Merge pull request #6797 from DolbyLaboratories:dev-v2-ac4-drm

PiperOrigin-RevId: 289092332

RELEASENOTES.md

@@ -61,6 +61,7 @@
   on earlier releases, but only when embedded in a non-FLAC container such as
   Matroska or MP4.
 * Javadocs: Add favicon for easier identification in browser tabs
+* FMP4: Add support for encrypted AC-4 tracks.
 
 ### 2.11.1 (2019-12-20) ###
 

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4Extractor.java

@@ -1265,14 +1265,19 @@ public class FragmentedMp4Extractor implements Extractor {
         sampleSize -= Atom.HEADER_SIZE;
         input.skipFully(Atom.HEADER_SIZE);
       }
-      sampleBytesWritten = currentTrackBundle.outputSampleEncryptionData();
+
-      sampleSize += sampleBytesWritten;
       if (MimeTypes.AUDIO_AC4.equals(currentTrackBundle.track.format.sampleMimeType)) {
+        // AC4 samples need to be prefixed with a clear sample header.
+        sampleBytesWritten =
+            currentTrackBundle.outputSampleEncryptionData(sampleSize, Ac4Util.SAMPLE_HEADER_SIZE);
         Ac4Util.getAc4SampleHeader(sampleSize, scratch);
         currentTrackBundle.output.sampleData(scratch, Ac4Util.SAMPLE_HEADER_SIZE);
         sampleBytesWritten += Ac4Util.SAMPLE_HEADER_SIZE;
-        sampleSize += Ac4Util.SAMPLE_HEADER_SIZE;
+      } else {
+        sampleBytesWritten =
+            currentTrackBundle.outputSampleEncryptionData(sampleSize, /* clearHeaderSize= */ 0);
       }
+      sampleSize += sampleBytesWritten;
       parserState = STATE_READING_SAMPLE_CONTINUE;
       sampleCurrentNalBytesRemaining = 0;
     }
@@ -1471,8 +1476,11 @@ public class FragmentedMp4Extractor implements Extractor {
    */
   private static final class TrackBundle {
 
+    private static final int SINGLE_SUBSAMPLE_ENCRYPTION_DATA_LENGTH = 8;
+
     public final TrackOutput output;
     public final TrackFragment fragment;
+    public final ParsableByteArray scratch;
 
     public Track track;
     public DefaultSampleValues defaultSampleValues;
@@ -1487,6 +1495,7 @@ public class FragmentedMp4Extractor implements Extractor {
     public TrackBundle(TrackOutput output) {
       this.output = output;
       fragment = new TrackFragment();
+      scratch = new ParsableByteArray();
       encryptionSignalByte = new ParsableByteArray(1);
       defaultInitializationVector = new ParsableByteArray();
     }
@@ -1555,9 +1564,13 @@ public class FragmentedMp4Extractor implements Extractor {
     /**
      * Outputs the encryption data for the current sample.
      *
+     * @param sampleSize The size of the current sample in bytes, excluding any additional clear
+     *     header that will be prefixed to the sample by the extractor.
+     * @param clearHeaderSize The size of a clear header that will be prefixed to the sample by the
+     *     extractor, or 0.
      * @return The number of written bytes.
      */
-    public int outputSampleEncryptionData() {
+    public int outputSampleEncryptionData(int sampleSize, int clearHeaderSize) {
       TrackEncryptionBox encryptionBox = getEncryptionBoxIfEncrypted();
       if (encryptionBox == null) {
         return 0;
@@ -1576,23 +1589,61 @@ public class FragmentedMp4Extractor implements Extractor {
         vectorSize = initVectorData.length;
       }
 
-      boolean subsampleEncryption = fragment.sampleHasSubsampleEncryptionTable(currentSampleIndex);
+      boolean haveSubsampleEncryptionTable =
+          fragment.sampleHasSubsampleEncryptionTable(currentSampleIndex);
+      boolean writeSubsampleEncryptionData = haveSubsampleEncryptionTable || clearHeaderSize != 0;
 
