[feat] use an adapter layer to convert SystemClock into webrtc Clock

src/channel/rtp_channel/rtp_video_receiver.cpp

@@ -10,47 +10,47 @@
 #define NV12_BUFFER_SIZE (1280 * 720 * 3 / 2)
 #define RTCP_RR_INTERVAL 1000
 
-RtpVideoReceiver::RtpVideoReceiver(std::shared_ptr<Clock> clock)
+RtpVideoReceiver::RtpVideoReceiver(std::shared_ptr<SystemClock> clock)
     : feedback_ssrc_(GenerateUniqueSsrc()),
       active_remb_module_(nullptr),
       receive_side_congestion_controller_(
-          clock,
+          clock_,
           [this](std::vector<std::unique_ptr<RtcpPacket>> packets) {
             SendCombinedRtcpPacket(std::move(packets));
           },
           [this](int64_t bitrate_bps, std::vector<uint32_t> ssrcs) {
             SendRemb(bitrate_bps, ssrcs);
           }),
-      clock_(clock),
       rtcp_sender_(std::make_unique<RtcpSender>(
           [this](const uint8_t* buffer, size_t size) -> int {
             return data_send_func_((const char*)buffer, size);
           },
           1200)),
-      nack_(std::make_unique<NackRequester>(clock, this, this)) {
+      nack_(std::make_unique<NackRequester>(clock_, this, this)),
+      clock_(webrtc::Clock::GetWebrtcClockShared(clock)) {
   SetPeriod(std::chrono::milliseconds(5));
   // rtcp_thread_ = std::thread(&RtpVideoReceiver::RtcpThread, this);
 }
 
-RtpVideoReceiver::RtpVideoReceiver(std::shared_ptr<Clock> clock,
+RtpVideoReceiver::RtpVideoReceiver(std::shared_ptr<SystemClock> clock,
                                    std::shared_ptr<IOStatistics> io_statistics)
     : io_statistics_(io_statistics),
       feedback_ssrc_(GenerateUniqueSsrc()),
       receive_side_congestion_controller_(
-          clock,
+          clock_,
           [this](std::vector<std::unique_ptr<RtcpPacket>> packets) {
             SendCombinedRtcpPacket(std::move(packets));
           },
           [this](int64_t bitrate_bps, std::vector<uint32_t> ssrcs) {
             SendRemb(bitrate_bps, ssrcs);
           }),
-      clock_(clock),
       rtcp_sender_(std::make_unique<RtcpSender>(
           [this](const uint8_t* buffer, size_t size) -> int {
             return data_send_func_((const char*)buffer, size);
           },
           1200)),
-      nack_(std::make_unique<NackRequester>(clock, this, this)) {
+      nack_(std::make_unique<NackRequester>(clock_, this, this)),
+      clock_(webrtc::Clock::GetWebrtcClockShared(clock)) {
   SetPeriod(std::chrono::milliseconds(5));
   // rtcp_thread_ = std::thread(&RtpVideoReceiver::RtcpThread, this);
 

src/channel/rtp_channel/rtp_video_receiver.h

@@ -7,6 +7,7 @@
 #include <set>
 
 #include "api/clock/clock.h"
+#include "clock/system_clock.h"
 #include "fec_decoder.h"
 #include "io_statistics.h"
 #include "nack_requester.h"
@@ -28,8 +29,8 @@ class RtpVideoReceiver : public ThreadBase,
                          public KeyFrameRequestSender,
                          public NackSender {
  public:
-  RtpVideoReceiver(std::shared_ptr<Clock> clock);
-  RtpVideoReceiver(std::shared_ptr<Clock> clock,
+  RtpVideoReceiver(std::shared_ptr<SystemClock> clock);
+  RtpVideoReceiver(std::shared_ptr<SystemClock> clock,
                    std::shared_ptr<IOStatistics> io_statistics);
   virtual ~RtpVideoReceiver();
 
