content: /*
   * Copyright (C) 2020 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.mp3;
  
  import static com.google.android.exoplayer2.extractor.mp3.Mp3Extractor.FLAG_ENABLE_INDEX_SEEKING;
  import static com.google.android.exoplayer2.testutil.TestUtil.extractAllSamplesFromFile;
  import static com.google.common.truth.Truth.assertThat;
  
  import android.net.Uri;
  import androidx.test.core.app.ApplicationProvider;
  import androidx.test.ext.junit.runners.AndroidJUnit4;
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.extractor.SeekMap;
  import com.google.android.exoplayer2.testutil.FakeExtractorOutput;
  import com.google.android.exoplayer2.testutil.FakeTrackOutput;
  import com.google.android.exoplayer2.testutil.TestUtil;
  import com.google.android.exoplayer2.upstream.DefaultDataSource;
  import com.google.android.exoplayer2.util.Util;
  import java.io.IOException;
  import java.util.List;
  import org.junit.Before;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  
  /** Tests for {@link IndexSeeker}. */
  @RunWith(AndroidJUnit4.class)
  public class IndexSeekerTest {
  
    private static final String TEST_FILE_NO_SEEK_TABLE = "media/mp3/bear-vbr-no-seek-table.mp3";
    private static final int TEST_FILE_NO_SEEK_TABLE_DURATION = 2_808_000;
  
    private Mp3Extractor extractor;
    private FakeExtractorOutput extractorOutput;
    private DefaultDataSource dataSource;
  
    @Before
    public void setUp() throws Exception {
      extractor = new Mp3Extractor(FLAG_ENABLE_INDEX_SEEKING);
      extractorOutput = new FakeExtractorOutput();
      dataSource =
          new DefaultDataSource.Factory(ApplicationProvider.getApplicationContext())
              .createDataSource();
    }
  
    @Test
    public void mp3ExtractorReads_returnsSeekableSeekMap() throws Exception {
      Uri fileUri = TestUtil.buildAssetUri(TEST_FILE_NO_SEEK_TABLE);
  
      SeekMap seekMap = TestUtil.extractSeekMap(extractor, extractorOutput, dataSource, fileUri);
  
      assertThat(seekMap.isSeekable()).isTrue();
    }
  
    @Test
    public void mp3ExtractorReads_correctsInexactDuration() throws Exception {
      FakeExtractorOutput extractorOutput =
          TestUtil.extractAllSamplesFromFile(
              extractor, ApplicationProvider.getApplicationContext(), TEST_FILE_NO_SEEK_TABLE);
  
      SeekMap seekMap = extractorOutput.seekMap;
  
      assertThat(seekMap.getDurationUs()).isEqualTo(TEST_FILE_NO_SEEK_TABLE_DURATION);
    }
  
    @Test
    public void seeking_handlesSeekToZero() throws Exception {
      String fileName = TEST_FILE_NO_SEEK_TABLE;
      Uri fileUri = TestUtil.buildAssetUri(fileName);
      SeekMap seekMap = TestUtil.extractSeekMap(extractor, extractorOutput, dataSource, fileUri);
      FakeTrackOutput trackOutput = extractorOutput.trackOutputs.get(0);
  
      long targetSeekTimeUs = 0;
      int extractedFrameIndex =
          TestUtil.seekToTimeUs(
              extractor, seekMap, targetSeekTimeUs, dataSource, trackOutput, fileUri);
  
      assertThat(extractedFrameIndex).isNotEqualTo(C.INDEX_UNSET);
      assertFirstFrameAfterSeekIsWithinMinDifference(
          fileName, trackOutput, targetSeekTimeUs, extractedFrameIndex);
      assertFirstFrameAfterSeekHasCorrectData(fileName, trackOutput, extractedFrameIndex);
    }
  
    @Test
    public void seeking_handlesSeekToEof() throws Exception {
      String fileName = TEST_FILE_NO_SEEK_TABLE;
      Uri fileUri = TestUtil.buildAssetUri(fileName);
      SeekMap seekMap = TestUtil.extractSeekMap(extractor, extractorOutput, dataSource, fileUri);
      FakeTrackOutput trackOutput = extractorOutput.trackOutputs.get(0);
  
      long targetSeekTimeUs = TEST_FILE_NO_SEEK_TABLE_DURATION;
      int extractedFrameIndex =
          TestUtil.seekToTimeUs(
              extractor, seekMap, targetSeekTimeUs, dataSource, trackOutput, fileUri);
  
      assertThat(extractedFrameIndex).isNotEqualTo(C.INDEX_UNSET);
      assertFirstFrameAfterSeekIsWithinMinDifference(
          fileName, trackOutput, targetSeekTimeUs, extractedFrameIndex);
      assertFirstFrameAfterSeekHasCorrectData(fileName, trackOutput, extractedFrameIndex);
    }
  
