Clean up AudioTagPayloadReader

library/src/main/java/com/google/android/exoplayer2/extractor/flv/AudioTagPayloadReader.java

@@ -15,8 +15,6 @@
  */
 package com.google.android.exoplayer2.extractor.flv;
 
-import android.media.AudioFormat;
-import android.media.AudioTrack;
 import android.util.Pair;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
@@ -31,20 +29,13 @@ import java.util.Collections;
  */
 /* package */ final class AudioTagPayloadReader extends TagPayloadReader {
 
-  // Audio format
   private static final int AUDIO_FORMAT_ALAW = 7;
   private static final int AUDIO_FORMAT_ULAW = 8;
   private static final int AUDIO_FORMAT_AAC = 10;
 
-  // AAC PACKET TYPE
   private static final int AAC_PACKET_TYPE_SEQUENCE_HEADER = 0;
   private static final int AAC_PACKET_TYPE_AAC_RAW = 1;
 
-  // SAMPLING RATES
-  private static final int[] AUDIO_SAMPLING_RATE_TABLE = new int[] {
-      5500, 11000, 22000, 44000
-  };
-
   // State variables
   private boolean hasParsedAudioDataHeader;
   private boolean hasOutputFormat;
@@ -64,25 +55,18 @@ import java.util.Collections;
     if (!hasParsedAudioDataHeader) {
       int header = data.readUnsignedByte();
       audioFormat = (header >> 4) & 0x0F;
-      int sampleRateIndex = (header >> 2) & 0x03;
-      int encodingSize = header & 0x01;
-      if (sampleRateIndex < 0 || sampleRateIndex >= AUDIO_SAMPLING_RATE_TABLE.length) {
-        throw new UnsupportedFormatException("Invalid sample rate index: " + sampleRateIndex);
-      }
       // TODO: Add support for MP3.
       if (audioFormat == AUDIO_FORMAT_ALAW || audioFormat == AUDIO_FORMAT_ULAW) {
-
-          String type = (audioFormat == AUDIO_FORMAT_ALAW) ? MimeTypes.AUDIO_ALAW : MimeTypes.AUDIO_ULAW;
-          int encoding = (encodingSize == 1) ? C.ENCODING_PCM_16BIT : C.ENCODING_PCM_8BIT;
-          Format format = Format.createAudioSampleFormat(null, type, null, Format.NO_VALUE, Format.NO_VALUE,
-                  1, 8000, encoding, null, null, 0, null);
-          output.format(format);
-
-          hasOutputFormat = true;
-      } else if (audioFormat != AUDIO_FORMAT_AAC ) {
-          throw new UnsupportedFormatException("Audio format not supported: " + audioFormat);
+        String type = audioFormat == AUDIO_FORMAT_ALAW ? MimeTypes.AUDIO_ALAW
+            : MimeTypes.AUDIO_ULAW;
+        int pcmEncoding = (header & 0x01) == 1 ? C.ENCODING_PCM_16BIT : C.ENCODING_PCM_8BIT;
+        Format format = Format.createAudioSampleFormat(null, type, null, Format.NO_VALUE,
+            Format.NO_VALUE, 1, 8000, pcmEncoding, null, null, 0, null);
+        output.format(format);
+        hasOutputFormat = true;
+      } else if (audioFormat != AUDIO_FORMAT_AAC) {
+        throw new UnsupportedFormatException("Audio format not supported: " + audioFormat);
       }
-
       hasParsedAudioDataHeader = true;
     } else {
       // Skip header if it was parsed previously.
@@ -94,22 +78,22 @@ import java.util.Collections;
   @Override
   protected void parsePayload(ParsableByteArray data, long timeUs) {
     int packetType = data.readUnsignedByte();
-
     if (packetType == AAC_PACKET_TYPE_SEQUENCE_HEADER && !hasOutputFormat) {
-      // Parse sequence header just in case it was not done before.
-      byte[] audioSpecifiConfig = new byte[data.bytesLeft()];
-      data.readBytes(audioSpecifiConfig, 0, audioSpecifiConfig.length);
+      // Parse the sequence header.
+      byte[] audioSpecificConfig = new byte[data.bytesLeft()];
+      data.readBytes(audioSpecificConfig, 0, audioSpecificConfig.length);
       Pair<Integer, Integer> audioParams = CodecSpecificDataUtil.parseAacAudioSpecificConfig(
-          audioSpecifiConfig);
+          audioSpecificConfig);
       Format format = Format.createAudioSampleFormat(null, MimeTypes.AUDIO_AAC, null,
           Format.NO_VALUE, Format.NO_VALUE, audioParams.second, audioParams.first,
-          Collections.singletonList(audioSpecifiConfig), null, 0, null);
+          Collections.singletonList(audioSpecificConfig), null, 0, null);
       output.format(format);
       hasOutputFormat = true;
     } else if (audioFormat != AUDIO_FORMAT_AAC || packetType == AAC_PACKET_TYPE_AAC_RAW) {
-      int bytes = data.bytesLeft();
-      output.sampleData(data, bytes);
-      output.sampleMetadata(timeUs, C.BUFFER_FLAG_KEY_FRAME, bytes, 0, null);
+      int sampleSize = data.bytesLeft();
+      output.sampleData(data, sampleSize);
+      output.sampleMetadata(timeUs, C.BUFFER_FLAG_KEY_FRAME, sampleSize, 0, null);
     }
   }
+
 }