Deduplicate ID3 header constants

PiperOrigin-RevId: 259479785

library/core/src/main/java/com/google/android/exoplayer2/extractor/Id3Peeker.java

@@ -53,7 +53,7 @@ public final class Id3Peeker {
     Metadata metadata = null;
     while (true) {
       try {
-        input.peekFully(scratch.data, 0, Id3Decoder.ID3_HEADER_LENGTH);
+        input.peekFully(scratch.data, /* offset= */ 0, Id3Decoder.ID3_HEADER_LENGTH);
       } catch (EOFException e) {
         // If input has less than ID3_HEADER_LENGTH, ignore the rest.
         break;

library/core/src/main/java/com/google/android/exoplayer2/extractor/ts/Ac3Extractor.java

@@ -16,6 +16,8 @@
 package com.google.android.exoplayer2.extractor.ts;
 
 import static com.google.android.exoplayer2.extractor.ts.TsPayloadReader.FLAG_DATA_ALIGNMENT_INDICATOR;
+import static com.google.android.exoplayer2.metadata.id3.Id3Decoder.ID3_HEADER_LENGTH;
+import static com.google.android.exoplayer2.metadata.id3.Id3Decoder.ID3_TAG;
 
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.audio.Ac3Util;
@@ -44,7 +46,6 @@ public final class Ac3Extractor implements Extractor {
   private static final int MAX_SNIFF_BYTES = 8 * 1024;
   private static final int AC3_SYNC_WORD = 0x0B77;
   private static final int MAX_SYNC_FRAME_SIZE = 2786;
-  private static final int ID3_TAG = 0x00494433;
 
   private final Ac3Reader reader;
   private final ParsableByteArray sampleData;
@@ -62,10 +63,10 @@ public final class Ac3Extractor implements Extractor {
   @Override
   public boolean sniff(ExtractorInput input) throws IOException, InterruptedException {
     // Skip any ID3 headers.
-    ParsableByteArray scratch = new ParsableByteArray(10);
+    ParsableByteArray scratch = new ParsableByteArray(ID3_HEADER_LENGTH);
     int startPosition = 0;
     while (true) {
-      input.peekFully(scratch.data, 0, 10);
+      input.peekFully(scratch.data, /* offset= */ 0, ID3_HEADER_LENGTH);
       scratch.setPosition(0);
       if (scratch.readUnsignedInt24() != ID3_TAG) {
         break;

library/core/src/main/java/com/google/android/exoplayer2/extractor/ts/Ac4Extractor.java

@@ -18,6 +18,8 @@ package com.google.android.exoplayer2.extractor.ts;
 import static com.google.android.exoplayer2.audio.Ac4Util.AC40_SYNCWORD;
 import static com.google.android.exoplayer2.audio.Ac4Util.AC41_SYNCWORD;
 import static com.google.android.exoplayer2.extractor.ts.TsPayloadReader.FLAG_DATA_ALIGNMENT_INDICATOR;
+import static com.google.android.exoplayer2.metadata.id3.Id3Decoder.ID3_HEADER_LENGTH;
+import static com.google.android.exoplayer2.metadata.id3.Id3Decoder.ID3_TAG;
 
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.audio.Ac4Util;
@@ -52,8 +54,6 @@ public final class Ac4Extractor implements Extractor {
   /** The size of the frame header, in bytes. */
   private static final int FRAME_HEADER_SIZE = 7;
 
-  private static final int ID3_TAG = 0x00494433;
-
   private final Ac4Reader reader;
   private final ParsableByteArray sampleData;
 
@@ -70,10 +70,10 @@ public final class Ac4Extractor implements Extractor {
   @Override
   public boolean sniff(ExtractorInput input) throws IOException, InterruptedException {
     // Skip any ID3 headers.
-    ParsableByteArray scratch = new ParsableByteArray(10);
+    ParsableByteArray scratch = new ParsableByteArray(ID3_HEADER_LENGTH);
     int startPosition = 0;
     while (true) {
-      input.peekFully(scratch.data, /* offset= */ 0, /* length= */ 10);
+      input.peekFully(scratch.data, /* offset= */ 0, ID3_HEADER_LENGTH);
       scratch.setPosition(0);
       if (scratch.readUnsignedInt24() != ID3_TAG) {
         break;

