sof/tools/tune/eq/eq_blob_plot.m

143 lines
3.0 KiB
Matlab

function eq = eq_blob_plot(blobfn, eqtype, fs, f, doplot)
% eq = eq_blob_plot(blobfn, eqtype, fs, f, doplot)
%
% Plot frequency response of IIR or FIR EQ coefficients blob
%
% Inputs
%
% blobfn - filename of the blob
% eqtype - 'iir' or 'fir', if omitted done via string search from blobfn
% fs - sample rate, defaults to 48 kHz if omitted
% f - frequency vector
% dpplot
% SPDX-License-Identifier: BSD-3-Clause
%
% Copyright (c) 2016-2020, Intel Corporation. All rights reserved.
%
% Author: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>
%% Handle input parameters
if nargin < 2
if findstr(blobfn, '_fir_')
eqtype = 'FIR';
else
eqtype = 'IIR';
end
end
if nargin < 3
fs = 48e3;
end
if nargin < 4 || isempty(f)
eq.f = logspace(log10(10),log10(fs/2), 1000);
f_single = [];
else
% Freqz() needs two frequency points or more
if length(f) < 2
f_single = 1;
eq.f = [f f];
else
f_single = 0;
eq.f = f;
end
end
if nargin < 5
doplot = 1;
end
%% Read blob as 32 bit integers
blob = eq_blob_read(blobfn);
%% Group delay with grpdelay() is not working in Octave
do_group_delay = ~exist('OCTAVE_VERSION', 'builtin');
%% Decode and compute response
eq.m = [];
eq.gd = [];
switch lower(eqtype)
case 'fir'
hd = eq_fir_blob_decode(blob);
eq.m = zeros(length(eq.f), hd.channels_in_config);
for i = 1:hd.channels_in_config
teq = eq_fir_blob_decode(blob, hd.assign_response(i));
h = freqz(teq.b, 1, eq.f, fs);
eq.m(:,i) = 20*log10(abs(h));
if do_group_delay
gd = grpdelay(teq.b, 1, eq.f, fs) / fs;
eq.gd(:,i) = gd;
end
end
case 'iir'
hd = eq_iir_blob_decode(blob);
eq.m = zeros(length(eq.f), hd.channels_in_config);
for i = 1:hd.channels_in_config
teq = eq_iir_blob_decode(blob, hd.assign_response(i));
h = freqz(teq.b, teq.a, eq.f, fs);
eq.m(:,i) = 20*log10(abs(h));
if do_group_delay
gd = grpdelay(teq.b, teq.a, eq.f, fs) / fs;
eq.gd(:,i) = gd;
end
end
end
%% Optional plots
if doplot
eq.fh(1) = figure;
semilogx(eq.f, eq.m);
ymin = max(min(min(eq.m)), -60);
ymax = max(max(eq.m));
axis([10 round(fs/2/10)*10 ymin-3 ymax+3 ]);
grid on;
channel_legends(hd.channels_in_config);
xlabel('Frequency (Hz)');
ylabel('Amplitude (dB)');
title(blobfn, 'Interpreter', 'None');
if do_group_delay
eq.fh(2) = figure;
semilogx(eq.f, eq.gd * 1e6);
ax = axis();
axis([10 round(fs/2/10)*10 ax(3:4) ]);
grid on;
channel_legends(hd.channels_in_config);
xlabel('Frequency (Hz)');
ylabel('Group delay (us)');
title(blobfn, 'Interpreter', 'None');
end
end
%% Trim avay the duplicated frequency point
if f_single
eq.f = eq.f(1);
eq.m = eq.m(1, :);
if do_group_delay
eq.gd = eq.gd(1, :);
end
end
end
%% Helper functions
function channel_legends(n)
switch n
case 2
legend('ch1', 'ch2');
case 4
legend('ch1', 'ch2', 'ch3', 'ch4');
case 6
legend('ch1', 'ch2', 'ch3', 'ch4', 'ch5', 'ch6');
case 8
legend('ch1', 'ch2', 'ch3', 'ch4', 'ch5', 'ch6', 'ch7', 'ch8');
otherwise
error('Illegal number of channels found');
end
end