Enhance SampleQueue/RollingSampleBuffer to support other use cases.

- This is a step toward hopefully converging HLS and CHUNK packages.
- Add support for encrypted samples.
- Add support for appending from a DataSource.

library/src/main/java/com/google/android/exoplayer/hls/parser/AdtsReader.java

@@ -88,7 +88,7 @@ import java.util.Collections;
           appendData(data, bytesToRead);
           bytesRead += bytesToRead;
           if (bytesRead == sampleSize) {
-            commitSample(true);
+            commitSample(C.SAMPLE_FLAG_SYNC);
             timeUs += frameDurationUs;
             bytesRead = 0;
             state = STATE_FINDING_SYNC;

library/src/main/java/com/google/android/exoplayer/hls/parser/H264Reader.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer.hls.parser;
 
+import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.MediaFormat;
 import com.google.android.exoplayer.mp4.Mp4Util;
 import com.google.android.exoplayer.upstream.BufferPool;
@@ -88,7 +89,7 @@ import java.util.List;
               if (isKeyframe && !hasMediaFormat() && sps.isCompleted() && pps.isCompleted()) {
                 parseMediaFormat(sps, pps);
               }
-              commitSample(isKeyframe, nalUnitOffsetInData);
+              commitSample(isKeyframe ? C.SAMPLE_FLAG_SYNC : 0, nalUnitOffsetInData);
             }
             startSample(pesTimeUs, nalUnitOffsetInData);
             isKeyframe = false;

library/src/main/java/com/google/android/exoplayer/hls/parser/Id3Reader.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer.hls.parser;
 
+import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.MediaFormat;
 import com.google.android.exoplayer.upstream.BufferPool;
 import com.google.android.exoplayer.util.ParsableByteArray;
@@ -41,7 +42,7 @@ import com.google.android.exoplayer.util.ParsableByteArray;
 
   @Override
   public void packetFinished() {
-    commitSample(true);
+    commitSample(C.SAMPLE_FLAG_SYNC);
   }
 
 }

library/src/main/java/com/google/android/exoplayer/hls/parser/RollingSampleBuffer.java

@@ -18,9 +18,11 @@ package com.google.android.exoplayer.hls.parser;
 import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.SampleHolder;
 import com.google.android.exoplayer.upstream.BufferPool;
+import com.google.android.exoplayer.upstream.DataSource;
 import com.google.android.exoplayer.util.Assertions;
 import com.google.android.exoplayer.util.ParsableByteArray;
 
+import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.concurrent.ConcurrentLinkedQueue;
 
@@ -29,12 +31,15 @@ import java.util.concurrent.ConcurrentLinkedQueue;
  */
 /* package */ final class RollingSampleBuffer {
 
+  private static final int INITIAL_SCRATCH_SIZE = 32;
+
   private final BufferPool fragmentPool;
   private final int fragmentLength;
 
   private final InfoQueue infoQueue;
   private final ConcurrentLinkedQueue<byte[]> dataQueue;
-  private final long[] dataOffsetHolder;
+  private final SampleExtrasHolder extrasHolder;
+  private final ParsableByteArray scratch;
 
   // Accessed only by the consuming thread.
   private long totalBytesDropped;
@@ -51,7 +56,8 @@ import java.util.concurrent.ConcurrentLinkedQueue;
     fragmentLength = bufferPool.bufferLength;
     infoQueue = new InfoQueue();
     dataQueue = new ConcurrentLinkedQueue<byte[]>();
-    dataOffsetHolder = new long[1];
+    extrasHolder = new SampleExtrasHolder();
+    scratch = new ParsableByteArray(INITIAL_SCRATCH_SIZE);
   }
 
   public void release() {
@@ -71,7 +77,7 @@ import java.util.concurrent.ConcurrentLinkedQueue;
    * @return True if the holder was filled. False if there is no current sample.
    */
   public boolean peekSample(SampleHolder holder) {
-    return infoQueue.peekSample(holder, dataOffsetHolder);
+    return infoQueue.peekSample(holder, extrasHolder);
   }
 
