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neteq_delay_analyzer.cc (12182B)


      1 /*
      2 *  Copyright (c) 2017 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 "modules/audio_coding/neteq/tools/neteq_delay_analyzer.h"
     12 
     13 #include <algorithm>
     14 #include <cstddef>
     15 #include <cstdint>
     16 #include <fstream>
     17 #include <ios>
     18 #include <limits>
     19 #include <ostream>  // no-presubmit-check TODO(webrtc:8982)
     20 #include <string>
     21 #include <utility>
     22 #include <vector>
     23 
     24 #include "absl/strings/string_view.h"
     25 #include "api/audio/audio_frame.h"
     26 #include "api/neteq/neteq.h"
     27 #include "api/rtp_packet_info.h"
     28 #include "modules/rtp_rtcp/source/rtp_packet_received.h"
     29 #include "rtc_base/checks.h"
     30 #include "rtc_base/numerics/sequence_number_unwrapper.h"
     31 
     32 namespace webrtc {
     33 namespace test {
     34 namespace {
     35 constexpr char kArrivalDelayX[] = "arrival_delay_x";
     36 constexpr char kArrivalDelayY[] = "arrival_delay_y";
     37 constexpr char kTargetDelayX[] = "target_delay_x";
     38 constexpr char kTargetDelayY[] = "target_delay_y";
     39 constexpr char kPlayoutDelayX[] = "playout_delay_x";
     40 constexpr char kPlayoutDelayY[] = "playout_delay_y";
     41 
     42 // Helper function for NetEqDelayAnalyzer::CreateGraphs. Returns the
     43 // interpolated value of a function at the point x. Vector x_vec contains the
     44 // sample points, and y_vec contains the function values at these points. The
     45 // return value is a linear interpolation between y_vec values.
     46 double LinearInterpolate(double x,
     47                         const std::vector<int64_t>& x_vec,
     48                         const std::vector<int64_t>& y_vec) {
     49  // Find first element which is larger than x.
     50  auto it = std::upper_bound(x_vec.begin(), x_vec.end(), x);
     51  if (it == x_vec.end()) {
     52    --it;
     53  }
     54  const size_t upper_ix = it - x_vec.begin();
     55 
     56  size_t lower_ix;
     57  if (upper_ix == 0 || x_vec[upper_ix] <= x) {
     58    lower_ix = upper_ix;
     59  } else {
     60    lower_ix = upper_ix - 1;
     61  }
     62  double y;
     63  if (lower_ix == upper_ix) {
     64    y = y_vec[lower_ix];
     65  } else {
     66    RTC_DCHECK_NE(x_vec[lower_ix], x_vec[upper_ix]);
     67    y = (x - x_vec[lower_ix]) * (y_vec[upper_ix] - y_vec[lower_ix]) /
     68            (x_vec[upper_ix] - x_vec[lower_ix]) +
     69        y_vec[lower_ix];
     70  }
     71  return y;
     72 }
     73 
     74 void PrintDelays(const NetEqDelayAnalyzer::Delays& delays,
     75                 int64_t ref_time_ms,
     76                 absl::string_view var_name_x,
     77                 absl::string_view var_name_y,
     78                 std::ofstream& output,
     79                 absl::string_view terminator = "") {
     80  output << var_name_x << " = [ ";
     81  for (const std::pair<int64_t, float>& delay : delays) {
     82    output << (delay.first - ref_time_ms) / 1000.f << ", ";
     83  }
     84  output << "]" << terminator << std::endl;
     85 
     86  output << var_name_y << " = [ ";
     87  for (const std::pair<int64_t, float>& delay : delays) {
     88    output << delay.second << ", ";
     89  }
     90  output << "]" << terminator << std::endl;
     91 }
     92 
     93 }  // namespace
     94 
     95 void NetEqDelayAnalyzer::AfterInsertPacket(const RtpPacketReceived& packet,
     96                                           NetEq* /* neteq */) {
     97  data_.insert(std::make_pair(packet.Timestamp(),
     98                              TimingData(packet.arrival_time().ms())));
     99  ssrcs_.insert(packet.Ssrc());
    100  payload_types_.insert(packet.PayloadType());
    101 }
    102 
    103 void NetEqDelayAnalyzer::BeforeGetAudio(NetEq* neteq) {
    104  last_sync_buffer_ms_ = neteq->SyncBufferSizeMs();
    105 }
    106 
    107 void NetEqDelayAnalyzer::AfterGetAudio(int64_t time_now_ms,
    108                                       const AudioFrame& audio_frame,
    109                                       bool /*muted*/,
    110                                       NetEq* neteq) {
    111  get_audio_time_ms_.push_back(time_now_ms);
    112  for (const RtpPacketInfo& info : audio_frame.packet_infos_) {
    113    auto it = data_.find(info.rtp_timestamp());
    114    if (it == data_.end()) {
    115      // This is a packet that was split out from another packet. Skip it.
