Support 32-bit WAV.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=122157513

library/src/main/java/com/google/android/exoplayer/C.java

@@ -79,6 +79,11 @@ public final class C {
    */
   public static final int ENCODING_PCM_24BIT = 0x80000000;
 
+  /**
+   * PCM encoding with 32 bits per sample.
+   */
+  public static final int ENCODING_PCM_32BIT = 0x40000000;
+
   /**
    * @see AudioFormat#ENCODING_AC3
    */

library/src/main/java/com/google/android/exoplayer/Format.java

@@ -134,8 +134,9 @@ public final class Format {
   public final int sampleRate;
   /**
    * The encoding for PCM audio streams. If {@link #sampleMimeType} is {@link MimeTypes#AUDIO_RAW}
-   * then one of {@link C#ENCODING_PCM_8BIT}, {@link C#ENCODING_PCM_16BIT} and
+   * then one of {@link C#ENCODING_PCM_8BIT}, {@link C#ENCODING_PCM_16BIT},
-   * {@link C#ENCODING_PCM_24BIT}. Set to {@link #NO_VALUE} for other media types.
+   * {@link C#ENCODING_PCM_24BIT} and {@link C#ENCODING_PCM_32BIT}. Set to {@link #NO_VALUE} for
+   * other media types.
    */
   public final int pcmEncoding;
   /**

library/src/main/java/com/google/android/exoplayer/audio/AudioTrack.java

@@ -341,7 +341,8 @@ public final class AudioTrack {
    * @param channelCount The number of channels.
    * @param sampleRate The sample rate in Hz.
    * @param pcmEncoding For PCM formats, the encoding used. One of {@link C#ENCODING_PCM_16BIT},
-   *     {@link C#ENCODING_PCM_16BIT} and {@link C#ENCODING_PCM_24BIT}.
+   *     {@link C#ENCODING_PCM_16BIT}, {@link C#ENCODING_PCM_24BIT} and
+   *     {@link C#ENCODING_PCM_32BIT}.
    */
   public void configure(String mimeType, int channelCount, int sampleRate, int pcmEncoding) {
     configure(mimeType, channelCount, sampleRate, pcmEncoding, 0);
@@ -354,7 +355,8 @@ public final class AudioTrack {
    * @param channelCount The number of channels.
    * @param sampleRate The sample rate in Hz.
    * @param pcmEncoding For PCM formats, the encoding used. One of {@link C#ENCODING_PCM_16BIT},
-   *     {@link C#ENCODING_PCM_16BIT} and {@link C#ENCODING_PCM_24BIT}.
+   *     {@link C#ENCODING_PCM_16BIT}, {@link C#ENCODING_PCM_24BIT} and
+   *     {@link C#ENCODING_PCM_32BIT}.
    * @param specifiedBufferSize A specific size for the playback buffer in bytes, or 0 to infer a
    *     suitable buffer size automatically.
    */
@@ -395,7 +397,7 @@ public final class AudioTrack {
     if (passthrough) {
       sourceEncoding = getEncodingForMimeType(mimeType);
     } else if (pcmEncoding == C.ENCODING_PCM_8BIT || pcmEncoding == C.ENCODING_PCM_16BIT
-        || pcmEncoding == C.ENCODING_PCM_24BIT) {
+        || pcmEncoding == C.ENCODING_PCM_24BIT || pcmEncoding == C.ENCODING_PCM_32BIT) {
       sourceEncoding = pcmEncoding;
     } else {
       throw new IllegalArgumentException("Unsupported PCM encoding: " + pcmEncoding);
@@ -711,7 +713,6 @@ public final class AudioTrack {
     audioTrackUtil.setPlaybackParameters(playbackParams);
   }
 
-
   /**
    * Sets the playback volume.
    */
@@ -991,6 +992,9 @@ public final class AudioTrack {
       case C.ENCODING_PCM_24BIT:
         resampledSize = (size / 3) * 2;
         break;
+      case C.ENCODING_PCM_32BIT:
+        resampledSize = size / 2;
+        break;
       default:
         // Never happens.
         throw new IllegalStateException();
@@ -1019,6 +1023,13 @@ public final class AudioTrack {
           resampledBuffer.put(buffer.get(i + 2));
         }
         break;
+      case C.ENCODING_PCM_32BIT:
+        // 32->16 bit resampling. Drop the two least significant bytes.
+        for (int i = offset; i < limit; i += 4) {
+          resampledBuffer.put(buffer.get(i + 2));
+          resampledBuffer.put(buffer.get(i + 3));
+        }
+        break;
       default:
         // Never happens.
         throw new IllegalStateException();

library/src/main/java/com/google/android/exoplayer/util/Util.java

@@ -780,10 +780,11 @@ public final class Util {
   /**
    * Converts a sample bit depth to a corresponding PCM encoding constant.
    *
-   * @param bitDepth The bit depth. Supported values are 8, 16 and 24.
+   * @param bitDepth The bit depth. Supported values are 8, 16, 24 and 32.
    * @return The corresponding encoding. One of {@link C#ENCODING_PCM_8BIT},
-   *     {@link C#ENCODING_PCM_16BIT} and {@link C#ENCODING_PCM_24BIT}. If the bit depth is
+   *     {@link C#ENCODING_PCM_16BIT}, {@link C#ENCODING_PCM_24BIT} and
-   *     unsupported then {@link C#ENCODING_INVALID} is returned.
+   *     {@link C#ENCODING_PCM_32BIT}. If the bit depth is unsupported then
+   *     {@link C#ENCODING_INVALID} is returned.
    */
   public static int getPcmEncoding(int bitDepth) {
     switch (bitDepth) {
@@ -793,6 +794,8 @@ public final class Util {
         return C.ENCODING_PCM_16BIT;
       case 24:
         return C.ENCODING_PCM_24BIT;
+      case 32:
+        return C.ENCODING_PCM_32BIT;
       default:
         return C.ENCODING_INVALID;
     }