function example_line_array()

% example_line_array()

%

% Creates a number of line array configuration blobs for devices

% with 2 microphones with spacing of 50 mm and 68 mm

% with 4 microphones with spacing of 28 mm, 68 mm, and 78 mm

% SPDX-License-Identifier: BSD-3-Clause

%

% Copyright (c) 2020, Intel Corporation. All rights reserved.

%

% Author: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>

%% 2 mic arrays

az = -90:15:90;

close all; line_one_beam(48e3, 50e-3, az, 2, 64);

close all; line_one_beam(48e3, 68e-3, az, 2, 64);

close all; line_one_beam(16e3, 50e-3, az, 2, 40);

close all; line_one_beam(16e3, 68e-3, az, 2, 40);

%% 4 mic arrays

close all; line_one_beam(48e3, 28e-3, az, 4, 80);

close all; line_one_beam(48e3, 68e-3, az, 4, 112);

close all; line_one_beam(48e3, 78e-3, az, 4, 120);

close all; line_one_beam(16e3, 28e-3, az, 4, 40);

close all; line_one_beam(16e3, 68e-3, az, 4, 52);

close all; line_one_beam(16e3, 78e-3, az, 4, 60);

end

function line_one_beam(fs, d, az, n_mic, n_fir)

% Get defaults

bf = bf_defaults();

bf.input_channel_select = 0:(n_mic-1); % Input all n channels to filters

bf.output_channel_mix = 3 * ones(1, n_mic); % Mix all filters to channel 1 and 2

bf.output_stream_mix = zeros(1, n_mic); % Mix filters to stream 0

bf.num_output_channels = 2; % Stereo

bf.num_output_streams = 1; % One sink stream

bf.array = 'line'; % Calculate xyz coordinates for line

bf.mic_n = n_mic;

% Mix only filters 1 and N to left and right stereo, it gives best

% passive stereo effect for beam off mode

bf.output_channel_mix_beam_off = [1 zeros(1, n_mic-2) 2];

% From parameters

bf.fs = fs;

bf.mic_d = d;

bf.steer_az = az;

bf.steer_el = 0 * az; % all 0 deg

if nargin > 4

bf.fir_length = n_fir;

end

% Design

bf = bf_filenames_helper(bf);

bf = bf_design(bf);

bf.export_note = 'Created with script example_line_array.m';

bf.export_howto = 'cd tools/tune/tdfb; octave --no-window-system example_line_array.m';

bf_export(bf);

end