Add configuration to support OPUS offload

To support OPUS offload, we need to provide a few configuration values
that are currently not set due to the lack of devices supporting
OPUS offload.

PiperOrigin-RevId: 491613716

library/common/src/main/java/com/google/android/exoplayer2/C.java

@@ -194,7 +194,7 @@ private C() {}
    * #ENCODING_PCM_16BIT_BIG_ENDIAN}, {@link #ENCODING_PCM_24BIT}, {@link #ENCODING_PCM_32BIT},
    * {@link #ENCODING_PCM_FLOAT}, {@link #ENCODING_MP3}, {@link #ENCODING_AC3}, {@link
    * #ENCODING_E_AC3}, {@link #ENCODING_E_AC3_JOC}, {@link #ENCODING_AC4}, {@link #ENCODING_DTS},
-   * {@link #ENCODING_DTS_HD} or {@link #ENCODING_DOLBY_TRUEHD}.
+   * {@link #ENCODING_DTS_HD}, {@link #ENCODING_DOLBY_TRUEHD} or {@link #ENCODING_OPUS}.
    */
   @Documented
   @Retention(RetentionPolicy.SOURCE)
@@ -221,7 +221,8 @@ private C() {}
     ENCODING_AC4,
     ENCODING_DTS,
     ENCODING_DTS_HD,
-    ENCODING_DOLBY_TRUEHD
+    ENCODING_DOLBY_TRUEHD,
+    ENCODING_OPUS,
   })
   public @interface Encoding {}
 
@@ -321,6 +322,10 @@ private C() {}
    * @see AudioFormat#ENCODING_DOLBY_TRUEHD
    */
   public static final int ENCODING_DOLBY_TRUEHD = AudioFormat.ENCODING_DOLBY_TRUEHD;
+  /**
+   * @see AudioFormat#ENCODING_OPUS
+   */
+  public static final int ENCODING_OPUS = AudioFormat.ENCODING_OPUS;
 
   /** Represents the behavior affecting whether spatialization will be used. */
   @Documented

library/common/src/main/java/com/google/android/exoplayer2/util/MimeTypes.java

@@ -567,6 +567,8 @@ public static String getMimeTypeFromMp4ObjectType(int objectType) {
         return C.ENCODING_DTS_HD;
       case MimeTypes.AUDIO_TRUEHD:
         return C.ENCODING_DOLBY_TRUEHD;
+      case MimeTypes.AUDIO_OPUS:
+        return C.ENCODING_OPUS;
       default:
         return C.ENCODING_INVALID;
     }

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

@@ -1666,6 +1666,8 @@ private static int getFramesPerEncodedSample(@C.Encoding int encoding, ByteBuffe
             ? 0
             : (Ac3Util.parseTrueHdSyncframeAudioSampleCount(buffer, syncframeOffset)
                 * Ac3Util.TRUEHD_RECHUNK_SAMPLE_COUNT);
+      case C.ENCODING_OPUS:
+        return OpusUtil.parsePacketAudioSampleCount(buffer);
       case C.ENCODING_PCM_16BIT:
       case C.ENCODING_PCM_16BIT_BIG_ENDIAN:
       case C.ENCODING_PCM_24BIT:

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

@@ -248,6 +248,8 @@ protected static int getMaximumEncodedRateBytesPerSecond(@C.Encoding int encodin
         return DtsUtil.DTS_HD_MAX_RATE_BYTES_PER_SECOND;
       case C.ENCODING_DOLBY_TRUEHD:
         return Ac3Util.TRUEHD_MAX_RATE_BYTES_PER_SECOND;
+      case C.ENCODING_OPUS:
+        return OpusUtil.MAX_BYTES_PER_SECOND;
       case C.ENCODING_PCM_16BIT:
       case C.ENCODING_PCM_16BIT_BIG_ENDIAN:
       case C.ENCODING_PCM_24BIT:

library/extractor/src/main/java/com/google/android/exoplayer2/audio/OpusUtil.java

@@ -27,6 +27,9 @@ public class OpusUtil {
   /** Opus streams are always 48000 Hz. */
   public static final int SAMPLE_RATE = 48_000;
 
