content: /*
   * Copyright (C) 2016 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.text;
  
  import com.google.android.exoplayer2.Format;
  import com.google.android.exoplayer2.text.cea.Cea608Decoder;
  import com.google.android.exoplayer2.text.cea.Cea708Decoder;
  import com.google.android.exoplayer2.text.dvb.DvbDecoder;
  import com.google.android.exoplayer2.text.pgs.PgsDecoder;
  import com.google.android.exoplayer2.text.ssa.SsaDecoder;
  import com.google.android.exoplayer2.text.subrip.SubripDecoder;
  import com.google.android.exoplayer2.text.ttml.TtmlDecoder;
  import com.google.android.exoplayer2.text.tx3g.Tx3gDecoder;
  import com.google.android.exoplayer2.text.webvtt.Mp4WebvttDecoder;
  import com.google.android.exoplayer2.text.webvtt.WebvttDecoder;
  import com.google.android.exoplayer2.util.MimeTypes;
  
  /**
   * A factory for {@link SubtitleDecoder} instances.
   */
  public interface SubtitleDecoderFactory {
  
    /**
     * Returns whether the factory is able to instantiate a {@link SubtitleDecoder} for the given
     * {@link Format}.
     *
     * @param format The {@link Format}.
     * @return Whether the factory can instantiate a suitable {@link SubtitleDecoder}.
     */
    boolean supportsFormat(Format format);
  
    /**
     * Creates a {@link SubtitleDecoder} for the given {@link Format}.
     *
     * @param format The {@link Format}.
     * @return A new {@link SubtitleDecoder}.
     * @throws IllegalArgumentException If the {@link Format} is not supported.
     */
    SubtitleDecoder createDecoder(Format format);
  
    /**
     * Default {@link SubtitleDecoderFactory} implementation.
     *
     * <p>The formats supported by this factory are:
     *
     * <ul>
     *   <li>WebVTT ({@link WebvttDecoder})
     *   <li>WebVTT (MP4) ({@link Mp4WebvttDecoder})
     *   <li>TTML ({@link TtmlDecoder})
     *   <li>SubRip ({@link SubripDecoder})
     *   <li>SSA/ASS ({@link SsaDecoder})
     *   <li>TX3G ({@link Tx3gDecoder})
     *   <li>Cea608 ({@link Cea608Decoder})
     *   <li>Cea708 ({@link Cea708Decoder})
     *   <li>DVB ({@link DvbDecoder})
     *   <li>PGS ({@link PgsDecoder})
     * </ul>
     */
    SubtitleDecoderFactory DEFAULT =
        new SubtitleDecoderFactory() {
  
          @Override
          public boolean supportsFormat(Format format) {
            String mimeType = format.sampleMimeType;
            return MimeTypes.TEXT_VTT.equals(mimeType)
                || MimeTypes.TEXT_SSA.equals(mimeType)
                || MimeTypes.APPLICATION_TTML.equals(mimeType)
                || MimeTypes.APPLICATION_MP4VTT.equals(mimeType)
                || MimeTypes.APPLICATION_SUBRIP.equals(mimeType)
                || MimeTypes.APPLICATION_TX3G.equals(mimeType)
                || MimeTypes.APPLICATION_CEA608.equals(mimeType)
                || MimeTypes.APPLICATION_MP4CEA608.equals(mimeType)
                || MimeTypes.APPLICATION_CEA708.equals(mimeType)
                || MimeTypes.APPLICATION_DVBSUBS.equals(mimeType)
                || MimeTypes.APPLICATION_PGS.equals(mimeType);
          }
  
          @Override
          public SubtitleDecoder createDecoder(Format format) {
            switch (format.sampleMimeType) {
              case MimeTypes.TEXT_VTT:
                return new WebvttDecoder();
              case MimeTypes.TEXT_SSA:
                return new SsaDecoder(format.initializationData);
              case MimeTypes.APPLICATION_MP4VTT:
                return new Mp4WebvttDecoder();
              case MimeTypes.APPLICATION_TTML:
                return new TtmlDecoder();
              case MimeTypes.APPLICATION_SUBRIP:
                return new SubripDecoder();
              case MimeTypes.APPLICATION_TX3G:
                return new Tx3gDecoder(format.initializationData);
              case MimeTypes.APPLICATION_CEA608:
              case MimeTypes.APPLICATION_MP4CEA608:
                return new Cea608Decoder(format.sampleMimeType, format.accessibilityChannel);
              case MimeTypes.APPLICATION_CEA708:
                return new Cea708Decoder(format.accessibilityChannel);
              case MimeTypes.APPLICATION_DVBSUBS:
                return new DvbDecoder(format.initializationData);
              case MimeTypes.APPLICATION_PGS:
                return new PgsDecoder();
              default:
                throw new IllegalArgumentException(
                    "Attempted to create decoder for unsupported format");
            }
          }
        };
  }
  