Support 8-bit and 24-bit PCM with re-sampling.

This is a cleaned up version of the pull request below,
which will be merged with this change then applied on top.

https://github.com/google/ExoPlayer/pull/1490

Issue: #1246
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=121926682

extensions/flac/src/main/java/com/google/android/exoplayer/ext/flac/FlacExtractor.java

@@ -105,8 +105,8 @@ public final class FlacExtractor implements Extractor {
       });
 
       Format mediaFormat = Format.createAudioSampleFormat(null, MimeTypes.AUDIO_RAW,
-          streamInfo.bitRate(), Format.NO_VALUE, streamInfo.channels, streamInfo.sampleRate, null,
-          null, null);
+          streamInfo.bitRate(), Format.NO_VALUE, streamInfo.channels, streamInfo.sampleRate,
+          C.ENCODING_PCM_16BIT, null, null, null);
       trackOutput.format(mediaFormat);
 
       outputBuffer = new ParsableByteArray(streamInfo.maxDecodedFrameSize());

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

@@ -60,6 +60,26 @@ public final class C {
   public static final int CRYPTO_MODE_AES_CTR = MediaCodec.CRYPTO_MODE_AES_CTR;
 
   /**
+   * @see AudioFormat#ENCODING_INVALID
+   */
+  public static final int ENCODING_INVALID = AudioFormat.ENCODING_INVALID;
+
+  /**
+   * @see AudioFormat#ENCODING_PCM_8BIT
+   */
+  public static final int ENCODING_PCM_8BIT = AudioFormat.ENCODING_PCM_8BIT;
+
+  /**
+   * @see AudioFormat#ENCODING_PCM_16BIT
+   */
+  public static final int ENCODING_PCM_16BIT = AudioFormat.ENCODING_PCM_16BIT;
+
+  /**
+   * PCM encoding with 24 bits per sample.
+   */
+  public static final int ENCODING_PCM_24BIT = 0x80000000;
+
+  /**
    * @see AudioFormat#ENCODING_AC3
    */
   @SuppressWarnings("InlinedApi")

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

@@ -333,10 +333,11 @@ public final class FrameworkSampleSource implements SampleSource {
       initializationData.add(data);
       buffer.flip();
     }
+    int pcmEncoding = MimeTypes.AUDIO_RAW.equals(mimeType) ? C.ENCODING_PCM_16BIT : Format.NO_VALUE;
     Format format = new Format(Integer.toString(index), null, mimeType, Format.NO_VALUE,
         maxInputSize, width, height, frameRate, rotationDegrees, Format.NO_VALUE, channelCount,
-        sampleRate, encoderDelay, encoderPadding, language, Format.OFFSET_SAMPLE_RELATIVE,
-        initializationData, drmInitData, false);
+        sampleRate, pcmEncoding, encoderDelay, encoderPadding, language,
+        Format.OFFSET_SAMPLE_RELATIVE, initializationData, drmInitData, false);
     format.setFrameworkMediaFormatV16(mediaFormat);
     return format;
   }

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

@@ -70,6 +70,7 @@ public class MediaCodecAudioTrackRenderer extends MediaCodecTrackRenderer implem
 
   private boolean passthroughEnabled;
   private android.media.MediaFormat passthroughMediaFormat;
+  private int pcmEncoding;
   private int audioSessionId;
   private long currentPositionUs;
   private boolean allowPositionDiscontinuity;
@@ -235,6 +236,15 @@ public class MediaCodecAudioTrackRenderer extends MediaCodecTrackRenderer implem
   }
 
   @Override
+  protected void onInputFormatChanged(FormatHolder holder) throws ExoPlaybackException {
+    super.onInputFormatChanged(holder);
+    // If the input format is anything other than PCM then we assume that the audio decoder will
+    // output 16-bit PCM.
+    pcmEncoding = MimeTypes.AUDIO_RAW.equals(holder.format.sampleMimeType)
+        ? holder.format.pcmEncoding : C.ENCODING_PCM_16BIT;
+  }
+
+  @Override
   protected void onOutputFormatChanged(MediaCodec codec, MediaFormat outputFormat) {
     boolean passthrough = passthroughMediaFormat != null;
     String mimeType = passthrough
@@ -243,7 +253,7 @@ public class MediaCodecAudioTrackRenderer extends MediaCodecTrackRenderer implem
     android.media.MediaFormat format = passthrough ? passthroughMediaFormat : outputFormat;
     int channelCount = format.getInteger(android.media.MediaFormat.KEY_CHANNEL_COUNT);
     int sampleRate = format.getInteger(android.media.MediaFormat.KEY_SAMPLE_RATE);
-    audioTrack.configure(mimeType, channelCount, sampleRate);
+    audioTrack.configure(mimeType, channelCount, sampleRate, pcmEncoding);
   }
 
