Improved ID3 chapter parsing code from feedback given.

library/src/main/java/com/google/android/exoplayer2/metadata/id3/ChapterFrame.java → library/src/main/java/com/google/android/exoplayer2/metadata/id3/ChapFrame.java

 /*
- * Copyright (C) 2016 The Android Open Source Project
+ * Copyright (C) 2017 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.
@@ -22,7 +22,7 @@ import com.google.android.exoplayer2.util.Util;
 /**
  * Chapter information "CHAP" ID3 frame.
  */
-public final class ChapterFrame extends Id3Frame {
+public final class ChapFrame extends Id3Frame {
 
   public static final String ID = "CHAP";
 
@@ -35,8 +35,8 @@ public final class ChapterFrame extends Id3Frame {
   public final String url;
   public final ApicFrame image;
 
-  public ChapterFrame(String chapterId, int startTime, int endTime, int startOffset, int endOffset,
-    String title, String url, ApicFrame image) {
+  public ChapFrame(String chapterId, int startTime, int endTime, int startOffset, int endOffset,
+                   String title, String url, ApicFrame image) {
     super(ID);
     this.chapterId = chapterId;
     this.startTime = startTime;
@@ -48,7 +48,7 @@ public final class ChapterFrame extends Id3Frame {
     this.image = image;
   }
 
-  /* package */ ChapterFrame(Parcel in) {
+  /* package */ ChapFrame(Parcel in) {
     super(ID);
     this.chapterId = in.readString();
     this.startTime = in.readInt();
@@ -68,15 +68,15 @@ public final class ChapterFrame extends Id3Frame {
     if (obj == null || getClass() != obj.getClass()) {
       return false;
     }
-    ChapterFrame other = (ChapterFrame) obj;
-    return Util.areEqual(chapterId, other.chapterId)
-      && startTime == other.startTime
+    ChapFrame other = (ChapFrame) obj;
+    return startTime == other.startTime
       && endTime == other.endTime
       && startOffset == other.startOffset
       && endOffset == other.endOffset
-      && title != null ? title.equals(other.title) : other.title == null
-      && url != null ? url.equals(other.url) : other.url == null
-      && image != null ? image.equals(other.image) : other.image == null;
+      && Util.areEqual(chapterId, other.chapterId)
+      && Util.areEqual(title, other.title)
+      && Util.areEqual(url, other.url)
+      && Util.areEqual(image, other.image);
   }
 
   @Override
@@ -103,7 +103,7 @@ public final class ChapterFrame extends Id3Frame {
     dest.writeString(title);
     dest.writeString(url);
     dest.writeString(title);
-    dest.writeParcelable(this.image, flags);
+    dest.writeParcelable(image, flags);
   }
 
   @Override
@@ -111,15 +111,15 @@ public final class ChapterFrame extends Id3Frame {
     return 0;
   }
 
-  public static final Creator<ChapterFrame> CREATOR = new Creator<ChapterFrame>() {
+  public static final Creator<ChapFrame> CREATOR = new Creator<ChapFrame>() {
     @Override
-    public ChapterFrame createFromParcel(Parcel in) {
-      return new ChapterFrame(in);
+    public ChapFrame createFromParcel(Parcel in) {
+      return new ChapFrame(in);
     }
 
     @Override
-    public ChapterFrame[] newArray(int size) {
-      return new ChapterFrame[size];
+    public ChapFrame[] newArray(int size) {
+      return new ChapFrame[size];
     }
   };
 }

library/src/main/java/com/google/android/exoplayer2/metadata/id3/ChapterTOCFrame.java → library/src/main/java/com/google/android/exoplayer2/metadata/id3/CtocFrame.java

 /*
- * Copyright (C) 2016 The Android Open Source Project
+ * Copyright (C) 2017 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.
@@ -17,12 +17,14 @@ package com.google.android.exoplayer2.metadata.id3;
 
 import android.os.Parcel;
 
+import com.google.android.exoplayer2.util.Util;
+
 import java.util.Arrays;
 
 /**
  * Chapter table of contents information "CTOC" ID3 frame.
  */
-public class ChapterTOCFrame extends Id3Frame {
+public final class CtocFrame extends Id3Frame {
 
   public static final String ID = "CTOC";
 
@@ -32,7 +34,7 @@ public class ChapterTOCFrame extends Id3Frame {
   public final String[] children;
   public final String title;
 