       // Write the signal byte, containing the vector size and the subsample encryption flag.
-      encryptionSignalByte.data[0] = (byte) (vectorSize | (subsampleEncryption ? 0x80 : 0));
+      encryptionSignalByte.data[0] =
+          (byte) (vectorSize | (writeSubsampleEncryptionData ? 0x80 : 0));
       encryptionSignalByte.setPosition(0);
       output.sampleData(encryptionSignalByte, 1);
       // Write the vector.
       output.sampleData(initializationVectorData, vectorSize);
-      // If we don't have subsample encryption data, we're done.
+
-      if (!subsampleEncryption) {
+      if (!writeSubsampleEncryptionData) {
         return 1 + vectorSize;
       }
-      // Write the subsample encryption data.
+
+      if (!haveSubsampleEncryptionTable) {
+        // The sample is fully encrypted, except for the additional clear header that the extractor
+        // is going to prefix. We need to synthesize subsample encryption data that takes the header
+        // into account.
+        scratch.reset(SINGLE_SUBSAMPLE_ENCRYPTION_DATA_LENGTH);
+        // subsampleCount = 1 (unsigned short)
+        scratch.data[0] = (byte) 0;
+        scratch.data[1] = (byte) 1;
+        // clearDataSize = clearHeaderSize (unsigned short)
+        scratch.data[2] = (byte) ((clearHeaderSize >> 8) & 0xFF);
+        scratch.data[3] = (byte) (clearHeaderSize & 0xFF);
+        // encryptedDataSize = sampleSize (unsigned short)
+        scratch.data[4] = (byte) ((sampleSize >> 24) & 0xFF);
+        scratch.data[5] = (byte) ((sampleSize >> 16) & 0xFF);
+        scratch.data[6] = (byte) ((sampleSize >> 8) & 0xFF);
+        scratch.data[7] = (byte) (sampleSize & 0xFF);
+        output.sampleData(scratch, SINGLE_SUBSAMPLE_ENCRYPTION_DATA_LENGTH);
+        return 1 + vectorSize + SINGLE_SUBSAMPLE_ENCRYPTION_DATA_LENGTH;
+      }
+
       ParsableByteArray subsampleEncryptionData = fragment.sampleEncryptionData;
       int subsampleCount = subsampleEncryptionData.readUnsignedShort();
       subsampleEncryptionData.skipBytes(-2);
       int subsampleDataLength = 2 + 6 * subsampleCount;
+
+      if (clearHeaderSize != 0) {
+        // We need to account for the additional clear header by adding clearHeaderSize to
+        // clearDataSize for the first subsample specified in the subsample encryption data.
+        scratch.reset(subsampleDataLength);
+        scratch.readBytes(subsampleEncryptionData.data, /* offset= */ 0, subsampleDataLength);
+        subsampleEncryptionData.skipBytes(subsampleDataLength);
+
+        int clearDataSize = (scratch.data[2] & 0xFF) << 8 | (scratch.data[3] & 0xFF);
+        int adjustedClearDataSize = clearDataSize + clearHeaderSize;
+        scratch.data[2] = (byte) ((adjustedClearDataSize >> 8) & 0xFF);
+        scratch.data[3] = (byte) (adjustedClearDataSize & 0xFF);
+        subsampleEncryptionData = scratch;
+      }
+
       output.sampleData(subsampleEncryptionData, subsampleDataLength);
       return 1 + vectorSize + subsampleDataLength;
     }

