/* Effect: dither/noise-shape   Copyright (c) 2008-9 robs@users.sourceforge.net
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at
 * your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser
 * General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

typedef struct {
  int  rate;
  enum {fir, iir} type;
  size_t len;
  int gain_cB; /* Chosen so clips are few if any, but not guaranteed none. */
  double const * coefs;
  enum SwrDitherType name;
} filter_t;

static double const lip44[] = {2.033, -2.165, 1.959, -1.590, .6149};
static double const fwe44[] = {
  2.412, -3.370, 3.937, -4.174, 3.353, -2.205, 1.281, -.569, .0847};
static double const mew44[] = {
  1.662, -1.263, .4827, -.2913, .1268, -.1124, .03252, -.01265, -.03524};
static double const iew44[] = {
  2.847, -4.685, 6.214, -7.184, 6.639, -5.032, 3.263, -1.632, .4191};
static double const ges44[] = {
  2.2061, -.4706, -.2534, -.6214, 1.0587, .0676, -.6054, -.2738};
static double const ges48[] = {
  2.2374, -.7339, -.1251, -.6033, .903, .0116, -.5853, -.2571};

static double const shi48[] = {
  2.8720729351043701172,  -5.0413231849670410156,   6.2442994117736816406,
  -5.8483986854553222656, 3.7067542076110839844,  -1.0495119094848632812,
  -1.1830236911773681641,   2.1126792430877685547, -1.9094531536102294922,
  0.99913084506988525391, -0.17090806365013122559, -0.32615602016448974609,
  0.39127644896507263184, -0.26876461505889892578,  0.097676105797290802002,
  -0.023473845794796943665,
};
static double const shi44[] = {
  2.6773197650909423828,  -4.8308925628662109375,   6.570110321044921875,
  -7.4572014808654785156, 6.7263274192810058594,  -4.8481650352478027344,
  2.0412089824676513672,   0.7006359100341796875, -2.9537565708160400391,
  4.0800385475158691406,  -4.1845216751098632812,   3.3311812877655029297,
  -2.1179926395416259766,   0.879302978515625,      -0.031759146600961685181,
  -0.42382788658142089844, 0.47882103919982910156, -0.35490813851356506348,
  0.17496839165687561035, -0.060908168554306030273,
};
static double const shi38[] = {
  1.6335992813110351562,  -2.2615492343902587891,   2.4077029228210449219,
  -2.6341717243194580078, 2.1440362930297851562,  -1.8153258562088012695,
  1.0816224813461303711,  -0.70302653312683105469, 0.15991993248462677002,
  0.041549518704414367676, -0.29416576027870178223,  0.2518316805362701416,
  -0.27766478061676025391,  0.15785403549671173096, -0.10165894031524658203,
  0.016833892092108726501,
};
static double const shi32[] =
{ /* dmaker 32000: bestmax=4.99659 (inverted) */
0.82118552923202515,
-1.0063692331314087,
0.62341964244842529,
-1.0447187423706055,
0.64532512426376343,
-0.87615132331848145,
0.52219754457473755,
-0.67434263229370117,
0.44954317808151245,
-0.52557498216629028,
0.34567299485206604,
-0.39618203043937683,
0.26791760325431824,
-0.28936097025871277,
0.1883765310049057,
-0.19097308814525604,
0.10431359708309174,
-0.10633844882249832,
0.046832218766212463,
-0.039653312414884567,
};
static double const shi22[] =
{ /* dmaker 22050: bestmax=5.77762 (inverted) */
0.056581053882837296,
-0.56956905126571655,
-0.40727734565734863,
-0.33870288729667664,
-0.29810553789138794,
-0.19039161503314972,
-0.16510021686553955,
-0.13468159735202789,
-0.096633769571781158,
-0.081049129366874695,
-0.064953058958053589,
-0.054459091275930405,
-0.043378707021474838,
-0.03660014271736145,
-0.026256965473294258,
-0.018786206841468811,
-0.013387725688517094,
-0.0090983230620622635,
-0.0026585909072309732,
-0.00042083300650119781,
};
static double const shi16[] =
{ /* dmaker 16000: bestmax=5.97128 (inverted) */
-0.37251132726669312,
-0.81423574686050415,
-0.55010956525802612,
-0.47405767440795898,
-0.32624706625938416,
-0.3161766529083252,
-0.2286367267370224,
-0.22916607558727264,
-0.19565616548061371,
-0.18160104751586914,
-0.15423151850700378,
-0.14104481041431427,
-0.11844276636838913,
-0.097583092749118805,
-0.076493598520755768,
-0.068106919527053833,
-0.041881654411554337,
-0.036922425031661987,
-0.019364040344953537,
-0.014994367957115173,
};
static double const shi11[] =
{ /* dmaker 11025: bestmax=5.9406 (inverted) */
-0.9264228343963623,
-0.98695987462997437,
-0.631156325340271,
-0.51966935396194458,
-0.39738872647285461,
-0.35679301619529724,
-0.29720726609230042,
-0.26310476660728455,
-0.21719355881214142,
-0.18561814725399017,
-0.15404847264289856,
-0.12687471508979797,
-0.10339745879173279,
-0.083688631653785706,
-0.05875682458281517,
-0.046893671154975891,
-0.027950936928391457,
-0.020740609616041183,
-0.009366452693939209,
-0.0060260160826146603,
};
static double const shi08[] =
{ /* dmaker 8000: bestmax=5.56234 (inverted) */
-1.202863335609436,
-0.94103097915649414,
-0.67878556251525879,
-0.57650017738342285,
-0.50004476308822632,
-0.44349345564842224,
-0.37833768129348755,
-0.34028723835945129,
-0.29413089156150818,
-0.24994957447052002,
-0.21715600788593292,
-0.18792112171649933,
-0.15268312394618988,
-0.12135542929172516,
-0.099610626697540283,
-0.075273610651493073,
-0.048787496984004974,
-0.042586319148540497,
-0.028991291299462318,
-0.011869125068187714,
};
static double const shl48[] = {
  2.3925774097442626953,  -3.4350297451019287109,   3.1853709220886230469,
  -1.8117271661758422852, -0.20124770700931549072,  1.4759907722473144531,
  -1.7210904359817504883,   0.97746700048446655273, -0.13790138065814971924,
  -0.38185903429985046387,  0.27421241998672485352,  0.066584214568138122559,
  -0.35223302245140075684,  0.37672343850135803223, -0.23964276909828186035,
  0.068674825131893157959,
};
static double const shl44[] = {
  2.0833916664123535156,  -3.0418450832366943359,   3.2047898769378662109,
  -2.7571926116943359375, 1.4978630542755126953,  -0.3427594602108001709,
  -0.71733748912811279297,  1.0737057924270629883, -1.0225815773010253906,
  0.56649994850158691406, -0.20968692004680633545, -0.065378531813621520996,
  0.10322438180446624756, -0.067442022264003753662, -0.00495197344571352005,
  0,
};
static double const shh44[] = {
   3.0259189605712890625, -6.0268716812133789062,   9.195003509521484375,
   -11.824929237365722656, 12.767142295837402344, -11.917946815490722656,
   9.1739168167114257812,  -5.3712320327758789062, 1.1393624544143676758,
   2.4484779834747314453,  -4.9719839096069335938,   6.0392003059387207031,
   -5.9359521865844726562,  4.903278350830078125,   -3.5527443885803222656,
   2.1909697055816650391, -1.1672389507293701172,  0.4903914332389831543,
   -0.16519790887832641602,  0.023217858746647834778,
};

