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rtp_sender_video.h (11088B)


      1 /*
      2 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
      3 *
      4 *  Use of this source code is governed by a BSD-style license
      5 *  that can be found in the LICENSE file in the root of the source
      6 *  tree. An additional intellectual property rights grant can be found
      7 *  in the file PATENTS.  All contributing project authors may
      8 *  be found in the AUTHORS file in the root of the source tree.
      9 */
     10 
     11 #ifndef MODULES_RTP_RTCP_SOURCE_RTP_SENDER_VIDEO_H_
     12 #define MODULES_RTP_RTCP_SOURCE_RTP_SENDER_VIDEO_H_
     13 
     14 #include <cstddef>
     15 #include <cstdint>
     16 #include <map>
     17 #include <memory>
     18 #include <optional>
     19 #include <vector>
     20 
     21 #include "api/array_view.h"
     22 #include "api/field_trials_view.h"
     23 #include "api/frame_transformer_interface.h"
     24 #include "api/scoped_refptr.h"
     25 #include "api/task_queue/task_queue_factory.h"
     26 #include "api/transport/rtp/dependency_descriptor.h"
     27 #include "api/units/data_rate.h"
     28 #include "api/units/time_delta.h"
     29 #include "api/units/timestamp.h"
     30 #include "api/video/color_space.h"
     31 #include "api/video/encoded_image.h"
     32 #include "api/video/video_codec_type.h"
     33 #include "api/video/video_layers_allocation.h"
     34 #include "api/video/video_rotation.h"
     35 #include "api/video/video_timing.h"
     36 #include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
     37 #include "modules/rtp_rtcp/source/absolute_capture_time_sender.h"
     38 #include "modules/rtp_rtcp/source/active_decode_targets_helper.h"
     39 #include "modules/rtp_rtcp/source/rtp_sender.h"
     40 #include "modules/rtp_rtcp/source/rtp_sender_video_frame_transformer_delegate.h"
     41 #include "modules/rtp_rtcp/source/rtp_video_header.h"
     42 #include "modules/rtp_rtcp/source/video_fec_generator.h"
     43 #include "rtc_base/bitrate_tracker.h"
     44 #include "rtc_base/frequency_tracker.h"
     45 #include "rtc_base/one_time_event.h"
     46 #include "rtc_base/race_checker.h"
     47 #include "rtc_base/synchronization/mutex.h"
     48 #include "rtc_base/thread_annotations.h"
     49 #include "system_wrappers/include/clock.h"
     50 
     51 namespace webrtc {
     52 
     53 class FrameEncryptorInterface;
     54 class RtpPacketizer;
     55 class RtpPacketToSend;
     56 
     57 // kConditionallyRetransmitHigherLayers allows retransmission of video frames
     58 // in higher layers if either the last frame in that layer was too far back in
     59 // time, or if we estimate that a new frame will be available in a lower layer
     60 // in a shorter time than it would take to request and receive a retransmission.
     61 enum RetransmissionMode : uint8_t {
     62  kRetransmitOff = 0x0,
     63  kRetransmitBaseLayer = 0x2,
     64  kRetransmitHigherLayers = 0x4,
     65  kRetransmitAllLayers = 0x6,
     66  kConditionallyRetransmitHigherLayers = 0x8
     67 };
     68 
     69 class RTPSenderVideo : public RTPVideoFrameSenderInterface {
     70 public:
     71  static constexpr TimeDelta kTLRateWindowSize = TimeDelta::Millis(2'500);
     72 
     73  struct Config {
     74    Config() = default;
     75    Config(const Config&) = delete;
     76    Config(Config&&) = default;
     77 
     78    // All members of this struct, with the exception of `field_trials`, are
     79    // expected to outlive the RTPSenderVideo object they are passed to.
     80    Clock* clock = nullptr;
     81    RTPSender* rtp_sender = nullptr;
     82    // Some FEC data is duplicated here in preparation of moving FEC to
     83    // the egress stage.
     84    std::optional<VideoFecGenerator::FecType> fec_type;
     85    size_t fec_overhead_bytes = 0;  // Per packet max FEC overhead.
