Construct codecs string for AAC in MP4/TS/FLV

PiperOrigin-RevId: 297578984

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

@@ -23,11 +23,26 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
-/**
- * Provides static utility methods for manipulating various types of codec specific data.
- */
+/** Provides utilities for handling various types of codec-specific data. */
 public final class CodecSpecificDataUtil {
 
+  /** Holds sample format information for AAC audio. */
+  public static final class AacConfig {
+
+    /** The sample rate in Hertz. */
+    public final int sampleRateHz;
+    /** The number of channels. */
+    public final int channelCount;
+    /** The RFC 6381 codecs string. */
+    public final String codecs;
+
+    private AacConfig(int sampleRateHz, int channelCount, String codecs) {
+      this.sampleRateHz = sampleRateHz;
+      this.channelCount = channelCount;
+      this.codecs = codecs;
+    }
+  }
+
   private static final byte[] NAL_START_CODE = new byte[] {0, 0, 0, 1};
 
   private static final int AUDIO_SPECIFIC_CONFIG_FREQUENCY_INDEX_ARBITRARY = 0xF;
@@ -70,14 +85,20 @@ public final class CodecSpecificDataUtil {
         AUDIO_SPECIFIC_CONFIG_CHANNEL_CONFIGURATION_INVALID
       };
 
+  /**
+   * Prefix for the RFC 6381 codecs string for AAC formats. To form a full codecs string, suffix the
+   * decimal AudioObjectType.
+   */
+  private static final String AAC_CODECS_STRING_PREFIX = "mp4a.40.";
+
   // Advanced Audio Coding Low-Complexity profile.
   private static final int AUDIO_OBJECT_TYPE_AAC_LC = 2;
   // Spectral Band Replication.
-  private static final int AUDIO_OBJECT_TYPE_SBR = 5;
+  private static final int AUDIO_OBJECT_TYPE_AAC_SBR = 5;
   // Error Resilient Bit-Sliced Arithmetic Coding.
-  private static final int AUDIO_OBJECT_TYPE_ER_BSAC = 22;
+  private static final int AUDIO_OBJECT_TYPE_AAC_ER_BSAC = 22;
   // Parametric Stereo.
-  private static final int AUDIO_OBJECT_TYPE_PS = 29;
+  private static final int AUDIO_OBJECT_TYPE_AAC_PS = 29;
   // Escape code for extended audio object types.
   private static final int AUDIO_OBJECT_TYPE_ESCAPE = 31;
 
@@ -87,12 +108,13 @@ public final class CodecSpecificDataUtil {
    * Parses an AAC AudioSpecificConfig, as defined in ISO 14496-3 1.6.2.1
    *
    * @param audioSpecificConfig A byte array containing the AudioSpecificConfig to parse.
-   * @return A pair consisting of the sample rate in Hz and the channel count.
+   * @return The parsed configuration.
    * @throws ParserException If the AudioSpecificConfig cannot be parsed as it's not supported.
    */
-  public static Pair<Integer, Integer> parseAacAudioSpecificConfig(byte[] audioSpecificConfig)
+  public static AacConfig parseAacAudioSpecificConfig(byte[] audioSpecificConfig)
       throws ParserException {
-    return parseAacAudioSpecificConfig(new ParsableBitArray(audioSpecificConfig), false);
+    return parseAacAudioSpecificConfig(
+        new ParsableBitArray(audioSpecificConfig), /* forceReadToEnd= */ false);
   }
 