@@ -113,7 +114,7 @@ class RtpVideoReceiver : public ThreadBase,
   int rtcp_tcc_interval_ms_ = 200;
 
  private:
-  std::shared_ptr<Clock> clock_;
+  std::shared_ptr<webrtc::Clock> clock_;
   ReceiveSideCongestionController receive_side_congestion_controller_;
   RtcpFeedbackSenderInterface* active_remb_module_;
   uint32_t feedback_ssrc_ = 0;

src/channel/rtp_channel/rtp_video_sender.cpp

@@ -2,6 +2,7 @@
 
 #include <chrono>
 
+#include "api/clock/clock.h"
 #include "common.h"
 #include "log.h"
 
@@ -11,12 +12,12 @@
 
 RtpVideoSender::RtpVideoSender() {}
 
-RtpVideoSender::RtpVideoSender(std::shared_ptr<webrtc::Clock> clock,
+RtpVideoSender::RtpVideoSender(std::shared_ptr<SystemClock> clock,
                                std::shared_ptr<IOStatistics> io_statistics)
     : ssrc_(GenerateUniqueSsrc()),
-      clock_(clock),
       io_statistics_(io_statistics),
-      rtp_packet_history_(std::make_unique<RtpPacketHistory>(clock)) {
+      rtp_packet_history_(std::make_unique<RtpPacketHistory>(clock_)),
+      clock_(webrtc::Clock::GetWebrtcClockShared(clock)) {
   SetPeriod(std::chrono::milliseconds(5));
 #ifdef SAVE_RTP_SENT_STREAM
   file_rtp_sent_ = fopen("rtp_sent_stream.h264", "w+b");

src/channel/rtp_channel/rtp_video_sender.h

@@ -3,6 +3,8 @@
 
 #include <functional>
 
+#include "api/clock/clock.h"
+#include "clock/system_clock.h"
 #include "io_statistics.h"
 #include "ringbuffer.h"
 #include "rtp_packet.h"
@@ -15,7 +17,7 @@
 class RtpVideoSender : public ThreadBase {
  public:
   RtpVideoSender();
-  RtpVideoSender(std::shared_ptr<webrtc::Clock> clock,
+  RtpVideoSender(std::shared_ptr<SystemClock> clock,
                  std::shared_ptr<IOStatistics> io_statistics);
   virtual ~RtpVideoSender();
 

src/channel/video_channel_receive.cpp

@@ -5,7 +5,7 @@
 VideoChannelReceive::VideoChannelReceive() {}
 
 VideoChannelReceive::VideoChannelReceive(
-    std::shared_ptr<webrtc::Clock> clock, std::shared_ptr<IceAgent> ice_agent,
+    std::shared_ptr<SystemClock> clock, std::shared_ptr<IceAgent> ice_agent,
     std::shared_ptr<IOStatistics> ice_io_statistics,
     std::function<void(VideoFrame &)> on_receive_complete_frame)
     : ice_agent_(ice_agent),

src/channel/video_channel_receive.h

@@ -7,7 +7,7 @@
 #ifndef _VIDEO_CHANNEL_RECEIVE_H_
 #define _VIDEO_CHANNEL_RECEIVE_H_
 
-#include "api/clock/clock.h"
+#include "clock/system_clock.h"
 #include "ice_agent.h"
 #include "rtp_video_receiver.h"
 
@@ -15,7 +15,7 @@ class VideoChannelReceive {
  public:
   VideoChannelReceive();
   VideoChannelReceive(
-      std::shared_ptr<webrtc::Clock> clock, std::shared_ptr<IceAgent> ice_agent,
+      std::shared_ptr<SystemClock> clock, std::shared_ptr<IceAgent> ice_agent,
       std::shared_ptr<IOStatistics> ice_io_statistics,
       std::function<void(VideoFrame &)> on_receive_complete_frame);
 
@@ -34,7 +34,7 @@ class VideoChannelReceive {
   std::function<void(VideoFrame &)> on_receive_complete_frame_ = nullptr;
 
  private:
-  std::shared_ptr<Clock> clock_;
+  std::shared_ptr<SystemClock> clock_;
 };
 
