git.sesse.net Git - nageru/blob - print_latency.cpp

   1 #include "print_latency.h"
   2
   3 #include "flags.h"
   4 #include "metrics.h"
   5
   6 #include <stdio.h>
   7 #include <chrono>
   8 #include <string>
   9
  10 using namespace std;
  11 using namespace std::chrono;
  12
  13 ReceivedTimestamps find_received_timestamp(const vector<RefCountedFrame> &input_frames)
  14 {
  15         // Find min and max timestamp of all input frames that have a timestamp.
  16         steady_clock::time_point min_ts = steady_clock::time_point::max(), max_ts = steady_clock::time_point::min();
  17         for (const RefCountedFrame &input_frame : input_frames) {
  18                 if (input_frame && input_frame->received_timestamp > steady_clock::time_point::min()) {
  19                         min_ts = min(min_ts, input_frame->received_timestamp);
  20                         max_ts = max(max_ts, input_frame->received_timestamp);
  21                 }
  22         }
  23         return { min_ts, max_ts };
  24 }
  25
  26 void LatencyHistogram::init(const string &measuring_point)
  27 {
  28         histogram_lowest_latency_input.init_geometric(0.001, 10.0, 30);
  29         histogram_highest_latency_input.init_geometric(0.001, 10.0, 30);
  30         histogram_lowest_latency_input_bframe.init_geometric(0.001, 10.0, 30);
  31         histogram_highest_latency_input_bframe.init_geometric(0.001, 10.0, 30);
  32
  33         global_metrics.add("latency_seconds",
  34                 {{ "measuring_point", measuring_point }, { "input", "lowest_latency" }, { "frame_type", "i/p" }},
  35                 &histogram_lowest_latency_input);
  36         global_metrics.add("latency_seconds",
  37                 {{ "measuring_point", measuring_point }, { "input", "highest_latency" }, { "frame_type", "i/p" }},
  38                 &histogram_highest_latency_input);
  39         global_metrics.add("latency_seconds",
  40                 {{ "measuring_point", measuring_point }, { "input", "lowest_latency" }, { "frame_type", "b" }},
  41                 &histogram_lowest_latency_input_bframe);
  42         global_metrics.add("latency_seconds",
  43                 {{ "measuring_point", measuring_point }, { "input", "highest_latency" }, { "frame_type", "b" }},
  44                 &histogram_highest_latency_input_bframe);
  45 }
  46
  47 void print_latency(const string &header, const ReceivedTimestamps &received_ts, bool is_b_frame, int *frameno, LatencyHistogram *histogram)
  48 {
  49         if (received_ts.max_ts == steady_clock::time_point::min())
  50                 return;
  51
  52         const steady_clock::time_point now = steady_clock::now();
  53         duration<double> lowest_latency = now - received_ts.max_ts;
  54         duration<double> highest_latency = now - received_ts.min_ts;
  55
  56         if (is_b_frame) {
  57                 histogram->histogram_lowest_latency_input_bframe.count_event(lowest_latency.count());
  58                 histogram->histogram_highest_latency_input_bframe.count_event(highest_latency.count());
  59         } else {
  60                 histogram->histogram_lowest_latency_input.count_event(lowest_latency.count());
  61                 histogram->histogram_highest_latency_input.count_event(highest_latency.count());
  62         }
  63
  64         // 101 is chosen so that it's prime, which is unlikely to get the same frame type every time.
  65         if (global_flags.print_video_latency && (++*frameno % 101) == 0) {
  66                 printf("%-60s %4.0f ms (lowest-latency input), %4.0f ms (highest-latency input)",
  67                         header.c_str(), 1e3 * lowest_latency.count(), 1e3 * highest_latency.count());
  68
  69                 if (is_b_frame) {
  70                         printf("  [on B-frame; potential extra latency]\n");
  71                 } else {
  72                         printf("\n");
  73                 }
  74         }
  75 }