Mpeg2 TS stream parser for media source.

media/mp2t/ts_packet.h

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MEDIA_MP2T_TS_PACKET_H_
+#define MEDIA_MP2T_TS_PACKET_H_
+
+#include "base/basictypes.h"
+
+namespace media {
+
+class BitReader;
+
+namespace mp2t {
+
+class TsPacket {
+ public:
+  static const int kPacketSize = 188;
+
+  // Return the number of bytes to discard
+  // to be synchronized on a TS syncword.
+  static int Sync(const uint8* buf, int size);
+
+  // Parse a TS packet.
+  // Return a TsPacket only when parsing was successful.
+  // Return NULL otherwise.
+  static TsPacket* Parse(const uint8* buf, int size);
+
+  ~TsPacket();
+
+  // TS header accessors.
+  bool payload_unit_start_indicator() const {
+    return payload_unit_start_indicator_;
+  }
+  int pid() const { return pid_; }
+  int continuity_counter() const { return continuity_counter_; }
+  bool discontinuity_indicator() const { return discontinuity_indicator_; }
+  bool random_access_indicator() const { return random_access_indicator_; }
+
+  // Return the offset and the size of the payload.
+  const uint8* payload() const { return payload_; }
+  int payload_size() const { return payload_size_; }
+
+ private:
+  TsPacket();
+
+  // Parse an Mpeg2 TS header.
+  // The buffer size should be at least |kPacketSize|
+  bool ParseHeader(const uint8* buf);
+  bool ParseAdaptationField(BitReader* bit_reader,
+                            int adaptation_field_length);
+
+  // Size of the payload.
+  const uint8* payload_;
+  int payload_size_;
+
+  // TS header.
+  bool payload_unit_start_indicator_;
+  int pid_;
+  int continuity_counter_;
+
+  // Params from the adaptation field.
+  bool discontinuity_indicator_;
+  bool random_access_indicator_;
+
+  DISALLOW_COPY_AND_ASSIGN(TsPacket);
+};
+
+}  // namespace mp2t
+}  // namespace media
+
+#endif
+