amp;auto_play=false&amp;amp;hide_related=false&amp;amp;show_artwork=true" class="soundcloud_embed"></iframe>
    </div>
    <script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>
    <script src="waveform.js"></script>
    <!-- endbuild-->
  </body>
</html>


## thumbnail.png

      
          Raw
        
        
              thumbnail.png
            
          
## waveform.css
* {
  margin:      0;
  font-family: 'Amatic SC', cursive;
}
html {
  margin: 1.0em;
}
h1 {
  font-size:    48px;
  font-weight:  bold;
}
h1 a,
h1 a:visited {
  text-decoration:  none;
  font-weight:      normal;
  font-size:        90%;
  color:            #000;
  border-bottom:    1px dashed #bbb;
}
h1 a:hover {
  color: red;
}
.waveform > svg,
.waveform > div {
  border:       2px solid #ddd;
  height:       140px;
  margin-left:  40px;
  padding:      2px;
  position:     relative;
  width:        880px;
}
.waveform h2 {
  margin-left:  40px;
  font-size:    36px;
}
.waveform > div div.bar {
  background-color:  red;
  position:          absolute;
}
.waveform .svg g rect {
  fill:     red;
  opacity:  0.5;
}
.soundcloud_embed {
  display:     none;
  opacity:     0.5;
  margin-left: 40px;
  width:       968px;
  /* weird padding offset; SC embed is slightly too short? */
}
.axis {
  position: absolute;
  top:      4px;
  left:    -40px;
}
.axis g path.domain {
  display: none;
}
.axis g text {
  font-family: 'Roboto', sans-serif;
  opacity:      0.5;
  font-size:    10px;
}

## waveform.js
var wave_json;
var wave_uri = "http://public.jm3.net/d3/geiger.json";
var max_points = 1024;

var width = 880,
height    = 140;

d3.json( wave_uri, function(error, json) {
  wave_json = json.data.slice(1, max_points);
  div_render( wave_json, ".waveform >  div" );
  svg_render( wave_json, ".waveform > .svg" );
});

function div_render( data, div ) {
  var y = d3.scale.linear().range([height, -height]);
  var x = d3.scale.linear().domain([0, data.length]);
  var max_val = d3.max(data, function(d) { return d; });
  y.domain([-max_val, max_val]);
  var bar_width = width/data.length;

  d3.select( div ).selectAll("div")
    .data(wave_json)
    .enter()
    .append("div")
    .attr("class", "bar")
    .style("width", bar_width + "px" )
    .style("height", function(d,i) {
      return y(d) + "px";
    })
    .style("bottom", function(d) {
      // 2px slide up because 2px padding
      var bottom = height - Math.abs(y(d)/2) - height/2 + 2;
      return bottom + "px";
    })
    .style("left", function(d,i) {
      var left =  x(i)*width; // could also do: i * bar_width;
      return left + "px";
    });


  var axis = d3.svg.axis()
    .scale(y)
    .ticks(12)
    .orient("left");

  d3.select(".waveform > div").append("svg")
    .attr("class", "axis")
    .attr("width", 60)
    .attr("height", height)
    .append("g")
    .attr("transform", "translate(40," + (height/2) + ")" )
    .call(axis);
}

function svg_render( data, svg ) {
  var node = d3.select(svg).append("svg")
    .attr("class","chart")
    .attr("width", width)
    .attr("height", height);

  var y = d3.scale.linear().range([height, -height]);
  var max_val = d3.max(data, function(d) { return d; });
  y.domain([-max_val, max_val]);
  var x = d3.scale.linear().domain([0, data.length]);
  var bar_width = width / data.length;

  var chart = node.attr("width", width).attr("height", height);

  var bar = chart.selectAll("g")
    .data(data)
    .enter().append("g") // svg "group"
    .attr("transform", function(d, i) {
      return "translate(" + i * bar_width + ",0)";
    });

  bar.append("rect")
    .attr("y", function(d) {
      var yv = height - Math.abs(y(d)/2) - height/2 + 2;
      return yv;
    })
    .attr("height", function(d) {
      return Math.abs(y(d)); })
    .attr("width", bar_width );

  var axis = d3.svg.axis()
    .scale(y)
    .ticks(12)
    .orient("left");

  d3.select(".svg").append("svg")
    .attr("class", "axis")
    .attr("width", 60)
    .attr("height", height)
    .append("g")
    .attr("transform", "translate(40," + (height/2) + ")" )
    .call(axis);
}

function d( s ) {
  console.log( "log: " + s );
}