1 files changed, 134 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/SectionReader.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/SectionReader.java
new file mode 100644
index 0000000000..61b53cfa72
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/SectionReader.java
@@ -0,0 +1,134 @@
+/*
+ * 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.extractor.ts;
+
+import org.mozilla.thirdparty.com.google.android.exoplayer2.C;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ExtractorOutput;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.ParsableByteArray;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.TimestampAdjuster;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Util;
+
+/**
+ * Reads section data packets and feeds the whole sections to a given {@link SectionPayloadReader}.
+ * Useful information on PSI sections can be found in ISO/IEC 13818-1, section 2.4.4.
+ */
+public final class SectionReader implements TsPayloadReader {
+
+  private static final int SECTION_HEADER_LENGTH = 3;
+  private static final int DEFAULT_SECTION_BUFFER_LENGTH = 32;
+  private static final int MAX_SECTION_LENGTH = 4098;
+
+  private final SectionPayloadReader reader;
+  private final ParsableByteArray sectionData;
+
+  private int totalSectionLength;
+  private int bytesRead;
+  private boolean sectionSyntaxIndicator;
+  private boolean waitingForPayloadStart;
+
+  public SectionReader(SectionPayloadReader reader) {
+    this.reader = reader;
+    sectionData = new ParsableByteArray(DEFAULT_SECTION_BUFFER_LENGTH);
+  }
+
+  @Override
+  public void init(TimestampAdjuster timestampAdjuster, ExtractorOutput extractorOutput,
+      TrackIdGenerator idGenerator) {
+    reader.init(timestampAdjuster, extractorOutput, idGenerator);
+    waitingForPayloadStart = true;
+  }
+
+  @Override
+  public void seek() {
+    waitingForPayloadStart = true;
+  }
+
+  @Override
+  public void consume(ParsableByteArray data, @Flags int flags) {
+    boolean payloadUnitStartIndicator = (flags & FLAG_PAYLOAD_UNIT_START_INDICATOR) != 0;
+    int payloadStartPosition = C.POSITION_UNSET;
+    if (payloadUnitStartIndicator) {
+      int payloadStartOffset = data.readUnsignedByte();
+      payloadStartPosition = data.getPosition() + payloadStartOffset;
+    }
+
+    if (waitingForPayloadStart) {
+      if (!payloadUnitStartIndicator) {
+        return;
+      }
+      waitingForPayloadStart = false;
+      data.setPosition(payloadStartPosition);
+      bytesRead = 0;
+    }
+
+    while (data.bytesLeft() > 0) {
+      if (bytesRead < SECTION_HEADER_LENGTH) {
+        // Note: see ISO/IEC 13818-1, section 2.4.4.3 for detailed information on the format of
+        // the header.
+        if (bytesRead == 0) {
+          int tableId = data.readUnsignedByte();
+          data.setPosition(data.getPosition() - 1);
+          if (tableId == 0xFF /* forbidden value */) {
+            // No more sections in this ts packet.
+            waitingForPayloadStart = true;
+            return;
+          }
+        }
+        int headerBytesToRead = Math.min(data.bytesLeft(), SECTION_HEADER_LENGTH - bytesRead);
+        data.readBytes(sectionData.data, bytesRead, headerBytesToRead);
+        bytesRead += headerBytesToRead;
+        if (bytesRead == SECTION_HEADER_LENGTH) {
+          sectionData.reset(SECTION_HEADER_LENGTH);
+          sectionData.skipBytes(1); // Skip table id (8).
+          int secondHeaderByte = sectionData.readUnsignedByte();
+          int thirdHeaderByte = sectionData.readUnsignedByte();
+          sectionSyntaxIndicator = (secondHeaderByte & 0x80) != 0;
+          totalSectionLength =
+              (((secondHeaderByte & 0x0F) << 8) | thirdHeaderByte) + SECTION_HEADER_LENGTH;
+          if (sectionData.capacity() < totalSectionLength) {
+            // Ensure there is enough space to keep the whole section.
+            byte[] bytes = sectionData.data;
+            sectionData.reset(
+                Math.min(MAX_SECTION_LENGTH, Math.max(totalSectionLength, bytes.length * 2)));
+            System.arraycopy(bytes, 0, sectionData.data, 0, SECTION_HEADER_LENGTH);
+          }
+        }
+      } else {
+        // Reading the body.
+        int bodyBytesToRead = Math.min(data.bytesLeft(), totalSectionLength - bytesRead);
+        data.readBytes(sectionData.data, bytesRead, bodyBytesToRead);
+        bytesRead += bodyBytesToRead;
+        if (bytesRead == totalSectionLength) {
+          if (sectionSyntaxIndicator) {
+            // This section has common syntax as defined in ISO/IEC 13818-1, section 2.4.4.11.
+            if (Util.crc32(sectionData.data, 0, totalSectionLength, 0xFFFFFFFF) != 0) {
+              // The CRC is invalid so discard the section.
+              waitingForPayloadStart = true;
+              return;
+            }
+            sectionData.reset(totalSectionLength - 4); // Exclude the CRC_32 field.
+          } else {
+            // This is a private section with private defined syntax.
+            sectionData.reset(totalSectionLength);
+          }
+          reader.consume(sectionData);
+          bytesRead = 0;
+        }
+      }
+    }
+  }
+
+}