Add trun parsing to the inspector

Parse out sample metadata stored in a track run box.

@@ -669,6 +669,41 @@ test('can parse a moof', function() {
             }]);
 });
 
+test('can parse a trun', function() {
+  var data = box('trun',
+                0x00, // version
+                0x00, 0x0b, 0x05, // flags
+                0x00, 0x00, 0x00, 0x02, // sample_count
+                0x00, 0x00, 0x00, 0x01, // data_offset
+                0x01, 0x02, 0x03, 0x04, // first_sample_flags
+
+                0x00, 0x00, 0x00, 0x09, // sample_duration
+                0x00, 0x00, 0x00, 0xff, // sample_size
+                0x00, 0x00, 0x00, 0x00, // sample_composition_time_offset
+
+                0x00, 0x00, 0x00, 0x08, // sample_duration
+                0x00, 0x00, 0x00, 0xfe, // sample_size
+                0x00, 0x00, 0x00, 0x00); // sample_composition_time_offset
+  deepEqual(videojs.inspectMp4(new Uint8Array(data)),
+            [{
+              type: 'trun',
+              version: 0,
+              size: 48,
+              flags: new Uint8Array([0, 0x0b, 0x05]),
+              dataOffset: 1,
+              samples: [{
+                duration: 9,
+                size: 0xff,
+                flags: 0x01020304,
+                compositionTimeOffset: 0
+              }, {
+                duration: 8,
+                size: 0xfe,
+                compositionTimeOffset: 0
+              }]
+            }]);
+});
+
 test('can parse a series of boxes', function() {
   var ftyp = [
     0x00, 0x00, 0x00, 0x18 // size 4 * 6 = 24

@@ -456,6 +456,70 @@ var
         sampleDegradationPriority: view.getUint16(22)
       };
     },
+    trun: function(data) {
+      var
+        result = {
+          version: data[0],
+          flags: new Uint8Array(data.subarray(1, 4)),
+          samples: []
+        },
+        view = new DataView(data.buffer, data.byteOffset, data.byteLength),
+        dataOffsetPresent = result.flags[2] & 0x01,
+        firstSampleFlagsPresent = result.flags[2] & 0x04,
+        sampleDurationPresent = result.flags[1] & 0x01,
+        sampleSizePresent = result.flags[1] & 0x02,
+        sampleFlagsPresent = result.flags[1] & 0x04,
+        sampleCompositionTimeOffsetPresent = result.flags[1] & 0x08,
+        sampleCount = view.getUint32(4),
+        offset = 8,
+        sample;
+
+      if (dataOffsetPresent) {
+        result.dataOffset = view.getUint32(offset);
+        offset += 4;
+      }
+      if (firstSampleFlagsPresent && sampleCount) {
+        sample = {
+          flags: view.getUint32(offset)
+        };
+        offset += 4;
+        if (sampleDurationPresent) {
+          sample.duration = view.getUint32(offset);
+          offset += 4;
+        }
+        if (sampleSizePresent) {
+          sample.size = view.getUint32(offset);
+          offset += 4;
+        }
+        if (sampleCompositionTimeOffsetPresent) {
+          sample.compositionTimeOffset = view.getUint32(offset);
+          offset += 4;
+        }
+        result.samples.push(sample);
+        sampleCount--;
+      };
+      while (sampleCount--) {
+        sample = {};
+        if (sampleFlagsPresent) {
+          sample.flags = view.getUint32(offset);
+          offset += 4;
+        }
+        if (sampleDurationPresent) {
+          sample.duration = view.getUint32(offset);
+          offset += 4;
+        }
+        if (sampleSizePresent) {
+          sample.size = view.getUint32(offset);
+          offset += 4;
+        }
+        if (sampleCompositionTimeOffsetPresent) {
+          sample.compositionTimeOffset = view.getUint32(offset);
+          offset += 4;
+        }
+        result.samples.push(sample);
+      }
+      return result;
+    },
     'url ': function(data) {
       return {
         version: data[0],