1 files changed, 217 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/audio/DtsUtil.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/audio/DtsUtil.java
new file mode 100644
index 0000000000..6e5d749fdf
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/audio/DtsUtil.java
@@ -0,0 +1,217 @@
+/*
+ * Copyright (C) 2016 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 org.mozilla.thirdparty.com.google.android.exoplayer2.audio;
+
+import androidx.annotation.Nullable;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.Format;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.drm.DrmInitData;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.MimeTypes;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.ParsableBitArray;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+
+/**
+ * Utility methods for parsing DTS frames.
+ */
+public final class DtsUtil {
+
+  private static final int SYNC_VALUE_BE = 0x7FFE8001;
+  private static final int SYNC_VALUE_14B_BE = 0x1FFFE800;
+  private static final int SYNC_VALUE_LE = 0xFE7F0180;
+  private static final int SYNC_VALUE_14B_LE = 0xFF1F00E8;
+  private static final byte FIRST_BYTE_BE = (byte) (SYNC_VALUE_BE >>> 24);
+  private static final byte FIRST_BYTE_14B_BE = (byte) (SYNC_VALUE_14B_BE >>> 24);
+  private static final byte FIRST_BYTE_LE = (byte) (SYNC_VALUE_LE >>> 24);
+  private static final byte FIRST_BYTE_14B_LE = (byte) (SYNC_VALUE_14B_LE >>> 24);
+
+  /**
+   * Maps AMODE to the number of channels. See ETSI TS 102 114 table 5.4.
+   */
+  private static final int[] CHANNELS_BY_AMODE = new int[] {1, 2, 2, 2, 2, 3, 3, 4, 4, 5, 6, 6, 6,
+      7, 8, 8};
+
+  /**
+   * Maps SFREQ to the sampling frequency in Hz. See ETSI TS 102 144 table 5.5.
+   */
+  private static final int[] SAMPLE_RATE_BY_SFREQ = new int[] {-1, 8000, 16000, 32000, -1, -1,
+      11025, 22050, 44100, -1, -1, 12000, 24000, 48000, -1, -1};
+
+  /**
+   * Maps RATE to 2 * bitrate in kbit/s. See ETSI TS 102 144 table 5.7.
+   */
+  private static final int[] TWICE_BITRATE_KBPS_BY_RATE = new int[] {64, 112, 128, 192, 224, 256,
+      384, 448, 512, 640, 768, 896, 1024, 1152, 1280, 1536, 1920, 2048, 2304, 2560, 2688, 2816,
+      2823, 2944, 3072, 3840, 4096, 6144, 7680};
+
+  /**
+   * Returns whether a given integer matches a DTS sync word. Synchronization and storage modes are
+   * defined in ETSI TS 102 114 V1.1.1 (2002-08), Section 5.3.
+   *
+   * @param word An integer.
+   * @return Whether a given integer matches a DTS sync word.
+   */
+  public static boolean isSyncWord(int word) {
+    return word == SYNC_VALUE_BE
+        || word == SYNC_VALUE_LE
+        || word == SYNC_VALUE_14B_BE
+        || word == SYNC_VALUE_14B_LE;
+  }
+
+  /**
+   * Returns the DTS format given {@code data} containing the DTS frame according to ETSI TS 102 114
+   * subsections 5.3/5.4.
+   *
+   * @param frame The DTS frame to parse.
+   * @param trackId The track identifier to set on the format.
+   * @param language The language to set on the format.
+   * @param drmInitData {@link DrmInitData} to be included in the format.
+   * @return The DTS format parsed from data in the header.
+   */
+  public static Format parseDtsFormat(
+      byte[] frame, String trackId, @Nullable String language, @Nullable DrmInitData drmInitData) {
+    ParsableBitArray frameBits = getNormalizedFrameHeader(frame);
+    frameBits.skipBits(32 + 1 + 5 + 1 + 7 + 14); // SYNC, FTYPE, SHORT, CPF, NBLKS, FSIZE
+    int amode = frameBits.readBits(6);
+    int channelCount = CHANNELS_BY_AMODE[amode];
+    int sfreq = frameBits.readBits(4);
+    int sampleRate = SAMPLE_RATE_BY_SFREQ[sfreq];
+    int rate = frameBits.readBits(5);
+    int bitrate = rate >= TWICE_BITRATE_KBPS_BY_RATE.length ? Format.NO_VALUE
+        : TWICE_BITRATE_KBPS_BY_RATE[rate] * 1000 / 2;
+    frameBits.skipBits(10); // MIX, DYNF, TIMEF, AUXF, HDCD, EXT_AUDIO_ID, EXT_AUDIO, ASPF
+    channelCount += frameBits.readBits(2) > 0 ? 1 : 0; // LFF
+    return Format.createAudioSampleFormat(trackId, MimeTypes.AUDIO_DTS, null, bitrate,
+        Format.NO_VALUE, channelCount, sampleRate, null, drmInitData, 0, language);
+  }
+
+  /**
+   * Returns the number of audio samples represented by the given DTS frame.
+   *
+   * @param data The frame to parse.
+   * @return The number of audio samples represented by the frame.
