Add support for cbc1 encryption scheme

Issue:#1661
Issue:#1989
Issue:#2089

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=159553419

demo/src/main/assets/media.exolist.json

@@ -138,28 +138,52 @@
         "uri": "https://storage.googleapis.com/wvmedia/clear/h264/tears/tears_uhd.mpd"
       },
       {
-        "name": "WV: Secure SD & HD (MP4,H264)",
+        "name": "WV: Secure SD & HD (cenc,MP4,H264)",
         "uri": "https://storage.googleapis.com/wvmedia/cenc/h264/tears/tears.mpd",
         "drm_scheme": "widevine",
         "drm_license_url": "https://proxy.uat.widevine.com/proxy?provider=widevine_test"
       },
       {
-        "name": "WV: Secure SD (MP4,H264)",
+        "name": "WV: Secure SD (cenc,MP4,H264)",
         "uri": "https://storage.googleapis.com/wvmedia/cenc/h264/tears/tears_sd.mpd",
         "drm_scheme": "widevine",
         "drm_license_url": "https://proxy.uat.widevine.com/proxy?provider=widevine_test"
       },
       {
-        "name": "WV: Secure HD (MP4,H264)",
+        "name": "WV: Secure HD (cenc,MP4,H264)",
         "uri": "https://storage.googleapis.com/wvmedia/cenc/h264/tears/tears_hd.mpd",
         "drm_scheme": "widevine",
         "drm_license_url": "https://proxy.uat.widevine.com/proxy?provider=widevine_test"
       },
       {
-        "name": "WV: Secure UHD (MP4,H264)",
+        "name": "WV: Secure UHD (cenc,MP4,H264)",
         "uri": "https://storage.googleapis.com/wvmedia/cenc/h264/tears/tears_uhd.mpd",
         "drm_scheme": "widevine",
         "drm_license_url": "https://proxy.uat.widevine.com/proxy?provider=widevine_test"
+      },
+      {
+        "name": "WV: Secure SD & HD (cbc1,MP4,H264)",
+        "uri": "https://storage.googleapis.com/wvmedia/cbc1/h264/tears/tears_aes_cbc1.mpd",
+        "drm_scheme": "widevine",
+        "drm_license_url": "https://proxy.uat.widevine.com/proxy?provider=widevine_test"
+      },
+      {
+        "name": "WV: Secure SD (cbc1,MP4,H264)",
+        "uri": "https://storage.googleapis.com/wvmedia/cbc1/h264/tears/tears_aes_cbc1_sd.mpd",
+        "drm_scheme": "widevine",
+        "drm_license_url": "https://proxy.uat.widevine.com/proxy?provider=widevine_test"
+      },
+      {
+        "name": "WV: Secure HD (cbc1,MP4,H264)",
+        "uri": "https://storage.googleapis.com/wvmedia/cbc1/h264/tears/tears_aes_cbc1_hd.mpd",
+        "drm_scheme": "widevine",
+        "drm_license_url": "https://proxy.uat.widevine.com/proxy?provider=widevine_test"
+      },
+      {
+        "name": "WV: Secure UHD (cbc1,MP4,H264)",
+        "uri": "https://storage.googleapis.com/wvmedia/cbc1/h264/tears/tears_aes_cbc1_uhd.mpd",
+        "drm_scheme": "widevine",
+        "drm_license_url": "https://proxy.uat.widevine.com/proxy?provider=widevine_test"
       }
     ]
   },

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

@@ -1128,24 +1128,18 @@ private boolean readSample(ExtractorInput input) throws IOException, Interrupted
       sampleTimeUs = timestampAdjuster.adjustSampleTimestamp(sampleTimeUs);
     }
 
-    @C.BufferFlags int sampleFlags = (fragment.definesEncryptionData ? C.BUFFER_FLAG_ENCRYPTED : 0)
-        | (fragment.sampleIsSyncFrameTable[sampleIndex] ? C.BUFFER_FLAG_KEY_FRAME : 0);
+    @C.BufferFlags int sampleFlags = fragment.sampleIsSyncFrameTable[sampleIndex]
+        ? C.BUFFER_FLAG_KEY_FRAME : 0;
 
