const double samplerate = data_->samplerate();
const double start_time = data_->get_start_time();
const int64_t last_sample = snapshot->get_sample_count() - 1;
const double samplerate = data_->samplerate();
const double start_time = data_->get_start_time();
const int64_t last_sample = snapshot->get_sample_count() - 1;