Further enhance ID3 decoder + support

library/src/main/java/com/google/android/exoplayer2/extractor/GaplessInfoHolder.java

@@ -16,6 +16,8 @@
 package com.google.android.exoplayer2.extractor;
 package com.google.android.exoplayer2.extractor;
 
 
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.metadata.Metadata;
+import com.google.android.exoplayer2.metadata.id3.CommentFrame;
 import java.util.regex.Matcher;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.regex.Pattern;
 
 
@@ -66,6 +68,25 @@ public final class GaplessInfoHolder {
   }
   }
 
 
   /**
   /**
+   * Populates the holder with data parsed from ID3 {@link Metadata}.
+   *
+   * @param metadata The metadata from which to parse the gapless information.
+   * @return Whether the holder was populated.
+   */
+  public boolean setFromMetadata(Metadata metadata) {
+    for (int i = 0; i < metadata.length(); i++) {
+      Metadata.Entry entry = metadata.get(i);
+      if (entry instanceof CommentFrame) {
+        CommentFrame commentFrame = (CommentFrame) entry;
+        if (setFromComment(commentFrame.description, commentFrame.text)) {
+          return true;
+        }
+      }
+    }
+    return false;
+  }
+
+  /**
    * Populates the holder with data parsed from a gapless playback comment (stored in an ID3 header
    * Populates the holder with data parsed from a gapless playback comment (stored in an ID3 header
    * or MPEG 4 user data), if valid and non-zero.
    * or MPEG 4 user data), if valid and non-zero.
    *
    *

library/src/main/java/com/google/android/exoplayer2/extractor/mp3/Id3Util.java

-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.google.android.exoplayer2.extractor.mp3;
-
-import com.google.android.exoplayer2.extractor.ExtractorInput;
-import com.google.android.exoplayer2.metadata.Metadata;
-import com.google.android.exoplayer2.metadata.MetadataDecoderException;
-import com.google.android.exoplayer2.metadata.id3.Id3Decoder;
-import com.google.android.exoplayer2.util.ParsableByteArray;
-import com.google.android.exoplayer2.util.Util;
-import java.io.IOException;
-
-/**
- * Utility for parsing ID3 version 2 metadata in MP3 files.
- */
-/* package */ final class Id3Util {
-
-  /**
-   * The maximum valid length for metadata in bytes.
-   */
-  private static final int MAXIMUM_METADATA_SIZE = 3 * 1024 * 1024;
-
-  private static final int ID3_TAG = Util.getIntegerCodeForString("ID3");
-
-  /**
-   * Peeks data from the input and parses ID3 metadata, including gapless playback information.
-   *
-   * @param input The {@link ExtractorInput} from which data should be peeked.
-   * @return The metadata, if present, {@code null} otherwise.
-   * @throws IOException If an error occurred peeking from the input.
-   * @throws InterruptedException If the thread was interrupted.
-   */
-  public static Metadata parseId3(ExtractorInput input)
-      throws IOException, InterruptedException {
-    Metadata result = null;
-    ParsableByteArray scratch = new ParsableByteArray(10);
-    int peekedId3Bytes = 0;
-    while (true) {
-      input.peekFully(scratch.data, 0, 10);
-      scratch.setPosition(0);
-      if (scratch.readUnsignedInt24() != ID3_TAG) {
-        break;
-      }
-
-      int majorVersion = scratch.readUnsignedByte();
-      int minorVersion = scratch.readUnsignedByte();
-      int flags = scratch.readUnsignedByte();
-      int length = scratch.readSynchSafeInt();
-      int frameLength = length + 10;
-
-      try {
-        if (canParseMetadata(majorVersion, minorVersion, flags, length)) {
-          input.resetPeekPosition();
-          byte[] frame = new byte[frameLength];
-          input.peekFully(frame, 0, frameLength);
-          return new Id3Decoder().decode(frame, frameLength);
-        } else {
-          input.advancePeekPosition(length);
-        }
-      } catch (MetadataDecoderException e) {
-        e.printStackTrace();
-      }
-
-      peekedId3Bytes += frameLength;
-    }
-    input.resetPeekPosition();
-    input.advancePeekPosition(peekedId3Bytes);
-    return result;
-  }
-
-  private static boolean canParseMetadata(int majorVersion, int minorVersion, int flags,
-      int length) {
-    return minorVersion != 0xFF && majorVersion >= 2 && majorVersion <= 4
-        && length <= MAXIMUM_METADATA_SIZE
-        && !(majorVersion == 2 && ((flags & 0x3F) != 0 || (flags & 0x40) != 0))
-        && !(majorVersion == 3 && (flags & 0x1F) != 0)
-        && !(majorVersion == 4 && (flags & 0x0F) != 0);
-  }
-
-  private Id3Util() {}
-
-}

