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channel_receive_frame_transformer_delegate.cc (9428B)


      1 /*
      2 *  Copyright (c) 2020 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 #include "audio/channel_receive_frame_transformer_delegate.h"
     12 
     13 #include <algorithm>
     14 #include <cstdint>
     15 #include <memory>
     16 #include <optional>
     17 #include <string>
     18 #include <utility>
     19 
     20 #include "api/array_view.h"
     21 #include "api/frame_transformer_interface.h"
     22 #include "api/rtp_headers.h"
     23 #include "api/scoped_refptr.h"
     24 #include "api/sequence_checker.h"
     25 #include "api/task_queue/task_queue_base.h"
     26 #include "api/units/time_delta.h"
     27 #include "api/units/timestamp.h"
     28 #include "rtc_base/buffer.h"
     29 #include "rtc_base/checks.h"
     30 #include "system_wrappers/include/ntp_time.h"
     31 
     32 namespace webrtc {
     33 
     34 class TransformableIncomingAudioFrame
     35    : public TransformableAudioFrameInterface {
     36 public:
     37  TransformableIncomingAudioFrame(ArrayView<const uint8_t> payload,
     38                                  const RTPHeader& header,
     39                                  uint32_t ssrc,
     40                                  const std::string& codec_mime_type,
     41                                  Timestamp receive_time)
     42      : TransformableAudioFrameInterface(Passkey()),
     43        payload_(payload.data(), payload.size()),
     44        header_(header),
     45        ssrc_(ssrc),
     46        codec_mime_type_(codec_mime_type),
     47        receive_time_(receive_time) {}
     48  ~TransformableIncomingAudioFrame() override = default;
     49  ArrayView<const uint8_t> GetData() const override { return payload_; }
     50 
     51  void SetData(ArrayView<const uint8_t> data) override {
     52    payload_.SetData(data.data(), data.size());
     53  }
     54 
     55  void SetRTPTimestamp(uint32_t timestamp) override {
     56    header_.timestamp = timestamp;
     57  }
     58 
     59  uint8_t GetPayloadType() const override { return header_.payloadType; }
     60  uint32_t GetSsrc() const override { return ssrc_; }
     61  uint32_t GetTimestamp() const override { return header_.timestamp; }
     62  ArrayView<const uint32_t> GetContributingSources() const override {
     63    return ArrayView<const uint32_t>(header_.arrOfCSRCs, header_.numCSRCs);
     64  }
     65  Direction GetDirection() const override { return Direction::kReceiver; }
     66 
     67  std::string GetMimeType() const override { return codec_mime_type_; }
     68  const std::optional<uint16_t> SequenceNumber() const override {
     69    return header_.sequenceNumber;
     70  }
     71 
     72  std::optional<uint64_t> AbsoluteCaptureTimestamp() const override {
     73    // This could be extracted from received header extensions + extrapolation,
     74    // if required in future, eg for being able to re-send received frames.
     75    return std::nullopt;
     76  }
     77  const RTPHeader& Header() const { return header_; }
     78 
     79  FrameType Type() const override {
     80    if (!header_.extension.audio_level()) {
     81      // Audio level extension not set.
     82      return FrameType::kAudioFrameCN;
     83    }
     84    return header_.extension.audio_level()->voice_activity()
     85               ? FrameType::kAudioFrameSpeech
     86               : FrameType::kAudioFrameCN;
     87  }
     88 
     89  std::optional<uint8_t> AudioLevel() const override {
     90    if (header_.extension.audio_level()) {
     91      return header_.extension.audio_level()->level();
     92    }
     93    return std::nullopt;
     94  }
     95 
     96  bool CanSetAudioLevel() const override { return true; }
     97 
     98  void SetAudioLevel(std::optional<uint8_t> audio_level_dbov) override {
     99    header_.extension.set_audio_level(
    100        audio_level_dbov.has_value()
    101            ? std::make_optional(webrtc::AudioLevel(
    102                  /*voice_activity=*/true,
    103                  std::min(*audio_level_dbov, static_cast<uint8_t>(127u))))
    104            : std::nullopt);
    105  }
    106 
    107  std::optional<Timestamp> ReceiveTime() const override {
    108    return receive_time_ == Timestamp::MinusInfinity()
    109               ? std::nullopt
    110               : std::optional<Timestamp>(receive_time_);
    111  }
    112 
    113  std::optional<Timestamp> CaptureTime() const override {
    114    if (header_.extension.absolute_capture_time) {
    115      return Timestamp::Micros(UQ32x32ToInt64Us(
    116          header_.extension.absolute_capture_time->absolute_capture_timestamp));
    117    }
    118    return std::nullopt;
    119  }
    120 
    121  std::optional<TimeDelta> SenderCaptureTimeOffset() const override {
    122    if (header_.extension.absolute_capture_time &&
    123        header_.extension.absolute_capture_time
    124            ->estimated_capture_clock_offset) {
    125      return TimeDelta::Micros(
    126          Q32x32ToInt64Us(*header_.extension.absolute_capture_time
    127                               ->estimated_capture_clock_offset));
    128    }
    129    return std::nullopt;
    130  }
    131 
    132 private:
    133  Buffer payload_;
    134  RTPHeader header_;
    135  uint32_t ssrc_;
    136  std::string codec_mime_type_;
