MpegAudioChunkHandler cleanup and Tests

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/avi/MpegAudioChunkHandler.java

@@ -51,7 +51,12 @@ public class MpegAudioChunkHandler extends ChunkHandler {
       syncTime();
       return true;
     }
-    chunkRemaining = size;
+    this.size = chunkRemaining = size;
+    return resume(input);
+  }
+
+  @Override
+  boolean resume(@NonNull ExtractorInput input) throws IOException {
     if (process(input)) {
       // Fail Over: If the scratch is the entire chunk, we didn't find a MP3 header.
       // Dump the chunk as is and hope the decoder can handle it.
@@ -59,17 +64,8 @@ public class MpegAudioChunkHandler extends ChunkHandler {
         scratch.setPosition(0);
         trackOutput.sampleData(scratch, size);
         scratch.reset(0);
+        done(size);
       }
-      clock.advance();
-      return true;
-    }
-    return false;
-  }
-
-  @Override
-  boolean resume(@NonNull ExtractorInput input) throws IOException {
-    if (process(input)) {
-      clock.advance();
       return true;
     }
     return false;
@@ -101,7 +97,6 @@ public class MpegAudioChunkHandler extends ChunkHandler {
     scratch.ensureCapacity(scratch.limit() + chunkRemaining);
     int toRead = 4;
     while (chunkRemaining > 0 && readScratch(input, toRead) != C.RESULT_END_OF_INPUT) {
-      readScratch(input, toRead);
       while (scratch.bytesLeft() >= 4) {
         if (header.setForHeaderData(scratch.readInt())) {
           scratch.skipBytes(-4);
@@ -127,7 +122,7 @@ public class MpegAudioChunkHandler extends ChunkHandler {
         trackOutput.sampleData(scratch, scratchBytes);
         frameRemaining = header.frameSize - scratchBytes;
       } else {
-        return chunkRemaining == 0;
+        return true;
       }
     }
     final int bytes = trackOutput.sampleData(input, Math.min(frameRemaining, chunkRemaining), false);
@@ -151,4 +146,14 @@ public class MpegAudioChunkHandler extends ChunkHandler {
     timeUs = clock.getUs();
     frameRemaining = 0;
   }
+
+  @VisibleForTesting(otherwise = VisibleForTesting.NONE)
+  long getTimeUs() {
+    return timeUs;
+  }
+
+  @VisibleForTesting(otherwise = VisibleForTesting.NONE)
+  int getFrameRemaining() {
+    return frameRemaining;
+  }
 }

library/extractor/src/test/java/com/google/android/exoplayer2/extractor/avi/MpegAudioChunkHandlerTest.java

