content: /*
   * Copyright 2002-2019 Drew Noakes and contributors
   *
   *    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
   *
   *        https://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.
   *
   * More information about this project is available at:
   *
   *    https://drewnoakes.com/code/exif/
   *    https://github.com/drewnoakes/metadata-extractor
   */
  package com.drew.imaging.quicktime;
  
  import com.drew.lang.StreamReader;
  import com.drew.lang.annotations.NotNull;
  import com.drew.metadata.mov.QuickTimeContext;
  import com.drew.metadata.mov.atoms.Atom;
  
  import java.io.IOException;
  import java.io.InputStream;
  
  /**
   * @author Payton Garland
   */
  public class QuickTimeReader
  {
      private QuickTimeReader() {}
  
      public static void extract(@NotNull InputStream inputStream, @NotNull QuickTimeHandler<?> handler)
      {
          StreamReader reader = new StreamReader(inputStream);
          reader.setMotorolaByteOrder(true);
  
          QuickTimeContext context = new QuickTimeContext();
  
          processAtoms(reader, -1, handler, context);
      }
  
      private static void processAtoms(StreamReader reader, long atomEnd, QuickTimeHandler<?> handler, QuickTimeContext context)
      {
          try {
              while (atomEnd == -1 || reader.getPosition() < atomEnd) {
  
                  Atom atom = new Atom(reader);
  
                  // Determine if fourCC is container/atom and process accordingly.
                  // Unknown atoms will be skipped
  
                  if (atom.size > Integer.MAX_VALUE) {
                      handler.addError("Atom size too large.");
                      break;
                  }
  
                  if (atom.size < 8) {
                      handler.addError("Atom size too small.");
                      break;
                  }
  
                  if (handler.shouldAcceptContainer(atom)) {
                      processAtoms(reader, atom.size + reader.getPosition() - 8, handler.processContainer(atom, context), context);
                  } else if (handler.shouldAcceptAtom(atom)) {
                      handler = handler.processAtom(atom, reader.getBytes((int)atom.size - 8), context);
                  } else if (atom.size > 8) {
                      reader.skip(atom.size - 8);
                  } else if (atom.size == -1) {
                      break;
                  }
              }
          } catch (IOException e) {
              handler.addError(e.getMessage());
          }
      }
  }
  