Remove WavExtractor from the nullness blacklist

PiperOrigin-RevId: 288292488

Remove WavExtractor from the nullness blacklist
PiperOrigin-RevId: 288292488
1f85cd9a · olly · Oliver Woodman · d609c3b6 · 1f85cd9a
Commit 1f85cd9a authored Jan 06, 2020 by olly Committed by Oliver Woodman Jan 17, 2020
Showing with 63 additions and 50 deletions
library/core/src/main/java/com/google/android/exoplayer2/extractor/wav/WavExtractor.java
--- a/library/core/src/main/java/com/google/android/exoplayer2/extractor/wav/WavExtractor.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/extractor/wav/WavExtractor.java
@@ -31,6 +31,8 @@ import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.android.exoplayer2.util.Util;
 import java.io.IOException;
+import org.checkerframework.checker.nullness.qual.EnsuresNonNull;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 /**
 * Extracts data from WAV byte streams.
@@ -47,9 +49,9 @@ public final class WavExtractor implements Extractor {
  /** Factory for {@link WavExtractor} instances. */
  public static final ExtractorsFactory FACTORY = () -> new Extractor[] {new WavExtractor()};
-  private ExtractorOutput extractorOutput;
+  @MonotonicNonNull private ExtractorOutput extractorOutput;
-  private TrackOutput trackOutput;
+  @MonotonicNonNull private TrackOutput trackOutput;
-  private OutputWriter outputWriter;
+  @MonotonicNonNull private OutputWriter outputWriter;
  private int dataStartPosition;
  private long dataEndPosition;
@@ -85,6 +87,7 @@ public final class WavExtractor implements Extractor {
  @Override
  public int read(ExtractorInput input, PositionHolder seekPosition)
      throws IOException, InterruptedException {
+    assertInitialized();
    if (outputWriter == null) {
      WavHeader header = WavHeaderReader.peek(input);
      if (header == null) {
@@ -136,6 +139,12 @@ public final class WavExtractor implements Extractor {
    return outputWriter.sampleData(input, bytesLeft) ? RESULT_END_OF_INPUT : RESULT_CONTINUE;
  }
+  @EnsuresNonNull({"extractorOutput", "trackOutput"})
+  private void assertInitialized() {
+    Assertions.checkStateNotNull(trackOutput);
+    Util.castNonNull(extractorOutput);
+  }
  /** Writes to the extractor's output. */
  private interface OutputWriter {
@@ -201,12 +210,19 @@ public final class WavExtractor implements Extractor {
        TrackOutput trackOutput,
        WavHeader header,
        String mimeType,
-        @C.PcmEncoding int pcmEncoding) {
+        @C.PcmEncoding int pcmEncoding)
+        throws ParserException {
      this.extractorOutput = extractorOutput;
      this.trackOutput = trackOutput;
      this.header = header;
-      // Blocks are expected to correspond to single frames. This is validated in init(int, long).
-      int bytesPerFrame = header.blockSize;
+      int bytesPerFrame = header.numChannels * header.bitsPerSample / 8;
+      // Validate the header. Blocks are expected to correspond to single frames.
+      if (header.blockSize != bytesPerFrame) {
+        throw new ParserException(
+            "Expected block size: " + bytesPerFrame + "; got: " + header.blockSize);
+      }
      targetSampleSizeBytes =
          Math.max(bytesPerFrame, header.frameRateHz * bytesPerFrame / TARGET_SAMPLES_PER_SECOND);
      format =
@@ -233,15 +249,7 @@ public final class WavExtractor implements Extractor {
    }
    @Override
-    public void init(int dataStartPosition, long dataEndPosition) throws ParserException {
+    public void init(int dataStartPosition, long dataEndPosition) {
-      // Validate the header.
-      int bytesPerFrame = header.numChannels * header.bitsPerSample / 8;
-      if (header.blockSize != bytesPerFrame) {
-        throw new ParserException(
-            "Expected block size: " + bytesPerFrame + "; got: " + header.blockSize);
-      }
-      // Output the seek map and format.
      extractorOutput.seekMap(
          new WavSeekMap(header, /* framesPerBlock= */ 1, dataStartPosition, dataEndPosition));
      trackOutput.format(format);
@@ -302,18 +310,20 @@ public final class WavExtractor implements Extractor {
    private final ExtractorOutput extractorOutput;
    private final TrackOutput trackOutput;
    private final WavHeader header;
+    /** Number of frames per block of the input (yet to be decoded) data. */
+    private final int framesPerBlock;
+    /** Target for the input (yet to be decoded) data. */
+    private final byte[] inputData;
+    /** Target for decoded (yet to be output) data. */
+    private final ParsableByteArray decodedData;
    /** The target size of each output sample, in frames. */
    private final int targetSampleSizeFrames;
+    /** The output format. */
+    private final Format format;
-    // Properties of the input (yet to be decoded) data.
