1 #include "print_latency.h"
4 #include "shared/metrics.h"
13 using namespace std::chrono;
15 ReceivedTimestamps find_received_timestamp(const vector<RefCountedFrame> &input_frames)
17 assert(input_frames.size() == MAX_VIDEO_CARDS * FRAME_HISTORY_LENGTH);
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());
27 ts.ts.push_back(input_frame->received_timestamp);
34 void LatencyHistogram::init(const string &measuring_point)
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);
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);
75 void print_latency(const char *header, const ReceivedTimestamps &received_ts, bool is_b_frame, int *frameno, LatencyHistogram *histogram)
77 if (received_ts.ts.empty())
80 const steady_clock::time_point now = steady_clock::now();
82 if (global_mixer == nullptr) {
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());
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()) {
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());
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);
116 duration<double> lowest_latency = now - max_ts;
117 duration<double> highest_latency = now - min_ts;
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());
123 printf(" [on B-frame; potential extra latency]\n");