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

@@ -15,6 +15,7 @@
  */
  */
 package com.google.android.exoplayer2.extractor.mp3;
 package com.google.android.exoplayer2.extractor.mp3;
 
 
+import android.util.Log;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.ParserException;
 import com.google.android.exoplayer2.ParserException;
@@ -28,7 +29,8 @@ import com.google.android.exoplayer2.extractor.PositionHolder;
 import com.google.android.exoplayer2.extractor.SeekMap;
 import com.google.android.exoplayer2.extractor.SeekMap;
 import com.google.android.exoplayer2.extractor.TrackOutput;
 import com.google.android.exoplayer2.extractor.TrackOutput;
 import com.google.android.exoplayer2.metadata.Metadata;
 import com.google.android.exoplayer2.metadata.Metadata;
-import com.google.android.exoplayer2.metadata.id3.CommentFrame;
+import com.google.android.exoplayer2.metadata.MetadataDecoderException;
+import com.google.android.exoplayer2.metadata.id3.Id3Decoder;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.util.Util;
 import java.io.EOFException;
 import java.io.EOFException;
@@ -51,6 +53,8 @@ public final class Mp3Extractor implements Extractor {
 
 
   };
   };
 
 
+  private static final String TAG = "Mp3Extractor";
+
   /**
   /**
    * The maximum number of bytes to search when synchronizing, before giving up.
    * The maximum number of bytes to search when synchronizing, before giving up.
    */
    */
@@ -59,6 +63,18 @@ public final class Mp3Extractor implements Extractor {
    * The maximum number of bytes to peek when sniffing, excluding the ID3 header, before giving up.
    * The maximum number of bytes to peek when sniffing, excluding the ID3 header, before giving up.
    */
    */
   private static final int MAX_SNIFF_BYTES = MpegAudioHeader.MAX_FRAME_SIZE_BYTES;
   private static final int MAX_SNIFF_BYTES = MpegAudioHeader.MAX_FRAME_SIZE_BYTES;
+  /**
+   * First three bytes of a well formed ID3 tag header.
+   */
+  private static final int ID3_TAG = Util.getIntegerCodeForString("ID3");
+  /**
+   * Length of an ID3 tag header.
+   */
+  private static final int ID3_HEADER_LENGTH = 10;
+  /**
+   * Maximum length of data read into {@link #scratch}.
+   */
+  private static final int SCRATCH_LENGTH = 10;
 