   /**
@@ -85,23 +91,99 @@ import java.util.concurrent.ConcurrentLinkedQueue;
   /**
    * Reads the current sample, advancing the read index to the next sample.
    *
-   * @param holder The holder into which the current sample should be written.
+   * @param sampleHolder The holder into which the current sample should be written.
    */
-  public void readSample(SampleHolder holder) {
-    // Write the sample information into the holder.
-    infoQueue.peekSample(holder, dataOffsetHolder);
-    // Write the sample data into the holder.
-    if (holder.data == null || holder.data.capacity() < holder.size) {
-      holder.replaceBuffer(holder.size);
+  public void readSample(SampleHolder sampleHolder) {
+    // Write the sample information into the holder and extrasHolder.
+    infoQueue.peekSample(sampleHolder, extrasHolder);
+    // Read encryption data if the sample is encrypted.
+    if ((sampleHolder.flags & C.SAMPLE_FLAG_ENCRYPTED) != 0) {
+      readEncryptionData(sampleHolder, extrasHolder);
     }
-    if (holder.data != null) {
-      readData(dataOffsetHolder[0], holder.data, holder.size);
+    // Write the sample data into the holder.
+    if (sampleHolder.data == null || sampleHolder.data.capacity() < sampleHolder.size) {
+      sampleHolder.replaceBuffer(sampleHolder.size);
+    }
+    if (sampleHolder.data != null) {
+      readData(extrasHolder.offset, sampleHolder.data, sampleHolder.size);
     }
     // Advance the read head.
     long nextOffset = infoQueue.moveToNextSample();
     dropFragmentsTo(nextOffset);
   }
 
+  /**
+   * Reads encryption data for the current sample.
+   * <p>
+   * The encryption data is written into {@code sampleHolder.cryptoInfo}, and
+   * {@code sampleHolder.size} is adjusted to subtract the number of bytes that were read. The
+   * same value is added to {@code extrasHolder.offset}.
+   *
+   * @param sampleHolder The holder into which the encryption data should be written.
+   * @param extrasHolder The extras holder whose offset should be read and subsequently adjusted.
+   */
+  private void readEncryptionData(SampleHolder sampleHolder, SampleExtrasHolder extrasHolder) {
+    long offset = extrasHolder.offset;
+
+    // Read the signal byte.
+    readData(offset, scratch.data, 1);
+    offset++;
+    byte signalByte = scratch.data[0];
+    boolean subsampleEncryption = (signalByte & 0x80) != 0;
+    int ivSize = signalByte & 0x7F;
+
+    // Read the initialization vector.
+    if (sampleHolder.cryptoInfo.iv == null) {
+      sampleHolder.cryptoInfo.iv = new byte[16];
+    }
+    readData(offset, sampleHolder.cryptoInfo.iv, ivSize);
+    offset += ivSize;
+
+    // Read the subsample count, if present.
+    int subsampleCount;
+    if (subsampleEncryption) {
+      readData(offset, scratch.data, 2);
+      offset += 2;
+      scratch.setPosition(0);
+      subsampleCount = scratch.readUnsignedShort();
+    } else {
+      subsampleCount = 1;
+    }
+
+    // Write the clear and encrypted subsample sizes.
+    int[] clearDataSizes = sampleHolder.cryptoInfo.numBytesOfClearData;
+    if (clearDataSizes == null || clearDataSizes.length < subsampleCount) {
+      clearDataSizes = new int[subsampleCount];
+    }
+    int[] encryptedDataSizes = sampleHolder.cryptoInfo.numBytesOfEncryptedData;
+    if (encryptedDataSizes == null || encryptedDataSizes.length < subsampleCount) {
+      encryptedDataSizes = new int[subsampleCount];
+    }
+    if (subsampleEncryption) {
+      int subsampleDataLength = 6 * subsampleCount;
+      ensureCapacity(scratch, subsampleDataLength);
+      readData(offset, scratch.data, subsampleDataLength);
+      offset += subsampleDataLength;
+      scratch.setPosition(0);
+      for (int i = 0; i < subsampleCount; i++) {
+        clearDataSizes[i] = scratch.readUnsignedShort();
+        encryptedDataSizes[i] = scratch.readUnsignedIntToInt();
+      }
+    } else {
+      clearDataSizes[0] = 0;
+      encryptedDataSizes[0] = sampleHolder.size - (int) (offset - extrasHolder.offset);
+    }
+
+    // Populate the cryptoInfo.
+    sampleHolder.cryptoInfo.set(subsampleCount, clearDataSizes, encryptedDataSizes,
+        extrasHolder.encryptionKeyId, sampleHolder.cryptoInfo.iv, C.CRYPTO_MODE_AES_CTR);
+
+    // Adjust the offset and size to take into account the bytes read.
+    int bytesRead = (int) (offset - extrasHolder.offset);
+    extrasHolder.offset += bytesRead;
+    sampleHolder.size -= bytesRead;
+  }
+
   /**
    * Reads data from the front of the rolling buffer.
    *
@@ -121,6 +203,26 @@ import java.util.concurrent.ConcurrentLinkedQueue;
     }
   }
 
