Add an sdtp box to each traf

Working examples of segmented mp4s have included an sdtp box, even though it's duplicative of information in the trun box. It's easy to generate however, so add it to the inspector and generator, and update the transmuxer tests to expect sane output.

Add an sdtp box to each traf
Working examples of segmented mp4s have included an sdtp box, even though it's duplicative of information in the trun box. It's easy to generate however, so add it to the inspector and generator, and update the transmuxer tests to expect sane output.
David LaPalomento
Showing 5 changed files with 80 additions and 23 deletions
src/mp4-generator.js
test/mp4-generator_test.js
test/mp4-inspector_test.js
test/muxer/js/mp4-inspector.js
test/transmuxer_test.js
--- a/src/mp4-generator.js
View file @e6559cc
+++ b/src/mp4-generator.js
View file @e6559cc
@@ -2,10 +2,10 @@
 'use strict';
 var box, dinf, ftyp, mdat, mfhd, minf, moof, moov, mvex, mvhd, trak,
-    tkhd, mdia, mdhd, hdlr, stbl, stsd, styp, traf, trex, trun, types,
+    tkhd, mdia, mdhd, hdlr, sdtp, stbl, stsd, styp, traf, trex, trun,
-    MAJOR_BRAND, MINOR_VERSION, AVC1_BRAND, VIDEO_HDLR, AUDIO_HDLR,
+    types, MAJOR_BRAND, MINOR_VERSION, AVC1_BRAND, VIDEO_HDLR,
-    HDLR_TYPES, VMHD, DREF, STCO, STSC, STSZ, STTS, Uint8Array,
+    AUDIO_HDLR, HDLR_TYPES, VMHD, DREF, STCO, STSC, STSZ, STTS,
-    DataView;
+    Uint8Array, DataView;
 Uint8Array = window.Uint8Array;
 DataView = window.DataView;
@@ -30,6 +30,7 @@ DataView = window.DataView;
    moov: [],
    mvex: [],
    mvhd: [],
+    sdtp: [],
    stbl: [],
    stco: [],
    stsc: [],
@@ -276,6 +277,27 @@ mvhd = function(duration) {
  return box(types.mvhd, bytes);
 };
+sdtp = function(track) {
+  var
+    samples = track.samples || [],
+    bytes = new Uint8Array(4 + samples.length),
+    sample,
+    i;
+  // leave the full box header (4 bytes) all zero
+  // write the sample table
+  for (i = 0; i < samples.length; i++) {
+    sample = samples[i];
+    bytes[i + 4] = (sample.flags.dependsOn << 4) |
+      (sample.flags.isDependedOn << 2) |
+      (sample.flags.hasRedundancy);
+  }
+  return box(types.sdtp,
+             bytes);
+};
 stbl = function(track) {
  return box(types.stbl,
             stsd(track),
@@ -414,7 +436,8 @@ traf = function(track) {
               0x00, 0x00, 0x00, // flags
               0x00, 0x00, 0x00, 0x00 // baseMediaDecodeTime
             ])),
-             trun(track));
+             trun(track),
+             sdtp(track));
 };
 /**
--- a/test/mp4-generator_test.js
View file @e6559cc
+++ b/test/mp4-generator_test.js
View file @e6559cc
@@ -307,8 +307,8 @@ test('generates a minimal moof', function() {
        size: 10,
        flags: {
          isLeading: 0,
-          dependsOn: 0,
+          dependsOn: 2,
-          isDependedOn: 0,
+          isDependedOn: 1,
          hasRedundancy: 0,
          paddingValue: 0,
          isNonSyncSample: 0,
@@ -320,7 +320,7 @@ test('generates a minimal moof', function() {
        size: 11,
        flags: {
          isLeading: 0,
-          dependsOn: 0,
+          dependsOn: 1,
          isDependedOn: 0,
          hasRedundancy: 0,
          paddingValue: 0,
@@ -331,7 +331,8 @@ test('generates a minimal moof', function() {
      }]
    }]),
    moof = videojs.inspectMp4(data),
-    trun;
+    trun,
+    sdtp;
  equal(moof.length, 1, 'generated one box');
  equal(moof[0].type, 'moof', 'generated a moof box');
@@ -339,7 +340,7 @@ 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, 3, 'generated track fragment info');
+  equal(moof[0].boxes[1].boxes.length, 4, '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].baseDataOffset, undefined, 'did not set a base data offset');
@@ -358,8 +359,8 @@ test('generates a minimal moof', function() {
  equal(trun.samples[0].size, 10, 'wrote a sample size');