 
   /**
   /**
    * Mask that includes the audio header values that must match between frames.
    * Mask that includes the audio header values that must match between frames.
@@ -100,7 +116,7 @@ public final class Mp3Extractor implements Extractor {
    */
    */
   public Mp3Extractor(long forcedFirstSampleTimestampUs) {
   public Mp3Extractor(long forcedFirstSampleTimestampUs) {
     this.forcedFirstSampleTimestampUs = forcedFirstSampleTimestampUs;
     this.forcedFirstSampleTimestampUs = forcedFirstSampleTimestampUs;
-    scratch = new ParsableByteArray(4);
+    scratch = new ParsableByteArray(SCRATCH_LENGTH);
     synchronizedHeader = new MpegAudioHeader();
     synchronizedHeader = new MpegAudioHeader();
     gaplessInfoHolder = new GaplessInfoHolder();
     gaplessInfoHolder = new GaplessInfoHolder();
     basisTimeUs = C.TIME_UNSET;
     basisTimeUs = C.TIME_UNSET;
@@ -147,7 +163,7 @@ public final class Mp3Extractor implements Extractor {
       trackOutput.format(Format.createAudioSampleFormat(null, synchronizedHeader.mimeType, null,
       trackOutput.format(Format.createAudioSampleFormat(null, synchronizedHeader.mimeType, null,
           Format.NO_VALUE, MpegAudioHeader.MAX_FRAME_SIZE_BYTES, synchronizedHeader.channels,
           Format.NO_VALUE, MpegAudioHeader.MAX_FRAME_SIZE_BYTES, synchronizedHeader.channels,
           synchronizedHeader.sampleRate, Format.NO_VALUE, gaplessInfoHolder.encoderDelay,
           synchronizedHeader.sampleRate, Format.NO_VALUE, gaplessInfoHolder.encoderDelay,
-          gaplessInfoHolder.encoderPadding, null, null, 0, null, metadata));
+          gaplessInfoHolder.encoderPadding, null, null, 0, null, null));
     }
     }
     return readSample(input);
     return readSample(input);
   }
   }
@@ -202,18 +218,7 @@ public final class Mp3Extractor implements Extractor {
     int searchLimitBytes = sniffing ? MAX_SNIFF_BYTES : MAX_SYNC_BYTES;
     int searchLimitBytes = sniffing ? MAX_SNIFF_BYTES : MAX_SYNC_BYTES;
     input.resetPeekPosition();
     input.resetPeekPosition();
     if (input.getPosition() == 0) {
     if (input.getPosition() == 0) {
-      metadata = Id3Util.parseId3(input);
-      if (!gaplessInfoHolder.hasGaplessInfo()) {
-        for (int i = 0; i < metadata.length(); i++) {
-          Metadata.Entry entry = metadata.get(i);
-          if (entry instanceof CommentFrame) {
-            CommentFrame commentFrame = (CommentFrame) entry;
-            if (gaplessInfoHolder.setFromComment(commentFrame.description, commentFrame.text)) {
-              break;
-            }
-          }
-        }
-      }
+      peekId3Data(input);
       peekedId3Bytes = (int) input.getPeekPosition();
       peekedId3Bytes = (int) input.getPeekPosition();
       if (!sniffing) {
       if (!sniffing) {
         input.skipFully(peekedId3Bytes);
         input.skipFully(peekedId3Bytes);
@@ -268,6 +273,49 @@ public final class Mp3Extractor implements Extractor {
   }
   }
 
 
   /**
   /**
+   * Peeks ID3 data from the input, including gapless playback information.
+   *
+   * @param input The {@link ExtractorInput} from which data should be peeked.
+   * @throws IOException If an error occurred peeking from the input.
+   * @throws InterruptedException If the thread was interrupted.
+   */
+  private void peekId3Data(ExtractorInput input) throws IOException, InterruptedException {
+    int peekedId3Bytes = 0;
+    while (true) {
+      input.peekFully(scratch.data, 0, ID3_HEADER_LENGTH);
+      scratch.setPosition(0);
+      if (scratch.readUnsignedInt24() != ID3_TAG) {
+        // Not an ID3 tag.
+        break;
+      }
+      scratch.skipBytes(3); // Skip major version, minor version and flags.
+      int framesLength = scratch.readSynchSafeInt();
+      int tagLength = ID3_HEADER_LENGTH + framesLength;
+
+      try {
+        if (metadata == null) {
+          byte[] id3Data = new byte[tagLength];
+          System.arraycopy(scratch.data, 0, id3Data, 0, ID3_HEADER_LENGTH);
+          input.peekFully(id3Data, ID3_HEADER_LENGTH, framesLength);
+          metadata = new Id3Decoder().decode(id3Data, tagLength);
+          if (metadata != null) {
+            gaplessInfoHolder.setFromMetadata(metadata);
+          }
+        } else {
+          input.advancePeekPosition(framesLength);
+        }
+      } catch (MetadataDecoderException e) {
+        Log.e(TAG, "Failed to decode ID3 tag", e);
+      }
+
+      peekedId3Bytes += tagLength;
+    }
+
+    input.resetPeekPosition();
+    input.advancePeekPosition(peekedId3Bytes);
+  }
+
+  /**
    * Returns a {@link Seeker} to seek using metadata read from {@code input}, which should provide
    * Returns a {@link Seeker} to seek using metadata read from {@code input}, which should provide
    * data from the start of the first frame in the stream. On returning, the input's position will
    * data from the start of the first frame in the stream. On returning, the input's position will
    * be set to the start of the first frame of audio.
    * be set to the start of the first frame of audio.