   /**
@@ -102,23 +124,25 @@ public final class CodecSpecificDataUtil {
    *     position is advanced to the end of the AudioSpecificConfig.
    * @param forceReadToEnd Whether the entire AudioSpecificConfig should be read. Required for
    *     knowing the length of the configuration payload.
-   * @return A pair consisting of the sample rate in Hz and the channel count.
+   * @return The parsed configuration.
    * @throws ParserException If the AudioSpecificConfig cannot be parsed as it's not supported.
    */
-  public static Pair<Integer, Integer> parseAacAudioSpecificConfig(
+  public static AacConfig parseAacAudioSpecificConfig(
       ParsableBitArray bitArray, boolean forceReadToEnd) throws ParserException {
     int audioObjectType = getAacAudioObjectType(bitArray);
-    int sampleRate = getAacSamplingFrequency(bitArray);
+    int sampleRateHz = getAacSamplingFrequency(bitArray);
     int channelConfiguration = bitArray.readBits(4);
-    if (audioObjectType == AUDIO_OBJECT_TYPE_SBR || audioObjectType == AUDIO_OBJECT_TYPE_PS) {
+    String codecs = AAC_CODECS_STRING_PREFIX + audioObjectType;
+    if (audioObjectType == AUDIO_OBJECT_TYPE_AAC_SBR
+        || audioObjectType == AUDIO_OBJECT_TYPE_AAC_PS) {
       // For an AAC bitstream using spectral band replication (SBR) or parametric stereo (PS) with
       // explicit signaling, we return the extension sampling frequency as the sample rate of the
       // content; this is identical to the sample rate of the decoded output but may differ from
       // the sample rate set above.
       // Use the extensionSamplingFrequencyIndex.
-      sampleRate = getAacSamplingFrequency(bitArray);
+      sampleRateHz = getAacSamplingFrequency(bitArray);
       audioObjectType = getAacAudioObjectType(bitArray);
-      if (audioObjectType == AUDIO_OBJECT_TYPE_ER_BSAC) {
+      if (audioObjectType == AUDIO_OBJECT_TYPE_AAC_ER_BSAC) {
         // Use the extensionChannelConfiguration.
         channelConfiguration = bitArray.readBits(4);
       }
@@ -160,7 +184,7 @@ public final class CodecSpecificDataUtil {
     // For supported containers, bits_to_decode() is always 0.
     int channelCount = AUDIO_SPECIFIC_CONFIG_CHANNEL_COUNT_TABLE[channelConfiguration];
     Assertions.checkArgument(channelCount != AUDIO_SPECIFIC_CONFIG_CHANNEL_CONFIGURATION_INVALID);
-    return Pair.create(sampleRate, channelCount);
+    return new AacConfig(sampleRateHz, channelCount, codecs);
   }
 
   /**

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

@@ -15,12 +15,12 @@
  */
 package com.google.android.exoplayer2.extractor.flv;
 
-import android.util.Pair;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.ParserException;
 import com.google.android.exoplayer2.extractor.TrackOutput;
 import com.google.android.exoplayer2.util.CodecSpecificDataUtil;
+import com.google.android.exoplayer2.util.CodecSpecificDataUtil.AacConfig;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import java.util.Collections;
@@ -109,11 +109,16 @@ import java.util.Collections;
         // Parse the sequence header.
         byte[] audioSpecificConfig = new byte[data.bytesLeft()];
         data.readBytes(audioSpecificConfig, 0, audioSpecificConfig.length);
-        Pair<Integer, Integer> audioParams = CodecSpecificDataUtil.parseAacAudioSpecificConfig(
-            audioSpecificConfig);
-        Format format = Format.createAudioSampleFormat(null, MimeTypes.AUDIO_AAC, null,
-            Format.NO_VALUE, Format.NO_VALUE, audioParams.second, audioParams.first,
-            Collections.singletonList(audioSpecificConfig), null, 0, null);
+        AacConfig aacConfig =
+            CodecSpecificDataUtil.parseAacAudioSpecificConfig(audioSpecificConfig);
+        Format format =
+            new Format.Builder()
+                .setSampleMimeType(MimeTypes.AUDIO_AAC)
+                .setCodecs(aacConfig.codecs)
+                .setChannelCount(aacConfig.channelCount)
+                .setSampleRate(aacConfig.sampleRateHz)
+                .setInitializationData(Collections.singletonList(audioSpecificConfig))
+                .build();
         output.format(format);
         hasOutputFormat = true;
         return false;

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java

@@ -29,6 +29,7 @@ import com.google.android.exoplayer2.extractor.GaplessInfoHolder;
 import com.google.android.exoplayer2.metadata.Metadata;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.CodecSpecificDataUtil;
+import com.google.android.exoplayer2.util.CodecSpecificDataUtil.AacConfig;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.ParsableByteArray;
@@ -1086,6 +1087,7 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     int channelCount;
     int sampleRate;
     @C.PcmEncoding int pcmEncoding = Format.NO_VALUE;
+    @Nullable String codecs = null;
 
     if (quickTimeSoundDescriptionVersion == 0 || quickTimeSoundDescriptionVersion == 1) {
       channelCount = parent.readUnsignedShort();
@@ -1182,10 +1184,11 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
           if (MimeTypes.AUDIO_AAC.equals(mimeType) && initializationData != null) {
             // Update sampleRate and channelCount from the AudioSpecificConfig initialization data,
             // which is more reliable. See [Internal: b/10903778].
-            Pair<Integer, Integer> audioSpecificConfig =
+            AacConfig aacConfig =
                 CodecSpecificDataUtil.parseAacAudioSpecificConfig(initializationData);
-            sampleRate = audioSpecificConfig.first;
-            channelCount = audioSpecificConfig.second;
+            sampleRate = aacConfig.sampleRateHz;
+            channelCount = aacConfig.channelCount;
+            codecs = aacConfig.codecs;
           }
         }
       } else if (childAtomType == Atom.TYPE_dac3) {
@@ -1237,10 +1240,19 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
     }
 
