From 711933f337b31d110ed0319f96802efe0bd00dd6 Mon Sep 17 00:00:00 2001
From: Tim Branyen <tim@tabdeveloper.com>
Date: Fri, 5 Apr 2019 12:41:26 -0700
Subject: [PATCH] Support senc, encryption sampling

---
 src/isofile-write.js | 24 +++++++++++++++++-------
 src/parsing/senc.js  | 43 ++++++++++++++++++++++---------------------
 src/writing/senc.js  | 16 ++++++++++++++++
 3 files changed, 55 insertions(+), 28 deletions(-)
 create mode 100644 src/writing/senc.js

diff --git a/src/isofile-write.js b/src/isofile-write.js
index dc3e3862..5a3a3a17 100644
--- a/src/isofile-write.js
+++ b/src/isofile-write.js
@@ -17,18 +17,28 @@ ISOFile.prototype.createFragment = function(track_id, sampleNumber, stream_) {
 		}
 		return null;
 	}
-	
+
 	var stream = stream_ || new DataStream();
 	stream.endianness = DataStream.BIG_ENDIAN;
 
 	var moof = ISOFile.createSingleSampleMoof(sample);
+
+	// Extract sample encryption.
+	var senc = this.getBox('senc');
+
+	// Add sample encryption if it exists.
+	if (senc) {
+		moof.trafs[0].senc = senc;
+		moof.trafs[0].boxes.push(senc);
+	}
+
 	moof.write(stream);
 
 	/* adjusting the data_offset now that the moof size is known*/
 	moof.trafs[0].truns[0].data_offset = moof.size+8; //8 is mdat header
 	Log.debug("MP4Box", "Adjusting data_offset with new value "+moof.trafs[0].truns[0].data_offset);
 	stream.adjustUint32(moof.trafs[0].truns[0].data_offset_position, moof.trafs[0].truns[0].data_offset);
-		
+
 	var mdat = new BoxParser.mdatBox();
 	mdat.data = sample.data;
 	mdat.write(stream);
@@ -47,7 +57,7 @@ ISOFile.writeInitializationSegment = function(ftyp, moov, total_duration, sample
 	var stream = new DataStream();
 	stream.endianness = DataStream.BIG_ENDIAN;
 	ftyp.write(stream);
-	
+
 	/* we can now create the new mvex box */
 	var mvex = moov.add("mvex");
 	if (total_duration) {
@@ -70,7 +80,7 @@ ISOFile.prototype.save = function(name) {
 	var stream = new DataStream();
 	stream.endianness = DataStream.BIG_ENDIAN;
 	this.write(stream);
-	stream.save(name);	
+	stream.save(name);
 }
 
 ISOFile.prototype.getBuffer = function() {
@@ -91,11 +101,11 @@ ISOFile.prototype.initializeSegmentation = function() {
 		Log.warn("MP4Box", "No segmentation callback set!");
 	}
 	if (!this.isFragmentationInitialized) {
-		this.isFragmentationInitialized = true;		
+		this.isFragmentationInitialized = true;
 		this.nextMoofNumber = 0;
 		this.resetTables();
-	}	
-	initSegs = [];	
+	}
+	initSegs = [];
 	for (i = 0; i < this.fragmentedTracks.length; i++) {
 		var moov = new BoxParser.moovBox();
 		moov.mvhd = this.moov.mvhd;
diff --git a/src/parsing/senc.js b/src/parsing/senc.js
index 2dc9e372..2ea7abad 100644
--- a/src/parsing/senc.js
+++ b/src/parsing/senc.js
@@ -1,23 +1,24 @@
-// Cannot be fully parsed because Per_Sample_IV_Size needs to be known
-BoxParser.createFullBoxCtor("senc" /*, function(stream) {
+BoxParser.createFullBoxCtor("senc", function(stream) {
 	this.parseFullHeader(stream);
 	var sample_count = stream.readUint32();
-	this.samples = [];
-	for (var i = 0; i < sample_count; i++) {
-		var sample = {};
-		// tenc.default_Per_Sample_IV_Size or seig.Per_Sample_IV_Size
-		sample.InitializationVector = this.readUint8Array(Per_Sample_IV_Size*8);
-		if (this.flags & 0x2) {
-			sample.subsamples = [];
-			subsample_count = stream.readUint16();
-			for (var j = 0; j < subsample_count; j++) {
-				var subsample = {};
-				subsample.BytesOfClearData = stream.readUint16();
-				subsample.BytesOfProtectedData = stream.readUint32();
-				sample.subsamples.push(subsample);
-			}
-		}
-		// TODO
-		this.samples.push(sample);
-	}
-}*/);
+	this.data = stream.readUint8Array(this.size - this.hdr_size - 4);
+	// Cannot be fully parsed because Per_Sample_IV_Size needs to be known
+	//this.samples = [];
+	//for (var i = 0; i < sample_count; i++) {
+	//	var sample = {};
+	//	// tenc.default_Per_Sample_IV_Size or seig.Per_Sample_IV_Size
+	//	sample.InitializationVector = this.readUint8Array(Per_Sample_IV_Size*8);
+	//	if (this.flags & 0x2) {
+	//		sample.subsamples = [];
+	//		subsample_count = stream.readUint16();
+	//		for (var j = 0; j < subsample_count; j++) {
+	//			var subsample = {};
+	//			subsample.BytesOfClearData = stream.readUint16();
+	//			subsample.BytesOfProtectedData = stream.readUint32();
+	//			sample.subsamples.push(subsample);
+	//		}
+	//	}
+	//	// TODO
+	//	this.samples.push(sample);
+	//}
+});
diff --git a/src/writing/senc.js b/src/writing/senc.js
new file mode 100644
index 00000000..1f5d05a1
--- /dev/null
+++ b/src/writing/senc.js
@@ -0,0 +1,16 @@
+BoxParser.sencBox.prototype.write = function(stream) {
+	// Calculate the full box size.
+	this.size = this.hdr_size + this.data.byteLength;
+
+	// Write out the BMFF box header.
+	stream.writeInt32(this.size);
+	stream.writeString(this.type, null, 4);
+
+	//// Write out the full box header.
+	stream.writeUint8(this.version);
+	stream.writeUint24(this.flags);
+
+	//// Write out the pssh data.
+	stream.writeUint32(this.data.byteLength);
+	stream.writeUint8Array(this.data);
+}