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

   1 #include "print_latency.h"
   2
   3 #include "flags.h"
   4 #include "shared/metrics.h"
   5 #include "mixer.h"
   6
   7 #include <stdio.h>
   8 #include <algorithm>
   9 #include <chrono>
  10 #include <string>
  11
  12 using namespace std;
  13 using namespace std::chrono;
  14
  15 ReceivedTimestamps find_received_timestamp(const vector<RefCountedFrame> &input_frames)
  16 {
  17         assert(input_frames.size() == MAX_VIDEO_CARDS * FRAME_HISTORY_LENGTH);
  18
  19         ReceivedTimestamps ts;
  20         for (unsigned card_index = 0; card_index < MAX_VIDEO_CARDS; ++card_index) {
  21                 for (unsigned frame_index = 0; frame_index < FRAME_HISTORY_LENGTH; ++frame_index) {
  22                         const RefCountedFrame &input_frame = input_frames[card_index * FRAME_HISTORY_LENGTH + frame_index];
  23                         if (input_frame == nullptr ||
  24                             (frame_index > 0 && input_frame.get() == input_frames[card_index * FRAME_HISTORY_LENGTH + frame_index - 1].get())) {
  25                                 ts.ts.push_back(steady_clock::time_point::min());
  26                         } else {
  27                                 ts.ts.push_back(input_frame->received_timestamp);
  28                         }
  29                 }
  30         }
  31         return ts;
  32 }
  33
  34 void LatencyHistogram::init(const string &measuring_point)
  35 {
  36         summaries.resize(MAX_VIDEO_CARDS * FRAME_HISTORY_LENGTH * 2);
  37         for (unsigned card_index = 0; card_index < MAX_VIDEO_CARDS; ++card_index) {
  38                 char card_index_str[64];
  39                 snprintf(card_index_str, sizeof(card_index_str), "%u", card_index);
  40                 summaries[card_index].resize(FRAME_HISTORY_LENGTH);
  41                 for (unsigned frame_index = 0; frame_index < FRAME_HISTORY_LENGTH; ++frame_index) {
  42                         char frame_index_str[64];
  43                         snprintf(frame_index_str, sizeof(frame_index_str), "%u", frame_index);
  44
  45                         vector<double> quantiles{0.01, 0.1, 0.25, 0.5, 0.75, 0.9, 0.99};
  46                         summaries[card_index][frame_index].reset(new Summary[3]);
  47                         summaries[card_index][frame_index][0].init(quantiles, 60.0);
  48                         summaries[card_index][frame_index][1].init(quantiles, 60.0);
  49                         summaries[card_index][frame_index][2].init(quantiles, 60.0);
  50                         global_metrics.add("latency_seconds",
  51                                 {{ "measuring_point", measuring_point },
  52                                  { "card", card_index_str },
  53                                  { "frame_age", frame_index_str },
  54                                  { "frame_type", "i/p" }},
  55                                  &summaries[card_index][frame_index][0],
  56                                 Metrics::PRINT_WHEN_NONEMPTY);
  57                         global_metrics.add("latency_seconds",
  58                                 {{ "measuring_point", measuring_point },
  59                                  { "card", card_index_str },
  60                                  { "frame_age", frame_index_str },
  61                                  { "frame_type", "b" }},
  62                                  &summaries[card_index][frame_index][1],
  63                                 Metrics::PRINT_WHEN_NONEMPTY);
  64                         global_metrics.add("latency_seconds",
  65                                 {{ "measuring_point", measuring_point },
  66                                  { "card", card_index_str },
  67                                  { "frame_age", frame_index_str },
  68                                  { "frame_type", "total" }},
  69                                  &summaries[card_index][frame_index][2],
  70                                 Metrics::PRINT_WHEN_NONEMPTY);
  71                 }
  72         }
  73 }
  74
  75 void print_latency(const char *header, const ReceivedTimestamps &received_ts, bool is_b_frame, int *frameno, LatencyHistogram *histogram)
  76 {
  77         if (received_ts.ts.empty())
  78                 return;
  79
  80         const steady_clock::time_point now = steady_clock::now();
  81
  82         if (global_mixer == nullptr) {
  83                 // Kaeru.
  84                 assert(received_ts.ts.size() == 1);
  85                 steady_clock::time_point ts = received_ts.ts[0];
  86                 if (ts != steady_clock::time_point::min()) {
  87                         duration<double> latency = now - ts;
  88                         histogram->summaries[0][0][is_b_frame].count_event(latency.count());
  89                         histogram->summaries[0][0][2].count_event(latency.count());
  90                 }
  91         } else {
  92                 assert(received_ts.ts.size() == MAX_VIDEO_CARDS * FRAME_HISTORY_LENGTH);
  93                 for (unsigned card_index = 0; card_index < MAX_VIDEO_CARDS; ++card_index) {
  94                         for (unsigned frame_index = 0; frame_index < FRAME_HISTORY_LENGTH; ++frame_index) {
  95                                 steady_clock::time_point ts = received_ts.ts[card_index * FRAME_HISTORY_LENGTH + frame_index];
  96                                 if (ts == steady_clock::time_point::min()) {
  97                                         continue;
  98                                 }
  99                                 duration<double> latency = now - ts;
 100                                 histogram->summaries[card_index][frame_index][is_b_frame].count_event(latency.count());
 101                                 histogram->summaries[card_index][frame_index][2].count_event(latency.count());
 102                         }
 103                 }
 104         }
 105
 106         // 101 is chosen so that it's prime, which is unlikely to get the same frame type every time.
 107         if (global_flags.print_video_latency && (++*frameno % 101) == 0) {
 108                 // Find min and max timestamp of all input frames that have a timestamp.
 109                 steady_clock::time_point min_ts = steady_clock::time_point::max(), max_ts = steady_clock::time_point::min();
 110                 for (const auto &ts : received_ts.ts) {
 111                         if (ts > steady_clock::time_point::min()) {
 112                                 min_ts = min(min_ts, ts);
 113                                 max_ts = max(max_ts, ts);
 114                         }
 115                 }
 116                 duration<double> lowest_latency = now - max_ts;
 117                 duration<double> highest_latency = now - min_ts;
 118
 119                 printf("%-60s %4.0f ms (lowest-latency input), %4.0f ms (highest-latency input)",
 120                         header, 1e3 * lowest_latency.count(), 1e3 * highest_latency.count());
 121
 122                 if (is_b_frame) {
 123                         printf("  [on B-frame; potential extra latency]\n");
 124                 } else {
 125                         printf("\n");
 126                 }
 127         }
 128 }