Deepstream Component latency

[adityawasnik91]

Hardware :- Jetson Nano
DS :- DS5.0

Im using this probe function to get the frame latency

static GstPadProbeReturn latency_measurement_buf_prob(GstPad *pad,
                                                      GstPadProbeInfo *info,
                                                      gpointer u_data) {
    LatencyCtx *ctx = (LatencyCtx *)u_data;
    static int batch_num = 0;
    guint i = 0, num_sources_in_batch = 0;
    if (nvds_enable_latency_measurement) {
        GstBuffer *buf = (GstBuffer *)info->data;
        NvDsFrameLatencyInfo *latency_info = NULL;
        _NvDsMetaCompLatency *comp_latency = NULL;
        g_mutex_lock(ctx->lock);
        latency_info = (NvDsFrameLatencyInfo *)calloc(
            1, ctx->num_sources * sizeof(NvDsFrameLatencyInfo));
        ;
        g_print("\n************BATCH-NUM = %d**************\n", batch_num);
        num_sources_in_batch = nvds_measure_buffer_latency(buf, latency_info);
        for (i = 0; i < num_sources_in_batch; i++) {
            g_print("Src id=%d Frame_no=%d Frame latency=%lf (ms) \n",
                    latency_info[i].source_id, latency_info[i].frame_num,
                    latency_info[i].latency);
            std::cout << "\n\n" << std::endl;
        }
        g_mutex_unlock(ctx->lock);
        batch_num++;
    }


    return GST_PAD_PROBE_OK;
}

and I’m getting this :-

************BATCH-NUM = 11**************
Comp name = nvv4l2-decoder in_system_timestamp = 1688384797240.604004 out_system_timestamp = 1688384797384.811035               component latency= 144.207031
Comp name = stream-muxer in_system_timestamp = 1688384797384.909912 out_system_timestamp = 1688384797454.275879               component latency= 69.365967
Comp name = primary-nvinference-engine in_system_timestamp = 1688384797454.298096 out_system_timestamp = 1688384797546.986084               component latency= 92.687988
Comp name = tracker in_system_timestamp = 1688384797547.008057 out_system_timestamp = 1688384797669.364014               component latency= 122.355957

************BATCH-NUM = 12**************
Comp name = nvv4l2-decoder in_system_timestamp = 1688384797312.167969 out_system_timestamp = 1688384797456.635986               component latency= 144.468018
Comp name = stream-muxer in_system_timestamp = 1688384797456.710938 out_system_timestamp = 1688384797526.450928               component latency= 69.739990
Comp name = primary-nvinference-engine in_system_timestamp = 1688384797526.474121 out_system_timestamp = 1688384797619.053955               component latency= 92.579834
Comp name = tracker in_system_timestamp = 1688384797619.077881 out_system_timestamp = 1688384797740.842041               component latency= 121.764160

in the above probe function, nvds_measure_buffer_latency() has been called. According to documentation, this function will return NvDsFrameLatencyInfo , and NOT _NvDsMetaCompLatency, is this correct ?

question is, what is printing these logs ? which function exactly ? nvds_measure_buffer_latency()?

[yuweiw]

Yes. It’s nvds_measure_buffer_latency(). This part of the code is not open source.

[adityawasnik91]

oh, okay. thanks.