Write track fragment metadata

Output real tfhd info. Prepare trun to accept sample information-- this still needs to be generated properly by the transmuxer.

@@ -2,7 +2,7 @@
 'use strict';
 
 var box, dinf, ftyp, mdat, mfhd, minf, moof, moov, mvex, mvhd, trak,
-    tkhd, mdia, mdhd, hdlr, stbl, stsd, styp, trex, types,
+    tkhd, mdia, mdhd, hdlr, stbl, stsd, styp, traf, trex, trun, types,
     MAJOR_BRAND, MINOR_VERSION, AVC1_BRAND, VIDEO_HDLR, AUDIO_HDLR,
     HDLR_TYPES, VMHD, DREF, STCO, STSC, STSZ, STTS, Uint8Array,
     DataView;
@@ -40,6 +40,7 @@ DataView = window.DataView;
     tfhd: [],
     traf: [],
     trak: [],
+    trun: [],
     trex: [],
     tkhd: [],
     vmhd: []
@@ -202,23 +203,16 @@ minf = function(track) {
 };
 moof = function(sequenceNumber, tracks) {
   var
-    trafCall = [],
+    trackFragments = [],
     i = tracks.length;
-  // build tfhd boxes for each track fragment
+  // build traf boxes for each track fragment
   while (i--) {
-    trafCall[i] = box(types.tfhd, new Uint8Array([
-      0x00, // version 0
-      0x00, 0x00, 0x00, // flags
-      (tracks[i].trackId & 0xFF000000) >> 24,
-      (tracks[i].trackId & 0xFF0000) >> 16,
-      (tracks[i].trackId & 0xFF00) >> 8,
-      (tracks[i].trackId & 0xFF),
-    ]));
+    trackFragments[i] = traf(tracks[i]);
   }
-  trafCall.unshift(types.traf);
-  return box(types.moof,
-             mfhd(sequenceNumber),
-             box.apply(null, trafCall));
+  return box.apply(null, [
+    types.moof,
+    mfhd(sequenceNumber)
+  ].concat(trackFragments));
 };
 /**
  * @param tracks... (optional) {array} the tracks associated with this movie
@@ -404,6 +398,19 @@ tkhd = function(track) {
   ]));
 };
 
+traf = function(track) {
+  return box(types.traf,
+             box(types.tfhd, new Uint8Array([
+               0x00, // version 0
+               0x00, 0x00, 0x00, // flags
+               (track.id & 0xFF000000) >> 24,
+               (track.id & 0xFF0000) >> 16,
+               (track.id & 0xFF00) >> 8,
+               (track.id & 0xFF),
+             ])),
+             trun(track));
+};
+
 /**
  * Generate a track box.
  * @param track {object} a track definition
@@ -431,6 +438,44 @@ trex = function(track) {
   ]));
 };
 
+trun = function(track) {
+  var bytes, samples, sample, i;
+
+  samples = track.samples || [];
+
+  bytes = [
+    0x00, // version 0
+    0x00, 0x0f, 0x00, // flags
+    (samples.length & 0xFF000000) >>> 24,
+    (samples.length & 0xFF0000) >>> 16,
+    (samples.length & 0xFF00) >>> 8,
+    samples.length & 0xFF // sample_count
+  ];
+
+  for (i = 0; i < samples.length; i++) {
+    sample = samples[i];
+    bytes = bytes.concat([
+      (sample.duration & 0xFF000000) >>> 24,
+      (sample.duration & 0xFF0000) >>> 16,
+      (sample.duration & 0xFF00) >>> 8,
+      sample.duration & 0xFF, // sample_duration
+      (sample.size & 0xFF000000) >>> 24,
+      (sample.size & 0xFF0000) >>> 16,
+      (sample.size & 0xFF00) >>> 8,
+      sample.size & 0xFF, // sample_size
+      (sample.flags & 0xFF000000) >>> 24,
+      (sample.flags & 0xFF0000) >>> 16,
+      (sample.flags & 0xFF00) >>> 8,
+      sample.flags & 0xFF, // sample_flags
+      (sample.compositionTimeOffset & 0xFF000000) >>> 24,
+      (sample.compositionTimeOffset & 0xFF0000) >>> 16,
+      (sample.compositionTimeOffset & 0xFF00) >>> 8,
+      sample.compositionTimeOffset & 0xFF, // sample_composition_time_offset
+    ]);
+  }
+  return box(types.trun, new Uint8Array(bytes));
+};
+
 window.videojs.mp4 = {
   ftyp: ftyp,
   mdat: mdat,

@@ -737,7 +737,7 @@ Transmuxer = function() {
   flushVideo = function() {
     var moof, mdat, boxes, i, data;
 
-    moof = mp4.moof(sequenceNumber, []);
+    moof = mp4.moof(sequenceNumber, tracks);
 