     if (out.format == null && mimeType != null) {
-      out.format = Format.createAudioSampleFormat(Integer.toString(trackId), mimeType, null,
-          Format.NO_VALUE, Format.NO_VALUE, channelCount, sampleRate, pcmEncoding,
-          initializationData == null ? null : Collections.singletonList(initializationData),
-          drmInitData, 0, language);
+      out.format =
+          new Format.Builder()
+              .setId(Integer.toString(trackId))
+              .setSampleMimeType(mimeType)
+              .setCodecs(codecs)
+              .setChannelCount(channelCount)
+              .setSampleRate(sampleRate)
+              .setPcmEncoding(pcmEncoding)
+              .setInitializationData(
+                  initializationData == null ? null : Collections.singletonList(initializationData))
+              .setDrmInitData(drmInitData)
+              .setLanguage(language)
+              .build();
     }
   }
 

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/ts/AdtsReader.java

@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.extractor.ts;
 
-import android.util.Pair;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
@@ -26,6 +25,7 @@ import com.google.android.exoplayer2.extractor.TrackOutput;
 import com.google.android.exoplayer2.extractor.ts.TsPayloadReader.TrackIdGenerator;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.CodecSpecificDataUtil;
+import com.google.android.exoplayer2.util.CodecSpecificDataUtil.AacConfig;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.ParsableBitArray;
@@ -469,12 +469,17 @@ public final class AdtsReader implements ElementaryStreamReader {
       byte[] audioSpecificConfig =
           CodecSpecificDataUtil.buildAacAudioSpecificConfig(
               audioObjectType, firstFrameSampleRateIndex, channelConfig);
-      Pair<Integer, Integer> audioParams = CodecSpecificDataUtil.parseAacAudioSpecificConfig(
-          audioSpecificConfig);
-
-      Format format = Format.createAudioSampleFormat(formatId, MimeTypes.AUDIO_AAC, null,
-          Format.NO_VALUE, Format.NO_VALUE, audioParams.second, audioParams.first,
-          Collections.singletonList(audioSpecificConfig), null, 0, language);
+      AacConfig aacConfig = CodecSpecificDataUtil.parseAacAudioSpecificConfig(audioSpecificConfig);
+      Format format =
+          new Format.Builder()
+              .setId(formatId)
+              .setSampleMimeType(MimeTypes.AUDIO_AAC)
+              .setCodecs(aacConfig.codecs)
+              .setChannelCount(aacConfig.channelCount)
+              .setSampleRate(aacConfig.sampleRateHz)
+              .setInitializationData(Collections.singletonList(audioSpecificConfig))
+              .setLanguage(language)
+              .build();
       // In this class a sample is an access unit, but the MediaFormat sample rate specifies the
       // number of PCM audio samples per second.
       sampleDurationUs = (C.MICROS_PER_SECOND * 1024) / format.sampleRate;

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/ts/LatmReader.java

@@ -15,7 +15,6 @@
  */
 package com.google.android.exoplayer2.extractor.ts;
 
-import android.util.Pair;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
@@ -25,6 +24,7 @@ import com.google.android.exoplayer2.extractor.TrackOutput;
 import com.google.android.exoplayer2.extractor.ts.TsPayloadReader.TrackIdGenerator;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.CodecSpecificDataUtil;
+import com.google.android.exoplayer2.util.CodecSpecificDataUtil.AacConfig;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.ParsableBitArray;
 import com.google.android.exoplayer2.util.ParsableByteArray;
@@ -273,9 +273,10 @@ public final class LatmReader implements ElementaryStreamReader {
 
   private int parseAudioSpecificConfig(ParsableBitArray data) throws ParserException {
     int bitsLeft = data.bitsLeft();
-    Pair<Integer, Integer> config = CodecSpecificDataUtil.parseAacAudioSpecificConfig(data, true);
-    sampleRateHz = config.first;
-    channelCount = config.second;
+    AacConfig config =
+        CodecSpecificDataUtil.parseAacAudioSpecificConfig(data, /* forceReadToEnd= */ true);
+    sampleRateHz = config.sampleRateHz;
+    channelCount = config.channelCount;
     return bitsLeft - data.bitsLeft();
   }