  deepEqual(trun.samples[0].flags, {
    isLeading: 0,
-    dependsOn: 0,
+    dependsOn: 2,
-    isDependedOn: 0,
+    isDependedOn: 1,
    hasRedundancy: 0,
    paddingValue: 0,
    isNonSyncSample: 0,
@@ -371,7 +372,7 @@ test('generates a minimal moof', function() {
  equal(trun.samples[1].size, 11, 'wrote a sample size');
  deepEqual(trun.samples[1].flags, {
    isLeading: 0,
-    dependsOn: 0,
+    dependsOn: 1,
    isDependedOn: 0,
    hasRedundancy: 0,
    paddingValue: 0,
@@ -379,6 +380,20 @@ test('generates a minimal moof', function() {
    degradationPriority: 9
  }, 'wrote the sample flags');
  equal(trun.samples[1].compositionTimeOffset, 1000, 'wrote the composition time offset');
+  sdtp = moof[0].boxes[1].boxes[3];
+  equal(sdtp.type, 'sdtp', 'generated an sdtp box');
+  equal(sdtp.samples.length, 2, 'wrote two samples');
+  deepEqual(sdtp.samples[0], {
+      dependsOn: 2,
+      isDependedOn: 1,
+      hasRedundancy: 0
+  }, 'wrote the sample data table');
+  deepEqual(sdtp.samples[1], {
+    dependsOn: 1,
+    isDependedOn: 0,
+    hasRedundancy: 0
+  }, 'wrote the sample data table');
 });
 test('can generate a traf without samples', function() {
--- a/test/mp4-inspector_test.js
View file @e6559cc
+++ b/test/mp4-inspector_test.js
View file @e6559cc
@@ -782,13 +782,13 @@ test('can parse an sdtp', function() {
    flags: new Uint8Array([0, 0, 0]),
    size: 14,
    samples: [{
-      sampleDependsOn: 1,
+      dependsOn: 1,
-      sampleIsDependedOn: 1,
+      isDependedOn: 1,
-      sampleHasRedundancy: 1
+      hasRedundancy: 1
    }, {
-      sampleDependsOn: 2,
+      dependsOn: 2,
-      sampleIsDependedOn: 1,
+      isDependedOn: 1,
-      sampleHasRedundancy: 3
+      hasRedundancy: 3
    }]
  }]);
 });
--- a/test/muxer/js/mp4-inspector.js
View file @e6559cc
+++ b/test/muxer/js/mp4-inspector.js
View file @e6559cc
@@ -287,9 +287,9 @@ var
      for (i = 4; i < data.byteLength; i++) {
        result.samples.push({
-          sampleDependsOn: (data[i] & 0x30) >> 4,
+          dependsOn: (data[i] & 0x30) >> 4,
-          sampleIsDependedOn: (data[i] & 0x0c) >> 2,
+          isDependedOn: (data[i] & 0x0c) >> 2,
-          sampleHasRedundancy: data[i] & 0x03
+          hasRedundancy: data[i] & 0x03
        });
      }
      return result;
--- a/test/transmuxer_test.js
View file @e6559cc
+++ b/test/transmuxer_test.js
View file @e6559cc
@@ -874,8 +874,9 @@ validateTrack = function(track, metadata) {
 };
 validateTrackFragment = function(track, metadata) {
-  var tfhd, trun, i, sample;
+  var tfhd, trun, sdtp, i, sample;
  equal(track.type, 'traf', 'wrote a track fragment');
+  equal(track.boxes.length, 4, 'wrote four track fragment children');
  tfhd = track.boxes[0];
  equal(tfhd.type, 'tfhd', 'wrote a track fragment header');
  equal(tfhd.trackId, metadata.trackId, 'wrote the track id');
@@ -902,6 +903,24 @@ validateTrackFragment = function(track, metadata) {
    equal(sample.flags.hasRedundancy, 0, 'sample redundancy is unknown');
    equal(sample.flags.degradationPriority, 0, 'sample degradation priority is zero');
  }
+  sdtp = track.boxes[3];
+  equal(trun.samples.length,
+        sdtp.samples.length,
+        'wrote an equal number of trun and sdtp samples');
+  for (i = 0; i < sdtp.samples.length; i++) {
+    sample = sdtp.samples[i];
+    notEqual(sample.dependsOn, 0, 'sample dependency is not unknown');
+    equal(trun.samples[i].flags.dependsOn,
+          sample.dependsOn,
+          'wrote a consistent dependsOn');
+    equal(trun.samples[i].flags.isDependedOn,
+          sample.isDependedOn,
+          'wrote a consistent isDependedOn');
+    equal(trun.samples[i].flags.hasRedundancy,
+          sample.hasRedundancy,
+          'wrote a consistent hasRedundancy');
+  }
 };
 test('parses an example mp2t file and generates media segments', function() {