Move MpegAudioHeader to MpegUtil

This makes MPEG audio utilities similar to utilities we have for WAV,
AC-3 etc., and moves them out of the extractor package so that an
extractor module can be split out without needing to have a class in the
extractor package in the common library.

PiperOrigin-RevId: 290595089

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

@@ -28,7 +28,6 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.PlaybackParameters;
 import com.google.android.exoplayer2.audio.AudioProcessor.UnhandledAudioFormatException;
-import com.google.android.exoplayer2.extractor.MpegAudioHeader;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.Util;
@@ -1159,7 +1158,7 @@ public final class DefaultAudioSink implements AudioSink {
   private static int getFramesPerEncodedSample(@C.Encoding int encoding, ByteBuffer buffer) {
     switch (encoding) {
       case C.ENCODING_MP3:
-        return MpegAudioHeader.getFrameSampleCount(buffer.get(buffer.position()));
+        return MpegAudioUtil.parseMpegAudioFrameSampleCount(buffer.get(buffer.position()));
       case C.ENCODING_DTS:
       case C.ENCODING_DTS_HD:
         return DtsUtil.parseDtsAudioSampleCount(buffer);

library/core/src/main/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractor.java

@@ -24,6 +24,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.ParserException;
 import com.google.android.exoplayer2.audio.Ac3Util;
+import com.google.android.exoplayer2.audio.MpegAudioUtil;
 import com.google.android.exoplayer2.drm.DrmInitData;
 import com.google.android.exoplayer2.drm.DrmInitData.SchemeData;
 import com.google.android.exoplayer2.extractor.ChunkIndex;
@@ -31,7 +32,6 @@ import com.google.android.exoplayer2.extractor.Extractor;
 import com.google.android.exoplayer2.extractor.ExtractorInput;
 import com.google.android.exoplayer2.extractor.ExtractorOutput;
 import com.google.android.exoplayer2.extractor.ExtractorsFactory;
-import com.google.android.exoplayer2.extractor.MpegAudioHeader;
 import com.google.android.exoplayer2.extractor.PositionHolder;
 import com.google.android.exoplayer2.extractor.SeekMap;
 import com.google.android.exoplayer2.extractor.TrackOutput;
@@ -1989,11 +1989,11 @@ public class MatroskaExtractor implements Extractor {
           break;
         case CODEC_ID_MP2:
           mimeType = MimeTypes.AUDIO_MPEG_L2;
-          maxInputSize = MpegAudioHeader.MAX_FRAME_SIZE_BYTES;
+          maxInputSize = MpegAudioUtil.MAX_FRAME_SIZE_BYTES;
           break;
         case CODEC_ID_MP3:
           mimeType = MimeTypes.AUDIO_MPEG;
-          maxInputSize = MpegAudioHeader.MAX_FRAME_SIZE_BYTES;
+          maxInputSize = MpegAudioUtil.MAX_FRAME_SIZE_BYTES;
           break;
         case CODEC_ID_AC3:
           mimeType = MimeTypes.AUDIO_AC3;

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp3/ConstantBitrateSeeker.java

@@ -16,8 +16,8 @@
 package com.google.android.exoplayer2.extractor.mp3;
 
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.audio.MpegAudioUtil;
 import com.google.android.exoplayer2.extractor.ConstantBitrateSeekMap;
-import com.google.android.exoplayer2.extractor.MpegAudioHeader;
 
 /**
  * MP3 seeker that doesn't rely on metadata and seeks assuming the source has a constant bitrate.
@@ -30,7 +30,7 @@ import com.google.android.exoplayer2.extractor.MpegAudioHeader;
    * @param mpegAudioHeader The MPEG audio header associated with the first frame.
    */
   public ConstantBitrateSeeker(
-      long inputLength, long firstFramePosition, MpegAudioHeader mpegAudioHeader) {
+      long inputLength, long firstFramePosition, MpegAudioUtil.Header mpegAudioHeader) {
     super(inputLength, firstFramePosition, mpegAudioHeader.bitrate, mpegAudioHeader.frameSize);
   }
 

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp3/Mp3Extractor.java

@@ -20,13 +20,13 @@ import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.ParserException;
+import com.google.android.exoplayer2.audio.MpegAudioUtil;
 import com.google.android.exoplayer2.extractor.Extractor;
 import com.google.android.exoplayer2.extractor.ExtractorInput;
 import com.google.android.exoplayer2.extractor.ExtractorOutput;
 import com.google.android.exoplayer2.extractor.ExtractorsFactory;
 import com.google.android.exoplayer2.extractor.GaplessInfoHolder;
 import com.google.android.exoplayer2.extractor.Id3Peeker;
-import com.google.android.exoplayer2.extractor.MpegAudioHeader;
 import com.google.android.exoplayer2.extractor.PositionHolder;
 import com.google.android.exoplayer2.extractor.TrackOutput;
 import com.google.android.exoplayer2.extractor.mp3.Seeker.UnseekableSeeker;
@@ -107,7 +107,7 @@ public final class Mp3Extractor implements Extractor {
   @Flags private final int flags;
   private final long forcedFirstSampleTimestampUs;
   private final ParsableByteArray scratch;
-  private final MpegAudioHeader synchronizedHeader;
+  private final MpegAudioUtil.Header synchronizedHeader;
   private final GaplessInfoHolder gaplessInfoHolder;
   private final Id3Peeker id3Peeker;
 