+   */
+  public static int parseDtsAudioSampleCount(byte[] data) {
+    int nblks;
+    switch (data[0]) {
+      case FIRST_BYTE_LE:
+        nblks = ((data[5] & 0x01) << 6) | ((data[4] & 0xFC) >> 2);
+        break;
+      case FIRST_BYTE_14B_LE:
+        nblks = ((data[4] & 0x07) << 4) | ((data[7] & 0x3C) >> 2);
+        break;
+      case FIRST_BYTE_14B_BE:
+        nblks = ((data[5] & 0x07) << 4) | ((data[6] & 0x3C) >> 2);
+        break;
+      default:
+        // We blindly assume FIRST_BYTE_BE if none of the others match.
+        nblks = ((data[4] & 0x01) << 6) | ((data[5] & 0xFC) >> 2);
+    }
+    return (nblks + 1) * 32;
+  }
+
+  /**
+   * Like {@link #parseDtsAudioSampleCount(byte[])} but reads from a {@link ByteBuffer}. The
+   * buffer's position is not modified.
+   *
+   * @param buffer The {@link ByteBuffer} from which to read.
+   * @return The number of audio samples represented by the syncframe.
+   */
+  public static int parseDtsAudioSampleCount(ByteBuffer buffer) {
+    // See ETSI TS 102 114 subsection 5.4.1.
+    int position = buffer.position();
+    int nblks;
+    switch (buffer.get(position)) {
+      case FIRST_BYTE_LE:
+        nblks = ((buffer.get(position + 5) & 0x01) << 6) | ((buffer.get(position + 4) & 0xFC) >> 2);
+        break;
+      case FIRST_BYTE_14B_LE:
+        nblks = ((buffer.get(position + 4) & 0x07) << 4) | ((buffer.get(position + 7) & 0x3C) >> 2);
+        break;
+      case FIRST_BYTE_14B_BE:
+        nblks = ((buffer.get(position + 5) & 0x07) << 4) | ((buffer.get(position + 6) & 0x3C) >> 2);
+        break;
+      default:
+        // We blindly assume FIRST_BYTE_BE if none of the others match.
+        nblks = ((buffer.get(position + 4) & 0x01) << 6) | ((buffer.get(position + 5) & 0xFC) >> 2);
+    }
+    return (nblks + 1) * 32;
+  }
+
+  /**
+   * Returns the size in bytes of the given DTS frame.
+   *
+   * @param data The frame to parse.
+   * @return The frame's size in bytes.
+   */
+  public static int getDtsFrameSize(byte[] data) {
+    int fsize;
+    boolean uses14BitPerWord = false;
+    switch (data[0]) {
+      case FIRST_BYTE_14B_BE:
+        fsize = (((data[6] & 0x03) << 12) | ((data[7] & 0xFF) << 4) | ((data[8] & 0x3C) >> 2)) + 1;
+        uses14BitPerWord = true;
+        break;
+      case FIRST_BYTE_LE:
+        fsize = (((data[4] & 0x03) << 12) | ((data[7] & 0xFF) << 4) | ((data[6] & 0xF0) >> 4)) + 1;
+        break;
+      case FIRST_BYTE_14B_LE:
+        fsize = (((data[7] & 0x03) << 12) | ((data[6] & 0xFF) << 4) | ((data[9] & 0x3C) >> 2)) + 1;
+        uses14BitPerWord = true;
+        break;
+      default:
+        // We blindly assume FIRST_BYTE_BE if none of the others match.
+        fsize = (((data[5] & 0x03) << 12) | ((data[6] & 0xFF) << 4) | ((data[7] & 0xF0) >> 4)) + 1;
+    }
+
+    // If the frame is stored in 14-bit mode, adjust the frame size to reflect the actual byte size.
+    return uses14BitPerWord ? fsize * 16 / 14 : fsize;
+  }
+
+  private static ParsableBitArray getNormalizedFrameHeader(byte[] frameHeader) {
+    if (frameHeader[0] == FIRST_BYTE_BE) {
+      // The frame is already 16-bit mode, big endian.
+      return new ParsableBitArray(frameHeader);
+    }
+    // Data is not normalized, but we don't want to modify frameHeader.
+    frameHeader = Arrays.copyOf(frameHeader, frameHeader.length);
+    if (isLittleEndianFrameHeader(frameHeader)) {
+      // Change endianness.
+      for (int i = 0; i < frameHeader.length - 1; i += 2) {
+        byte temp = frameHeader[i];
+        frameHeader[i] = frameHeader[i + 1];
+        frameHeader[i + 1] = temp;
+      }
+    }
+    ParsableBitArray frameBits = new ParsableBitArray(frameHeader);
+    if (frameHeader[0] == (byte) (SYNC_VALUE_14B_BE >> 24)) {
+      // Discard the 2 most significant bits of each 16 bit word.
+      ParsableBitArray scratchBits = new ParsableBitArray(frameHeader);
+      while (scratchBits.bitsLeft() >= 16) {
+        scratchBits.skipBits(2);
+        frameBits.putInt(scratchBits.readBits(14), 14);
+      }
+    }
+    frameBits.reset(frameHeader);
+    return frameBits;
+  }
+
+  private static boolean isLittleEndianFrameHeader(byte[] frameHeader) {
+    return frameHeader[0] == FIRST_BYTE_LE || frameHeader[0] == FIRST_BYTE_14B_LE;
+  }
+
+  private DtsUtil() {}
+
+}