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

@@ -16,6 +16,8 @@
 package com.google.android.exoplayer2.extractor.ts;
 
 import static com.google.android.exoplayer2.extractor.ts.TsPayloadReader.FLAG_DATA_ALIGNMENT_INDICATOR;
+import static com.google.android.exoplayer2.metadata.id3.Id3Decoder.ID3_HEADER_LENGTH;
+import static com.google.android.exoplayer2.metadata.id3.Id3Decoder.ID3_TAG;
 
 import androidx.annotation.IntDef;
 import androidx.annotation.Nullable;
@@ -65,7 +67,6 @@ public final class AdtsExtractor implements Extractor {
   public static final int FLAG_ENABLE_CONSTANT_BITRATE_SEEKING = 1;
 
   private static final int MAX_PACKET_SIZE = 2 * 1024;
-  private static final int ID3_TAG = 0x00494433;
   /**
    * The maximum number of bytes to search when sniffing, excluding the header, before giving up.
    * Frame sizes are represented by 13-bit fields, so expect a valid frame in the first 8192 bytes.
@@ -109,7 +110,8 @@ public final class AdtsExtractor implements Extractor {
     packetBuffer = new ParsableByteArray(MAX_PACKET_SIZE);
     averageFrameSize = C.LENGTH_UNSET;
     firstFramePosition = C.POSITION_UNSET;
-    scratch = new ParsableByteArray(10);
+    // Allocate scratch space for an ID3 header. The same buffer is also used to read 4 byte values.
+    scratch = new ParsableByteArray(ID3_HEADER_LENGTH);
     scratchBits = new ParsableBitArray(scratch.data);
   }
 
@@ -209,7 +211,7 @@ public final class AdtsExtractor implements Extractor {
   private int peekId3Header(ExtractorInput input) throws IOException, InterruptedException {
     int firstFramePosition = 0;
     while (true) {
-      input.peekFully(scratch.data, 0, 10);
+      input.peekFully(scratch.data, /* offset= */ 0, ID3_HEADER_LENGTH);
       scratch.setPosition(0);
       if (scratch.readUnsignedInt24() != ID3_TAG) {
         break;

library/core/src/main/java/com/google/android/exoplayer2/extractor/ts/Id3Reader.java

@@ -16,6 +16,7 @@
 package com.google.android.exoplayer2.extractor.ts;
 
 import static com.google.android.exoplayer2.extractor.ts.TsPayloadReader.FLAG_DATA_ALIGNMENT_INDICATOR;
+import static com.google.android.exoplayer2.metadata.id3.Id3Decoder.ID3_HEADER_LENGTH;
 
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
@@ -33,8 +34,6 @@ public final class Id3Reader implements ElementaryStreamReader {
 
   private static final String TAG = "Id3Reader";
 
-  private static final int ID3_HEADER_SIZE = 10;
-
   private final ParsableByteArray id3Header;
 
   private TrackOutput output;
@@ -48,7 +47,7 @@ public final class Id3Reader implements ElementaryStreamReader {
   private int sampleBytesRead;
 
   public Id3Reader() {
-    id3Header = new ParsableByteArray(ID3_HEADER_SIZE);
+    id3Header = new ParsableByteArray(ID3_HEADER_LENGTH);
   }
 
   @Override
@@ -81,12 +80,12 @@ public final class Id3Reader implements ElementaryStreamReader {
       return;
     }
     int bytesAvailable = data.bytesLeft();
-    if (sampleBytesRead < ID3_HEADER_SIZE) {
+    if (sampleBytesRead < ID3_HEADER_LENGTH) {
       // We're still reading the ID3 header.
-      int headerBytesAvailable = Math.min(bytesAvailable, ID3_HEADER_SIZE - sampleBytesRead);
+      int headerBytesAvailable = Math.min(bytesAvailable, ID3_HEADER_LENGTH - sampleBytesRead);
       System.arraycopy(data.data, data.getPosition(), id3Header.data, sampleBytesRead,
           headerBytesAvailable);
-      if (sampleBytesRead + headerBytesAvailable == ID3_HEADER_SIZE) {
+      if (sampleBytesRead + headerBytesAvailable == ID3_HEADER_LENGTH) {
         // We've finished reading the ID3 header. Extract the sample size.
         id3Header.setPosition(0);
         if ('I' != id3Header.readUnsignedByte() || 'D' != id3Header.readUnsignedByte()
@@ -96,7 +95,7 @@ public final class Id3Reader implements ElementaryStreamReader {
           return;
         }
         id3Header.skipBytes(3); // version (2) + flags (1)
-        sampleSize = ID3_HEADER_SIZE + id3Header.readSynchSafeInt();
+        sampleSize = ID3_HEADER_LENGTH + id3Header.readSynchSafeInt();
       }
     }
     // Write data to the output.