     86    FrameEncryptorInterface* frame_encryptor = nullptr;
     87    bool require_frame_encryption = false;
     88    bool enable_retransmit_all_layers = false;
     89    std::optional<int> red_payload_type;
     90    const FieldTrialsView* field_trials = nullptr;
     91    scoped_refptr<FrameTransformerInterface> frame_transformer;
     92    TaskQueueFactory* task_queue_factory = nullptr;
     93    bool raw_packetization = false;
     94  };
     95 
     96  explicit RTPSenderVideo(const Config& config);
     97 
     98  virtual ~RTPSenderVideo();
     99 
    100  // `capture_time` and `clock::CurrentTime` should be using the same epoch.
    101  // `expected_retransmission_time.IsFinite()` -> retransmission allowed.
    102  // `encoder_output_size` is the size of the video frame as it came out of the
    103  // video encoder, excluding any additional overhead.
    104  // Calls to this method are assumed to be externally serialized.
    105  bool SendVideo(int payload_type,
    106                 std::optional<VideoCodecType> codec_type,
    107                 uint32_t rtp_timestamp,
    108                 Timestamp capture_time,
    109                 ArrayView<const uint8_t> payload,
    110                 size_t encoder_output_size,
    111                 RTPVideoHeader video_header,
    112                 TimeDelta expected_retransmission_time,
    113                 std::vector<uint32_t> csrcs) override;
    114 
    115  bool SendEncodedImage(int payload_type,
    116                        std::optional<VideoCodecType> codec_type,
    117                        uint32_t rtp_timestamp,
    118                        const EncodedImage& encoded_image,
    119                        RTPVideoHeader video_header,
    120                        TimeDelta expected_retransmission_time,
    121                        const std::vector<uint32_t>& csrcs = {});
    122 
    123  // Configures video structures produced by encoder to send using the
    124  // dependency descriptor rtp header extension. Next call to SendVideo should
    125  // have video_header.frame_type == kVideoFrameKey.
    126  // All calls to SendVideo after this call must use video_header compatible
    127  // with the video_structure.
    128  void SetVideoStructure(const FrameDependencyStructure* video_structure);
    129  // Should only be used by a RTPSenderVideoFrameTransformerDelegate and exists
    130  // to ensure correct syncronization.
    131  void SetVideoStructureAfterTransformation(
    132      const FrameDependencyStructure* video_structure) override;
    133 
    134  // Sets current active VideoLayersAllocation. The allocation will be sent
    135  // using the rtp video layers allocation extension. The allocation will be
    136  // sent in full on every key frame. The allocation will be sent once on a
    137  // none discardable delta frame per call to this method and will not contain
    138  // resolution and frame rate.
    139  void SetVideoLayersAllocation(VideoLayersAllocation allocation);
    140  // Should only be used by a RTPSenderVideoFrameTransformerDelegate and exists
    141  // to ensure correct syncronization.
    142  void SetVideoLayersAllocationAfterTransformation(
    143      VideoLayersAllocation allocation) override;
    144 
    145  // Returns the current post encode overhead rate, in bps. Note that this is
    146  // the payload overhead, eg the VP8 payload headers and any other added
    147  // metadata added by transforms. It does not include the RTP headers or
    148  // extensions.
    149  // TODO(sprang): Consider moving this to RtpSenderEgress so it's in the same
    150  // place as the other rate stats.
    151  DataRate PostEncodeOverhead() const;
    152 
    153  // 'retransmission_mode' is either a value of enum RetransmissionMode, or
    154  // computed with bitwise operators on values of enum RetransmissionMode.
    155  void SetRetransmissionSetting(int32_t retransmission_settings);
    156 
    157 protected:
    158  static uint8_t GetTemporalId(const RTPVideoHeader& header);
    159  bool AllowRetransmission(uint8_t temporal_id,
    160                           int32_t retransmission_settings,
    161                           TimeDelta expected_retransmission_time);
    162 
    163 private:
    164  struct TemporalLayerStats {
    165    FrequencyTracker frame_rate{kTLRateWindowSize};
    166    Timestamp last_frame_time = Timestamp::Zero();
    167  };
    168 
    169  enum class SendVideoLayersAllocation {
    170    kSendWithResolution,
    171    kSendWithoutResolution,
    172    kDontSend
    173  };
    174 
    175  void SetVideoStructureInternal(
    176      const FrameDependencyStructure* video_structure);
    177  void SetVideoLayersAllocationInternal(VideoLayersAllocation allocation);
    178 
    179  void AddRtpHeaderExtensions(const RTPVideoHeader& video_header,
    180                              bool first_packet,
    181                              bool last_packet,
    182                              RtpPacketToSend* packet) const
    183      RTC_EXCLUSIVE_LOCKS_REQUIRED(send_checker_);
    184 
    185  size_t FecPacketOverhead() const RTC_EXCLUSIVE_LOCKS_REQUIRED(send_checker_);
    186 
    187  void LogAndSendToNetwork(
    188      std::vector<std::unique_ptr<RtpPacketToSend>> packets,
    189      size_t encoder_output_size);
    190 
    191  bool red_enabled() const { return red_payload_type_.has_value(); }
    192 
    193  bool UpdateConditionalRetransmit(uint8_t temporal_id,
    194                                   TimeDelta expected_retransmission_time)
    195      RTC_EXCLUSIVE_LOCKS_REQUIRED(stats_mutex_);
    196 
    197  void MaybeUpdateCurrentPlayoutDelay(const RTPVideoHeader& header)
    198      RTC_EXCLUSIVE_LOCKS_REQUIRED(send_checker_);
    199 
    200  RTPSender* const rtp_sender_;
    201  Clock* const clock_;
    202 
    203  // These members should only be accessed from within SendVideo() to avoid
    204  // potential race conditions.
