Initial upload of NetEq4

This is the first public upload of the new NetEq, version 4.

It has been through extensive internal review during the course of
the project.

TEST=trybots

Review URL: https://webrtc-codereview.appspot.com/1073005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3425 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_coding/neteq4/packet_buffer.h b/webrtc/modules/audio_coding/neteq4/packet_buffer.h
new file mode 100644
index 0000000..3e203af
--- /dev/null
+++ b/webrtc/modules/audio_coding/neteq4/packet_buffer.h
@@ -0,0 +1,139 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_CODING_NETEQ4_PACKET_BUFFER_H_
+#define WEBRTC_MODULES_AUDIO_CODING_NETEQ4_PACKET_BUFFER_H_
+
+#include "webrtc/modules/audio_coding/neteq4/packet.h"
+#include "webrtc/system_wrappers/interface/constructor_magic.h"
+#include "webrtc/typedefs.h"
+
+namespace webrtc {
+
+// Forward declaration.
+class DecoderDatabase;
+
+// This is the actual buffer holding the packets before decoding.
+class PacketBuffer {
+ public:
+  enum BufferReturnCodes {
+    kOK = 0,
+    kFlushed,
+    kNotFound,
+    kBufferEmpty,
+    kInvalidPacket,
+    kInvalidPointer,
+    kOversizePacket
+  };
+
+  // Constructor creates a buffer which can hold a maximum of
+  // |max_number_of_packets| packets and |max_payload_memory| bytes of payload,
+  // excluding RTP headers.
+  PacketBuffer(size_t max_number_of_packets, size_t max_payload_memory);
+
+  // Deletes all packets in the buffer before destroying the buffer.
+  virtual ~PacketBuffer();
+
+  // Flushes the buffer and deletes all packets in it.
+  virtual void Flush();
+
+  // Returns true for an empty buffer.
+  virtual bool Empty() const { return buffer_.empty(); }
+
+  // Inserts |packet| into the buffer. The buffer will take over ownership of
+  // the packet object.
+  // Returns PacketBuffer::kOK on success, PacketBuffer::kFlushed if the buffer
+  // was flushed due to overfilling.
+  virtual int InsertPacket(Packet* packet);
+
+  // Inserts a list of packets into the buffer. The buffer will take over
+  // ownership of the packet objects.
+  // Returns PacketBuffer::kOK if all packets were inserted successfully.
+  // If the buffer was flushed due to overfilling, only a subset of the list is
+  // inserted, and PacketBuffer::kFlushed is returned.
+  // The last three parameters are included for legacy compatibility.
+  // TODO(hlundin): Redesign to not use current_*_payload_type and
+  // decoder_database.
+  virtual int InsertPacketList(PacketList* packet_list,
+                               const DecoderDatabase& decoder_database,
+                               uint8_t* current_rtp_payload_type,
+                               uint8_t* current_cng_rtp_payload_type);
+
+  // Gets the timestamp for the first packet in the buffer and writes it to the
+  // output variable |next_timestamp|.
+  // Returns PacketBuffer::kBufferEmpty if the buffer is empty,
+  // PacketBuffer::kOK otherwise.
+  virtual int NextTimestamp(uint32_t* next_timestamp) const;
+
+  // Gets the timestamp for the first packet in the buffer with a timestamp no
+  // lower than the input limit |timestamp|. The result is written to the output
+  // variable |next_timestamp|.
+  // Returns PacketBuffer::kBufferEmpty if the buffer is empty,
+  // PacketBuffer::kOK otherwise.
+  virtual int NextHigherTimestamp(uint32_t timestamp,
+                                  uint32_t* next_timestamp) const;
+
+  // Returns a (constant) pointer the RTP header of the first packet in the
+  // buffer. Returns NULL if the buffer is empty.
+  virtual const RTPHeader* NextRtpHeader() const;
+
+  // Extracts the first packet in the buffer and returns a pointer to it.
+  // Returns NULL if the buffer is empty. The caller is responsible for deleting
+  // the packet.
+  // Subsequent packets with the same timestamp as the one extracted will be
+  // discarded and properly deleted. The number of discarded packets will be
+  // written to the output variable |discard_count|.
+  virtual Packet* GetNextPacket(int* discard_count);
+
+  // Discards the first packet in the buffer. The packet is deleted.
+  // Returns PacketBuffer::kBufferEmpty if the buffer is empty,
+  // PacketBuffer::kOK otherwise.
+  virtual int DiscardNextPacket();
+
+  // Discards all packets that are (strictly) older than |timestamp_limit|.
+  // Returns number of packets discarded.
+  virtual int DiscardOldPackets(uint32_t timestamp_limit);
+
+  // Returns the number of packets in the buffer, including duplicates and
+  // redundant packets.
+  virtual int NumPacketsInBuffer() const {
+    return static_cast<int>(buffer_.size());
+  }
+
+  // Returns the number of samples in the buffer, including samples carried in
+  // duplicate and redundant packets.
+  virtual int NumSamplesInBuffer(DecoderDatabase* decoder_database,
+                                 int last_decoded_length) const;
+
+  // Increase the waiting time counter for every packet in the buffer by |inc|.
+  // The default value for |inc| is 1.
+  virtual void IncrementWaitingTimes(int inc = 1);
+
+  virtual int current_memory_bytes() const { return current_memory_bytes_; }
+
+  // Static method that properly deletes the first packet, and its payload
+  // array, in |packet_list|. Returns false if |packet_list| already was empty,
+  // otherwise true.
+  static bool DeleteFirstPacket(PacketList* packet_list);
+
+  // Static method that properly deletes all packets, and their payload arrays,
+  // in |packet_list|.
+  static void DeleteAllPackets(PacketList* packet_list);
+
+ private:
+  size_t max_number_of_packets_;
+  size_t max_memory_bytes_;
+  int current_memory_bytes_;
+  PacketList buffer_;
+  DISALLOW_COPY_AND_ASSIGN(PacketBuffer);
+};
+
+}  // namespace webrtc
+#endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ4_PACKET_BUFFER_H_