    116      continue;
    117    }
    118    auto& it_timing = it->second;
    119    RTC_CHECK(!it_timing.decode_get_audio_count)
    120        << "Decode time already written";
    121    it_timing.decode_get_audio_count = get_audio_count_;
    122    RTC_CHECK(!it_timing.sync_delay_ms) << "Decode time already written";
    123    it_timing.sync_delay_ms = last_sync_buffer_ms_;
    124    it_timing.target_delay_ms = neteq->TargetDelayMs();
    125    it_timing.current_delay_ms = neteq->FilteredCurrentDelayMs();
    126  }
    127  last_sample_rate_hz_ = audio_frame.sample_rate_hz_;
    128  ++get_audio_count_;
    129 }
    130 
    131 void NetEqDelayAnalyzer::CreateGraphs(Delays* arrival_delay_ms,
    132                                      Delays* corrected_arrival_delay_ms,
    133                                      Delays* playout_delay_ms,
    134                                      Delays* target_delay_ms) const {
    135  if (get_audio_time_ms_.empty()) {
    136    return;
    137  }
    138  // Create nominal_get_audio_time_ms, a vector starting at
    139  // get_audio_time_ms_[0] and increasing by 10 for each element.
    140  std::vector<int64_t> nominal_get_audio_time_ms(get_audio_time_ms_.size());
    141  nominal_get_audio_time_ms[0] = get_audio_time_ms_[0];
    142  std::transform(
    143      nominal_get_audio_time_ms.begin(), nominal_get_audio_time_ms.end() - 1,
    144      nominal_get_audio_time_ms.begin() + 1, [](int64_t& x) { return x + 10; });
    145  RTC_DCHECK(
    146      std::is_sorted(get_audio_time_ms_.begin(), get_audio_time_ms_.end()));
    147 
    148  std::vector<double> rtp_timestamps_ms;
    149  double offset = std::numeric_limits<double>::max();
    150  RtpTimestampUnwrapper unwrapper;
    151  // This loop traverses data_ and populates rtp_timestamps_ms as well as
    152  // calculates the base offset.
    153  for (auto& d : data_) {
    154    rtp_timestamps_ms.push_back(static_cast<double>(unwrapper.Unwrap(d.first)) /
    155                                CheckedDivExact(last_sample_rate_hz_, 1000));
    156    offset =
    157        std::min(offset, d.second.arrival_time_ms - rtp_timestamps_ms.back());
    158  }
    159 
    160  // This loop traverses the data again and populates the graph vectors. The
    161  // reason to have two loops and traverse twice is that the offset cannot be
    162  // known until the first traversal is done. Meanwhile, the final offset must
    163  // be known already at the start of this second loop.
    164  size_t i = 0;
    165  for (const auto& data : data_) {
    166    const double offset_send_time_ms = rtp_timestamps_ms[i++] + offset;
    167    const auto& timing = data.second;
    168    corrected_arrival_delay_ms->push_back(std::make_pair(
    169        timing.arrival_time_ms,
    170        LinearInterpolate(timing.arrival_time_ms, get_audio_time_ms_,
    171                          nominal_get_audio_time_ms) -
    172            offset_send_time_ms));
    173    arrival_delay_ms->push_back(std::make_pair(
    174        timing.arrival_time_ms, timing.arrival_time_ms - offset_send_time_ms));
    175 
    176    if (timing.decode_get_audio_count) {
    177      // This packet was decoded.
    178      RTC_DCHECK(timing.sync_delay_ms);
    179      const int64_t get_audio_time =
    180          *timing.decode_get_audio_count * 10 + get_audio_time_ms_[0];
    181      const float playout_ms =
    182          get_audio_time + *timing.sync_delay_ms - offset_send_time_ms;
    183      playout_delay_ms->push_back(std::make_pair(get_audio_time, playout_ms));
    184      RTC_DCHECK(timing.target_delay_ms);
    185      RTC_DCHECK(timing.current_delay_ms);
    186      const float target =
    187          playout_ms - *timing.current_delay_ms + *timing.target_delay_ms;
    188      target_delay_ms->push_back(std::make_pair(get_audio_time, target));
    189    }
    190  }
    191 }
    192 
    193 void NetEqDelayAnalyzer::CreateMatlabScript(
    194    absl::string_view script_name) const {
    195  Delays arrival_delay_ms;
    196  Delays corrected_arrival_delay_ms;
    197  Delays playout_delay_ms;
    198  Delays target_delay_ms;
    199  CreateGraphs(&arrival_delay_ms, &corrected_arrival_delay_ms,
    200               &playout_delay_ms, &target_delay_ms);
    201 
    202  // Maybe better to find the actually smallest timestamp, to surely avoid
    203  // x-axis starting from negative.
    204  const int64_t ref_time_ms = arrival_delay_ms.front().first;
    205 
    206  // Create an output file stream to Matlab script file.
