content: /*
   * Copyright 2021 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.extractor.jpeg;
  
  import com.google.android.exoplayer2.extractor.ExtractorOutput;
  import com.google.android.exoplayer2.extractor.SeekMap;
  import com.google.android.exoplayer2.extractor.SeekPoint;
  import com.google.android.exoplayer2.extractor.TrackOutput;
  
  /**
   * An extractor output that wraps another extractor output and applies a give start byte offset to
   * seek positions.
   *
   * <p>This is useful for extracting from a container that's concatenated after some prefix data but
   * where the container's extractor doesn't handle a non-zero start offset (for example, because it
   * seeks to absolute positions read from the container data).
   */
  public final class StartOffsetExtractorOutput implements ExtractorOutput {
  
    private final long startOffset;
    private final ExtractorOutput extractorOutput;
  
    /** Creates a new wrapper reading from the given start byte offset. */
    public StartOffsetExtractorOutput(long startOffset, ExtractorOutput extractorOutput) {
      this.startOffset = startOffset;
      this.extractorOutput = extractorOutput;
    }
  
    @Override
    public TrackOutput track(int id, int type) {
      return extractorOutput.track(id, type);
    }
  
    @Override
    public void endTracks() {
      extractorOutput.endTracks();
    }
  
    @Override
    public void seekMap(SeekMap seekMap) {
      extractorOutput.seekMap(
          new SeekMap() {
            @Override
            public boolean isSeekable() {
              return seekMap.isSeekable();
            }
  
            @Override
            public long getDurationUs() {
              return seekMap.getDurationUs();
            }
  
            @Override
            public SeekPoints getSeekPoints(long timeUs) {
              SeekPoints seekPoints = seekMap.getSeekPoints(timeUs);
              return new SeekPoints(
                  new SeekPoint(seekPoints.first.timeUs, seekPoints.first.position + startOffset),
                  new SeekPoint(seekPoints.second.timeUs, seekPoints.second.position + startOffset));
            }
          });
    }
  }
  