-  public ChapterTOCFrame(String elementId, boolean isRoot, boolean isOrdered, String[] children, String title) {
+  public CtocFrame(String elementId, boolean isRoot, boolean isOrdered, String[] children, String title) {
     super(ID);
     this.elementId = elementId;
     this.isRoot = isRoot;
@@ -41,7 +43,7 @@ public class ChapterTOCFrame extends Id3Frame {
     this.title = title;
   }
 
-  /* package */ ChapterTOCFrame(Parcel in) {
+  /* package */ CtocFrame(Parcel in) {
     super(ID);
     this.elementId = in.readString();
     this.isRoot = in.readByte() != 0;
@@ -58,12 +60,12 @@ public class ChapterTOCFrame extends Id3Frame {
     if (obj == null || getClass() != obj.getClass()) {
       return false;
     }
-    ChapterTOCFrame other = (ChapterTOCFrame) obj;
-    return elementId != null ? elementId.equals(other.elementId) : other.elementId == null
-      && isRoot == other.isRoot
+    CtocFrame other = (CtocFrame) obj;
+    return isRoot == other.isRoot
       && isOrdered == other.isOrdered
-      && Arrays.equals(children, other.children)
-      && title != null ? title.equals(other.title) : other.title == null;
+      && Util.areEqual(elementId, other.elementId)
+      && Util.areEqual(title, other.title)
+      && Arrays.equals(children, other.children);
   }
 
   @Override
@@ -79,22 +81,22 @@ public class ChapterTOCFrame extends Id3Frame {
 
   @Override
   public void writeToParcel(Parcel dest, int flags) {
-    dest.writeString(this.elementId);
-    dest.writeByte((byte)(this.isRoot ? 1 : 0));
-    dest.writeByte((byte)(this.isOrdered ? 1 : 0));
-    dest.writeStringArray(this.children);
-    dest.writeString(this.title);
+    dest.writeString(elementId);
+    dest.writeByte((byte)(isRoot ? 1 : 0));
+    dest.writeByte((byte)(isOrdered ? 1 : 0));
+    dest.writeStringArray(children);
+    dest.writeString(title);
   }
 
-  public static final Creator<ChapterTOCFrame> CREATOR = new Creator<ChapterTOCFrame>() {
+  public static final Creator<CtocFrame> CREATOR = new Creator<CtocFrame>() {
     @Override
-    public ChapterTOCFrame createFromParcel(Parcel in) {
-      return new ChapterTOCFrame(in);
+    public CtocFrame createFromParcel(Parcel in) {
+      return new CtocFrame(in);
     }
 
     @Override
-    public ChapterTOCFrame[] newArray(int size) {
-      return new ChapterTOCFrame[size];
+    public CtocFrame[] newArray(int size) {
+      return new CtocFrame[size];
     }
   };
 }

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

@@ -84,7 +84,7 @@ public final class Id3Decoder implements MetadataDecoder {
 
     int frameHeaderSize = id3Header.majorVersion == 2 ? 6 : 10;
     while (id3Data.bytesLeft() >= frameHeaderSize) {
-      Id3Frame frame = decodeFrame(id3Header.majorVersion, id3Data, unsignedIntFrameSizeHack);
+      Id3Frame frame = decodeFrame(id3Header.majorVersion, id3Data, unsignedIntFrameSizeHack, frameHeaderSize);
       if (frame != null) {
         id3Frames.add(frame);
       }
@@ -190,7 +190,7 @@ public final class Id3Decoder implements MetadataDecoder {
   }
 
