Formatting cleanup

library/core/src/main/java/com/google/android/exoplayer2/audio/Ac3Util.java

@@ -34,12 +34,30 @@ public final class Ac3Util {
   public static final class Ac3SyncFrameInfo {
 
     /**
+     * Undefined AC3 stream type.
+     */
+    public static final int STREAM_TYPE_UNDEFINED = -1;
+    /**
+     * Type 0 AC3 stream type. See ETSI TS 102 366 E.1.3.1.1.
+     */
+    public static final int STREAM_TYPE_TYPE0 = 0;
+    /**
+     * Type 1 AC3 stream type. See ETSI TS 102 366 E.1.3.1.1.
+     */
+    public static final int STREAM_TYPE_TYPE1 = 1;
+    /**
+     * Type 2 AC3 stream type. See ETSI TS 102 366 E.1.3.1.1.
+     */
+    public static final int STREAM_TYPE_TYPE2 = 2;
+
+    /**
      * The sample mime type of the bitstream. One of {@link MimeTypes#AUDIO_AC3} and
      * {@link MimeTypes#AUDIO_E_AC3}.
      */
     public final String mimeType;
     /**
-     * The type of the bitstream, only for AUDIO_E_AC3
+     * The type of the stream if {@link #mimeType} is {@link MimeTypes#AUDIO_E_AC3}, or
+     * {@link #STREAM_TYPE_UNDEFINED} otherwise.
      */
     public final int streamType;
     /**
@@ -107,13 +125,6 @@ public final class Ac3Util {
       121, 139, 174, 208, 243, 278, 348, 417, 487, 557, 696, 835, 975, 1114, 1253, 1393};
 
   /**
-   * Stream type. See ETSI TS 102 366 E.1.3.1.1.
-   */
-  public static final int STREAM_TYPE_UNDEFINED = -1;
-  public static final int STREAM_TYPE_TYPE0 = 0;
-  public static final int STREAM_TYPE_TYPE1 = 1;
-
-  /**
    * Returns the AC-3 format given {@code data} containing the AC3SpecificBox according to
    * ETSI TS 102 366 Annex F. The reading position of {@code data} will be modified.
    *
@@ -150,8 +161,7 @@ public final class Ac3Util {
       String language, DrmInitData drmInitData) {
     data.skipBytes(2); // data_rate, num_ind_sub
 
-    // Read only the first independent substream.
-    // TODO: Read later independent substreams?
+    // Read the first independent substream.
     int fscod = (data.readUnsignedByte() & 0xC0) >> 6;
     int sampleRate = SAMPLE_RATE_BY_FSCOD[fscod];
     int nextByte = data.readUnsignedByte();
@@ -160,8 +170,7 @@ public final class Ac3Util {
       channelCount++;
     }
 
-    // Read only the first dependent substream.
-    // TODO: Read later dependent substreams?
+    // Read the first dependent substream.
     nextByte = data.readUnsignedByte();
     int numDepSub = ((nextByte & 0x1E) >> 1);
     if (numDepSub > 0) {
@@ -189,7 +198,7 @@ public final class Ac3Util {
     boolean isEac3 = data.readBits(5) == 16;
     data.setPosition(initialPosition);
     String mimeType;
-    int streamType;
+    int streamType = Ac3SyncFrameInfo.STREAM_TYPE_UNDEFINED;
     int sampleRate;
     int acmod;
     int frameSize;
@@ -215,7 +224,6 @@ public final class Ac3Util {
     } else /* is AC-3 */ {
       mimeType = MimeTypes.AUDIO_AC3;
       data.skipBits(16 + 16); // syncword, crc1
-      streamType = STREAM_TYPE_UNDEFINED; // AC-3 stream hasn't streamType
       int fscod = data.readBits(2);
       int frmsizecod = data.readBits(6);
       frameSize = getAc3SyncframeSize(fscod, frmsizecod);
@@ -235,8 +243,8 @@ public final class Ac3Util {
     }
     boolean lfeon = data.readBit();
     int channelCount = CHANNEL_COUNT_BY_ACMOD[acmod] + (lfeon ? 1 : 0);
-    return new Ac3SyncFrameInfo(mimeType, streamType, channelCount, sampleRate,
-        frameSize, sampleCount);
+    return new Ac3SyncFrameInfo(mimeType, streamType, channelCount, sampleRate, frameSize,
+        sampleCount);
   }
 
   /**

library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/DashManifestParser.java

@@ -690,9 +690,9 @@ public class DashManifestParser extends DefaultHandler
       throws XmlPullParserException, IOException {
     String schemeIdUri = parseString(xpp, "schemeIdUri", null);
     int audioChannels = "urn:mpeg:dash:23003:3:audio_channel_configuration:2011".equals(schemeIdUri)
-        ? parseInt(xpp, "value", Format.NO_VALUE) :
-        ("tag:dolby.com,2014:dash:audio_channel_configuration:2011".equals(schemeIdUri)
-        ? parseDolbyChannelConfiguration(xpp, "value", Format.NO_VALUE) : Format.NO_VALUE);
+        ? parseInt(xpp, "value", Format.NO_VALUE)
+        : ("tag:dolby.com,2014:dash:audio_channel_configuration:2011".equals(schemeIdUri)
+        ? parseDolbyChannelConfiguration(xpp) : Format.NO_VALUE);
     do {
       xpp.next();
     } while (!XmlPullParserUtil.isEndTag(xpp, "AudioChannelConfiguration"));
@@ -903,31 +903,32 @@ public class DashManifestParser extends DefaultHandler
     return value == null ? defaultValue : value;
   }
 
-  protected static int parseDolbyChannelConfiguration(XmlPullParser xpp, String name,
-      int defaultValue) {
-    String value = Util.toLowerInvariant(xpp.getAttributeValue(null, name));
+  /**
+   * Parses the number of channels from the value attribute of an AudioElementConfiguration with
+   * schemeIdUri "tag:dolby.com,2014:dash:audio_channel_configuration:2011", as defined by table E.5
+   * in ETSI TS 102 366.
+   *
+   * @param xpp The parser from which to read.
+   * @return The parsed number of channels, or {@link Format#NO_VALUE} if the channel count could
+   *     not be parsed.
+   */
+  protected static int parseDolbyChannelConfiguration(XmlPullParser xpp) {
+    String value = Util.toLowerInvariant(xpp.getAttributeValue(null, "value"));
     if (value == null) {
-      return defaultValue;
+      return Format.NO_VALUE;
     }
-    int channels;
-    // TODO: Parse other channel configurations
     switch (value) {
       case "4000":
-        channels = 1;
-        break;
+        return 1;
       case "a000":
-        channels = 2;
-        break;
+        return 2;
       case "f801":
-        channels = 6;
-        break;
+        return 6;
       case "fa01":
-        channels = 8;
-        break;
+        return 8;
       default:
-        channels = defaultValue;
+        return Format.NO_VALUE;
     }
-    return channels;
   }
 
   private static final class RepresentationInfo {