1 files changed, 101 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/metadata/icy/IcyDecoder.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/metadata/icy/IcyDecoder.java
new file mode 100644
index 0000000000..1d44219eda
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/metadata/icy/IcyDecoder.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2018 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 org.mozilla.thirdparty.com.google.android.exoplayer2.metadata.icy;
+
+import androidx.annotation.Nullable;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.C;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.metadata.Metadata;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.metadata.MetadataDecoder;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.metadata.MetadataInputBuffer;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Assertions;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Util;
+import java.nio.ByteBuffer;
+import java.nio.charset.CharacterCodingException;
+import java.nio.charset.Charset;
+import java.nio.charset.CharsetDecoder;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/** Decodes ICY stream information. */
+public final class IcyDecoder implements MetadataDecoder {
+
+  private static final Pattern METADATA_ELEMENT = Pattern.compile("(.+?)='(.*?)';", Pattern.DOTALL);
+  private static final String STREAM_KEY_NAME = "streamtitle";
+  private static final String STREAM_KEY_URL = "streamurl";
+
+  private final CharsetDecoder utf8Decoder;
+  private final CharsetDecoder iso88591Decoder;
+
+  public IcyDecoder() {
+    utf8Decoder = Charset.forName(C.UTF8_NAME).newDecoder();
+    iso88591Decoder = Charset.forName(C.ISO88591_NAME).newDecoder();
+  }
+
+  @Override
+  @SuppressWarnings("ByteBufferBackingArray")
+  public Metadata decode(MetadataInputBuffer inputBuffer) {
+    ByteBuffer buffer = Assertions.checkNotNull(inputBuffer.data);
+    @Nullable String icyString = decodeToString(buffer);
+    byte[] icyBytes = new byte[buffer.limit()];
+    buffer.get(icyBytes);
+
+    if (icyString == null) {
+      return new Metadata(new IcyInfo(icyBytes, /* title= */ null, /* url= */ null));
+    }
+
+    @Nullable String name = null;
+    @Nullable String url = null;
+    int index = 0;
+    Matcher matcher = METADATA_ELEMENT.matcher(icyString);
+    while (matcher.find(index)) {
+      @Nullable String key = Util.toLowerInvariant(matcher.group(1));
+      @Nullable String value = matcher.group(2);
+      switch (key) {
+        case STREAM_KEY_NAME:
+          name = value;
+          break;
+        case STREAM_KEY_URL:
+          url = value;
+          break;
+      }
+      index = matcher.end();
+    }
+    return new Metadata(new IcyInfo(icyBytes, name, url));
+  }
+
+  // The ICY spec doesn't specify a character encoding, and there's no way to communicate one
+  // either. So try decoding UTF-8 first, then fall back to ISO-8859-1.
+  // https://github.com/google/ExoPlayer/issues/6753
+  @Nullable
+  private String decodeToString(ByteBuffer data) {
+    try {
+      return utf8Decoder.decode(data).toString();
+    } catch (CharacterCodingException e) {
+      // Fall through to try ISO-8859-1 decoding.
+    } finally {
+      utf8Decoder.reset();
+      data.rewind();
+    }
+    try {
+      return iso88591Decoder.decode(data).toString();
+    } catch (CharacterCodingException e) {
+      return null;
+    } finally {
+      iso88591Decoder.reset();
+      data.rewind();
+    }
+  }
+}