   private static Id3Frame decodeFrame(int majorVersion, ParsableByteArray id3Data,
-      boolean unsignedIntFrameSizeHack)  {
+      boolean unsignedIntFrameSizeHack, int frameHeaderSize)  {
     int frameId0 = id3Data.readUnsignedByte();
     int frameId1 = id3Data.readUnsignedByte();
     int frameId2 = id3Data.readUnsignedByte();
@@ -282,12 +282,15 @@ public final class Id3Decoder implements MetadataDecoder {
       } else if (frameId0 == 'C' && frameId1 == 'O' && frameId2 == 'M'
           && (frameId3 == 'M' || majorVersion == 2)) {
         frame = decodeCommentFrame(id3Data, frameSize);
-      } else if (frameId0 == 'W' && frameId1 == 'X' && frameId2 == 'X' && frameId3 == 'X') {
-        frame = decodeUrlLinkFrame(id3Data, frameSize);
+      } else if (majorVersion == 2 ? (frameId0 == 'W' && frameId1 == 'X' && frameId2 == 'X')
+          : (frameId0 == 'W' && frameId1 == 'X' && frameId2 == 'X' && frameId3 == 'X')) {
+        frame = decodeWxxxFrame(id3Data, frameSize);
       } else if (frameId0 == 'C' && frameId1 == 'H' && frameId2 == 'A' && frameId3 == 'P') {
-        frame = decodeChapterFrame(id3Data, frameSize, majorVersion, unsignedIntFrameSizeHack);
+        frame = decodeChapFrame(id3Data, frameSize, majorVersion, unsignedIntFrameSizeHack,
+          frameHeaderSize);
       } else if (frameId0 == 'C' && frameId1 == 'T' && frameId2 == 'O' && frameId3 == 'C') {
-        frame = decodeChapterTOCFrame(id3Data, frameSize, majorVersion, unsignedIntFrameSizeHack);
+        frame = decodeCtocFrame(id3Data, frameSize, majorVersion, unsignedIntFrameSizeHack,
+          frameHeaderSize);
       } else {
         String id = majorVersion == 2
             ? String.format(Locale.US, "%c%c%c", frameId0, frameId1, frameId2)
@@ -450,7 +453,7 @@ public final class Id3Decoder implements MetadataDecoder {
     return new TextInformationFrame(id, description);
   }
 
-  private static UrlLinkFrame decodeUrlLinkFrame(ParsableByteArray id3Data,
+  private static WxxxFrame decodeWxxxFrame(ParsableByteArray id3Data,
       int frameSize) throws UnsupportedEncodingException {
     int encoding = id3Data.readUnsignedByte();
     String charset = getCharsetName(encoding);
@@ -461,16 +464,21 @@ public final class Id3Decoder implements MetadataDecoder {
     int descriptionEndIndex = indexOfEos(data, 0, encoding);
     String description = new String(data, 0, descriptionEndIndex, charset);
 
-    int urlStartIndex = descriptionEndIndex + 1;
-    int urlEndIndex = indexOfEos(data, urlStartIndex, encoding);
-    int urlLength = urlEndIndex - urlStartIndex;
-    String url = new String(data, urlStartIndex, urlLength, charset);
+    String url;
+    int urlStartIndex = descriptionEndIndex + delimiterLength(encoding);
+    if (urlStartIndex < data.length) {
+      int urlEndIndex = indexOfEos(data, urlStartIndex, encoding);
+      url = new String(data, urlStartIndex, urlEndIndex - urlStartIndex, charset);
+    } else {
+      url = "";
+    }
 
-    return new UrlLinkFrame(description, url);
+    return new WxxxFrame(description, url);
   }
 
-  private static ChapterFrame decodeChapterFrame(ParsableByteArray id3Data, int frameSize,
-      int majorVersion, boolean unsignedIntFrameSizeHack) throws UnsupportedEncodingException {
+  private static ChapFrame decodeChapFrame(ParsableByteArray id3Data, int frameSize,
+      int majorVersion, boolean unsignedIntFrameSizeHack, int frameHeaderSize)
+      throws UnsupportedEncodingException {
     byte[] frameBytes = new byte[frameSize];
     id3Data.readBytes(frameBytes, 0, frameSize - 1);
 
@@ -489,9 +497,9 @@ public final class Id3Decoder implements MetadataDecoder {
     String url = null;
     ApicFrame image = null;
 
-    int frameHeaderSize = majorVersion == 2 ? 6 : 10;
     while (chapterData.bytesLeft() >= frameHeaderSize) {
-      Id3Frame frame = decodeFrame(majorVersion, chapterData, unsignedIntFrameSizeHack);
+      Id3Frame frame = decodeFrame(majorVersion, chapterData, unsignedIntFrameSizeHack,
+        frameHeaderSize);
       if (frame == null) {
         continue;
       }
@@ -501,8 +509,8 @@ public final class Id3Decoder implements MetadataDecoder {
           title = textFrame.description;
         }
       }
-      else if (frame instanceof UrlLinkFrame) {
-        UrlLinkFrame linkFrame = (UrlLinkFrame)frame;
+      else if (frame instanceof WxxxFrame) {
+        WxxxFrame linkFrame = (WxxxFrame)frame;
         url = linkFrame.url;
       }
       else if (frame instanceof ApicFrame) {
@@ -510,11 +518,12 @@ public final class Id3Decoder implements MetadataDecoder {
       }
     }
 
-    return new ChapterFrame(chapterId, startTime, endTime, startOffset, endOffset, title, url, image);
+    return new ChapFrame(chapterId, startTime, endTime, startOffset, endOffset, title, url, image);
   }
 