library/src/main/java/com/google/android/exoplayer2/metadata/id3/Id3Decoder.java

@@ -63,7 +63,7 @@ public final class Id3Decoder implements MetadataDecoder {
 
 
     int frameHeaderSize = id3Header.majorVersion == 2 ? 6 : 10;
     int frameHeaderSize = id3Header.majorVersion == 2 ? 6 : 10;
     while (id3Data.bytesLeft() >= frameHeaderSize) {
     while (id3Data.bytesLeft() >= frameHeaderSize) {
-      Id3Frame frame = decodeFrame(id3Header, id3Data);
+      Id3Frame frame = decodeFrame(id3Header.majorVersion, id3Data);
       if (frame != null) {
       if (frame != null) {
         id3Frames.add(frame);
         id3Frames.add(frame);
       }
       }
@@ -72,6 +72,40 @@ public final class Id3Decoder implements MetadataDecoder {
     return new Metadata(id3Frames);
     return new Metadata(id3Frames);
   }
   }
 
 
+  // TODO: Move the following three methods nearer to the bottom of the file.
+  private static int indexOfEos(byte[] data, int fromIndex, int encoding) {
+    int terminationPos = indexOfZeroByte(data, fromIndex);
+
+    // For single byte encoding charsets, we're done.
+    if (encoding == ID3_TEXT_ENCODING_ISO_8859_1 || encoding == ID3_TEXT_ENCODING_UTF_8) {
+      return terminationPos;
+    }
+
+    // Otherwise ensure an even index and look for a second zero byte.
+    while (terminationPos < data.length - 1) {
+      if (terminationPos % 2 == 0 && data[terminationPos + 1] == (byte) 0) {
+        return terminationPos;
+      }
+      terminationPos = indexOfZeroByte(data, terminationPos + 1);
+    }
+
+    return data.length;
+  }
+
+  private static int indexOfZeroByte(byte[] data, int fromIndex) {
+    for (int i = fromIndex; i < data.length; i++) {
+      if (data[i] == (byte) 0) {
+        return i;
+      }
+    }
+    return data.length;
+  }
+
+  private static int delimiterLength(int encodingByte) {
+    return (encodingByte == ID3_TEXT_ENCODING_ISO_8859_1 || encodingByte == ID3_TEXT_ENCODING_UTF_8)
+        ? 1 : 2;
+  }
+
   /**
   /**
    * @param data A {@link ParsableByteArray} from which the header should be read.
    * @param data A {@link ParsableByteArray} from which the header should be read.
    * @return The parsed header, or null if the ID3 tag is unsupported.
    * @return The parsed header, or null if the ID3 tag is unsupported.
@@ -126,15 +160,15 @@ public final class Id3Decoder implements MetadataDecoder {
     return new Id3Header(majorVersion, isUnsynchronized, framesSize);
     return new Id3Header(majorVersion, isUnsynchronized, framesSize);
   }
   }
 
 
-  private Id3Frame decodeFrame(Id3Header id3Header, ParsableByteArray id3Data)
+  private Id3Frame decodeFrame(int majorVersion, ParsableByteArray id3Data)
       throws MetadataDecoderException {
       throws MetadataDecoderException {
     int frameId0 = id3Data.readUnsignedByte();
     int frameId0 = id3Data.readUnsignedByte();
     int frameId1 = id3Data.readUnsignedByte();
     int frameId1 = id3Data.readUnsignedByte();
     int frameId2 = id3Data.readUnsignedByte();
     int frameId2 = id3Data.readUnsignedByte();
-    int frameId3 = id3Header.majorVersion >= 3 ? id3Data.readUnsignedByte() : 0;
+    int frameId3 = majorVersion >= 3 ? id3Data.readUnsignedByte() : 0;
 