@@ -145,7 +145,7 @@ public final class Mp3Extractor implements Extractor {
     this.flags = flags;
     this.forcedFirstSampleTimestampUs = forcedFirstSampleTimestampUs;
     scratch = new ParsableByteArray(SCRATCH_LENGTH);
-    synchronizedHeader = new MpegAudioHeader();
+    synchronizedHeader = new MpegAudioUtil.Header();
     gaplessInfoHolder = new GaplessInfoHolder();
     basisTimeUs = C.TIME_UNSET;
     id3Peeker = new Id3Peeker();
@@ -215,7 +215,7 @@ public final class Mp3Extractor implements Extractor {
               synchronizedHeader.mimeType,
               /* codecs= */ null,
               /* bitrate= */ Format.NO_VALUE,
-              MpegAudioHeader.MAX_FRAME_SIZE_BYTES,
+              MpegAudioUtil.MAX_FRAME_SIZE_BYTES,
               synchronizedHeader.channels,
               synchronizedHeader.sampleRate,
               /* pcmEncoding= */ Format.NO_VALUE,
@@ -258,13 +258,13 @@ public final class Mp3Extractor implements Extractor {
       scratch.setPosition(0);
       int sampleHeaderData = scratch.readInt();
       if (!headersMatch(sampleHeaderData, synchronizedHeaderData)
-          || MpegAudioHeader.getFrameSize(sampleHeaderData) == C.LENGTH_UNSET) {
+          || MpegAudioUtil.getFrameSize(sampleHeaderData) == C.LENGTH_UNSET) {
         // We have lost synchronization, so attempt to resynchronize starting at the next byte.
         extractorInput.skipFully(1);
         synchronizedHeaderData = 0;
         return RESULT_CONTINUE;
       }
-      MpegAudioHeader.populateHeader(sampleHeaderData, synchronizedHeader);
+      synchronizedHeader.setForHeaderData(sampleHeaderData);
       if (basisTimeUs == C.TIME_UNSET) {
         basisTimeUs = seeker.getTimeUs(extractorInput.getPosition());
         if (forcedFirstSampleTimestampUs != C.TIME_UNSET) {
@@ -325,8 +325,8 @@ public final class Mp3Extractor implements Extractor {
       int headerData = scratch.readInt();
       int frameSize;
       if ((candidateSynchronizedHeaderData != 0
-          && !headersMatch(headerData, candidateSynchronizedHeaderData))
-          || (frameSize = MpegAudioHeader.getFrameSize(headerData)) == C.LENGTH_UNSET) {
+              && !headersMatch(headerData, candidateSynchronizedHeaderData))
+          || (frameSize = MpegAudioUtil.getFrameSize(headerData)) == C.LENGTH_UNSET) {
         // The header doesn't match the candidate header or is invalid. Try the next byte offset.
         if (searchedBytes++ == searchLimitBytes) {
           if (!sniffing) {
@@ -346,7 +346,7 @@ public final class Mp3Extractor implements Extractor {
         // The header matches the candidate header and/or is valid.
         validFrameCount++;
         if (validFrameCount == 1) {
-          MpegAudioHeader.populateHeader(headerData, synchronizedHeader);
+          synchronizedHeader.setForHeaderData(headerData);
           candidateSynchronizedHeaderData = headerData;
         } else if (validFrameCount == 4) {
           break;
@@ -439,7 +439,7 @@ public final class Mp3Extractor implements Extractor {
       throws IOException, InterruptedException {
     input.peekFully(scratch.data, 0, 4);
     scratch.setPosition(0);
-    MpegAudioHeader.populateHeader(scratch.readInt(), synchronizedHeader);
+    synchronizedHeader.setForHeaderData(scratch.readInt());
     return new ConstantBitrateSeeker(input.getLength(), input.getPosition(), synchronizedHeader);
   }
 

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp3/VbriSeeker.java

@@ -17,7 +17,7 @@ package com.google.android.exoplayer2.extractor.mp3;
 
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.extractor.MpegAudioHeader;
+import com.google.android.exoplayer2.audio.MpegAudioUtil;
 import com.google.android.exoplayer2.extractor.SeekPoint;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.ParsableByteArray;
@@ -43,7 +43,10 @@ import com.google.android.exoplayer2.util.Util;
    */
   @Nullable
   public static VbriSeeker create(
-      long inputLength, long position, MpegAudioHeader mpegAudioHeader, ParsableByteArray frame) {
+      long inputLength,
+      long position,
+      MpegAudioUtil.Header mpegAudioHeader,
+      ParsableByteArray frame) {
     frame.skipBytes(10);
     int numFrames = frame.readInt();
     if (numFrames <= 0) {

