Do not partially encrypt a segment

Mimic iso-bmff behavior: either all the samples in a segment are encrypted
or all the samples are clear.

Change-Id: I03bdbbf5a4b690f4d87c4dceb0f8155e6fae941e

packager/media/formats/webm/encrypted_segmenter_unittest.cc

@@ -19,7 +19,6 @@ const std::string kKeyId = "4c6f72656d20697073756d20646f6c6f";
 const std::string kIv = "0123456789012345";
 const std::string kKey = "01234567890123456789012345678901";
 const std::string kPsshData = "";
-
 const uint8_t kBasicSupportData[] = {
   // ID: EBML Header, Payload Size: 31
   0x1a, 0x45, 0xdf, 0xa3, 0x9f,
@@ -37,8 +36,8 @@ const uint8_t kBasicSupportData[] = {
     0x42, 0x87, 0x81, 0x02,
     // DocTypeReadVersion: 2
     0x42, 0x85, 0x81, 0x02,
-  // ID: Segment, Payload Size: 411
+  // ID: Segment, Payload Size: 432
-  0x18, 0x53, 0x80, 0x67, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x9b,
+  0x18, 0x53, 0x80, 0x67, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xb0,
     // ID: SeekHead, Payload Size: 58
     0x11, 0x4d, 0x9b, 0x74, 0xba,
       // ID: Seek, Payload Size: 11
@@ -63,8 +62,8 @@ const uint8_t kBasicSupportData[] = {
       0x4d, 0xbb, 0x8c,
         // SeekID: binary(4) (Cues)
         0x53, 0xab, 0x84, 0x1c, 0x53, 0xbb, 0x6b,
-        // SeekPosition: 392
+        // SeekPosition: 398
-        0x53, 0xac, 0x82, 0x01, 0x88,
+        0x53, 0xac, 0x82, 0x01, 0x8e,
     // ID: Void, Payload Size: 24
     0xec, 0x98, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -131,8 +130,8 @@ const uint8_t kBasicSupportData[] = {
           0x54, 0xb0, 0x81, 0x64,
           // DisplayHeight: 100
           0x54, 0xba, 0x81, 0x64,
-    // ID: Cluster, Payload Size: 101
+    // ID: Cluster, Payload Size: 45
-    0x1f, 0x43, 0xb6, 0x75, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x65,
+    0x1f, 0x43, 0xb6, 0x75, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x2d,
       // Timecode: 0
       0xe7, 0x81, 0x00,
       // ID: SimpleBlock, Payload Size: 10
@@ -141,44 +140,48 @@ const uint8_t kBasicSupportData[] = {
         0x00,
         // Frame Data:
         0xde, 0xad, 0xbe, 0xef, 0x00,
-      // ID: SimpleBlock, Payload Size: 18
+      // ID: SimpleBlock, Payload Size: 10
-      0xa3, 0x92, 0x81, 0x03, 0xe8, 0x80,
+      0xa3, 0x8a, 0x81, 0x03, 0xe8, 0x80,
+        // Signal Byte: Clear
+        0x00,
+        // Frame Data:
+        0xde, 0xad, 0xbe, 0xef, 0x00,
+      // ID: BlockGroup, Payload Size: 16
+      0xa0, 0x90,
+        // ID: Block, Payload Size: 10
+        0xa1, 0x8a, 0x81, 0x07, 0xd0, 0x00,
+          // Signal Byte: Clear
+          0x00,
+          // Frame Data:
+          0xde, 0xad, 0xbe, 0xef, 0x00,
+        // BlockDuration: 1000
+        0x9b, 0x82, 0x03, 0xe8,
+    // ID: Cluster, Payload Size: 50
+    0x1f, 0x43, 0xb6, 0x75, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x32,
+      // Timecode: 3000
+      0xe7, 0x82, 0x0b, 0xb8,
+      // ID: SimpleBlock: Payload Size: 18
+      0xa3, 0x92, 0x81, 0x00,0x00, 0x80,
         // Signal Byte: Encrypted
         0x01,
         // IV:
         0x01, 0x23, 0x45, 0x67, 0x89, 0x01, 0x23, 0x45,
         // Frame Data:
         0xcc, 0x03, 0xef, 0xc4, 0xf4,
-      // ID: SimpleBlock, Payload Size: 18
-      0xa3, 0x92, 0x81, 0x07, 0xd0, 0x80,
-        // Signal Byte: Encrypted
-        0x01,
-        // IV:
-        0x01, 0x23, 0x45, 0x67, 0x89, 0x01, 0x23, 0x46,
-        // Frame Data:
-        0xbf, 0x38, 0x72, 0x20, 0xac,
-      // ID: SimpleBlock, Payload Size: 18
-      0xa3, 0x92, 0x81, 0x0b, 0xb8, 0x80,
-        // Signal Byte: Encrypted
-        0x01,
-        // IV:
-        0x01, 0x23, 0x45, 0x67, 0x89, 0x01, 0x23, 0x47,
-        // Frame Data:
-        0x0d, 0x8e, 0xae, 0xbe, 0xd0,
       // ID: BlockGroup, Payload Size: 24
       0xa0, 0x98,
         // ID: Block, Payload Size: 18
-        0xa1, 0x92, 0x81, 0x0f, 0xa0, 0x00,
+        0xa1, 0x92, 0x81, 0x03, 0xe8, 0x00,
           // Signal Byte: Encrypted
           0x01,
           // IV:
-          0x01, 0x23, 0x45, 0x67, 0x89, 0x01, 0x23, 0x48,
+          0x01, 0x23, 0x45, 0x67, 0x89, 0x01, 0x23, 0x46,
           // Frame Data:
-          0xa5, 0x97, 0xf8, 0x9e, 0x87,
+          0xbf, 0x38, 0x72, 0x20, 0xac,
         // BlockDuration: 1000
         0x9b, 0x82, 0x03, 0xe8,
-    // ID: Cues, Payload Size: 14
+    // ID: Cues, Payload Size: 29
-    0x1c, 0x53, 0xbb, 0x6b, 0x8e,
+    0x1c, 0x53, 0xbb, 0x6b, 0x9d,
       // ID: CuePoint, Payload Size: 12
       0xbb, 0x8c,
         // CueTime: 0
@@ -188,7 +191,17 @@ const uint8_t kBasicSupportData[] = {
           // CueTrack: 1
           0xf7, 0x81, 0x01,
           // CueClusterPosition: 279
-          0xf1, 0x82, 0x01, 0x17
+          0xf1, 0x82, 0x01, 0x17,
+      // ID: CuePoint, Payload Size: 13
+      0xbb, 0x8d,
+        // CueTime: 3000
+        0xb3, 0x82, 0x0b, 0xb8,
+        // ID: CueTrackPositions, Payload Size: 7
+        0xb7, 0x87,
+          // CueTrack: 1
+          0xf7, 0x81, 0x01,
+          // CueClusterPosition: 336
+          0xf1, 0x82, 0x01, 0x50,
 };
 