    207  std::ofstream output(std::string{script_name});
    208 
    209  PrintDelays(corrected_arrival_delay_ms, ref_time_ms, kArrivalDelayX,
    210              kArrivalDelayY, output, ";");
    211 
    212  // PrintDelays(corrected_arrival_delay_x, kCorrectedArrivalDelayX,
    213  // kCorrectedArrivalDelayY, output);
    214 
    215  PrintDelays(playout_delay_ms, ref_time_ms, kPlayoutDelayX, kPlayoutDelayY,
    216              output, ";");
    217 
    218  PrintDelays(target_delay_ms, ref_time_ms, kTargetDelayX, kTargetDelayY,
    219              output, ";");
    220 
    221  output << "h=plot(" << kArrivalDelayX << ", " << kArrivalDelayY << ", "
    222         << kTargetDelayX << ", " << kTargetDelayY << ", 'g.', "
    223         << kPlayoutDelayX << ", " << kPlayoutDelayY << ");" << std::endl;
    224  output << "set(h(1),'color',0.75*[1 1 1]);" << std::endl;
    225  output << "set(h(2),'markersize',6);" << std::endl;
    226  output << "set(h(3),'linew',1.5);" << std::endl;
    227  output << "ax1=axis;" << std::endl;
    228  output << "axis tight" << std::endl;
    229  output << "ax2=axis;" << std::endl;
    230  output << "axis([ax2(1:3) ax1(4)])" << std::endl;
    231  output << "xlabel('time [s]');" << std::endl;
    232  output << "ylabel('relative delay [ms]');" << std::endl;
    233  if (!ssrcs_.empty()) {
    234    auto ssrc_it = ssrcs_.cbegin();
    235    output << "title('SSRC: 0x" << std::hex << static_cast<int64_t>(*ssrc_it++);
    236    while (ssrc_it != ssrcs_.end()) {
    237      output << ", 0x" << std::hex << static_cast<int64_t>(*ssrc_it++);
    238    }
    239    output << std::dec;
    240    auto pt_it = payload_types_.cbegin();
    241    output << "; Payload Types: " << *pt_it++;
    242    while (pt_it != payload_types_.end()) {
    243      output << ", " << *pt_it++;
    244    }
    245    output << "');" << std::endl;
    246  }
    247 }
    248 
    249 void NetEqDelayAnalyzer::CreatePythonScript(
    250    absl::string_view script_name) const {
    251  Delays arrival_delay_ms;
    252  Delays corrected_arrival_delay_ms;
    253  Delays playout_delay_ms;
    254  Delays target_delay_ms;
    255  CreateGraphs(&arrival_delay_ms, &corrected_arrival_delay_ms,
    256               &playout_delay_ms, &target_delay_ms);
    257 
    258  // Maybe better to find the actually smallest timestamp, to surely avoid
    259  // x-axis starting from negative.
    260  const int64_t ref_time_ms = arrival_delay_ms.front().first;
    261 
    262  // Create an output file stream to the python script file.
    263  std::ofstream output(std::string{script_name});
    264 
    265  // Necessary includes
    266  output << "import numpy as np" << std::endl;
    267  output << "import matplotlib.pyplot as plt" << std::endl;
    268 
    269  PrintDelays(corrected_arrival_delay_ms, ref_time_ms, kArrivalDelayX,
    270              kArrivalDelayY, output);
    271 
    272  // PrintDelays(corrected_arrival_delay_x, kCorrectedArrivalDelayX,
    273  // kCorrectedArrivalDelayY, output);
    274 
    275  PrintDelays(playout_delay_ms, ref_time_ms, kPlayoutDelayX, kPlayoutDelayY,
    276              output);
    277 
    278  PrintDelays(target_delay_ms, ref_time_ms, kTargetDelayX, kTargetDelayY,
    279              output);
    280 
    281  output << "if __name__ == '__main__':" << std::endl;
    282  output << "  h=plt.plot(" << kArrivalDelayX << ", " << kArrivalDelayY << ", "
    283         << kTargetDelayX << ", " << kTargetDelayY << ", 'g.', "
    284         << kPlayoutDelayX << ", " << kPlayoutDelayY << ")" << std::endl;
    285  output << "  plt.setp(h[0],'color',[.75, .75, .75])" << std::endl;
    286  output << "  plt.setp(h[1],'markersize',6)" << std::endl;
    287  output << "  plt.setp(h[2],'linewidth',1.5)" << std::endl;
    288  output << "  plt.axis('tight')" << std::endl;
    289  output << "  plt.xlabel('time [s]')" << std::endl;
    290  output << "  plt.ylabel('relative delay [ms]')" << std::endl;
    291  if (!ssrcs_.empty()) {
    292    auto ssrc_it = ssrcs_.cbegin();
    293    output << "  plt.legend((\"arrival delay\", \"target delay\", \"playout "
    294              "delay\"))"
    295           << std::endl;
    296    output << "  plt.title('SSRC: 0x" << std::hex
    297           << static_cast<int64_t>(*ssrc_it++);
    298    while (ssrc_it != ssrcs_.end()) {
    299      output << ", 0x" << std::hex << static_cast<int64_t>(*ssrc_it++);
    300    }
    301    output << std::dec;
    302    auto pt_it = payload_types_.cbegin();
    303    output << "; Payload Types: " << *pt_it++;
    304    while (pt_it != payload_types_.end()) {
    305      output << ", " << *pt_it++;
    306    }
    307    output << "')" << std::endl;
    308  }
    309  output << "  plt.show()" << std::endl;
    310 }
    311 
    312 }  // namespace test
    313 }  // namespace webrtc