+    /** The number of pending bytes in {@link #inputData}. */
-    private int framesPerBlock;
-    private byte[] inputData;
    private int pendingInputBytes;
-    // Target for decoded (yet to be output) data.
-    private ParsableByteArray decodedData;
-    // Properties of the output.
    /** The time at which the writer was last {@link #reset}. */
    private long startTimeUs;
    /**
@@ -329,33 +339,21 @@ public final class WavExtractor implements Extractor {
    private long outputFrameCount;
    public ImaAdPcmOutputWriter(
-        ExtractorOutput extractorOutput, TrackOutput trackOutput, WavHeader header) {
+        ExtractorOutput extractorOutput, TrackOutput trackOutput, WavHeader header)
+        throws ParserException {
      this.extractorOutput = extractorOutput;
      this.trackOutput = trackOutput;
      this.header = header;
      targetSampleSizeFrames = Math.max(1, header.frameRateHz / TARGET_SAMPLES_PER_SECOND);
-    }
-    @Override
-    public void reset(long timeUs) {
-      // Reset the input side.
-      pendingInputBytes = 0;
-      // Reset the output side.
-      startTimeUs = timeUs;
-      pendingOutputBytes = 0;
-      outputFrameCount = 0;
-    }
-    @Override
-    public void init(int dataStartPosition, long dataEndPosition) throws ParserException {
-      // Validate the header.
      ParsableByteArray scratch = new ParsableByteArray(header.extraData);
      scratch.readLittleEndianUnsignedShort();
      framesPerBlock = scratch.readLittleEndianUnsignedShort();
-      // This calculation is defined in "Microsoft Multimedia Standards Update - New Multimedia
-      // Types and Data Techniques" (1994). See the "IMA ADPCM Wave Type" and
-      // "DVI ADPCM Wave Type" sections, and the calculation of wSamplesPerBlock in the latter.
      int numChannels = header.numChannels;
+      // Validate the header. This calculation is defined in "Microsoft Multimedia Standards Update
+      // - New Multimedia Types and Data Techniques" (1994). See the "IMA ADPCM Wave Type" and "DVI
+      // ADPCM Wave Type" sections, and the calculation of wSamplesPerBlock in the latter.
      int expectedFramesPerBlock =
          (((header.blockSize - (4 * numChannels)) * 8) / (header.bitsPerSample * numChannels)) + 1;
      if (framesPerBlock != expectedFramesPerBlock) {
@@ -368,22 +366,19 @@ public final class WavExtractor implements Extractor {
      int maxBlocksToDecode = Util.ceilDivide(targetSampleSizeFrames, framesPerBlock);
      inputData = new byte[maxBlocksToDecode * header.blockSize];
      decodedData =
-          new ParsableByteArray(maxBlocksToDecode * numOutputFramesToBytes(framesPerBlock));
+          new ParsableByteArray(
+              maxBlocksToDecode * numOutputFramesToBytes(framesPerBlock, numChannels));
-      // Output the seek map.
+      // Create the format. We calculate the bitrate of the data before decoding, since this is the
-      extractorOutput.seekMap(
-          new WavSeekMap(header, framesPerBlock, dataStartPosition, dataEndPosition));
-      // Output the format. We calculate the bitrate of the data before decoding, since this is the
      // bitrate of the stream itself.
      int bitrate = header.frameRateHz * header.blockSize * 8 / framesPerBlock;
-      Format format =
+      format =
          Format.createAudioSampleFormat(
              /* id= */ null,
              MimeTypes.AUDIO_RAW,
              /* codecs= */ null,
              bitrate,
-              /* maxInputSize= */ numOutputFramesToBytes(targetSampleSizeFrames),
+              /* maxInputSize= */ numOutputFramesToBytes(targetSampleSizeFrames, numChannels),
              header.numChannels,
              header.frameRateHz,
              C.ENCODING_PCM_16BIT,
@@ -391,6 +386,20 @@ public final class WavExtractor implements Extractor {
              /* drmInitData= */ null,
              /* selectionFlags= */ 0,
              /* language= */ null);
+    }
+    @Override
+    public void reset(long timeUs) {
+      pendingInputBytes = 0;
+      startTimeUs = timeUs;
+      pendingOutputBytes = 0;
+      outputFrameCount = 0;
+    }
+    @Override
+    public void init(int dataStartPosition, long dataEndPosition) {
+      extractorOutput.seekMap(
+          new WavSeekMap(header, framesPerBlock, dataStartPosition, dataEndPosition));
      trackOutput.format(format);
    }
@@ -543,7 +552,11 @@ public final class WavExtractor implements Extractor {
    }
    private int numOutputFramesToBytes(int frames) {
-      return frames * 2 * header.numChannels;
+      return numOutputFramesToBytes(frames, header.numChannels);
+    }
+    private static int numOutputFramesToBytes(int frames, int numChannels) {
+      return frames * 2 * numChannels;
    }
  }
 }