    205  RaceChecker send_checker_;
    206  int32_t retransmission_settings_ RTC_GUARDED_BY(send_checker_);
    207  VideoRotation last_rotation_ RTC_GUARDED_BY(send_checker_);
    208  std::optional<ColorSpace> last_color_space_ RTC_GUARDED_BY(send_checker_);
    209  bool transmit_color_space_next_frame_ RTC_GUARDED_BY(send_checker_);
    210  std::unique_ptr<FrameDependencyStructure> video_structure_
    211      RTC_GUARDED_BY(send_checker_);
    212  std::optional<VideoLayersAllocation> allocation_
    213      RTC_GUARDED_BY(send_checker_);
    214  // Flag indicating if we should send `allocation_`.
    215  SendVideoLayersAllocation send_allocation_ RTC_GUARDED_BY(send_checker_);
    216  std::optional<VideoLayersAllocation> last_full_sent_allocation_
    217      RTC_GUARDED_BY(send_checker_);
    218 
    219  // Current target playout delay.
    220  std::optional<VideoPlayoutDelay> current_playout_delay_
    221      RTC_GUARDED_BY(send_checker_);
    222  // Flag indicating if we need to send `current_playout_delay_` in order
    223  // to guarantee it gets delivered.
    224  bool playout_delay_pending_;
    225  // Set by the field trial WebRTC-ForceSendPlayoutDelay to override the playout
    226  // delay of outgoing video frames.
    227  const std::optional<VideoPlayoutDelay> forced_playout_delay_;
    228 
    229  // Should never be held when calling out of this class.
    230  Mutex mutex_;
    231 
    232  const std::optional<int> red_payload_type_;
    233  std::optional<VideoFecGenerator::FecType> fec_type_;
    234  const size_t fec_overhead_bytes_;  // Per packet max FEC overhead.
    235 
    236  mutable Mutex stats_mutex_;
    237  BitrateTracker post_encode_overhead_bitrate_ RTC_GUARDED_BY(stats_mutex_);
    238 
    239  std::map<int, TemporalLayerStats> frame_stats_by_temporal_layer_
    240      RTC_GUARDED_BY(stats_mutex_);
    241 
    242  OneTimeEvent first_frame_sent_;
    243 
    244  // E2EE Custom Video Frame Encryptor (optional)
    245  FrameEncryptorInterface* const frame_encryptor_ = nullptr;
    246  // If set to true will require all outgoing frames to pass through an
    247  // initialized frame_encryptor_ before being sent out of the network.
    248  // Otherwise these payloads will be dropped.
    249  const bool require_frame_encryption_;
    250  // Set to true if the generic descriptor should be authenticated.
    251  const bool generic_descriptor_auth_experiment_;
    252 
    253  const bool raw_packetization_;
    254 
    255  AbsoluteCaptureTimeSender absolute_capture_time_sender_
    256      RTC_GUARDED_BY(send_checker_);
    257  // Tracks updates to the active decode targets and decides when active decode
    258  // targets bitmask should be attached to the dependency descriptor.
    259  ActiveDecodeTargetsHelper active_decode_targets_tracker_;
    260 
    261  const scoped_refptr<RTPSenderVideoFrameTransformerDelegate>
    262      frame_transformer_delegate_;
    263 };
    264 
    265 }  // namespace webrtc
    266 
    267 #endif  // MODULES_RTP_RTCP_SOURCE_RTP_SENDER_VIDEO_H_