_analysis_gain = f.optional_number_child<double> ("AnalysisGain");
_samples_per_point = f.number_child<int64_t> ("SamplesPerPoint");
_sample_rate = f.number_child<int64_t> ("SampleRate");
_analysis_gain = f.optional_number_child<double> ("AnalysisGain");
_samples_per_point = f.number_child<int64_t> ("SamplesPerPoint");
_sample_rate = f.number_child<int64_t> ("SampleRate");