84 lines
2.9 KiB
Matlab
84 lines
2.9 KiB
Matlab
function test = thdnf_test_measure(test)
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%%
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% Copyright (c) 2017, Intel Corporation
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% All rights reserved.
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%
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% Redistribution and use in source and binary forms, with or without
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% modification, are permitted provided that the following conditions are met:
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% * Redistributions of source code must retain the above copyright
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% notice, this list of conditions and the following disclaimer.
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% * Redistributions in binary form must reproduce the above copyright
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% notice, this list of conditions and the following disclaimer in the
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% documentation and/or other materials provided with the distribution.
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% * Neither the name of the Intel Corporation nor the
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% names of its contributors may be used to endorse or promote products
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% derived from this software without specific prior written permission.
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%
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% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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% POSSIBILITY OF SUCH DAMAGE.
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%
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% Author: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>
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%
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%% Reference: AES17 6.3.2 THD+N ratio vs frequency
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% http://www.aes.org/publications/standards/
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%% Load output file
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[x, nx] = load_test_output(test);
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if nx == 0
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test.g_db = NaN;
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test.fail = 1;
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return
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end
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%% Standard low-pass
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y0 = stdlpf(x, test.fu, test.fs);
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%% Find sync
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[d, nt, nt_use, nt_skip] = find_test_signal(y0, test);
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%% Measure all test frequencies
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ml = zeros(test.nf,test.na);
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mn = zeros(test.nf,test.na);
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n_notch_settle = round(test.fs*test.nst);
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nn = 1;
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for m=1:test.na
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for n=1:test.nf
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fprintf('Measuring %.0f Hz ...\n', test.f(n));
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i1 = d+(nn-1)*nt+nt_skip;
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i2 = i1+nt_use-1;
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nn = nn+1;
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y0n = stdnotch(y0(i1:i2), test.f(n), test.fs);
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ml(n,m) = level_dbfs(y0(i1:i2));
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mn(n,m) = level_dbfs(y0n(n_notch_settle:end));
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end
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end
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test.thdnf = mn - ml;
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test.thdnf_high = test.thdnf(:,1);
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test.thdnf_low = test.thdnf(:,2);
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if max(max(test.thdnf)) > test.thdnf_max
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test.fail = 1;
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else
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test.fail = 0;
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end
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test.fh = figure('visible', test.visible);
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semilogx(test.f, test.thdnf(:,1), 'b', test.f, test.thdnf(:,2), 'g--');
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grid on;
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xlabel('Frequency (Hz)');
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ylabel('THD+N (dB)');
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legend('-1 dBFS','-20 dBFS');
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end
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