   /**

library/src/main/java/com/google/android/exoplayer/extractor/mkv/MatroskaExtractor.java

@@ -1207,6 +1207,7 @@ public final class MatroskaExtractor implements Extractor {
     public void initializeOutput(ExtractorOutput output, int trackId) throws ParserException {
       String mimeType;
       int maxInputSize = Format.NO_VALUE;
+      int pcmEncoding = Format.NO_VALUE;
       List<byte[]> initializationData = null;
       switch (codecId) {
         case CODEC_ID_VP8:
@@ -1291,13 +1292,15 @@ public final class MatroskaExtractor implements Extractor {
           if (!parseMsAcmCodecPrivate(new ParsableByteArray(codecPrivate))) {
             throw new ParserException("Non-PCM MS/ACM is unsupported");
           }
-          if (audioBitDepth != 16) {
+          pcmEncoding = Util.getPcmEncoding(audioBitDepth);
+          if (pcmEncoding == C.ENCODING_INVALID) {
             throw new ParserException("Unsupported PCM bit depth: " + audioBitDepth);
           }
           break;
         case CODEC_ID_PCM_INT_LIT:
           mimeType = MimeTypes.AUDIO_RAW;
-          if (audioBitDepth != 16) {
+          pcmEncoding = Util.getPcmEncoding(audioBitDepth);
+          if (pcmEncoding == C.ENCODING_INVALID) {
             throw new ParserException("Unsupported PCM bit depth: " + audioBitDepth);
           }
           break;
@@ -1320,8 +1323,8 @@ public final class MatroskaExtractor implements Extractor {
       // into the trackId passed when creating the formats.
       if (MimeTypes.isAudio(mimeType)) {
         format = Format.createAudioSampleFormat(Integer.toString(trackId), mimeType,
-            Format.NO_VALUE, maxInputSize, channelCount, sampleRate, initializationData, language,
-            drmInitData);
+            Format.NO_VALUE, maxInputSize, channelCount, sampleRate, pcmEncoding,
+            initializationData, drmInitData, language);
       } else if (MimeTypes.isVideo(mimeType)) {
         if (displayUnit == Track.DISPLAY_UNIT_PIXELS) {
           displayWidth = displayWidth == Format.NO_VALUE ? width : displayWidth;

library/src/main/java/com/google/android/exoplayer/extractor/mp3/Mp3Extractor.java

@@ -127,7 +127,7 @@ public final class Mp3Extractor implements Extractor {
       extractorOutput.seekMap(seeker);
       trackOutput.format(Format.createAudioSampleFormat(null, synchronizedHeader.mimeType,
           Format.NO_VALUE, MpegAudioHeader.MAX_FRAME_SIZE_BYTES, synchronizedHeader.channels,
-          synchronizedHeader.sampleRate, gaplessInfoHolder.encoderDelay,
+          synchronizedHeader.sampleRate, Format.NO_VALUE, gaplessInfoHolder.encoderDelay,
           gaplessInfoHolder.encoderPadding, null, null, null));
     }
     return readSample(input);

library/src/main/java/com/google/android/exoplayer/extractor/mp4/AtomParsers.java

@@ -939,8 +939,8 @@ import java.util.List;
           || atomType == Atom.TYPE_dtsh || atomType == Atom.TYPE_dtsl)
           && childAtomType == Atom.TYPE_ddts) {
         out.format = Format.createAudioSampleFormat(Integer.toString(trackId), mimeType,
-            Format.NO_VALUE, Format.NO_VALUE, channelCount, sampleRate, null, language,
-            drmInitData);
+            Format.NO_VALUE, Format.NO_VALUE, channelCount, sampleRate, null, drmInitData,
+            language);
         return;
       }
       childAtomPosition += childAtomSize;
@@ -951,10 +951,13 @@ import java.util.List;
       return;
     }
 
