webrtc/webrtc/call.h

/*
 *  Copyright (c) 2013 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_CALL_H_
#define WEBRTC_CALL_H_

#include <string>
#include <vector>

#include "webrtc/common_types.h"
#include "webrtc/video_receive_stream.h"
#include "webrtc/video_send_stream.h"

namespace webrtc {

class VoiceEngine;

const char* Version();

class PacketReceiver {
 public:
  enum DeliveryStatus {
    DELIVERY_OK,
    DELIVERY_UNKNOWN_SSRC,
    DELIVERY_PACKET_ERROR,
  };

  virtual DeliveryStatus DeliverPacket(const uint8_t* packet,
                                       size_t length) = 0;

 protected:
  virtual ~PacketReceiver() {}
};

// Callback interface for reporting when a system overuse is detected.
class LoadObserver {
 public:
  enum Load { kOveruse, kUnderuse };

  // Triggered when overuse is detected or when we believe the system can take
  // more load.
  virtual void OnLoadUpdate(Load load) = 0;

 protected:
  virtual ~LoadObserver() {}
};

// A Call instance can contain several send and/or receive streams. All streams
// are assumed to have the same remote endpoint and will share bitrate estimates
// etc.
class Call {
 public:
  enum NetworkState {
    kNetworkUp,
    kNetworkDown,
  };
  struct Config {
    explicit Config(newapi::Transport* send_transport)
        : webrtc_config(NULL),
          send_transport(send_transport),
          voice_engine(NULL),
          overuse_callback(NULL) {}

    static const int kDefaultStartBitrateBps;

    webrtc::Config* webrtc_config;

    newapi::Transport* send_transport;

    // VoiceEngine used for audio/video synchronization for this Call.
    VoiceEngine* voice_engine;

    // Callback for overuse and normal usage based on the jitter of incoming
    // captured frames. 'NULL' disables the callback.
    LoadObserver* overuse_callback;

    // Bitrate config used until valid bitrate estimates are calculated. Also
    // used to cap total bitrate used.
    // Note: This is currently set only for video and is per-stream rather of
    // for the entire link.
    // TODO(pbos): Set start bitrate for entire Call.
    struct BitrateConfig {
      BitrateConfig()
          : min_bitrate_bps(0),
            start_bitrate_bps(kDefaultStartBitrateBps),
            max_bitrate_bps(-1) {}
      int min_bitrate_bps;
      int start_bitrate_bps;
      int max_bitrate_bps;
    } stream_bitrates;
  };

  struct Stats {
    Stats()
        : send_bandwidth_bps(0),
          recv_bandwidth_bps(0),
          pacer_delay_ms(0),
          rtt_ms(-1) {}

    int send_bandwidth_bps;
    int recv_bandwidth_bps;
    int64_t pacer_delay_ms;
    int64_t rtt_ms;
  };

  static Call* Create(const Call::Config& config);

  static Call* Create(const Call::Config& config,
                      const webrtc::Config& webrtc_config);

  virtual VideoSendStream* CreateVideoSendStream(
      const VideoSendStream::Config& config,
      const VideoEncoderConfig& encoder_config) = 0;

  virtual void DestroyVideoSendStream(VideoSendStream* send_stream) = 0;

  virtual VideoReceiveStream* CreateVideoReceiveStream(
      const VideoReceiveStream::Config& config) = 0;
  virtual void DestroyVideoReceiveStream(
      VideoReceiveStream* receive_stream) = 0;

  // All received RTP and RTCP packets for the call should be inserted to this
  // PacketReceiver. The PacketReceiver pointer is valid as long as the
  // Call instance exists.
  virtual PacketReceiver* Receiver() = 0;

  // Returns the call statistics, such as estimated send and receive bandwidth,
  // pacing delay, etc.
  virtual Stats GetStats() const = 0;

  // TODO(pbos): Like BitrateConfig above this is currently per-stream instead
  // of maximum for entire Call. This should be fixed along with the above.
  // Specifying a start bitrate (>0) will currently reset the current bitrate
  // estimate. This is due to how the 'x-google-start-bitrate' flag is currently
  // implemented.
  virtual void SetBitrateConfig(
      const Config::BitrateConfig& bitrate_config) = 0;
  virtual void SignalNetworkState(NetworkState state) = 0;

  virtual ~Call() {}
};
}  // namespace webrtc

#endif  // WEBRTC_CALL_H_