 
     int frameSize;
     int frameSize;
-    if (id3Header.majorVersion == 4) {
+    if (majorVersion == 4) {
       frameSize = id3Data.readUnsignedIntToInt();
       frameSize = id3Data.readUnsignedIntToInt();
       if ((frameSize & 0x808080L) == 0) {
       if ((frameSize & 0x808080L) == 0) {
         // Parse the frame size as a syncsafe integer, as per the spec.
         // Parse the frame size as a syncsafe integer, as per the spec.
@@ -144,13 +178,13 @@ public final class Id3Decoder implements MetadataDecoder {
         // Proceed using the frame size read as an unsigned integer.
         // Proceed using the frame size read as an unsigned integer.
         Log.w(TAG, "Frame size not specified as syncsafe integer");
         Log.w(TAG, "Frame size not specified as syncsafe integer");
       }
       }
-    } else if (id3Header.majorVersion == 3) {
+    } else if (majorVersion == 3) {
       frameSize = id3Data.readUnsignedIntToInt();
       frameSize = id3Data.readUnsignedIntToInt();
     } else /* id3Header.majorVersion == 2 */ {
     } else /* id3Header.majorVersion == 2 */ {
       frameSize = id3Data.readUnsignedInt24();
       frameSize = id3Data.readUnsignedInt24();
     }
     }
 
 
-    int flags = id3Header.majorVersion >= 2 ? id3Data.readShort() : 0;
+    int flags = majorVersion >= 3 ? id3Data.readShort() : 0;
     if (frameId0 == 0 && frameId1 == 0 && frameId2 == 0 && frameId3 == 0 && frameSize == 0
     if (frameId0 == 0 && frameId1 == 0 && frameId2 == 0 && frameId3 == 0 && frameSize == 0
         && flags == 0) {
         && flags == 0) {
       // We must be reading zero padding at the end of the tag.
       // We must be reading zero padding at the end of the tag.
@@ -159,6 +193,9 @@ public final class Id3Decoder implements MetadataDecoder {
     }
     }
 
 
     int nextFramePosition = id3Data.getPosition() + frameSize;
     int nextFramePosition = id3Data.getPosition() + frameSize;
+    if (nextFramePosition > id3Data.limit()) {
+      return null;
+    }
 
 
     // Frame flags.
     // Frame flags.
     boolean isCompressed = false;
     boolean isCompressed = false;
@@ -166,12 +203,12 @@ public final class Id3Decoder implements MetadataDecoder {
     boolean isUnsynchronized = false;
     boolean isUnsynchronized = false;
     boolean hasDataLength = false;
     boolean hasDataLength = false;
     boolean hasGroupIdentifier = false;
     boolean hasGroupIdentifier = false;
-    if (id3Header.majorVersion == 3) {
+    if (majorVersion == 3) {
       isCompressed = (flags & 0x0080) != 0;
       isCompressed = (flags & 0x0080) != 0;
       isEncrypted = (flags & 0x0040) != 0;
       isEncrypted = (flags & 0x0040) != 0;
       hasGroupIdentifier = (flags & 0x0020) != 0;
       hasGroupIdentifier = (flags & 0x0020) != 0;
       hasDataLength = isCompressed;
       hasDataLength = isCompressed;
-    } else if (id3Header.majorVersion == 4) {
+    } else if (majorVersion == 4) {
       hasGroupIdentifier = (flags & 0x0040) != 0;
       hasGroupIdentifier = (flags & 0x0040) != 0;
       isCompressed = (flags & 0x0008) != 0;
       isCompressed = (flags & 0x0008) != 0;
       isEncrypted = (flags & 0x0004) != 0;
       isEncrypted = (flags & 0x0004) != 0;
@@ -199,26 +236,29 @@ public final class Id3Decoder implements MetadataDecoder {
 