     // concatenate the video data and construct the mdat
     data = new Uint8Array(videoSamplesSize);

@@ -301,11 +301,21 @@ test('generates an initialization segment', function() {
 test('generates a minimal moof', function() {
   var
     data = mp4.moof(7, [{
-      trackId: 1
+      id: 17,
+      samples: [{
+        duration: 9000,
+        size: 10,
+        flags: 14,
+        compositionTimeOffset: 500
       }, {
-      trackId: 2
+        duration: 10000,
+        size: 11,
+        flags: 9,
+        compositionTimeOffset: 1000
+      }]
     }]),
-    moof = videojs.inspectMp4(data);
+    moof = videojs.inspectMp4(data),
+    trun;
 
   equal(moof.length, 1, 'generated one box');
   equal(moof[0].type, 'moof', 'generated a moof box');
@@ -313,10 +323,33 @@ test('generates a minimal moof', function() {
   equal(moof[0].boxes[0].type, 'mfhd', 'generated an mfhd box');
   equal(moof[0].boxes[0].sequenceNumber, 7, 'included the sequence_number');
   equal(moof[0].boxes[1].type, 'traf', 'generated a traf box');
-  equal(moof[0].boxes[1].boxes.length, 2, 'generated two fragment headers');
+  equal(moof[0].boxes[1].boxes.length, 2, 'generated track fragment info');
+  equal(moof[0].boxes[1].boxes[0].type, 'tfhd', 'generated a tfhd box');
+  equal(moof[0].boxes[1].boxes[0].trackId, 17, 'wrote the first track id');
   equal(moof[0].boxes[1].boxes[0].type, 'tfhd', 'generated a tfhd box');
-  equal(moof[0].boxes[1].boxes[0].trackId, 1, 'wrote the first track id');
-  equal(moof[0].boxes[1].boxes[1].trackId, 2, 'wrote the second track id');
+  trun = moof[0].boxes[1].boxes[1];
+  equal(trun.type, 'trun', 'generated a trun box');
+  equal(trun.samples.length, 2, 'wrote two samples');
+
+  equal(trun.samples[0].duration, 9000, 'wrote a sample duration');
+  equal(trun.samples[0].size, 10, 'wrote a sample size');
+  equal(trun.samples[0].flags, 14, 'wrote the sample flags');
+  equal(trun.samples[0].compositionTimeOffset, 500, 'wrote the composition time offset');
+
+  equal(trun.samples[1].duration, 10000, 'wrote a sample duration');
+  equal(trun.samples[1].size, 11, 'wrote a sample size');
+  equal(trun.samples[1].flags, 9, 'wrote the sample flags');
+  equal(trun.samples[1].compositionTimeOffset, 1000, 'wrote the composition time offset');
+});
+
+test('can generate a traf without samples', function() {
+  var
+    data = mp4.moof(8, [{
+      trackId: 13
+    }]),
+    moof = videojs.inspectMp4(data);
+
+  equal(moof[0].boxes[1].boxes[1].samples.length, 0, 'generated no samples');
 });
 
 test('generates an mdat', function() {

@@ -718,6 +718,32 @@ test('can parse a trun', function() {
             }]);
 });
 
+test('can parse a trun with per-sample flags', function() {
+  var data = box('trun',
+                 0x00, // version
+                 0x00, 0x0f, 0x00, // flags
+                 0x00, 0x00, 0x00, 0x01, // sample_count
+
+                 0x00, 0x00, 0x00, 0x09, // sample_duration
+                 0x00, 0x00, 0x00, 0xff, // sample_size
+                 0x01, 0x02, 0x03, 0x04, // sample_flags
+                 0x00, 0x00, 0x00, 0x00); // sample_composition_time_offset
+  deepEqual(videojs.inspectMp4(new Uint8Array(data)),
+            [{
+              type: 'trun',
+              version: 0,
+              size: 32,
+              flags: new Uint8Array([0, 0x0f, 0x00]),
+              samples: [{
+                duration: 9,
+                size: 0xff,
+                flags: 0x01020304,
+                compositionTimeOffset: 0
+              }]
+            }]);
+
+});
+
 test('can parse a sidx', function(){
   var data = box('sidx',
                 0x00, // version

@@ -537,10 +537,6 @@ var
       };
       while (sampleCount--) {
         sample = {};
-        if (sampleFlagsPresent) {
-          sample.flags = view.getUint32(offset);
-          offset += 4;
-        }
         if (sampleDurationPresent) {
           sample.duration = view.getUint32(offset);
           offset += 4;
@@ -549,6 +545,10 @@ var
           sample.size = view.getUint32(offset);
           offset += 4;
         }
+        if (sampleFlagsPresent) {
+          sample.flags = view.getUint32(offset);
+          offset += 4;
+        }
         if (sampleCompositionTimeOffsetPresent) {
           sample.compositionTimeOffset = view.getUint32(offset);
           offset += 4;