+  /**
+   * Reads data from the front of the rolling buffer.
+   *
+   * @param absolutePosition The absolute position from which data should be read.
+   * @param target The array into which data should be written.
+   * @param length The number of bytes to read.
+   */
+  // TODO: Consider reducing duplication of this method and the one above.
+  private void readData(long absolutePosition, byte[] target, int length) {
+    int remaining = length;
+    while (remaining > 0) {
+      dropFragmentsTo(absolutePosition);
+      int positionInFragment = (int) (absolutePosition - totalBytesDropped);
+      int toCopy = Math.min(remaining, fragmentLength - positionInFragment);
+      System.arraycopy(dataQueue.peek(), positionInFragment, target, 0, toCopy);
+      absolutePosition += toCopy;
+      remaining -= toCopy;
+    }
+  }
+
   /**
    * Discard any fragments that hold data prior to the specified absolute position, returning
    * them to the pool.
@@ -136,6 +238,15 @@ import java.util.concurrent.ConcurrentLinkedQueue;
     }
   }
 
+  /**
+   * Ensure that the passed {@link ParsableByteArray} is of at least the specified limit.
+   */
+  private static void ensureCapacity(ParsableByteArray byteArray, int limit) {
+    if (byteArray.limit() < limit) {
+      byteArray.reset(new byte[limit], limit);
+    }
+  }
+
   // Called by the loading thread.
 
   /**
@@ -151,12 +262,39 @@ import java.util.concurrent.ConcurrentLinkedQueue;
     pendingSampleOffset = totalBytesWritten + offset;
   }
 
+  /**
+   * Appends data to the rolling buffer.
+   *
+   * @param dataSource The source from which to read.
+   * @param length The maximum length of the read.
+   * @return The number of bytes read, or -1 if the the end of the source has been reached.
+   * @throws IOException If an error occurs reading from the source.
+   */
+  public int appendData(DataSource dataSource, int length) throws IOException {
+    int remainingWriteLength = length;
+    if (dataQueue.isEmpty() || lastFragmentOffset == fragmentLength) {
+      lastFragmentOffset = 0;
+      lastFragment = fragmentPool.allocateDirect();
+      dataQueue.add(lastFragment);
+    }
+    int thisWriteLength = Math.min(remainingWriteLength, fragmentLength - lastFragmentOffset);
+    int bytesRead = dataSource.read(lastFragment, lastFragmentOffset, thisWriteLength);
+    if (bytesRead == -1) {
+      return -1;
+    }
+    lastFragmentOffset += bytesRead;
+    remainingWriteLength -= bytesRead;
+    totalBytesWritten += bytesRead;
+    return bytesRead;
+  }
+
   /**
    * Appends data to the rolling buffer.
    *
    * @param buffer A buffer containing the data to append.
    * @param length The length of the data to append.
    */
+  // TODO: Consider reducing duplication of this method and the one above.
   public void appendData(ParsableByteArray buffer, int length) {
     int remainingWriteLength = length;
     while (remainingWriteLength > 0) {
@@ -176,21 +314,22 @@ import java.util.concurrent.ConcurrentLinkedQueue;
   /**
    * Indicates the end point for the current sample, making it available for consumption.
    *
-   * @param isKeyframe True if the sample being committed is a keyframe. False otherwise.
+   * @param flags Flags that accompany the sample. See {@link SampleHolder#flags}.
    * @param offset The offset of the first byte after the end of the sample's data, relative to
    *     the total number of bytes written to the buffer. Must be negative or zero.
+   * @param encryptionKey The encryption key associated with the sample, or null.
    */
-  public void commitSample(boolean isKeyframe, int offset) {
+  public void commitSample(int flags, int offset, byte[] encryptionKey) {
     Assertions.checkState(offset <= 0);
     int sampleSize = (int) (totalBytesWritten + offset - pendingSampleOffset);
-    infoQueue.commitSample(pendingSampleTimeUs, pendingSampleOffset, sampleSize,
-        isKeyframe ? C.SAMPLE_FLAG_SYNC : 0);
+    infoQueue.commitSample(pendingSampleTimeUs, pendingSampleOffset, sampleSize, flags,
+        encryptionKey);
   }
 