library/core/src/test/assets/mp4/sample_ac4_protected.mp4.0.dump

@@ -0,0 +1,145 @@
+seekMap:
+  isSeekable = true
+  duration = 760000
+  getPosition(0) = [[timeUs=0, position=950]]
+numberOfTracks = 1
+track 0:
+  format:
+    bitrate = -1
+    id = 1
+    containerMimeType = null
+    sampleMimeType = audio/ac4
+    maxInputSize = -1
+    width = -1
+    height = -1
+    frameRate = -1.0
+    rotationDegrees = 0
+    pixelWidthHeightRatio = 1.0
+    channelCount = 2
+    sampleRate = 48000
+    pcmEncoding = -1
+    encoderDelay = 0
+    encoderPadding = 0
+    subsampleOffsetUs = 9223372036854775807
+    selectionFlags = 0
+    language = und
+    drmInitData = -1683793742
+    metadata = null
+    initializationData:
+  total output bytes = 7936
+  sample count = 19
+  sample 0:
+    time = 0
+    flags = 1073741825
+    data = length 384, hash 96EFFFF3
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 1:
+    time = 40000
+    flags = 1073741825
+    data = length 384, hash 899279C6
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 2:
+    time = 80000
+    flags = 1073741825
+    data = length 384, hash 9EA9F45
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 3:
+    time = 120000
+    flags = 1073741825
+    data = length 384, hash 82D362A9
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 4:
+    time = 160000
+    flags = 1073741825
+    data = length 384, hash B8705CFB
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 5:
+    time = 200000
+    flags = 1073741825
+    data = length 384, hash 58B5628E
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 6:
+    time = 240000
+    flags = 1073741825
+    data = length 384, hash 87F3C13B
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 7:
+    time = 280000
+    flags = 1073741825
+    data = length 384, hash 54333DC5
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 8:
+    time = 320000
+    flags = 1073741825
+    data = length 384, hash 1C49C4B3
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 9:
+    time = 360000
+    flags = 1073741825
+    data = length 384, hash 5FDC324F
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 10:
+    time = 400000
+    flags = 1073741825
+    data = length 384, hash B2A7F444
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 11:
+    time = 440000
+    flags = 1073741825
+    data = length 512, hash 5FD06C1E
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 12:
+    time = 480000
+    flags = 1073741825
+    data = length 537, hash 7ABBDCB
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 13:
+    time = 520000
+    flags = 1073741825
+    data = length 616, hash 3F657E23
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 14:
+    time = 560000
+    flags = 1073741825
+    data = length 453, hash 8FCF0529
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 15:
+    time = 600000
+    flags = 1073741825
+    data = length 383, hash 7F8C9E19
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 16:
+    time = 640000
+    flags = 1073741825
+    data = length 410, hash 3727858D
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 17:
+    time = 680000
+    flags = 1073741825
+    data = length 391, hash E2931212
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 18:
+    time = 720000
+    flags = 1073741825
+    data = length 410, hash 63017D46
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+tracksEnded = true

library/core/src/test/assets/mp4/sample_ac4_protected.mp4.1.dump

@@ -0,0 +1,109 @@
+seekMap:
+  isSeekable = true
+  duration = 760000
+  getPosition(0) = [[timeUs=0, position=950]]
+numberOfTracks = 1
+track 0:
+  format:
+    bitrate = -1
+    id = 1
+    containerMimeType = null
+    sampleMimeType = audio/ac4
+    maxInputSize = -1
+    width = -1
+    height = -1
+    frameRate = -1.0
+    rotationDegrees = 0
+    pixelWidthHeightRatio = 1.0
+    channelCount = 2
+    sampleRate = 48000
+    pcmEncoding = -1
+    encoderDelay = 0
+    encoderPadding = 0
+    subsampleOffsetUs = 9223372036854775807
+    selectionFlags = 0
+    language = und
+    drmInitData = -1683793742
+    metadata = null
+    initializationData:
+  total output bytes = 5632
+  sample count = 13
+  sample 0:
+    time = 240000
+    flags = 1073741825
+    data = length 384, hash 87F3C13B
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 1:
+    time = 280000
+    flags = 1073741825
+    data = length 384, hash 54333DC5
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 2:
+    time = 320000
+    flags = 1073741825
+    data = length 384, hash 1C49C4B3
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 3:
+    time = 360000
+    flags = 1073741825
+    data = length 384, hash 5FDC324F
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 4:
+    time = 400000
+    flags = 1073741825
+    data = length 384, hash B2A7F444
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 5:
+    time = 440000
+    flags = 1073741825
+    data = length 512, hash 5FD06C1E
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 6:
+    time = 480000
+    flags = 1073741825
+    data = length 537, hash 7ABBDCB
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 7:
+    time = 520000
+    flags = 1073741825
+    data = length 616, hash 3F657E23
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 8:
+    time = 560000
+    flags = 1073741825
+    data = length 453, hash 8FCF0529
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 9:
+    time = 600000
+    flags = 1073741825
+    data = length 383, hash 7F8C9E19
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 10:
+    time = 640000
+    flags = 1073741825
+    data = length 410, hash 3727858D
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 11:
+    time = 680000
+    flags = 1073741825
+    data = length 391, hash E2931212
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 12:
+    time = 720000
+    flags = 1073741825
+    data = length 410, hash 63017D46
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+tracksEnded = true

