function example_crossover()

addpath ./../common

% Sampling Frequency and Frequency cut-offs for crossover

cr.fs = 48e3;

cr.fc_low = 200;

cr.fc_med = 1000;

cr.fc_high = 3000;

% 2 way crossover, pipeline IDs of sinks are 1 and 2 (IPC3)

% and component output pins 0 and 1 (IPC4)

cr.num_sinks = 2;

cr.sinks = [1 2];

export_crossover(cr);

cr.sinks = [0 1];

export_crossover(cr);

% 3 way crossover, pipeline IDs of sinks are 1 - 3

cr.num_sinks = 3;

cr.sinks = [1 2 3];

export_crossover(cr);

cr.sinks = [0 1 2];

export_crossover(cr);

% 4 way crossover, pipeline IDs of sinks are 1 - 4

cr.num_sinks = 4;

cr.sinks = [1 2 3 4];

export_crossover(cr);

cr.sinks = [0 1 2 3];

export_crossover(cr);

rmpath ./../common

end

function export_crossover(cr)

endian = "little";

tpath1 = '../../topology/topology1/m4/crossover';

tpath2 = '../../topology/topology2/include/components/crossover';

ctlpath = '../../ctl/ipc3';

str_way = sprintf('%dway', cr.num_sinks);

str_freq = get_str_freq(cr);

str_pid = get_str_pid(cr);

% Set the parameters here

tplg1_fn = sprintf('%s/coef_%s_%s_%s.m4', tpath1, str_way, str_freq, str_pid); % Control Bytes File

tplg2_fn = sprintf('%s/coef_%s_%s_%s.conf', tpath2, str_way, str_freq, str_pid);

% Use those files with sof-ctl to update the component's configuration

blob_fn = sprintf('%s/crossover_coef_%dway.blob', ctlpath, cr.num_sinks); % Blob binary file

alsa_fn = sprintf('%s/crossover_coef_%dway.txt', ctlpath, cr.num_sinks); % ALSA CSV format file

% This array is an example on how to assign a buffer from pipeline 1 to output 0,

% buffer from pipeline 2 to output 1, etc...

% Refer to sof/src/include/user/crossover.h for more information on assigning

% buffers to outputs.

assign_sinks = zeros(1, 4);

assign_sinks(1:cr.num_sinks) = cr.sinks;

% Generate zeros, poles and gain for crossover with the given frequencies

switch cr.num_sinks

case 2

crossover = crossover_gen_coefs(cr.fs, cr.fc_low); % 2 way crossover

case 3

crossover = crossover_gen_coefs(cr.fs, cr.fc_low, cr.fc_med); % 3 way crossover

case 4

crossover = crossover_gen_coefs(cr.fs, cr.fc_low, cr.fc_med, cr.fc_high); % 4 way crossover

otherwise

error('Illegal number of sinks %d\n', num_sinks);

end

% Convert the [a,b] coefficients to values usable with SOF

crossover_bqs = crossover_coef_quant(crossover.lp, crossover.hp);

% Convert coefficients to sof_crossover_config struct

config = crossover_generate_config(crossover_bqs, cr.num_sinks, assign_sinks);

% Convert struct to binary blob

blob8 = crossover_build_blob(config, endian, 3);

blob8_ipc4 = crossover_build_blob(config, endian, 4);

% Generate output files

mkdir_check(tpath1);

mkdir_check(tpath2);

mkdir_check(ctlpath);

tplg_write(tplg1_fn, blob8, "CROSSOVER");

tplg2_write(tplg2_fn, blob8_ipc4, "crossover_config", 'Exported Control Bytes');

blob_write(blob_fn, blob8);

alsactl_write(alsa_fn, blob8);

% Plot Magnitude and Phase Response of each sink

crossover_plot_freq(crossover.lp, crossover.hp, cr.fs, cr.num_sinks);

end

% Frequencies part for filename

function str = get_str_freq(cr)

switch cr.num_sinks

case 2

str = sprintf('%d_%d', cr.fs, cr.fc_low);

case 3

str = sprintf('%d_%d_%d', cr.fs, cr.fc_low, cr.fc_med);

case 4

str = sprintf('%d_%d_%d_%d', cr.fs, cr.fc_low, cr.fc_med, cr.fc_high);

end

end

% Pipeline IDs part of filename

function str = get_str_pid(cr)

str = sprintf('%d', cr.sinks(1));

for i = 2:cr.num_sinks

str = sprintf('%s_%d', str, cr.sinks(i));

end

end

% Check if directory exists, avoid warning print for existing

function mkdir_check(new_dir)

if ~exist(new_dir, 'dir')

mkdir(new_dir);

end

end