 }  // namespace
@@ -213,9 +226,12 @@ class EncrypedSegmenterTest : public SegmentTestBase {
 
 TEST_F(EncrypedSegmenterTest, BasicSupport) {
   MuxerOptions options = CreateMuxerOptions();
+  options.segment_duration = 3.0;
   ASSERT_NO_FATAL_FAILURE(InitializeSegmenter(options));
 
   // Write the samples to the Segmenter.
+  // There should be 2 segments with the first segment in clear and the second
+  // segment encrypted.
   for (int i = 0; i < 5; i++) {
     scoped_refptr<MediaSample> sample =
         CreateSample(kKeyFrame, kDuration, kNoSideData);
@@ -228,4 +244,3 @@ TEST_F(EncrypedSegmenterTest, BasicSupport) {
 
 }  // namespace media
 }  // namespace shaka
-

packager/media/formats/webm/segmenter.cc

@@ -32,6 +32,8 @@ int64_t kSecondsToNs = 1000000000L;
 Segmenter::Segmenter(const MuxerOptions& options)
     : reference_frame_timestamp_(0),
       options_(options),
+      clear_lead_(0),
+      enable_encryption_(false),
       info_(NULL),
       muxer_listener_(NULL),
       progress_listener_(NULL),
@@ -144,6 +146,15 @@ Status Segmenter::AddSample(scoped_refptr<MediaSample> sample) {
       segment_length_sec_ = 0;
       cluster_length_sec_ = 0;
       wrote_frame = true;
+
+      if (encryptor_ && !enable_encryption_) {
+        if (sample->pts() - first_timestamp_ >=
+            clear_lead_ * info_->time_scale()) {
+          enable_encryption_ = true;
+          if (muxer_listener_)
+            muxer_listener_->OnEncryptionStart();
+        }
+      }
     }
   } else if (cluster_length_sec_ >= options_.fragment_duration) {
     if (sample->is_key_frame() || !options_.fragment_sap_aligned) {
@@ -161,20 +172,13 @@ Status Segmenter::AddSample(scoped_refptr<MediaSample> sample) {
 
   // Encrypt the frame.
   if (encryptor_) {
-    const bool encrypt_frame =
+    status = encryptor_->EncryptFrame(sample, enable_encryption_);
-        static_cast<double>(sample->pts() - first_timestamp_) /
-            info_->time_scale() >=
-        clear_lead_;
-    status = encryptor_->EncryptFrame(sample, encrypt_frame);
     if (!status.ok()) {
       LOG(ERROR) << "Error encrypting frame.";
       return status;
     }
-    if (encrypt_frame && muxer_listener_)
-      muxer_listener_->OnEncryptionStart();
   }
 
-
   // Add the sample to the durations even though we have not written the frame
   // yet.  This is needed to make sure we split Clusters at the correct point.
   // These are only used in this method.

packager/media/formats/webm/segmenter.h

@@ -135,6 +135,7 @@ class Segmenter {
   const MuxerOptions& options_;
   std::unique_ptr<Encryptor> encryptor_;
   double clear_lead_;
+  bool enable_encryption_;  // Encryption is enabled only after clear_lead_.
 
   std::unique_ptr<mkvmuxer::Cluster> cluster_;
   mkvmuxer::Cues cues_;