    @Test
    public void seeking_handlesSeekingBackward() throws Exception {
      String fileName = TEST_FILE_NO_SEEK_TABLE;
      Uri fileUri = TestUtil.buildAssetUri(fileName);
      SeekMap seekMap = TestUtil.extractSeekMap(extractor, extractorOutput, dataSource, fileUri);
      FakeTrackOutput trackOutput = extractorOutput.trackOutputs.get(0);
  
      long firstSeekTimeUs = 1_234_000;
      TestUtil.seekToTimeUs(extractor, seekMap, firstSeekTimeUs, dataSource, trackOutput, fileUri);
      long targetSeekTimeUs = 987_000;
      int extractedFrameIndex =
          TestUtil.seekToTimeUs(
              extractor, seekMap, targetSeekTimeUs, dataSource, trackOutput, fileUri);
  
      assertThat(extractedFrameIndex).isNotEqualTo(C.INDEX_UNSET);
      assertFirstFrameAfterSeekIsWithinMinDifference(
          fileName, trackOutput, targetSeekTimeUs, extractedFrameIndex);
      assertFirstFrameAfterSeekHasCorrectData(fileName, trackOutput, extractedFrameIndex);
    }
  
    @Test
    public void seeking_handlesSeekingForward() throws Exception {
      String fileName = TEST_FILE_NO_SEEK_TABLE;
      Uri fileUri = TestUtil.buildAssetUri(fileName);
      SeekMap seekMap = TestUtil.extractSeekMap(extractor, extractorOutput, dataSource, fileUri);
      FakeTrackOutput trackOutput = extractorOutput.trackOutputs.get(0);
  
      long firstSeekTimeUs = 987_000;
      TestUtil.seekToTimeUs(extractor, seekMap, firstSeekTimeUs, dataSource, trackOutput, fileUri);
      long targetSeekTimeUs = 1_234_000;
      int extractedFrameIndex =
          TestUtil.seekToTimeUs(
              extractor, seekMap, targetSeekTimeUs, dataSource, trackOutput, fileUri);
  
      assertThat(extractedFrameIndex).isNotEqualTo(C.INDEX_UNSET);
      assertFirstFrameAfterSeekIsWithinMinDifference(
          fileName, trackOutput, targetSeekTimeUs, extractedFrameIndex);
      assertFirstFrameAfterSeekHasCorrectData(fileName, trackOutput, extractedFrameIndex);
    }
  
    private static void assertFirstFrameAfterSeekIsWithinMinDifference(
        String fileName,
        FakeTrackOutput trackOutput,
        long targetSeekTimeUs,
        int firstFrameIndexAfterSeek)
        throws IOException {
      FakeTrackOutput expectedTrackOutput = getExpectedTrackOutput(fileName);
      int exactFrameIndex = getFrameIndex(expectedTrackOutput, targetSeekTimeUs);
      long exactFrameTimeUs = expectedTrackOutput.getSampleTimeUs(exactFrameIndex);
      long foundTimeUs = trackOutput.getSampleTimeUs(firstFrameIndexAfterSeek);
  
      assertThat(exactFrameTimeUs - foundTimeUs).isAtMost(IndexSeeker.MIN_TIME_BETWEEN_POINTS_US);
    }
  
    private static void assertFirstFrameAfterSeekHasCorrectData(
        String fileName, FakeTrackOutput trackOutput, int firstFrameIndexAfterSeek)
        throws IOException {
      FakeTrackOutput expectedTrackOutput = getExpectedTrackOutput(fileName);
      long foundTimeUs = trackOutput.getSampleTimeUs(firstFrameIndexAfterSeek);
      int foundFrameIndex = getFrameIndex(expectedTrackOutput, foundTimeUs);
  
      trackOutput.assertSample(
          firstFrameIndexAfterSeek,
          expectedTrackOutput.getSampleData(foundFrameIndex),
          expectedTrackOutput.getSampleTimeUs(foundFrameIndex),
          expectedTrackOutput.getSampleFlags(foundFrameIndex),
          expectedTrackOutput.getSampleCryptoData(foundFrameIndex));
    }
  
    private static FakeTrackOutput getExpectedTrackOutput(String fileName) throws IOException {
      return extractAllSamplesFromFile(
              new Mp3Extractor(FLAG_ENABLE_INDEX_SEEKING),
              ApplicationProvider.getApplicationContext(),
              fileName)
          .trackOutputs
          .get(0);
    }
  
    private static int getFrameIndex(FakeTrackOutput trackOutput, long targetSeekTimeUs) {
      List<Long> frameTimes = trackOutput.getSampleTimesUs();
      return Util.binarySearchFloor(
          frameTimes, targetSeekTimeUs, /* inclusive= */ true, /* stayInBounds= */ false);
    }
  }
  