 
     try {
     try {
       Id3Frame frame;
       Id3Frame frame;
-      if (frameId0 == 'T' && frameId1 == 'X' && frameId2 == 'X' && frameId3 == 'X') {
+      if (frameId0 == 'T' && frameId1 == 'X' && frameId2 == 'X'
+          && (majorVersion == 2 || frameId3 == 'X')) {
         frame = decodeTxxxFrame(id3Data, frameSize);
         frame = decodeTxxxFrame(id3Data, frameSize);
       } else if (frameId0 == 'P' && frameId1 == 'R' && frameId2 == 'I' && frameId3 == 'V') {
       } else if (frameId0 == 'P' && frameId1 == 'R' && frameId2 == 'I' && frameId3 == 'V') {
         frame = decodePrivFrame(id3Data, frameSize);
         frame = decodePrivFrame(id3Data, frameSize);
-      } else if (frameId0 == 'G' && frameId1 == 'E' && frameId2 == 'O' && frameId3 == 'B') {
+      } else if (frameId0 == 'G' && frameId1 == 'E' && frameId2 == 'O'
+          && (frameId3 == 'B' || majorVersion == 2)) {
         frame = decodeGeobFrame(id3Data, frameSize);
         frame = decodeGeobFrame(id3Data, frameSize);
-      } else if (frameId0 == 'A' && frameId1 == 'P' && frameId2 == 'I' && frameId3 == 'C') {
-        frame = decodeApicFrame(id3Data, frameSize);
+      } else if (majorVersion == 2 ? (frameId0 == 'P' && frameId1 == 'I' && frameId2 == 'C')
+          : (frameId0 == 'A' && frameId1 == 'P' && frameId2 == 'I' && frameId3 == 'C')) {
+        frame = decodeApicFrame(id3Data, frameSize, majorVersion);
       } else if (frameId0 == 'T') {
       } else if (frameId0 == 'T') {
-        String id = frameId3 != 0 ?
-            String.format(Locale.US, "%c%c%c%c", frameId0, frameId1, frameId2, frameId3) :
-            String.format(Locale.US, "%c%c%c", frameId0, frameId1, frameId2);
+        String id = majorVersion == 2
+            ? String.format(Locale.US, "%c%c%c", frameId0, frameId1, frameId2)
+            : String.format(Locale.US, "%c%c%c%c", frameId0, frameId1, frameId2, frameId3);
         frame = decodeTextInformationFrame(id3Data, frameSize, id);
         frame = decodeTextInformationFrame(id3Data, frameSize, id);
-      } else if (frameId0 == 'C' && frameId1 == 'O' && frameId2 == 'M' &&
-          (frameId3 == 'M' || frameId3 == 0)) {
+      } else if (frameId0 == 'C' && frameId1 == 'O' && frameId2 == 'M'
+          && (frameId3 == 'M' || majorVersion == 2)) {
         frame = decodeCommentFrame(id3Data, frameSize);
         frame = decodeCommentFrame(id3Data, frameSize);
       } else {
       } else {
-        String id = frameId3 != 0 ?
-            String.format(Locale.US, "%c%c%c%c", frameId0, frameId1, frameId2, frameId3) :
-            String.format(Locale.US, "%c%c%c", frameId0, frameId1, frameId2);
+        String id = majorVersion == 2
+            ? String.format(Locale.US, "%c%c%c", frameId0, frameId1, frameId2)
+            : String.format(Locale.US, "%c%c%c%c", frameId0, frameId1, frameId2, frameId3);
         frame = decodeBinaryFrame(id3Data, frameSize, id);
         frame = decodeBinaryFrame(id3Data, frameSize, id);
       }
       }
       return frame;
       return frame;
@@ -288,16 +328,29 @@ public final class Id3Decoder implements MetadataDecoder {
     return new GeobFrame(mimeType, filename, description, objectData);
     return new GeobFrame(mimeType, filename, description, objectData);
   }
   }
 
 
-  private static ApicFrame decodeApicFrame(ParsableByteArray id3Data, int frameSize)
-      throws UnsupportedEncodingException {
+  private static ApicFrame decodeApicFrame(ParsableByteArray id3Data, int frameSize,
+      int majorVersion) throws UnsupportedEncodingException {
     int encoding = id3Data.readUnsignedByte();
     int encoding = id3Data.readUnsignedByte();
     String charset = getCharsetName(encoding);
     String charset = getCharsetName(encoding);
 
 
     byte[] data = new byte[frameSize - 1];
     byte[] data = new byte[frameSize - 1];
     id3Data.readBytes(data, 0, frameSize - 1);
     id3Data.readBytes(data, 0, frameSize - 1);
 
 
-    int mimeTypeEndIndex = indexOfZeroByte(data, 0);
-    String mimeType = new String(data, 0, mimeTypeEndIndex, "ISO-8859-1");
+    String mimeType;
+    int mimeTypeEndIndex;
+    if (majorVersion == 2) {
+      mimeTypeEndIndex = 2;
+      mimeType = "image/" + new String(data, 0, 3, "ISO-8859-1").toLowerCase();
+      if (mimeType.equals("image/jpg")) {
+        mimeType = "image/jpeg";
+      }
+    } else {
+      mimeTypeEndIndex = indexOfZeroByte(data, 0);
+      mimeType = new String(data, 0, mimeTypeEndIndex, "ISO-8859-1").toLowerCase();
+      if (mimeType.indexOf('/') == -1) {
+        mimeType = "image/" + mimeType;
+      }
+    }
 
 
     int pictureType = data[mimeTypeEndIndex + 1] & 0xFF;
     int pictureType = data[mimeTypeEndIndex + 1] & 0xFF;
 