 #endif

src/channel/video_channel_send.cpp

@@ -8,7 +8,7 @@ VideoChannelSend::VideoChannelSend() {}
 VideoChannelSend::~VideoChannelSend() {}
 
 VideoChannelSend::VideoChannelSend(
-    std::shared_ptr<webrtc::Clock> clock, std::shared_ptr<IceAgent> ice_agent,
+    std::shared_ptr<SystemClock> clock, std::shared_ptr<IceAgent> ice_agent,
     std::shared_ptr<IOStatistics> ice_io_statistics,
     std::function<void(const webrtc::RtpPacketToSend& packet)>
         on_sent_packet_func)

src/channel/video_channel_send.h

@@ -7,9 +7,9 @@
 #ifndef _VIDEO_CHANNEL_SEND_H_
 #define _VIDEO_CHANNEL_SEND_H_
 
-#include "api/clock/clock.h"
 #include "api/transport/network_types.h"
 #include "api/units/timestamp.h"
+#include "clock/system_clock.h"
 #include "congestion_control.h"
 #include "congestion_control_feedback.h"
 #include "ice_agent.h"
@@ -20,7 +20,7 @@
 class VideoChannelSend {
  public:
   VideoChannelSend();
-  VideoChannelSend(std::shared_ptr<webrtc::Clock> clock,
+  VideoChannelSend(std::shared_ptr<SystemClock> clock,
                    std::shared_ptr<IceAgent> ice_agent,
                    std::shared_ptr<IOStatistics> ice_io_statistics,
                    std::function<void(const webrtc::RtpPacketToSend& packet)>
@@ -52,7 +52,7 @@ class VideoChannelSend {
       on_sent_packet_func_ = nullptr;
 
  private:
-  std::shared_ptr<Clock> clock_;
+  std::shared_ptr<SystemClock> clock_;
 };
 
 #endif

src/common/api/clock/clock.cc

@@ -43,25 +43,51 @@ NtpTime TimeMicrosToNtp(int64_t time_us) {
 
 }  // namespace
 
-class RealTimeClock : public Clock {
+class WebrtcClock : public Clock {
  public:
-  RealTimeClock() = default;
+  WebrtcClock(std::shared_ptr<SystemClock> system_clock)
+      : system_clock_(system_clock) {}
+  WebrtcClock() = delete;
 
   Timestamp CurrentTime() override {
-    return Timestamp::Micros(rtc::TimeMicros());
+    return Timestamp::Micros(system_clock_->CurrentTimeUs());
   }
 
   NtpTime ConvertTimestampToNtpTime(Timestamp timestamp) override {
-    return TimeMicrosToNtp(timestamp.us());
+    int64_t time_us = timestamp.us();
+    constexpr int64_t kNtpJan1970Sec = 2208988800;
+    int64_t clock_time = system_clock_->CurrentTimeUs();
+    int64_t utc_time = system_clock_->CurrentUtcTimeUs();
+    static int64_t ntp_offset_us =
+        utc_time - clock_time + kNtpJan1970Sec * rtc::kNumMicrosecsPerSec;
+
+    int64_t time_ntp_us = time_us + ntp_offset_us;
+
+    // Convert seconds to uint32 through uint64 for a well-defined cast.
+    // A wrap around, which will happen in 2036, is expected for NTP time.
+    uint32_t ntp_seconds =
+        static_cast<uint64_t>(time_ntp_us / rtc::kNumMicrosecsPerSec);
+
+    // Scale fractions of the second to NTP resolution.
+    constexpr int64_t kNtpFractionsInSecond = 1LL << 32;
+    int64_t us_fractions = time_ntp_us % rtc::kNumMicrosecsPerSec;
+    uint32_t ntp_fractions =
+        us_fractions * kNtpFractionsInSecond / rtc::kNumMicrosecsPerSec;
+
+    return NtpTime(ntp_seconds, ntp_fractions);
   }
+
+ private:
+  std::shared_ptr<SystemClock> system_clock_;
 };
 