@@ -0,0 +1,116 @@
+package com.google.android.exoplayer2.extractor.avi;
+
+import android.content.Context;
+import androidx.test.core.app.ApplicationProvider;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.audio.MpegAudioUtil;
+import com.google.android.exoplayer2.testutil.FakeExtractorInput;
+import com.google.android.exoplayer2.testutil.FakeTrackOutput;
+import com.google.android.exoplayer2.testutil.TestUtil;
+import com.google.android.exoplayer2.util.MimeTypes;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+public class MpegAudioChunkHandlerTest {
+  private static final int FPS = 24;
+  private Format MP3_FORMAT = new Format.Builder().setChannelCount(2).
+      setSampleMimeType(MimeTypes.AUDIO_MPEG).setSampleRate(44100).build();
+  private static final long CHUNK_MS = C.MICROS_PER_SECOND / FPS;
+  private final MpegAudioUtil.Header header = new MpegAudioUtil.Header();
+  private FakeTrackOutput fakeTrackOutput;
+  private MpegAudioChunkHandler mpegAudioChunkHandler;
+  private byte[] mp3Frame;
+  private long frameUs;
+
+  @Before
+  public void before() throws IOException {
+    fakeTrackOutput = new FakeTrackOutput(false);
+    fakeTrackOutput.format(MP3_FORMAT);
+    mpegAudioChunkHandler = new MpegAudioChunkHandler(0, fakeTrackOutput,
+        new ChunkClock(C.MICROS_PER_SECOND, FPS), MP3_FORMAT.sampleRate);
+
+    if (mp3Frame == null) {
+      final Context context = ApplicationProvider.getApplicationContext();
+      mp3Frame = TestUtil.getByteArray(context,"extractordumps/avi/frame.mp3.dump");
+      header.setForHeaderData(ByteBuffer.wrap(mp3Frame).getInt());
+      //About 26ms
+      frameUs = header.samplesPerFrame * C.MICROS_PER_SECOND / header.sampleRate;
+    }
+  }
+
+  @Test
+  public void newChunk_givenNonMpegData() throws IOException {
+    final FakeExtractorInput input = new FakeExtractorInput.Builder().setData(new byte[1024]).
+        build();
+
+    mpegAudioChunkHandler.newChunk((int)input.getLength(), input);
+    Assert.assertEquals(1024, fakeTrackOutput.getSampleData(0).length);
+    Assert.assertEquals(CHUNK_MS, mpegAudioChunkHandler.getClock().getUs());
+  }
+  @Test
+  public void newChunk_givenEmptyChunk() throws IOException {
+    final FakeExtractorInput input = new FakeExtractorInput.Builder().setData(new byte[0]).
+        build();
+    mpegAudioChunkHandler.newChunk((int)input.getLength(), input);
+    Assert.assertEquals(C.MICROS_PER_SECOND / 24, mpegAudioChunkHandler.getClock().getUs());
+  }
+
+  @Test
+  public void setIndex_given12frames() {
+    mpegAudioChunkHandler.setIndex(12);
+    Assert.assertEquals(500_000L, mpegAudioChunkHandler.getTimeUs());
+  }
+
+  @Test
+  public void newChunk_givenSingleFrame() throws IOException {
+    final FakeExtractorInput input = new FakeExtractorInput.Builder().setData(mp3Frame).build();
+
+    mpegAudioChunkHandler.newChunk(mp3Frame.length, input);
+    Assert.assertArrayEquals(mp3Frame, fakeTrackOutput.getSampleData(0));
+    Assert.assertEquals(frameUs, mpegAudioChunkHandler.getTimeUs());
+  }
+
+  @Test
+  public void newChunk_givenSeekAndFragmentedFrames() throws IOException {
+    ByteBuffer byteBuffer = ByteBuffer.allocate(mp3Frame.length * 2);
+    byteBuffer.put(mp3Frame, mp3Frame.length / 2, mp3Frame.length / 2);
+    byteBuffer.put(mp3Frame);
+    final int remainder = byteBuffer.remaining();
+    byteBuffer.put(mp3Frame, 0, remainder);
+
+    final FakeExtractorInput input = new FakeExtractorInput.Builder().setData(byteBuffer.array()).
+        build();
+
+    mpegAudioChunkHandler.setIndex(1); //Seek
+    Assert.assertFalse(mpegAudioChunkHandler.newChunk(byteBuffer.capacity(), input));
+    Assert.assertArrayEquals(mp3Frame, fakeTrackOutput.getSampleData(0));
+    Assert.assertEquals(frameUs + CHUNK_MS, mpegAudioChunkHandler.getTimeUs());
+
+    Assert.assertTrue(mpegAudioChunkHandler.resume(input));
+    Assert.assertEquals(header.frameSize - remainder, mpegAudioChunkHandler.getFrameRemaining());
+  }
+
+  @Test
+  public void newChunk_givenTwoFrames() throws IOException {
+    ByteBuffer byteBuffer = ByteBuffer.allocate(mp3Frame.length * 2);
+    byteBuffer.put(mp3Frame);
+    byteBuffer.put(mp3Frame);
+
+    final FakeExtractorInput input = new FakeExtractorInput.Builder().setData(byteBuffer.array()).
+        build();
+    Assert.assertFalse(mpegAudioChunkHandler.newChunk(byteBuffer.capacity(), input));
+    Assert.assertEquals(1, fakeTrackOutput.getSampleCount());
+    Assert.assertEquals(0L, fakeTrackOutput.getSampleTimeUs(0));
+
+    Assert.assertTrue(mpegAudioChunkHandler.resume(input));
+    Assert.assertEquals(2, fakeTrackOutput.getSampleCount());
+    Assert.assertEquals(frameUs, fakeTrackOutput.getSampleTimeUs(1));
+  }
+}