-  private static ChapterTOCFrame decodeChapterTOCFrame(ParsableByteArray id3Data, int frameSize,
-    int majorVersion, boolean unsignedIntFrameSizeHack) throws UnsupportedEncodingException {
+  private static CtocFrame decodeCtocFrame(ParsableByteArray id3Data, int frameSize,
+      int majorVersion, boolean unsignedIntFrameSizeHack, int frameHeaderSize)
+      throws UnsupportedEncodingException {
     byte[] frameBytes = new byte[frameSize];
     id3Data.readBytes(frameBytes, 0, frameSize - 1);
 
@@ -530,7 +539,7 @@ public final class Id3Decoder implements MetadataDecoder {
 
     int entryCount = tocData.readUnsignedByte();
     String[] children = new String[entryCount];
-    for (int i = 0; i < entryCount && tocData.bytesLeft() > 0; i++) {
+    for (int i = 0; i < entryCount; i++) {
       int startIndex = tocData.getPosition();
       int endIndex = indexOfZeroByte(frameBytes, startIndex) + 1;
       int stringLength = endIndex - startIndex;
@@ -539,21 +548,18 @@ public final class Id3Decoder implements MetadataDecoder {
     }
 
     String title = null;
-    int frameHeaderSize = majorVersion == 2 ? 6 : 10;
     while (tocData.bytesLeft() >= frameHeaderSize) {
-      Id3Frame frame = decodeFrame(majorVersion, tocData, unsignedIntFrameSizeHack);
-      if (frame == null) {
-        continue;
-      }
+      Id3Frame frame = decodeFrame(majorVersion, tocData, unsignedIntFrameSizeHack,
+        frameHeaderSize);
       if (frame instanceof TextInformationFrame) {
         TextInformationFrame textFrame = (TextInformationFrame)frame;
-        if (textFrame.id != null && textFrame.id.equals("TIT2")) {
+        if ("TIT2".equals(textFrame.id)) {
           title = textFrame.description;
         }
       }
     }
 
-    return new ChapterTOCFrame(id, isRoot, isOrdered, children, title);
+    return new CtocFrame(id, isRoot, isOrdered, children, title);
   }
 
   private static BinaryFrame decodeBinaryFrame(ParsableByteArray id3Data, int frameSize,

library/src/main/java/com/google/android/exoplayer2/metadata/id3/UrlLinkFrame.java → library/src/main/java/com/google/android/exoplayer2/metadata/id3/WxxxFrame.java

 /*
- * Copyright (C) 2016 The Android Open Source Project
+ * Copyright (C) 2017 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.
@@ -23,20 +23,20 @@ import com.google.android.exoplayer2.util.Util;
 /**
  * Url Frame "WXX" ID3 frame.
  */
-public class UrlLinkFrame extends Id3Frame {
+public final class WxxxFrame extends Id3Frame {
 
   public static final String ID = "WXXX";
 
   public final String description;
   public final String url;
 
-  public UrlLinkFrame(String description, String url) {
+  public WxxxFrame(String description, String url) {
     super(ID);
     this.description = description;
     this.url = url;
   }
 
-  /* package */ UrlLinkFrame(Parcel in) {
+  /* package */ WxxxFrame(Parcel in) {
     super(ID);
     description = in.readString();
     url = in.readString();
@@ -50,7 +50,7 @@ public class UrlLinkFrame extends Id3Frame {
     if (obj == null || getClass() != obj.getClass()) {
       return false;
     }
-    UrlLinkFrame other = (UrlLinkFrame) obj;
+    WxxxFrame other = (WxxxFrame) obj;
     return Util.areEqual(description, other.description)
         && Util.areEqual(url, other.url);
   }
@@ -69,17 +69,17 @@ public class UrlLinkFrame extends Id3Frame {
     dest.writeString(url);
   }
 
-  public static final Parcelable.Creator<UrlLinkFrame> CREATOR =
-      new Parcelable.Creator<UrlLinkFrame>() {
+  public static final Parcelable.Creator<WxxxFrame> CREATOR =
+      new Parcelable.Creator<WxxxFrame>() {
 
       @Override
-      public UrlLinkFrame createFromParcel(Parcel in) {
-        return new UrlLinkFrame(in);
+      public WxxxFrame createFromParcel(Parcel in) {
+        return new WxxxFrame(in);
       }
 
       @Override
-      public UrlLinkFrame[] newArray(int size) {
-        return new UrlLinkFrame[size];
+      public WxxxFrame[] newArray(int size) {
+        return new WxxxFrame[size];
       }
 
     };