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.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.Arrays;
  import java.util.List;
  import org.junit.Before;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  
  /** Tests for {@link ConstantBitrateSeeker}. */
  @RunWith(AndroidJUnit4.class)
  public class ConstantBitrateSeekerTest {
    private static final String CONSTANT_FRAME_SIZE_TEST_FILE =
        "media/mp3/bear-cbr-constant-frame-size-no-seek-table.mp3";
    private static final String VARIABLE_FRAME_SIZE_TEST_FILE =
        "media/mp3/bear-cbr-variable-frame-size-no-seek-table.mp3";
  
    private Mp3Extractor extractor;
    private FakeExtractorOutput extractorOutput;
    private DefaultDataSource dataSource;
  
    @Before
    public void setUp() throws Exception {
      extractor = new Mp3Extractor();
      extractorOutput = new FakeExtractorOutput();
      dataSource =
          new DefaultDataSource.Factory(ApplicationProvider.getApplicationContext())
              .createDataSource();
    }
  
    @Test
    public void mp3ExtractorReads_returnSeekableCbrSeeker() throws IOException {
      Uri fileUri = TestUtil.buildAssetUri(CONSTANT_FRAME_SIZE_TEST_FILE);
  
      SeekMap seekMap = TestUtil.extractSeekMap(extractor, extractorOutput, dataSource, fileUri);
  
      assertThat(seekMap.getClass()).isEqualTo(ConstantBitrateSeeker.class);
      assertThat(seekMap.getDurationUs()).isEqualTo(2_784_000);
      assertThat(seekMap.isSeekable()).isTrue();
    }
  
    @Test
    public void seeking_handlesSeekToZero() throws IOException {
      String fileName = CONSTANT_FRAME_SIZE_TEST_FILE;
      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);
      assertFirstFrameAfterSeekIsExactFrame(
          fileName, trackOutput, targetSeekTimeUs, extractedFrameIndex);
    }
  
    @Test
    public void seeking_handlesSeekToEoF() throws IOException {
      String fileName = CONSTANT_FRAME_SIZE_TEST_FILE;
      Uri fileUri = TestUtil.buildAssetUri(fileName);
      SeekMap seekMap = TestUtil.extractSeekMap(extractor, extractorOutput, dataSource, fileUri);
      FakeTrackOutput trackOutput = extractorOutput.trackOutputs.get(0);
  
      long targetSeekTimeUs = seekMap.getDurationUs();
      int extractedFrameIndex =
          TestUtil.seekToTimeUs(
              extractor, seekMap, targetSeekTimeUs, dataSource, trackOutput, fileUri);
  
      assertThat(extractedFrameIndex).isNotEqualTo(C.INDEX_UNSET);
      assertFirstFrameAfterSeekIsExactFrame(
          fileName, trackOutput, targetSeekTimeUs, extractedFrameIndex);
    }
  
    @Test
    public void seeking_handlesSeekingBackward() throws IOException {
      String fileName = CONSTANT_FRAME_SIZE_TEST_FILE;
      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);
      assertFirstFrameAfterSeekIsExactFrame(
          fileName, trackOutput, targetSeekTimeUs, extractedFrameIndex);
    }
  
    @Test
    public void seeking_handlesSeekingForward() throws IOException {
      String fileName = CONSTANT_FRAME_SIZE_TEST_FILE;
      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);
      assertFirstFrameAfterSeekIsExactFrame(
          fileName, trackOutput, targetSeekTimeUs, extractedFrameIndex);
    }
  
    @Test
    public void seeking_variableFrameSize_seeksNearlyExactlyToCorrectFrame() throws IOException {
      String fileName = VARIABLE_FRAME_SIZE_TEST_FILE;
      Uri fileUri = TestUtil.buildAssetUri(fileName);
      SeekMap seekMap = TestUtil.extractSeekMap(extractor, extractorOutput, dataSource, fileUri);
      FakeTrackOutput trackOutput = extractorOutput.trackOutputs.get(0);
  
      long targetSeekTimeUs = 1_234_000;
      int extractedFrameIndex =
          TestUtil.seekToTimeUs(
              extractor, seekMap, targetSeekTimeUs, dataSource, trackOutput, fileUri);
  
      assertThat(extractedFrameIndex).isNotEqualTo(C.INDEX_UNSET);
      assertFirstFrameAfterSeekIsWithin1FrameOfExactFrame(
          fileName, trackOutput, targetSeekTimeUs, extractedFrameIndex);
    }
  
    private static void assertFirstFrameAfterSeekIsExactFrame(
        String fileName,
        FakeTrackOutput trackOutput,
        long targetSeekTimeUs,
        int firstFrameIndexAfterSeek)
        throws IOException {
      FakeTrackOutput expectedTrackOutput = getExpectedTrackOutput(fileName);
      int exactFrameIndex = getFrameIndex(expectedTrackOutput, targetSeekTimeUs);
  
      assertThat(trackOutput.getSampleData(firstFrameIndexAfterSeek))
          .isEqualTo(expectedTrackOutput.getSampleData(exactFrameIndex));
    }
  
    private static void assertFirstFrameAfterSeekIsWithin1FrameOfExactFrame(
        String fileName,
        FakeTrackOutput trackOutput,
        long targetSeekTimeUs,
        int firstFrameIndexAfterSeek)
        throws IOException {
      FakeTrackOutput expectedTrackOutput = getExpectedTrackOutput(fileName);
      int exactFrameIndex = getFrameIndex(expectedTrackOutput, targetSeekTimeUs);
  
      boolean foundPreviousFrame =
          exactFrameIndex != 0
              && Arrays.equals(
                  trackOutput.getSampleData(firstFrameIndexAfterSeek),
                  expectedTrackOutput.getSampleData(exactFrameIndex - 1));
      boolean foundExactFrame =
          Arrays.equals(
              trackOutput.getSampleData(firstFrameIndexAfterSeek),
              expectedTrackOutput.getSampleData(exactFrameIndex));
      boolean foundNextFrame =
          exactFrameIndex != expectedTrackOutput.getSampleCount() - 1
              && Arrays.equals(
                  trackOutput.getSampleData(firstFrameIndexAfterSeek),
                  expectedTrackOutput.getSampleData(exactFrameIndex + 1));
  
      assertThat(foundPreviousFrame || foundExactFrame || foundNextFrame).isTrue();
    }
  
    private static FakeTrackOutput getExpectedTrackOutput(String fileName) throws IOException {
      return TestUtil.extractAllSamplesFromFile(
              new Mp3Extractor(), 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);
    }
  }
  