-Clock* Clock::GetRealTimeClock() {
-  static Clock* const clock = new RealTimeClock();
+Clock* Clock::GetWebrtcClock(std::shared_ptr<SystemClock> system_clock) {
+  static Clock* const clock = new WebrtcClock(system_clock);
   return clock;
 }
 
-std::shared_ptr<Clock> Clock::GetRealTimeClockShared() {
-  return std::make_shared<RealTimeClock>();
+std::shared_ptr<Clock> Clock::GetWebrtcClockShared(
+    std::shared_ptr<SystemClock> system_clock) {
+  return std::make_shared<WebrtcClock>(system_clock);
 }
 }  // namespace webrtc

src/common/api/clock/clock.h

@@ -18,6 +18,7 @@
 
 #include "api/ntp/ntp_time.h"
 #include "api/units/timestamp.h"
+#include "clock/system_clock.h"
 
 namespace webrtc {
 
@@ -65,8 +66,9 @@ class Clock {
   }
 
   // Returns an instance of the real-time system clock implementation.
-  static Clock* GetRealTimeClock();
-  static std::shared_ptr<Clock> GetRealTimeClockShared();
+  static Clock* GetWebrtcClock(std::shared_ptr<SystemClock> system_clock);
+  static std::shared_ptr<Clock> GetWebrtcClockShared(
+      std::shared_ptr<SystemClock> system_clock);
 };
 
 }  // namespace webrtc

src/common/clock/system_clock.cpp

@@ -69,15 +69,15 @@ int64_t SystemClock::CurrentNtpTime() {
 }
 
 int64_t SystemClock::CurrentNtpTimeMs() {
-  return CurrentTimeMs() + kNtpEpochOffset * 1000LL;
+  return CurrentUtcTimeMs() + kNtpEpochOffset * 1000LL;
 }
 
 int64_t SystemClock::CurrentNtpTimeUs() {
-  return CurrentTimeUs() + kNtpEpochOffset * 1000000LL;
+  return CurrentUtcTimeUs() + kNtpEpochOffset * 1000000LL;
 }
 
 int64_t SystemClock::CurrentNtpTimeNs() {
-  return CurrentTimeNs() + kNtpEpochOffset * 1000000000LL;
+  return CurrentUtcTimeNs() + kNtpEpochOffset * 1000000000LL;
 }
 
 int64_t SystemClock::CurrentUtcTimeNs() {
@@ -111,12 +111,3 @@ int64_t SystemClock::CurrentUtcTimeMs() {
 int64_t SystemClock::CurrentUtcTime() {
   return CurrentUtcTimeNs() / 1000000000LL;
 }
-
-static SystemClock* GetSystemClock() {
-  static SystemClock* const clock = new SystemClock();
-  return clock;
-}
-
-static std::shared_ptr<SystemClock> GetSystemClockShared() {
-  return std::make_shared<SystemClock>();
-}

src/common/clock/system_clock.h

@@ -33,7 +33,4 @@ class SystemClock {
   int64_t CurrentUtcTimeNs();
 };
 
-static SystemClock* GetSystemClock();
-static std::shared_ptr<SystemClock> GetSystemClockShared();
-
 #endif

src/pc/peer_connection.cpp

@@ -184,6 +184,7 @@ int PeerConnection::Init(PeerConnectionParams params,
     }
   };
 