+    // TODO: Determine the correct PCM encoding.
+    int pcmEncoding = MimeTypes.AUDIO_RAW.equals(mimeType) ? C.ENCODING_PCM_16BIT : Format.NO_VALUE;
+
     out.format = Format.createAudioSampleFormat(Integer.toString(trackId), mimeType,
-        Format.NO_VALUE, Format.NO_VALUE, channelCount, sampleRate,
+        Format.NO_VALUE, Format.NO_VALUE, channelCount, sampleRate, pcmEncoding,
         initializationData == null ? null : Collections.singletonList(initializationData),
-        language, drmInitData);
+        drmInitData, language);
   }
 
   /** Returns the position of the esds box within a parent, or -1 if no esds box is found */

library/src/main/java/com/google/android/exoplayer/extractor/wav/WavExtractor.java

@@ -74,7 +74,7 @@ public final class WavExtractor implements Extractor, SeekMap {
       }
       Format format = Format.createAudioSampleFormat(null, MimeTypes.AUDIO_RAW,
           wavHeader.getBitrate(), MAX_INPUT_SIZE, wavHeader.getNumChannels(),
-          wavHeader.getSampleRateHz(), null, null, null);
+          wavHeader.getSampleRateHz(), wavHeader.getEncoding(), null, null, null);
       trackOutput.format(format);
       bytesPerFrame = wavHeader.getBytesPerFrame();
     }

library/src/main/java/com/google/android/exoplayer/extractor/wav/WavHeader.java

@@ -30,22 +30,22 @@ import com.google.android.exoplayer.C;
   private final int blockAlignment;
   /** Bits per sample for the audio data. */
   private final int bitsPerSample;
+  /** The pcm encoding */
+  private final int encoding;
+
   /** Offset to the start of sample data. */
   private long dataStartPosition;
   /** Total size in bytes of the sample data. */
   private long dataSize;
 
-  public WavHeader(
-      int numChannels,
-      int sampleRateHz,
-      int averageBytesPerSecond,
-      int blockAlignment,
-      int bitsPerSample) {
+  public WavHeader(int numChannels, int sampleRateHz, int averageBytesPerSecond, int blockAlignment,
+      int bitsPerSample, int encoding) {
     this.numChannels = numChannels;
     this.sampleRateHz = sampleRateHz;
     this.averageBytesPerSecond = averageBytesPerSecond;
     this.blockAlignment = blockAlignment;
     this.bitsPerSample = bitsPerSample;
+    this.encoding = encoding;
   }
 
   /** Returns the duration in microseconds of this WAV. */
@@ -110,4 +110,10 @@ import com.google.android.exoplayer.C;
     this.dataStartPosition = dataStartPosition;
     this.dataSize = dataSize;
   }
+
+  /** Returns the PCM encoding. **/
+  public int getEncoding() {
+    return encoding;
+  }
+
 }

library/src/main/java/com/google/android/exoplayer/extractor/wav/WavHeaderReader.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer.extractor.wav;
 
+import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.ParserException;
 import com.google.android.exoplayer.extractor.ExtractorInput;
 import com.google.android.exoplayer.util.Assertions;
@@ -87,8 +88,10 @@ import java.io.IOException;
       throw new ParserException("Expected block alignment: " + expectedBlockAlignment + "; got: "
           + blockAlignment);
     }
-    if (bitsPerSample != 16) {
-      Log.e(TAG, "Only 16-bit WAVs are supported; got: " + bitsPerSample);
+
+    int encoding = Util.getPcmEncoding(bitsPerSample);
+    if (encoding == C.ENCODING_INVALID) {
+      Log.e(TAG, "Unsupported WAV bit depth: " + bitsPerSample);
       return null;
     }
 
@@ -100,8 +103,8 @@ import java.io.IOException;
     // If present, skip extensionSize, validBitsPerSample, channelMask, subFormatGuid, ...
     input.advancePeekPosition((int) chunkHeader.size - 16);
 
