text: /*
   *  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 VIDEO_RTP_VIDEO_STREAM_RECEIVER_H_
  #define VIDEO_RTP_VIDEO_STREAM_RECEIVER_H_
  
  #include <list>
  #include <map>
  #include <memory>
  #include <string>
  #include <vector>
  
  #include "absl/types/optional.h"
  
  #include "api/video_codecs/video_codec.h"
  #include "call/rtp_packet_sink_interface.h"
  #include "call/syncable.h"
  #include "call/video_receive_stream.h"
  #include "modules/include/module_common_types.h"
  #include "modules/rtp_rtcp/include/receive_statistics.h"
  #include "modules/rtp_rtcp/include/remote_ntp_time_estimator.h"
  #include "modules/rtp_rtcp/include/rtp_header_extension_map.h"
  #include "modules/rtp_rtcp/include/rtp_rtcp.h"
  #include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
  #include "modules/video_coding/h264_sps_pps_tracker.h"
  #ifndef DISABLE_H265
  #include "modules/video_coding/h265_vps_sps_pps_tracker.h"
  #endif
  #include "modules/video_coding/include/video_coding_defines.h"
  #include "modules/video_coding/packet_buffer.h"
  #include "modules/video_coding/rtp_frame_reference_finder.h"
  #include "rtc_base/constructormagic.h"
  #include "rtc_base/criticalsection.h"
  #include "rtc_base/numerics/sequence_number_util.h"
  #include "rtc_base/sequenced_task_checker.h"
  
  namespace webrtc {
  
  class NackModule;
  class PacketRouter;
  class ProcessThread;
  class ReceiveStatistics;
  class ReceiveStatisticsProxy;
  class RtcpRttStats;
  class RtpPacketReceived;
  class Transport;
  class UlpfecReceiver;
  
  class RtpVideoStreamReceiver : public RtpData,
                                 public RecoveredPacketReceiver,
                                 public RtpPacketSinkInterface,
                                 public VCMFrameTypeCallback,
                                 public VCMPacketRequestCallback,
                                 public video_coding::OnReceivedFrameCallback,
                                 public video_coding::OnCompleteFrameCallback {
   public:
    RtpVideoStreamReceiver(
        Transport* transport,
        RtcpRttStats* rtt_stats,
        PacketRouter* packet_router,
        const VideoReceiveStream::Config* config,
        ReceiveStatistics* rtp_receive_statistics,
        ReceiveStatisticsProxy* receive_stats_proxy,
        ProcessThread* process_thread,
        NackSender* nack_sender,
        KeyFrameRequestSender* keyframe_request_sender,
        video_coding::OnCompleteFrameCallback* complete_frame_callback);
    ~RtpVideoStreamReceiver();
  
    void AddReceiveCodec(const VideoCodec& video_codec,
                         const std::map<std::string, std::string>& codec_params);
  
    void StartReceive();
    void StopReceive();
  
    // Produces the transport-related timestamps; current_delay_ms is left unset.
    absl::optional<Syncable::Info> GetSyncInfo() const;
  
    bool DeliverRtcp(const uint8_t* rtcp_packet, size_t rtcp_packet_length);
  
    void FrameContinuous(int64_t seq_num);
  
    void FrameDecoded(int64_t seq_num);
  
    void SignalNetworkState(NetworkState state);
  
    // Returns number of different frames seen in the packet buffer.
    int GetUniqueFramesSeen() const;
  
    // Implements RtpPacketSinkInterface.
    void OnRtpPacket(const RtpPacketReceived& packet) override;
  
    // Implements RtpData.
    int32_t OnReceivedPayloadData(const uint8_t* payload_data,
                                  size_t payload_size,
                                  const WebRtcRTPHeader* rtp_header) override;
    // Implements RecoveredPacketReceiver.
    void OnRecoveredPacket(const uint8_t* packet, size_t packet_length) override;
  
    // Implements VCMFrameTypeCallback.
    int32_t RequestKeyFrame() override;
  
    bool IsUlpfecEnabled() const;
    bool IsRetransmissionsEnabled() const;
    // Don't use, still experimental.
    void RequestPacketRetransmit(const std::vector<uint16_t>& sequence_numbers);
  
    // Implements VCMPacketRequestCallback.
    int32_t ResendPackets(const uint16_t* sequenceNumbers,
                          uint16_t length) override;
  
