%% Design effect EQs and bundle them to parameter block %% % Copyright (c) 2016, Intel Corporation % All rights reserved. % % Redistribution and use in source and binary forms, with or without % modification, are permitted provided that the following conditions are met: % * Redistributions of source code must retain the above copyright % notice, this list of conditions and the following disclaimer. % * Redistributions in binary form must reproduce the above copyright % notice, this list of conditions and the following disclaimer in the % documentation and/or other materials provided with the distribution. % * Neither the name of the Intel Corporation nor the % names of its contributors may be used to endorse or promote products % derived from this software without specific prior written permission. % % THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" % AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE % IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE % ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE % LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR % CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF % SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS % INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN % CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) % ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE % POSSIBILITY OF SUCH DAMAGE. % % Author: Seppo Ingalsuo % function example_iir_eq() blob_fn = 'example_iir_eq.blob'; alsa_fn = 'example_iir_eq.txt'; endian = 'little'; fs = 48e3; %% Design IIR loudness equalizer eq_loud = loudness_iir_eq(fs); %% Define a passthru IIR EQ equalizer b_pass = [1 0 0]; a_pass = [1 0 0]; %% Quantize and pack filter coefficients plus shifts etc. bq_pass = eq_iir_blob_quant(b_pass, a_pass); bq_loud = eq_iir_blob_quant(eq_loud.b_p, eq_loud.a_p); %% Build blob platform_max_channels = 4; % Setup max 4 channels EQ assign_response = [1 1 1 1]; % Switch to response #1 num_responses = 2; % Two responses: pass, loud bm = eq_iir_blob_merge(platform_max_channels, ... num_responses, ... assign_response, ... [bq_pass bq_loud]); %% Pack and write file bp = eq_iir_blob_pack(bm); eq_blob_write(blob_fn, bp); eq_alsactl_write(alsa_fn, bp); end %% function eq = loudness_iir_eq(fs) %% Derived from Fletcher-Munson curves for 80 and 60 phon f = [ 20,21,22,24,25,27,28,30,32,34,36,38,40,43,45,48,51,54,57,60,64, ... 68,72,76,81,85,90,96,102,108,114,121,128,136,144,153,162,171, ... 182,192,204,216,229,243,257,273,289,306,324,344,364,386,409, ... 434,460,487,516,547,580,614,651,690,731,775,821,870,922,977, ... 1036,1098,1163,1233,1307,1385,1467,1555,1648,1747,1851,1962, ... 2079,2203,2335,2474,2622,2779,2945,3121,3308,3505,3715,3937, ... 4172,4421,4686,4966,5263,5577,5910,6264,6638,7035,7455,7901, ... 8373,8873,9404,9966,10561,11193,11861,12570,13322,14118,14962, ... 15856,16803,17808,18872,20000]; m = [ 0.00,-0.13,-0.27,-0.39,-0.52,-0.64,-0.77,-0.89,-1.02,-1.16, ... -1.31,-1.46,-1.61,-1.76,-1.91,-2.07,-2.24,-2.43,-2.64,-2.85, ... -3.04,-3.21,-3.35,-3.48,-3.62,-3.78,-3.96,-4.16,-4.35,-4.54, ... -4.72,-4.90,-5.08,-5.26,-5.45,-5.64,-5.83,-6.02,-6.19,-6.37, ... -6.57,-6.77,-6.98,-7.19,-7.40,-7.58,-7.76,-7.92,-8.08,-8.25, ... -8.43,-8.60,-8.76,-8.92,-9.08,-9.23,-9.38,-9.54,-9.69,-9.84, ... -9.97,-10.09,-10.18,-10.26,-10.33,-10.38,-10.43,-10.48,-10.54, ... -10.61,-10.70,-10.78,-10.85,-10.91,-10.95,-10.98,-11.02, ... -11.05,-11.07,-11.10,-11.11,-11.11,-11.10,-11.10,-11.11, ... -11.14,-11.17,-11.20,-11.21,-11.22,-11.21,-11.20,-11.20, ... -11.21,-11.21,-11.20,-11.17,-11.11,-11.02,-10.91,-10.78, ... -10.63,-10.46,-10.25,-10.00,-9.72,-9.39,-9.02,-8.62,-8.19, ... -7.73,-7.25,-6.75,-6.25,-5.75,-5.28,-4.87,-4.54,-4.33,-4.30]; %% Get defaults for equalizer design eq = eq_defaults(); eq.fs = fs; eq.target_f = f; eq.target_m_db = m; eq.enable_iir = 1; eq.norm_type = 'loudness'; eq.norm_offs_db = 0; %% Manually setup low-shelf and high shelf parametric equalizers % % Parametric EQs are PEQ_HP1, PEQ_HP2, PEQ_LP1, PEQ_LP2, PEQ_LS1, % PEQ_LS2, PEQ_HS1, PEQ_HS2 = 8, PEQ_PN2, PEQ_LP4, and PEQ_HP4. % % Parametric EQs take as second argument the cutoff frequency in Hz % and as second argument a dB value (or NaN when not applicable) . The % Third argument is a Q-value (or NaN when not applicable). eq.peq = [ ... eq.PEQ_LS1 40 +2 NaN ; ... eq.PEQ_LS1 80 +3 NaN ; ... eq.PEQ_LS1 200 +3 NaN ; ... eq.PEQ_LS1 400 +3 NaN ; ... eq.PEQ_HS2 13000 +7 NaN ; ... ]; %% Design EQ eq = eq_compute(eq); %% Plot eq_plot(eq); end