-    return new WavHeader(
-        numChannels, sampleRateHz, averageBytesPerSecond, blockAlignment, bitsPerSample);
+    return new WavHeader(numChannels, sampleRateHz, averageBytesPerSecond, blockAlignment,
+        bitsPerSample, encoding);
   }
 
   /**

library/src/main/java/com/google/android/exoplayer/util/Ac3Util.java

@@ -80,7 +80,7 @@ public final class Ac3Util {
       channelCount++;
     }
     return Format.createAudioSampleFormat(trackId, MimeTypes.AUDIO_AC3, Format.NO_VALUE,
-        Format.NO_VALUE, channelCount, sampleRate, null, language, drmInitData);
+        Format.NO_VALUE, channelCount, sampleRate, null, drmInitData, language);
   }
 
   /**
@@ -107,7 +107,7 @@ public final class Ac3Util {
       channelCount++;
     }
     return Format.createAudioSampleFormat(trackId, MimeTypes.AUDIO_E_AC3, Format.NO_VALUE,
-        Format.NO_VALUE, channelCount, sampleRate, null, language, drmInitData);
+        Format.NO_VALUE, channelCount, sampleRate, null, drmInitData, language);
   }
 
   /**
@@ -138,7 +138,7 @@ public final class Ac3Util {
     boolean lfeon = data.readBit();
     return Format.createAudioSampleFormat(trackId, MimeTypes.AUDIO_AC3, Format.NO_VALUE,
         Format.NO_VALUE, CHANNEL_COUNT_BY_ACMOD[acmod] + (lfeon ? 1 : 0),
-        SAMPLE_RATE_BY_FSCOD[fscod], null, language, drmInitData);
+        SAMPLE_RATE_BY_FSCOD[fscod], null, drmInitData, language);
   }
 
   /**
@@ -166,7 +166,7 @@ public final class Ac3Util {
     boolean lfeon = data.readBit();
     return Format.createAudioSampleFormat(trackId, MimeTypes.AUDIO_E_AC3, Format.NO_VALUE,
         Format.NO_VALUE, CHANNEL_COUNT_BY_ACMOD[acmod] + (lfeon ? 1 : 0), sampleRate, null,
-        language, drmInitData);
+        drmInitData, language);
   }
 
   /**

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

@@ -73,7 +73,7 @@ public final class DtsUtil {
     frameBits.skipBits(10); // MIX, DYNF, TIMEF, AUXF, HDCD, EXT_AUDIO_ID, EXT_AUDIO, ASPF
     channelCount += frameBits.readBits(2) > 0 ? 1 : 0; // LFF
     return Format.createAudioSampleFormat(trackId, MimeTypes.AUDIO_DTS, bitrate, Format.NO_VALUE,
-        channelCount, sampleRate, null, language, drmInitData);
+        channelCount, sampleRate, null, drmInitData, language);
   }
 
   /**

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

@@ -778,6 +778,27 @@ 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.
+   * @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
+   *     unsupported then {@link C#ENCODING_INVALID} is returned.
+   */
+  public static int getPcmEncoding(int bitDepth) {
+    switch (bitDepth) {
+      case 8:
+        return C.ENCODING_PCM_8BIT;
+      case 16:
+        return C.ENCODING_PCM_16BIT;
+      case 24:
+        return C.ENCODING_PCM_24BIT;
+      default:
+        return C.ENCODING_INVALID;
+    }
+  }
+
+  /**
    * Makes a best guess to infer the type from a file name.
    *
    * @param fileName Name of the file. It can include the path of the file.

library/src/main/java/com/google/android/exoplayer/util/extensions/AudioDecoderTrackRenderer.java

@@ -292,7 +292,8 @@ public abstract class AudioDecoderTrackRenderer extends TrackRenderer implements
     int result = readSource(formatHolder, null);
     if (result == TrackStream.FORMAT_READ) {
       format = formatHolder.format;
-      audioTrack.configure(MimeTypes.AUDIO_RAW, format.channelCount, format.sampleRate);
+      audioTrack.configure(MimeTypes.AUDIO_RAW, format.channelCount, format.sampleRate,
+          C.ENCODING_PCM_16BIT);
       return true;
     }
     return false;