CaptionConverter.java

/**
 * Licensed to The Apereo Foundation under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 *
 * The Apereo Foundation licenses this file to you under the Educational
 * Community 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://opensource.org/licenses/ecl2.txt
 *
 * 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.opencastproject.caption.api;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;

/**
 * Imports caption catalogs to a list of caption objects and exports these objects to catalog presentations.
 */
public interface CaptionConverter {

  /**
   * Imports captions to {@link List}. If caption format is capable of containing more than one language, language
   * parameter is used to define which captions are parsed.
   *
   * @param inputStream
   *          stream from where captions are read
   * @param language
   *          (optional) captions' language
   * @return {@link List} List of captions
   * @throws CaptionConverterException
   *           if parser encounters an exception
   */
  List<Caption> importCaption(InputStream inputStream, String language) throws CaptionConverterException;

  /**
   * Exports caption collection. Language parameter is used to set language of the captions for those caption format
   * that are capable of storing information about language.
   *
   * @param outputStream
   *          stream to which captions are written
   * @param captions
   *          collection to be exported
   * @param language
   *          (optional) captions' language
   * @throws IOException
   *           if exception occurs writing to output stream
   */
  void exportCaption(OutputStream outputStream, List<Caption> captions, String language) throws IOException;

  /**
   * Reads captions and return information about language if such information is available. Returns empty list
   * otherwise.
   *
   * @param inputStream
   *          stream from where captions are read
   * @return Array containing languages in captions
   * @throws CaptionConverterException
   *           if parser encounters exception
   */
  String[] getLanguageList(InputStream inputStream) throws CaptionConverterException;

  /**
   * Get extension of specific caption format.
   *
   * @return caption format extension
   */
  String getExtension();

}