+  clock_ = std::make_shared<SystemClock>();
   ws_transport_ = std::make_shared<WsClient>(on_receive_ws_msg_, on_ws_status_);
   uri_ = "ws://" + cfg_signal_server_ip_ + ":" + cfg_signal_server_port_;
   if (ws_transport_) {
@@ -595,8 +596,8 @@ void PeerConnection::ProcessIceWorkMsg(const IceWorkMsg &msg) {
 
       for (auto &remote_user_id : user_id_list) {
         ice_transport_list_[remote_user_id] = std::make_shared<IceTransport>(
-            true, transmission_id, user_id_, remote_user_id, ws_transport_,
-            on_ice_status_change_, user_data_);
+            clock_, true, transmission_id, user_id_, remote_user_id,
+            ws_transport_, on_ice_status_change_, user_data_);
 
         ice_transport_list_[remote_user_id]->SetLocalCapabilities(
             hardware_acceleration_, trickle_ice_, reliable_ice_, enable_turn_,
@@ -639,8 +640,8 @@ void PeerConnection::ProcessIceWorkMsg(const IceWorkMsg &msg) {
           ice_transport_list_.find(remote_user_id)) {
         // Enable TURN for answer peer by default
         ice_transport_list_[remote_user_id] = std::make_shared<IceTransport>(
-            false, transmission_id, user_id_, remote_user_id, ws_transport_,
-            on_ice_status_change_, user_data_);
+            clock_, false, transmission_id, user_id_, remote_user_id,
+            ws_transport_, on_ice_status_change_, user_data_);
 
         ice_transport_list_[remote_user_id]->SetLocalCapabilities(
             hardware_acceleration_, trickle_ice_, reliable_ice_, enable_turn_,

src/pc/peer_connection.h

@@ -13,6 +13,7 @@
 
 #include "audio_decoder.h"
 #include "audio_encoder.h"
+#include "clock/system_clock.h"
 #include "ice_transport.h"
 #include "video_decoder_factory.h"
 #include "video_encoder_factory.h"
@@ -152,6 +153,7 @@ class PeerConnection {
   std::vector<int> audio_payload_types_ = {rtp::PAYLOAD_TYPE::OPUS};
 
  private:
+  std::shared_ptr<SystemClock> clock_ = nullptr;
   std::shared_ptr<WsClient> ws_transport_ = nullptr;
   std::function<void(const std::string &)> on_receive_ws_msg_ = nullptr;
   std::function<void(WsStatus)> on_ws_status_ = nullptr;

src/transport/ice_transport.cpp

@@ -11,11 +11,13 @@
 using nlohmann::json;
 
 IceTransport::IceTransport(
-    bool offer_peer, std::string &transmission_id, std::string &user_id,
+    std::shared_ptr<SystemClock> clock, bool offer_peer,
+    std::string &transmission_id, std::string &user_id,
     std::string &remote_user_id, std::shared_ptr<WsClient> ice_ws_transmission,
     std::function<void(std::string, const std::string &)> on_ice_status_change,
     void *user_data)
-    : offer_peer_(offer_peer),
+    : clock_(clock),
+      offer_peer_(offer_peer),
       transmission_id_(transmission_id),
       user_id_(user_id),
       remote_user_id_(remote_user_id),
@@ -46,7 +48,7 @@ int IceTransport::InitIceTransmission(
     std::string &stun_ip, int stun_port, std::string &turn_ip, int turn_port,
     std::string &turn_username, std::string &turn_password,
     rtp::PAYLOAD_TYPE video_codec_payload_type) {
-  ice_transport_controller_ = std::make_shared<IceTransportController>();
+  ice_transport_controller_ = std::make_shared<IceTransportController>(clock_);
   ice_agent_ = std::make_unique<IceAgent>(
       offer_peer_, use_trickle_ice_, use_reliable_ice_, enable_turn_,
       force_turn_, stun_ip, stun_port, turn_ip, turn_port, turn_username,

src/transport/ice_transport.h

@@ -9,6 +9,7 @@
 
 #include <iostream>
 
+#include "clock/system_clock.h"
 #include "ice_agent.h"
 #include "ice_transport_controller.h"
 #include "io_statistics.h"
@@ -30,8 +31,9 @@ class IceTransport {
   enum TraversalType { TP2P = 0, TRelay = 1, TUnknown = 2 };
 