   /**
    * Holds information about the samples in the rolling buffer.
    */
-  private static class InfoQueue {
+  private static final class InfoQueue {
 
     private static final int SAMPLE_CAPACITY_INCREMENT = 1000;
 
@@ -200,6 +339,7 @@ import java.util.concurrent.ConcurrentLinkedQueue;
     private int[] sizes;
     private int[] flags;
     private long[] timesUs;
+    private byte[][] encryptionKeys;
 
     private int queueSize;
     private int readIndex;
@@ -211,6 +351,7 @@ import java.util.concurrent.ConcurrentLinkedQueue;
       timesUs = new long[capacity];
       flags = new int[capacity];
       sizes = new int[capacity];
+      encryptionKeys = new byte[capacity][];
     }
 
     // Called by the consuming thread.
@@ -224,18 +365,18 @@ import java.util.concurrent.ConcurrentLinkedQueue;
      * {@code offsetHolder[0]}.
      *
      * @param holder The holder into which the current sample information should be written.
-     * @param offsetHolder The holder into which the absolute position of the sample's data should
-     *     be written.
+     * @param extrasHolder The holder into which extra sample information should be written.
      * @return True if the holders were filled. False if there is no current sample.
      */
-    public synchronized boolean peekSample(SampleHolder holder, long[] offsetHolder) {
+    public synchronized boolean peekSample(SampleHolder holder, SampleExtrasHolder extrasHolder) {
       if (queueSize == 0) {
         return false;
       }
       holder.timeUs = timesUs[readIndex];
       holder.size = sizes[readIndex];
       holder.flags = flags[readIndex];
-      offsetHolder[0] = offsets[readIndex];
+      extrasHolder.offset = offsets[readIndex];
+      extrasHolder.encryptionKeyId = encryptionKeys[readIndex];
       return true;
     }
 
@@ -257,11 +398,13 @@ import java.util.concurrent.ConcurrentLinkedQueue;
 
     // Called by the loading thread.
 
