video_receive_stream.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_VIDEO_RECEIVE_STREAM_H_
#define WEBRTC_VIDEO_RECEIVE_STREAM_H_

#include <limits>
#include <map>
#include <string>
#include <vector>

#include "webrtc/api/call/transport.h"
#include "webrtc/common_types.h"
#include "webrtc/common_video/include/frame_callback.h"
#include "webrtc/config.h"
#include "webrtc/media/base/videosinkinterface.h"
#include "webrtc/rtc_base/platform_file.h"

namespace webrtc {

class VideoDecoder;

class VideoReceiveStream {
 public:
  // TODO(mflodman) Move all these settings to VideoDecoder and move the
  // declaration to common_types.h.
  struct Decoder {
    std::string ToString() const;

    // The actual decoder instance.
    VideoDecoder* decoder = nullptr;

    // Received RTP packets with this payload type will be sent to this decoder
    // instance.
    int payload_type = 0;

    // Name of the decoded payload (such as VP8). Maps back to the depacketizer
    // used to unpack incoming packets.
    std::string payload_name;

    // This map contains the codec specific parameters from SDP, i.e. the "fmtp"
    // parameters. It is the same as cricket::CodecParameterMap used in
    // cricket::VideoCodec.
    std::map<std::string, std::string> codec_params;
  };

  struct Stats {
    std::string ToString(int64_t time_ms) const;

    int network_frame_rate = 0;
    int decode_frame_rate = 0;
    int render_frame_rate = 0;
    uint32_t frames_rendered = 0;

    // Decoder stats.
    std::string decoder_implementation_name = "unknown";
    FrameCounts frame_counts;
    int decode_ms = 0;
    int max_decode_ms = 0;
    int current_delay_ms = 0;
    int target_delay_ms = 0;
    int jitter_buffer_ms = 0;
    int min_playout_delay_ms = 0;
    int render_delay_ms = 10;
    uint64_t interframe_delay_sum_ms = 0;
    uint32_t frames_decoded = 0;
    rtc::Optional<uint64_t> qp_sum;

    int current_payload_type = -1;

    int total_bitrate_bps = 0;
    int discarded_packets = 0;

    int width = 0;
    int height = 0;

    int sync_offset_ms = std::numeric_limits<int>::max();

    uint32_t ssrc = 0;
    std::string c_name;
    StreamDataCounters rtp_stats;
    RtcpPacketTypeCounter rtcp_packet_type_counts;
    RtcpStatistics rtcp_stats;
  };

  struct Config {
   private:
    // Access to the copy constructor is private to force use of the Copy()
    // method for those exceptional cases where we do use it.
    Config(const Config&) = default;

   public:
    Config() = delete;
    Config(Config&&) = default;
    explicit Config(Transport* rtcp_send_transport)
        : rtcp_send_transport(rtcp_send_transport) {}

    Config& operator=(Config&&) = default;
    Config& operator=(const Config&) = delete;

    // Mostly used by tests.  Avoid creating copies if you can.
    Config Copy() const { return Config(*this); }

    std::string ToString() const;

    // Decoders for every payload that we can receive.
    std::vector<Decoder> decoders;

    // Receive-stream specific RTP settings.
    struct Rtp {
      std::string ToString() const;

      // Synchronization source (stream identifier) to be received.
      uint32_t remote_ssrc = 0;

      // Sender SSRC used for sending RTCP (such as receiver reports).
      uint32_t local_ssrc = 0;

      // See RtcpMode for description.
      RtcpMode rtcp_mode = RtcpMode::kCompound;

      // Extended RTCP settings.
      struct RtcpXr {
        // True if RTCP Receiver Reference Time Report Block extension
        // (RFC 3611) should be enabled.
        bool receiver_reference_time_report = false;
      } rtcp_xr;

      // TODO(nisse): This remb setting is currently set but never
      // applied. REMB logic is now the responsibility of
      // PacketRouter, and it will generate REMB feedback if
      // OnReceiveBitrateChanged is used, which depends on how the
      // estimators belonging to the ReceiveSideCongestionController
      // are configured. Decide if this setting should be deleted, and
      // if it needs to be replaced by a setting in PacketRouter to
      // disable REMB feedback.

      // See draft-alvestrand-rmcat-remb for information.
      bool remb = false;

      // See draft-holmer-rmcat-transport-wide-cc-extensions for details.
      bool transport_cc = false;

      // See NackConfig for description.
      NackConfig nack;

      // See UlpfecConfig for description.
      UlpfecConfig ulpfec;

      // SSRC for retransmissions.
      uint32_t rtx_ssrc = 0;

      // Set if the stream is protected using FlexFEC.
      bool protected_by_flexfec = false;

      // Map from video payload type (apt) -> RTX payload type (pt).
      // For RTX to be enabled, both an SSRC and this mapping are needed.
      std::map<int, int> rtx_payload_types;

      // RTP header extensions used for the received stream.
      std::vector<RtpExtension> extensions;
    } rtp;

    // Transport for outgoing packets (RTCP).
    Transport* rtcp_send_transport = nullptr;

    // Must not be 'nullptr' when the stream is started.
    rtc::VideoSinkInterface<VideoFrame>* renderer = nullptr;

    // Expected delay needed by the renderer, i.e. the frame will be delivered
    // this many milliseconds, if possible, earlier than the ideal render time.
    // Only valid if 'renderer' is set.
    int render_delay_ms = 10;

    // If set, pass frames on to the renderer as soon as they are
    // available.
    bool disable_prerenderer_smoothing = false;

    // Identifier for an A/V synchronization group. Empty string to disable.
    // TODO(pbos): Synchronize streams in a sync group, not just video streams
    // to one of the audio streams.
    std::string sync_group;

    // Called for each incoming video frame, i.e. in encoded state. E.g. used
    // when
    // saving the stream to a file. 'nullptr' disables the callback.
    EncodedFrameObserver* pre_decode_callback = nullptr;

    // Target delay in milliseconds. A positive value indicates this stream is
    // used for streaming instead of a real-time call.
    int target_delay_ms = 0;
  };

  // Starts stream activity.
  // When a stream is active, it can receive, process and deliver packets.
  virtual void Start() = 0;
  // Stops stream activity.
  // When a stream is stopped, it can't receive, process or deliver packets.
  virtual void Stop() = 0;

  // TODO(pbos): Add info on currently-received codec to Stats.
  virtual Stats GetStats() const = 0;

  virtual rtc::Optional<TimingFrameInfo> GetAndResetTimingFrameInfo() = 0;

  // Takes ownership of the file, is responsible for closing it later.
  // Calling this method will close and finalize any current log.
  // Giving rtc::kInvalidPlatformFileValue disables logging.
  // If a frame to be written would make the log too large the write fails and
  // the log is closed and finalized. A |byte_limit| of 0 means no limit.
  virtual void EnableEncodedFrameRecording(rtc::PlatformFile file,
                                           size_t byte_limit) = 0;
  inline void DisableEncodedFrameRecording() {
    EnableEncodedFrameRecording(rtc::kInvalidPlatformFileValue, 0);
  }
  
  // End to End media encryption
  virtual bool SetMediaCryptoKey(
      const rtc::Optional<MediaCryptoKey>& media_crypto_key) = 0;
 protected:
  virtual ~VideoReceiveStream() {}
};

}  // namespace webrtc

#endif  // WEBRTC_VIDEO_RECEIVE_STREAM_H_