  public:
-  IceTransport(bool offer_peer, std::string &transmission_id,
-               std::string &user_id, std::string &remote_user_id,
+  IceTransport(std::shared_ptr<SystemClock> clock, bool offer_peer,
+               std::string &transmission_id, std::string &user_id,
+               std::string &remote_user_id,
                std::shared_ptr<WsClient> ice_ws_transmission,
                std::function<void(std::string, const std::string &)>
                    on_ice_status_change,
@@ -160,6 +162,7 @@ class IceTransport {
   void *user_data_ = nullptr;
 
  private:
+  std::shared_ptr<SystemClock> clock_;
   std::shared_ptr<IceAgent> ice_agent_ = nullptr;
   bool is_closed_ = false;
   std::shared_ptr<WsClient> ice_ws_transport_ = nullptr;

src/transport/ice_transport_controller.cpp

@@ -4,13 +4,14 @@
 #include "nvcodec_api.h"
 #endif
 
-IceTransportController::IceTransportController()
-    : b_force_i_frame_(true),
+IceTransportController::IceTransportController(
+    std::shared_ptr<SystemClock> clock)
+    : clock_(clock),
+      b_force_i_frame_(true),
       video_codec_inited_(false),
       audio_codec_inited_(false),
       load_nvcodec_dll_success_(false),
-      hardware_acceleration_(false),
-      clock_(webrtc::Clock::GetRealTimeClockShared()) {}
+      hardware_acceleration_(false) {}
 
 IceTransportController::~IceTransportController() {
   user_data_ = nullptr;
@@ -334,7 +335,7 @@ void IceTransportController::OnCongestionControlFeedback(
     const webrtc::rtcp::CongestionControlFeedback& feedback) {
   std::optional<webrtc::TransportPacketsFeedback> feedback_msg =
       transport_feedback_adapter_.ProcessCongestionControlFeedback(
-          feedback, clock_->CurrentTime());
+          feedback, Timestamp::Micros(clock_->CurrentTimeUs()));
   if (feedback_msg) {
     HandleTransportPacketsFeedback(*feedback_msg);
   }
@@ -353,13 +354,13 @@ void IceTransportController::OnSentRtpPacket(
   webrtc::PacedPacketInfo pacing_info;
   size_t transport_overhead_bytes_per_packet_ = 0;
   webrtc::Timestamp creation_time =
-      webrtc::Timestamp::Millis(clock_->TimeInMilliseconds());
+      webrtc::Timestamp::Millis(clock_->CurrentTimeMs());
   transport_feedback_adapter_.AddPacket(
       packet, pacing_info, transport_overhead_bytes_per_packet_, creation_time);
 
   rtc::SentPacket sent_packet;
   sent_packet.packet_id = packet.transport_sequence_number().value();
-  sent_packet.send_time_ms = clock_->TimeInMilliseconds();
+  sent_packet.send_time_ms = clock_->CurrentTimeMs();
   sent_packet.info.included_in_feedback = true;
   sent_packet.info.included_in_allocation = true;
   sent_packet.info.packet_size_bytes = packet.size();

src/transport/ice_transport_controller.h

@@ -14,6 +14,7 @@
 #include "audio_channel_send.h"
 #include "audio_decoder.h"
 #include "audio_encoder.h"
+#include "clock/system_clock.h"
 #include "congestion_control.h"
 #include "congestion_control_feedback.h"
 #include "data_channel_receive.h"
@@ -35,7 +36,7 @@ typedef void (*OnReceiveData)(const char *, size_t, const char *, const size_t,
 class IceTransportController
     : public std::enable_shared_from_this<IceTransportController> {
  public:
-  IceTransportController();
+  IceTransportController(std::shared_ptr<SystemClock> clock);
   ~IceTransportController();
 
  public:
@@ -97,7 +98,7 @@ class IceTransportController
   void *user_data_ = nullptr;
 
  private:
-  std::shared_ptr<Clock> clock_;
+  std::shared_ptr<SystemClock> clock_;
   webrtc::TransportFeedbackAdapter transport_feedback_adapter_;
   std::unique_ptr<CongestionControl> controller_;