-    public synchronized void commitSample(long timeUs, long offset, int size, int sampleFlags) {
+    public synchronized void commitSample(long timeUs, long offset, int size, int sampleFlags,
+        byte[] encryptionKey) {
       timesUs[writeIndex] = timeUs;
       offsets[writeIndex] = offset;
       sizes[writeIndex] = size;
       flags[writeIndex] = sampleFlags;
+      encryptionKeys[writeIndex] = encryptionKey;
       // Increment the write index.
       queueSize++;
       if (queueSize == capacity) {
@@ -271,20 +414,24 @@ import java.util.concurrent.ConcurrentLinkedQueue;
         long[] newTimesUs = new long[newCapacity];
         int[] newFlags = new int[newCapacity];
         int[] newSizes = new int[newCapacity];
+        byte[][] newEncryptionKeys = new byte[newCapacity][];
         int beforeWrap = capacity - readIndex;
         System.arraycopy(offsets, readIndex, newOffsets, 0, beforeWrap);
         System.arraycopy(timesUs, readIndex, newTimesUs, 0, beforeWrap);
         System.arraycopy(flags, readIndex, newFlags, 0, beforeWrap);
         System.arraycopy(sizes, readIndex, newSizes, 0, beforeWrap);
+        System.arraycopy(encryptionKeys, readIndex, newEncryptionKeys, 0, beforeWrap);
         int afterWrap = readIndex;
         System.arraycopy(offsets, 0, newOffsets, beforeWrap, afterWrap);
         System.arraycopy(timesUs, 0, newTimesUs, beforeWrap, afterWrap);
         System.arraycopy(flags, 0, newFlags, beforeWrap, afterWrap);
         System.arraycopy(sizes, 0, newSizes, beforeWrap, afterWrap);
+        System.arraycopy(encryptionKeys, 0, newEncryptionKeys, beforeWrap, afterWrap);
         offsets = newOffsets;
         timesUs = newTimesUs;
         flags = newFlags;
         sizes = newSizes;
+        encryptionKeys = newEncryptionKeys;
         readIndex = 0;
         writeIndex = capacity;
         queueSize = capacity;
@@ -300,4 +447,14 @@ import java.util.concurrent.ConcurrentLinkedQueue;
 
   }
 
+  /**
+   * Holds additional sample information not held by {@link SampleHolder}.
+   */
+  private static final class SampleExtrasHolder {
+
+    public long offset;
+    public byte[] encryptionKeyId;
+
+  }
+
 }

library/src/main/java/com/google/android/exoplayer/hls/parser/SampleQueue.java

@@ -19,8 +19,11 @@ import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.MediaFormat;
 import com.google.android.exoplayer.SampleHolder;
 import com.google.android.exoplayer.upstream.BufferPool;
+import com.google.android.exoplayer.upstream.DataSource;
 import com.google.android.exoplayer.util.ParsableByteArray;
 
+import java.io.IOException;
+
 /**
  * Wraps a {@link RollingSampleBuffer}, adding higher level functionality such as enforcing that
  * the first sample returned from the queue is a keyframe, allowing splicing to another queue, and
@@ -186,16 +189,24 @@ import com.google.android.exoplayer.util.ParsableByteArray;
     rollingBuffer.startSample(sampleTimeUs, offset);
   }
 
+  protected int appendData(DataSource dataSource, int length) throws IOException {
+    return rollingBuffer.appendData(dataSource, length);
+  }
+
   protected void appendData(ParsableByteArray buffer, int length) {
     rollingBuffer.appendData(buffer, length);
   }
 
-  protected void commitSample(boolean isKeyframe) {
-    commitSample(isKeyframe, 0);
+  protected void commitSample(int flags) {
+    commitSample(flags, 0, null);
   }
 
-  protected void commitSample(boolean isKeyframe, int offset) {
-    rollingBuffer.commitSample(isKeyframe, offset);
+  protected void commitSample(int flags, int offset) {
+    commitSample(flags, offset, null);
+  }
+
+  protected void commitSample(int flags, int offset, byte[] encryptionKey) {
+    rollingBuffer.commitSample(flags, offset, encryptionKey);
     writingSample = false;
   }
 

library/src/main/java/com/google/android/exoplayer/hls/parser/SeiReader.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer.hls.parser;
 
+import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.MediaFormat;
 import com.google.android.exoplayer.text.eia608.Eia608Parser;
 import com.google.android.exoplayer.upstream.BufferPool;
@@ -59,7 +60,7 @@ import com.google.android.exoplayer.util.ParsableByteArray;
       if (Eia608Parser.isSeiMessageEia608(payloadType, payloadSize, seiBuffer)) {
         startSample(pesTimeUs);
         appendData(seiBuffer, payloadSize);
-        commitSample(true);
+        commitSample(C.SAMPLE_FLAG_SYNC);
       } else {
         seiBuffer.skip(payloadSize);
       }