[SKIP CI] Test-case: Test if acoustic capture of ambient is normal

test-case/noise_capture_check.m

@@ -0,0 +1,148 @@
+function noise_capture_check(fn)
+
+t_min = 2.0; % Min 2.0s long clip
+t_skip = 1.0; % Trim out first 1.0s
+n_fft = 1024; % 1024 bits FFT
+clipped_db = -0.01; % Max. PCM code value in dB
+max_offset_db = -80; % Max. DC offset in dB
+mask.low_f   = [   0 1000 5000 7000 96000];
+mask.low_db  = [-160 -180 -200 -250  -250];
+mask.high_f  = [   0 7000 24000 96000];
+mask.high_db = [ -20  -30   -50   -60];
+
+%% Octave packages, skip for Matlab
+if exist('OCTAVE_VERSION', 'builtin')
+	pkg load signal;
+end
+
+%% Get audio recording
+[x0, fs] = audioread(fn);
+n_samples = size(x0, 1);
+n_channels = size(x0, 2);
+t_clip = n_samples / fs;
+if t_clip < t_min
+	fprintf(1, 'Error: The clip needs to be at least %.1fs long\n', t_min);
+	fail_check(1);
+end
+
+%% Trim sample, skip the beginning
+x = x0(t_skip * fs + 1:end,:);
+n_samples = size(x, 1);
+
+%% Check that all channels contain signal, fail for zero or DC value
+failed = 0;
+for i = 1:n_channels
+	abs_max_diff = max(abs(diff(x(:,i))));
+	if abs_max_diff < eps
+		fprintf(1, 'Error: Channel %d does not contain signal\n', i);
+		failed = 1;
+	end
+end
+fail_check(failed);
+
+%% Check for excessive offset
+failed = 0;
+for i = 1:n_channels
+	offset = 20*log10(abs(mean(x(:,i))));
+	if offset > max_offset_db
+		fprintf(1, 'Error: Channel %d offset %5.2f is too high\n', i, offset);
+		failed = 1;
+	end
+end
+fail_check(failed);
+
+%% Check that channels are unique
+failed = 0;
+for i = 1:n_channels
+	for j = 1:n_channels
+		if i == j
+			continue
+		end
+		delta = x(:,i) - x(:,j);
+		max_abs_delta = max(abs(delta));
+		if max_abs_delta < eps
+			fprintf(1, 'Error: Channels %d and %d are identical\n', i, j);
+			failed = 1;
+		end
+	end
+end
+fail_check(failed);
+
+%% Check that PCM code values are not saturated
+failed = 0;
+for i = 1:n_channels
+	if max(abs(x(:,i))) > 10^(clipped_db/20)
+		fprintf(1, 'Error: Channel %d contains clipped samples\n', i);
+		failed = 1;
+	end
+end
+fail_check(failed);
+
+%% Check for normal spectra shape
+failed = 0;
+for i = 1:n_channels
+	if fft_check_channel(x, i, fs, mask)
+		failed = 1;
+	end
+end
+fail_check(failed);
+
+
+end
+
+%% Helper functions
+
+function fail_check(fail)
+
+if fail
+	quit(1);
+end
+
+end
+
+function failed = fft_check_channel(x, ch, fs, mask)
+
+failed = 0;
+do_plot = 0;
+[f, mdb] = get_fft(x(:,ch), fs);
+mask_low = interp1(mask.low_f, mask.low_db, f)';
+mask_high = interp1(mask.high_f, mask.high_db, f)';
+if do_plot
+	figure
+	plot(f, mdb);
+	hold on
+	plot(f, mask_low, '--', f, mask_high, '--');
+	hold off
+	grid on;
+end
+
+idx = find(mdb < mask_low);
+if ~isempty(idx)
+	f_min = f(idx(1));
+	f_max = f(idx(end));
+	fprintf(1, 'Error: Channel %d is below mask in %.0f - %0.f Hz\n', ...
+		ch, f_min, f_max);
+	failed = 1;
+end
+idx = find(mdb > mask_high);
+if ~isempty(idx)
+	f_min = f(idx(1));
+	f_max = f(idx(end));
+	fprintf(1, 'Error: Channel %d is above mask in %.0f - %0.f Hz\n', ...
+		ch, f_min, f_max);
+	failed = 1;
+end
+
+end
+
+function [f, mdb] = get_fft(x, fs)
+
+n_fft = 8192;
+win = kaiser(n_fft, 20);
+idx = length(x) - n_fft + 1;
+s = fft(x(idx:end) .* win) / n_fft;
+s = s(1:n_fft/2 + 1);
+f = linspace(0, fs/2, length(s));
+mdb = 20*log10(abs(s));
+
+end

test-case/noise_capture_check.sh

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+#!/bin/bash
+
+set -e
+
+check_device_format () {
+    DEV=$1
+    FMT=$2
+    WAV=$(mktemp).wav
+    OCTAVE_SCRIPT="noise_capture_check('${WAV}')"
+    echo Testing "$DEV"
+    rm -f "$WAV"
+    arecord -D${DEV} $FMT -d 2 "$WAV"
+    octave --silent --no-gui --eval "$OCTAVE_SCRIPT"
+    status=$?
+    [ $status -eq 0 ] && echo Passed.
+    rm -f "$WAV"
+}
+
+check_device_format "hw:1,0" "-c 2 -r 48000 -f S16_LE"
+check_device_format "hw:1,6" "-c 2 -r 48000 -f S16_LE"
+check_device_format "hw:1,6" "-c 2 -r 48000 -f S32_LE"
+check_device_format "hw:1,7" "-c 2 -r 16000 -f S16_LE"
+check_device_format "hw:1,7" "-c 2 -r 16000 -f S32_LE"