library/core/src/test/assets/mp4/sample_ac4_protected.mp4.2.dump

@@ -0,0 +1,73 @@
+seekMap:
+  isSeekable = true
+  duration = 760000
+  getPosition(0) = [[timeUs=0, position=950]]
+numberOfTracks = 1
+track 0:
+  format:
+    bitrate = -1
+    id = 1
+    containerMimeType = null
+    sampleMimeType = audio/ac4
+    maxInputSize = -1
+    width = -1
+    height = -1
+    frameRate = -1.0
+    rotationDegrees = 0
+    pixelWidthHeightRatio = 1.0
+    channelCount = 2
+    sampleRate = 48000
+    pcmEncoding = -1
+    encoderDelay = 0
+    encoderPadding = 0
+    subsampleOffsetUs = 9223372036854775807
+    selectionFlags = 0
+    language = und
+    drmInitData = -1683793742
+    metadata = null
+    initializationData:
+  total output bytes = 3200
+  sample count = 7
+  sample 0:
+    time = 480000
+    flags = 1073741825
+    data = length 537, hash 7ABBDCB
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 1:
+    time = 520000
+    flags = 1073741825
+    data = length 616, hash 3F657E23
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 2:
+    time = 560000
+    flags = 1073741825
+    data = length 453, hash 8FCF0529
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 3:
+    time = 600000
+    flags = 1073741825
+    data = length 383, hash 7F8C9E19
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 4:
+    time = 640000
+    flags = 1073741825
+    data = length 410, hash 3727858D
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 5:
+    time = 680000
+    flags = 1073741825
+    data = length 391, hash E2931212
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+  sample 6:
+    time = 720000
+    flags = 1073741825
+    data = length 410, hash 63017D46
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+tracksEnded = true

library/core/src/test/assets/mp4/sample_ac4_protected.mp4.3.dump

@@ -0,0 +1,37 @@
+seekMap:
+  isSeekable = true
+  duration = 760000
+  getPosition(0) = [[timeUs=0, position=950]]
+numberOfTracks = 1
+track 0:
+  format:
+    bitrate = -1
+    id = 1
+    containerMimeType = null
+    sampleMimeType = audio/ac4
+    maxInputSize = -1
+    width = -1
+    height = -1
+    frameRate = -1.0
+    rotationDegrees = 0
+    pixelWidthHeightRatio = 1.0
+    channelCount = 2
+    sampleRate = 48000
+    pcmEncoding = -1
+    encoderDelay = 0
+    encoderPadding = 0
+    subsampleOffsetUs = 9223372036854775807
+    selectionFlags = 0
+    language = und
+    drmInitData = -1683793742
+    metadata = null
+    initializationData:
+  total output bytes = 410
+  sample count = 1
+  sample 0:
+    time = 720000
+    flags = 1073741825
+    data = length 410, hash 63017D46
+    crypto mode = 1
+    encryption key = length 16, hash 9FDDEA52
+tracksEnded = true

library/core/src/test/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4ExtractorTest.java

@@ -57,6 +57,12 @@ public final class FragmentedMp4ExtractorTest {
         getExtractorFactory(Collections.emptyList()), "mp4/sample_ac4_fragmented.mp4");
   }
 
+  @Test
+  public void testSampleWithProtectedAc4Track() throws Exception {
+    ExtractorAsserts.assertBehavior(
+        getExtractorFactory(Collections.emptyList()), "mp4/sample_ac4_protected.mp4");
+  }
+
   private static ExtractorFactory getExtractorFactory(final List<Format> closedCaptionFormats) {
     return () -> new FragmentedMp4Extractor(0, null, null, null, closedCaptionFormats);
   }