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp3/XingSeeker.java

@@ -17,7 +17,7 @@ package com.google.android.exoplayer2.extractor.mp3;
 
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.extractor.MpegAudioHeader;
+import com.google.android.exoplayer2.audio.MpegAudioUtil;
 import com.google.android.exoplayer2.extractor.SeekPoint;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
@@ -44,7 +44,10 @@ import com.google.android.exoplayer2.util.Util;
    */
   @Nullable
   public static XingSeeker create(
-      long inputLength, long position, MpegAudioHeader mpegAudioHeader, ParsableByteArray frame) {
+      long inputLength,
+      long position,
+      MpegAudioUtil.Header mpegAudioHeader,
+      ParsableByteArray frame) {
     int samplesPerFrame = mpegAudioHeader.samplesPerFrame;
     int sampleRate = mpegAudioHeader.sampleRate;
 

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

@@ -17,8 +17,8 @@ package com.google.android.exoplayer2.extractor.ts;
 
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.audio.MpegAudioUtil;
 import com.google.android.exoplayer2.extractor.ExtractorOutput;
-import com.google.android.exoplayer2.extractor.MpegAudioHeader;
 import com.google.android.exoplayer2.extractor.TrackOutput;
 import com.google.android.exoplayer2.extractor.ts.TsPayloadReader.TrackIdGenerator;
 import com.google.android.exoplayer2.util.Assertions;
@@ -39,7 +39,7 @@ public final class MpegAudioReader implements ElementaryStreamReader {
   private static final int HEADER_SIZE = 4;
 
   private final ParsableByteArray headerScratch;
-  private final MpegAudioHeader header;
+  private final MpegAudioUtil.Header header;
   @Nullable private final String language;
 
   private @MonotonicNonNull TrackOutput output;
@@ -68,7 +68,7 @@ public final class MpegAudioReader implements ElementaryStreamReader {
     // The first byte of an MPEG Audio frame header is always 0xFF.
     headerScratch = new ParsableByteArray(4);
     headerScratch.data[0] = (byte) 0xFF;
-    header = new MpegAudioHeader();
+    header = new MpegAudioUtil.Header();
     this.language = language;
   }
 
@@ -176,7 +176,7 @@ public final class MpegAudioReader implements ElementaryStreamReader {
     }
 
     headerScratch.setPosition(0);
-    boolean parsedHeader = MpegAudioHeader.populateHeader(headerScratch.readInt(), header);
+    boolean parsedHeader = header.setForHeaderData(headerScratch.readInt());
     if (!parsedHeader) {
       // We thought we'd located a frame header, but we hadn't.
       frameBytesRead = 0;
@@ -187,9 +187,19 @@ public final class MpegAudioReader implements ElementaryStreamReader {
     frameSize = header.frameSize;
     if (!hasOutputFormat) {
       frameDurationUs = (C.MICROS_PER_SECOND * header.samplesPerFrame) / header.sampleRate;
-      Format format = Format.createAudioSampleFormat(formatId, header.mimeType, null,
-          Format.NO_VALUE, MpegAudioHeader.MAX_FRAME_SIZE_BYTES, header.channels, header.sampleRate,
-          null, null, 0, language);
+      Format format =
+          Format.createAudioSampleFormat(
+              formatId,
+              header.mimeType,
+              null,
+              Format.NO_VALUE,
+              MpegAudioUtil.MAX_FRAME_SIZE_BYTES,
+              header.channels,
+              header.sampleRate,
+              null,
+              null,
+              0,
+              language);
       output.format(format);
       hasOutputFormat = true;
     }

library/core/src/test/java/com/google/android/exoplayer2/extractor/mp3/XingSeekerTest.java

@@ -19,7 +19,7 @@ import static com.google.common.truth.Truth.assertThat;
 
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.extractor.MpegAudioHeader;
+import com.google.android.exoplayer2.audio.MpegAudioUtil;
 import com.google.android.exoplayer2.extractor.SeekMap.SeekPoints;
 import com.google.android.exoplayer2.extractor.SeekPoint;
 import com.google.android.exoplayer2.util.ParsableByteArray;
@@ -59,8 +59,8 @@ public final class XingSeekerTest {
 
   @Before
   public void setUp() throws Exception {
-    MpegAudioHeader xingFrameHeader = new MpegAudioHeader();
-    MpegAudioHeader.populateHeader(XING_FRAME_HEADER_DATA, xingFrameHeader);
+    MpegAudioUtil.Header xingFrameHeader = new MpegAudioUtil.Header();
+    xingFrameHeader.setForHeaderData(XING_FRAME_HEADER_DATA);
     seeker = XingSeeker.create(C.LENGTH_UNSET, XING_FRAME_POSITION, xingFrameHeader,
         new ParsableByteArray(XING_FRAME_PAYLOAD));
     seekerWithInputLength = XingSeeker.create(STREAM_LENGTH,