static const filter_t filters[] = {
  {44100, fir,  5, 210, lip44,          SWR_DITHER_NS_LIPSHITZ},
  {46000, fir,  9, 276, fwe44,          SWR_DITHER_NS_F_WEIGHTED},
  {46000, fir,  9, 160, mew44,          SWR_DITHER_NS_MODIFIED_E_WEIGHTED},
  {46000, fir,  9, 321, iew44,          SWR_DITHER_NS_IMPROVED_E_WEIGHTED},
//   {48000, iir,  4, 220, ges48, SWR_DITHER_NS_GESEMANN},
//   {44100, iir,  4, 230, ges44, SWR_DITHER_NS_GESEMANN},
  {48000, fir, 16, 301, shi48,          SWR_DITHER_NS_SHIBATA},
  {44100, fir, 20, 333, shi44,          SWR_DITHER_NS_SHIBATA},
  {37800, fir, 16, 240, shi38,          SWR_DITHER_NS_SHIBATA},
  {32000, fir, 20, 240/*TBD*/, shi32,   SWR_DITHER_NS_SHIBATA},
  {22050, fir, 20, 240/*TBD*/, shi22,   SWR_DITHER_NS_SHIBATA},
  {16000, fir, 20, 240/*TBD*/, shi16,   SWR_DITHER_NS_SHIBATA},
  {11025, fir, 20, 240/*TBD*/, shi11,   SWR_DITHER_NS_SHIBATA},
  { 8000, fir, 20, 240/*TBD*/, shi08,   SWR_DITHER_NS_SHIBATA},
  {48000, fir, 16, 250, shl48,          SWR_DITHER_NS_LOW_SHIBATA},
  {44100, fir, 15, 250, shl44,          SWR_DITHER_NS_LOW_SHIBATA},
  {44100, fir, 20, 383, shh44,          SWR_DITHER_NS_HIGH_SHIBATA},
  {    0, fir,  0,   0,  NULL,          SWR_DITHER_NONE},
};
