content: /*
   * 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.
   * 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.metadata.emsg;
  
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.metadata.Metadata;
  import com.google.android.exoplayer2.metadata.MetadataDecoder;
  import com.google.android.exoplayer2.metadata.MetadataInputBuffer;
  import com.google.android.exoplayer2.util.ParsableByteArray;
  import com.google.android.exoplayer2.util.Util;
  import java.nio.ByteBuffer;
  import java.util.Arrays;
  
  /**
   * Decodes Event Message (emsg) atoms, as defined in ISO/IEC 23009-1:2014, Section 5.10.3.3.
   * <p>
   * Atom data should be provided to the decoder without the full atom header (i.e. starting from the
   * first byte of the scheme_id_uri field).
   */
  public final class EventMessageDecoder implements MetadataDecoder {
  
    @Override
    public Metadata decode(MetadataInputBuffer inputBuffer) {
      ByteBuffer buffer = inputBuffer.data;
      byte[] data = buffer.array();
      int size = buffer.limit();
      ParsableByteArray emsgData = new ParsableByteArray(data, size);
      String schemeIdUri = emsgData.readNullTerminatedString();
      String value = emsgData.readNullTerminatedString();
      long timescale = emsgData.readUnsignedInt();
      long presentationTimeUs = Util.scaleLargeTimestamp(emsgData.readUnsignedInt(),
          C.MICROS_PER_SECOND, timescale);
      long durationMs = Util.scaleLargeTimestamp(emsgData.readUnsignedInt(), 1000, timescale);
      long id = emsgData.readUnsignedInt();
      byte[] messageData = Arrays.copyOfRange(data, emsgData.getPosition(), size);
      return new Metadata(new EventMessage(schemeIdUri, value, durationMs, id, messageData,
          presentationTimeUs));
    }
  
  }
  