+  /** Maximum achievable Opus bitrate. */
+  public static final int MAX_BYTES_PER_SECOND = 510 * 1000 / 8; // See RFC 6716. Section 2.1.1
+
   private static final int DEFAULT_SEEK_PRE_ROLL_SAMPLES = 3840;
   private static final int FULL_CODEC_INITIALIZATION_DATA_BUFFER_COUNT = 3;
 
@@ -61,6 +64,62 @@ public static List<byte[]> buildInitializationData(byte[] header) {
     return initializationData;
   }
 
+  /**
+   * Returns the number of audio samples in the given audio packet.
+   *
+   * <p>The buffer's position is not modified.
+   *
+   * @param buffer The audio packet.
+   * @return Returns the number of audio samples in the packet.
+   */
+  public static int parsePacketAudioSampleCount(ByteBuffer buffer) {
+    long packetDurationUs =
+        getPacketDurationUs(buffer.get(0), buffer.limit() > 1 ? buffer.get(1) : 0);
+    return (int) (packetDurationUs * SAMPLE_RATE / C.MICROS_PER_SECOND);
+  }
+
+  /**
+   * Returns the duration of the given audio packet.
+   *
+   * @param buffer The audio packet.
+   * @return Returns the duration of the given audio packet, in microseconds.
+   */
+  public static long getPacketDurationUs(byte[] buffer) {
+    return getPacketDurationUs(buffer[0], buffer.length > 1 ? buffer[1] : 0);
+  }
+
+  private static long getPacketDurationUs(byte packetByte0, byte packetByte1) {
+    // See RFC6716, Sections 3.1 and 3.2.
+    int toc = packetByte0 & 0xFF;
+    int frames;
+    switch (toc & 0x3) {
+      case 0:
+        frames = 1;
+        break;
+      case 1:
+      case 2:
+        frames = 2;
+        break;
+      default:
+        frames = packetByte1 & 0x3F;
+        break;
+    }
+
+    int config = toc >> 3;
+    int length = config & 0x3;
+    int frameDurationUs;
+    if (config >= 16) {
+      frameDurationUs = 2500 << length;
+    } else if (config >= 12) {
+      frameDurationUs = 10000 << (length & 0x1);
+    } else if (length == 3) {
+      frameDurationUs = 60000;
+    } else {
+      frameDurationUs = 10000 << length;
+    }
+    return (long) frames * frameDurationUs;
+  }
+
   private static int getPreSkipSamples(byte[] header) {
     return ((header[11] & 0xFF) << 8) | (header[10] & 0xFF);
   }

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/ogg/OpusReader.java

@@ -54,7 +54,7 @@ protected void reset(boolean headerData) {
 
   @Override
   protected long preparePayload(ParsableByteArray packet) {
-    return convertTimeToGranule(getPacketDurationUs(packet.getData()));
+    return convertTimeToGranule(OpusUtil.getPacketDurationUs(packet.getData()));
   }
 
   @Override
@@ -121,42 +121,6 @@ protected boolean readHeaders(ParsableByteArray packet, long position, SetupData
     }
   }
 
-  /**
-   * Returns the duration of the given audio packet.
-   *
-   * @param packet Contains audio data.
-   * @return Returns the duration of the given audio packet.
-   */
-  private long getPacketDurationUs(byte[] packet) {
-    int toc = packet[0] & 0xFF;
-    int frames;
-    switch (toc & 0x3) {
-      case 0:
-        frames = 1;
-        break;
-      case 1:
-      case 2:
-        frames = 2;
-        break;
-      default:
-        frames = packet[1] & 0x3F;
-        break;
-    }
-
-    int config = toc >> 3;
-    int length = config & 0x3;
-    if (config >= 16) {
-      length = 2500 << length;
-    } else if (config >= 12) {
-      length = 10000 << (length & 0x1);
-    } else if (length == 3) {
-      length = 60000;
-    } else {
-      length = 10000 << length;
-    }
-    return (long) frames * length;
-  }
-
   /**
    * Returns true if the given {@link ParsableByteArray} starts with {@code expectedPrefix}. Does
    * not change the {@link ParsableByteArray#getPosition() position} of {@code packet}.