    137  Timestamp receive_time_;
    138 };
    139 
    140 ChannelReceiveFrameTransformerDelegate::ChannelReceiveFrameTransformerDelegate(
    141    ReceiveFrameCallback receive_frame_callback,
    142    scoped_refptr<FrameTransformerInterface> frame_transformer,
    143    TaskQueueBase* channel_receive_thread)
    144    : receive_frame_callback_(receive_frame_callback),
    145      frame_transformer_(std::move(frame_transformer)),
    146      channel_receive_thread_(channel_receive_thread) {}
    147 
    148 void ChannelReceiveFrameTransformerDelegate::Init() {
    149  RTC_DCHECK_RUN_ON(&sequence_checker_);
    150  frame_transformer_->RegisterTransformedFrameCallback(
    151      scoped_refptr<TransformedFrameCallback>(this));
    152 }
    153 
    154 void ChannelReceiveFrameTransformerDelegate::Reset() {
    155  RTC_DCHECK_RUN_ON(&sequence_checker_);
    156  frame_transformer_->UnregisterTransformedFrameCallback();
    157  frame_transformer_ = nullptr;
    158  receive_frame_callback_ = ReceiveFrameCallback();
    159 }
    160 
    161 void ChannelReceiveFrameTransformerDelegate::Transform(
    162    ArrayView<const uint8_t> packet,
    163    const RTPHeader& header,
    164    uint32_t ssrc,
    165    const std::string& codec_mime_type,
    166    Timestamp receive_time) {
    167  RTC_DCHECK_RUN_ON(&sequence_checker_);
    168  if (short_circuit_) {
    169    receive_frame_callback_(packet, header, receive_time);
    170  } else {
    171    frame_transformer_->Transform(
    172        std::make_unique<TransformableIncomingAudioFrame>(
    173            packet, header, ssrc, codec_mime_type, receive_time));
    174  }
    175 }
    176 
    177 void ChannelReceiveFrameTransformerDelegate::OnTransformedFrame(
    178    std::unique_ptr<TransformableFrameInterface> frame) {
    179  scoped_refptr<ChannelReceiveFrameTransformerDelegate> delegate(this);
    180  channel_receive_thread_->PostTask(
    181      [delegate = std::move(delegate), frame = std::move(frame)]() mutable {
    182        delegate->ReceiveFrame(std::move(frame));
    183      });
    184 }
    185 
    186 void ChannelReceiveFrameTransformerDelegate::StartShortCircuiting() {
    187  scoped_refptr<ChannelReceiveFrameTransformerDelegate> delegate(this);
    188  channel_receive_thread_->PostTask([delegate = std::move(delegate)]() mutable {
    189    RTC_DCHECK_RUN_ON(&delegate->sequence_checker_);
    190    delegate->short_circuit_ = true;
    191  });
    192 }
    193 
    194 void ChannelReceiveFrameTransformerDelegate::ReceiveFrame(
    195    std::unique_ptr<TransformableFrameInterface> frame) const {
    196  RTC_DCHECK_RUN_ON(&sequence_checker_);
    197  if (!receive_frame_callback_)
    198    return;
    199 
    200  auto* transformed_frame =
    201      static_cast<TransformableAudioFrameInterface*>(frame.get());
    202  Timestamp receive_time =
    203      transformed_frame->ReceiveTime().value_or(Timestamp::MinusInfinity());
    204  RTPHeader header;
    205  if (frame->GetDirection() ==
    206      TransformableFrameInterface::Direction::kSender) {
    207    header.payloadType = transformed_frame->GetPayloadType();
    208    header.timestamp = transformed_frame->GetTimestamp();
    209    header.ssrc = transformed_frame->GetSsrc();
    210    if (transformed_frame->AbsoluteCaptureTimestamp().has_value()) {
    211      header.extension.absolute_capture_time = AbsoluteCaptureTime();
    212      header.extension.absolute_capture_time->absolute_capture_timestamp =
    213          transformed_frame->AbsoluteCaptureTimestamp().value();
    214    }
    215    if (transformed_frame->AudioLevel().has_value()) {
    216      // TODO(crbug.com/webrtc/419746427): Add support for voice activity in
    217      // TransformableAudioFrameInterface.
    218      header.extension.set_audio_level(AudioLevel(
    219          /*voice_activity=*/true, *transformed_frame->AudioLevel()));
    220    }
    221  } else {
    222    auto* transformed_incoming_frame =
    223        static_cast<TransformableIncomingAudioFrame*>(frame.get());
    224    header = transformed_incoming_frame->Header();
    225  }
    226 
    227  // TODO(crbug.com/1464860): Take an explicit struct with the required
    228  // information rather than the RTPHeader to make it easier to
    229  // construct the required information when injecting transformed frames not
    230  // originally from this receiver.
    231  receive_frame_callback_(frame->GetData(), header, receive_time);
    232 }
    233 
    234 scoped_refptr<FrameTransformerInterface>
    235 ChannelReceiveFrameTransformerDelegate::FrameTransformer() {
    236  RTC_DCHECK_RUN_ON(&sequence_checker_);
    237  return frame_transformer_;
    238 }
    239 
    240 std::unique_ptr<TransformableAudioFrameInterface> CloneReceiverAudioFrame(
    241    TransformableAudioFrameInterface* original) {
    242  RTC_CHECK(original->GetDirection() ==
    243            TransformableFrameInterface::Direction::kReceiver);
    244 
    245  auto* original_incoming_frame =
    246      static_cast<TransformableIncomingAudioFrame*>(original);
    247  return std::make_unique<TransformableIncomingAudioFrame>(
    248      original->GetData(), original_incoming_frame->Header(),
    249      original->GetSsrc(), original->GetMimeType(),
    250      original->ReceiveTime().value_or(Timestamp::MinusInfinity()));
    251 }
    252 }  // namespace webrtc