 
@@ -312,20 +365,6 @@ public final class Id3Decoder implements MetadataDecoder {
     return new ApicFrame(mimeType, description, pictureType, pictureData);
     return new ApicFrame(mimeType, description, pictureType, pictureData);
   }
   }
 
 
-  private static TextInformationFrame decodeTextInformationFrame(ParsableByteArray id3Data,
-      int frameSize, String id) throws UnsupportedEncodingException {
-    int encoding = id3Data.readUnsignedByte();
-    String charset = getCharsetName(encoding);
-
-    byte[] data = new byte[frameSize - 1];
-    id3Data.readBytes(data, 0, frameSize - 1);
-
-    int descriptionEndIndex = indexOfEos(data, 0, encoding);
-    String description = new String(data, 0, descriptionEndIndex, charset);
-
-    return new TextInformationFrame(id, description);
-  }
-
   private static CommentFrame decodeCommentFrame(ParsableByteArray id3Data, int frameSize)
   private static CommentFrame decodeCommentFrame(ParsableByteArray id3Data, int frameSize)
       throws UnsupportedEncodingException {
       throws UnsupportedEncodingException {
     int encoding = id3Data.readUnsignedByte();
     int encoding = id3Data.readUnsignedByte();
@@ -348,6 +387,20 @@ public final class Id3Decoder implements MetadataDecoder {
     return new CommentFrame(language, description, text);
     return new CommentFrame(language, description, text);
   }
   }
 
 
+  private static TextInformationFrame decodeTextInformationFrame(ParsableByteArray id3Data,
+      int frameSize, String id) throws UnsupportedEncodingException {
+    int encoding = id3Data.readUnsignedByte();
+    String charset = getCharsetName(encoding);
+
+    byte[] data = new byte[frameSize - 1];
+    id3Data.readBytes(data, 0, frameSize - 1);
+
+    int descriptionEndIndex = indexOfEos(data, 0, encoding);
+    String description = new String(data, 0, descriptionEndIndex, charset);
+
+    return new TextInformationFrame(id, description);
+  }
+
   private static BinaryFrame decodeBinaryFrame(ParsableByteArray id3Data, int frameSize,
   private static BinaryFrame decodeBinaryFrame(ParsableByteArray id3Data, int frameSize,
       String id) {
       String id) {
     byte[] frame = new byte[frameSize];
     byte[] frame = new byte[frameSize];
@@ -395,39 +448,6 @@ public final class Id3Decoder implements MetadataDecoder {
     }
     }
   }
   }
 
 
-  private static int indexOfEos(byte[] data, int fromIndex, int encoding) {
-    int terminationPos = indexOfZeroByte(data, fromIndex);
-
-    // For single byte encoding charsets, we're done.
-    if (encoding == ID3_TEXT_ENCODING_ISO_8859_1 || encoding == ID3_TEXT_ENCODING_UTF_8) {
-      return terminationPos;
-    }
-
-    // Otherwise ensure an even index and look for a second zero byte.
-    while (terminationPos < data.length - 1) {
-      if (terminationPos % 2 == 0 && data[terminationPos + 1] == (byte) 0) {
-        return terminationPos;
-      }
-      terminationPos = indexOfZeroByte(data, terminationPos + 1);
-    }
-
-    return data.length;
-  }
-
-  private static int indexOfZeroByte(byte[] data, int fromIndex) {
-    for (int i = fromIndex; i < data.length; i++) {
-      if (data[i] == (byte) 0) {
-        return i;
-      }
-    }
-    return data.length;
-  }
-
-  private static int delimiterLength(int encodingByte) {
-    return (encodingByte == ID3_TEXT_ENCODING_ISO_8859_1 || encodingByte == ID3_TEXT_ENCODING_UTF_8)
-        ? 1 : 2;
-  }
-
   private static final class Id3Header {
   private static final class Id3Header {
 
 
     private final int majorVersion;
     private final int majorVersion;