     // Encryption data.
     TrackOutput.CryptoData cryptoData = null;
-    TrackEncryptionBox encryptionBox = null;
     if (fragment.definesEncryptionData) {
-      encryptionBox = fragment.trackEncryptionBox != null
+      sampleFlags |= C.BUFFER_FLAG_ENCRYPTED;
+      TrackEncryptionBox encryptionBox = fragment.trackEncryptionBox != null
           ? fragment.trackEncryptionBox
           : track.getSampleDescriptionEncryptionBox(fragment.header.sampleDescriptionIndex);
-      if (encryptionBox != currentTrackBundle.cachedEncryptionBox) {
-        cryptoData = new TrackOutput.CryptoData(C.CRYPTO_MODE_AES_CTR, encryptionBox.keyId);
-      } else {
-        cryptoData = currentTrackBundle.cachedCryptoData;
-      }
+      cryptoData = encryptionBox.cryptoData;
     }
-    currentTrackBundle.cachedCryptoData = cryptoData;
-    currentTrackBundle.cachedEncryptionBox = encryptionBox;
 
     output.sampleMetadata(sampleTimeUs, sampleFlags, sampleSize, 0, cryptoData);
 
@@ -1301,10 +1295,6 @@ private static final class TrackBundle {
     public int currentSampleInTrackRun;
     public int currentTrackRunIndex;
 
-    // Auxiliary references.
-    public TrackOutput.CryptoData cachedCryptoData;
-    public TrackEncryptionBox cachedEncryptionBox;
-
     public TrackBundle(TrackOutput output) {
       fragment = new TrackFragment();
       this.output = output;
@@ -1322,8 +1312,6 @@ public void reset() {
       currentSampleIndex = 0;
       currentTrackRunIndex = 0;
       currentSampleInTrackRun = 0;
-      cachedCryptoData = null;
-      cachedEncryptionBox = null;
     }
 
     public void updateDrmInitData(DrmInitData drmInitData) {

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

@@ -16,13 +16,18 @@
 package com.google.android.exoplayer2.extractor.mp4;
 
 import android.support.annotation.Nullable;
+import android.util.Log;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.extractor.TrackOutput;
 
 /**
  * Encapsulates information parsed from a track encryption (tenc) box or sample group description 
  * (sgpd) box in an MP4 stream.
  */
 public final class TrackEncryptionBox {
 
+  private static final String TAG = "TrackEncryptionBox";
+
   /**
    * Indicates the encryption state of the samples in the sample group.
    */
@@ -34,27 +39,47 @@ public final class TrackEncryptionBox {
   @Nullable public final String schemeType;
 
   /**
-   * The initialization vector size in bytes for the samples in the corresponding sample group.
+   * A {@link TrackOutput.CryptoData} instance containing the encryption information from this
+   * {@link TrackEncryptionBox}.
    */
-  public final int initializationVectorSize;
+  public final TrackOutput.CryptoData cryptoData;
 
   /**
-   * The key identifier for the samples in the corresponding sample group.
+   * The initialization vector size in bytes for the samples in the corresponding sample group.
    */
-  public final byte[] keyId;
+  public final int initializationVectorSize;
+
 
   /**
    * @param isEncrypted See {@link #isEncrypted}.
    * @param schemeType See {@link #schemeType}.
    * @param initializationVectorSize See {@link #initializationVectorSize}.
-   * @param keyId See {@link #keyId}.
+   * @param keyId See {@link TrackOutput.CryptoData#encryptionKey}.
    */
   public TrackEncryptionBox(boolean isEncrypted, @Nullable String schemeType,
       int initializationVectorSize, byte[] keyId) {
     this.isEncrypted = isEncrypted;
     this.schemeType = schemeType;
     this.initializationVectorSize = initializationVectorSize;
-    this.keyId = keyId;
+    cryptoData = new TrackOutput.CryptoData(schemeToCryptoMode(schemeType), keyId);
+  }
+
+  @C.CryptoMode
+  private static int schemeToCryptoMode(@Nullable String schemeType) {
+    if (schemeType == null) {
+      // If unknown, assume cenc.
+      return C.CRYPTO_MODE_AES_CTR;
+    }
+    switch (schemeType) {
+      case "cenc":
+        return C.CRYPTO_MODE_AES_CTR;
+      case "cbc1":
+        return C.CRYPTO_MODE_AES_CBC;
+      default:
+        Log.w(TAG, "Unsupported protection scheme type '" + schemeType + "'. Assuming AES-CTR "
+            + "crypto mode.");
+        return C.CRYPTO_MODE_AES_CTR;
+    }
   }
 
 }