    // Implements OnReceivedFrameCallback.
    void OnReceivedFrame(
        std::unique_ptr<video_coding::RtpFrameObject> frame) override;
  
    // Implements OnCompleteFrameCallback.
    void OnCompleteFrame(
        std::unique_ptr<video_coding::EncodedFrame> frame) override;
  
    // Called by VideoReceiveStream when stats are updated.
    void UpdateRtt(int64_t max_rtt_ms);
  
    absl::optional<int64_t> LastReceivedPacketMs() const;
    absl::optional<int64_t> LastReceivedKeyframePacketMs() const;
  
    // RtpDemuxer only forwards a given RTP packet to one sink. However, some
    // sinks, such as FlexFEC, might wish to be informed of all of the packets
    // a given sink receives (or any set of sinks). They may do so by registering
    // themselves as secondary sinks.
    void AddSecondarySink(RtpPacketSinkInterface* sink);
    void RemoveSecondarySink(const RtpPacketSinkInterface* sink);
  
   private:
    // Entry point doing non-stats work for a received packet. Called
    // for the same packet both before and after RED decapsulation.
    void ReceivePacket(const RtpPacketReceived& packet);
    // Parses and handles RED headers.
    // This function assumes that it's being called from only one thread.
    void ParseAndHandleEncapsulatingHeader(const uint8_t* packet,
                                           size_t packet_length,
                                           const RTPHeader& header);
    void NotifyReceiverOfEmptyPacket(uint16_t seq_num);
    bool IsPacketRetransmitted(const RTPHeader& header) const;
    void UpdateHistograms();
    bool IsRedEnabled() const;
    void InsertSpsPpsIntoTracker(uint8_t payload_type);
  
    Clock* const clock_;
    // Ownership of this object lies with VideoReceiveStream, which owns |this|.
    const VideoReceiveStream::Config& config_;
    PacketRouter* const packet_router_;
    ProcessThread* const process_thread_;
  
    RemoteNtpTimeEstimator ntp_estimator_;
  
    RtpHeaderExtensionMap rtp_header_extensions_;
    ReceiveStatistics* const rtp_receive_statistics_;
    std::unique_ptr<UlpfecReceiver> ulpfec_receiver_;
  
    rtc::SequencedTaskChecker worker_task_checker_;
    bool receiving_ RTC_GUARDED_BY(worker_task_checker_);
    int64_t last_packet_log_ms_ RTC_GUARDED_BY(worker_task_checker_);
  
    const std::unique_ptr<RtpRtcp> rtp_rtcp_;
  
    // Members for the new jitter buffer experiment.
    video_coding::OnCompleteFrameCallback* complete_frame_callback_;
    KeyFrameRequestSender* keyframe_request_sender_;
    std::unique_ptr<NackModule> nack_module_;
    rtc::scoped_refptr<video_coding::PacketBuffer> packet_buffer_;
    std::unique_ptr<video_coding::RtpFrameReferenceFinder> reference_finder_;
    rtc::CriticalSection last_seq_num_cs_;
    std::map<int64_t, uint16_t> last_seq_num_for_pic_id_
        RTC_GUARDED_BY(last_seq_num_cs_);
    video_coding::H264SpsPpsTracker tracker_;
  #ifndef DISABLE_H265
    video_coding::H265VpsSpsPpsTracker h265_tracker_;
  #endif
    absl::optional<uint32_t> last_received_rtp_timestamp_
        RTC_GUARDED_BY(last_seq_num_cs_);
    absl::optional<int64_t> last_received_rtp_system_time_ms_
        RTC_GUARDED_BY(last_seq_num_cs_);
    std::map<uint8_t, VideoCodecType> pt_codec_type_;
    // TODO(johan): Remove pt_codec_params_ once
    // https://bugs.chromium.org/p/webrtc/issues/detail?id=6883 is resolved.
    // Maps a payload type to a map of out-of-band supplied codec parameters.
    std::map<uint8_t, std::map<std::string, std::string>> pt_codec_params_;
    int16_t last_payload_type_ = -1;
  
    bool has_received_frame_;
  
    std::vector<RtpPacketSinkInterface*> secondary_sinks_
        RTC_GUARDED_BY(worker_task_checker_);
  };
  
  }  // namespace webrtc
  
  #endif  // VIDEO_RTP_VIDEO_STREAM_RECEIVER_H_
  