1/* 2 * Copyright (c) 1998 - 2009 Conifer Software 3 * 4 * This file is part of FFmpeg. 5 * 6 * FFmpeg is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * FFmpeg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with FFmpeg; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21/** 22 * @file 23 * ReplayGain scanner 24 */ 25 26#include "libavutil/avassert.h" 27#include "libavutil/channel_layout.h" 28#include "audio.h" 29#include "avfilter.h" 30#include "internal.h" 31 32#define HISTOGRAM_SLOTS 12000 33#define BUTTER_ORDER 2 34#define YULE_ORDER 10 35 36typedef struct ReplayGainFreqInfo { 37 int sample_rate; 38 double BYule[YULE_ORDER + 1]; 39 double AYule[YULE_ORDER + 1]; 40 double BButter[BUTTER_ORDER + 1]; 41 double AButter[BUTTER_ORDER + 1]; 42} ReplayGainFreqInfo; 43 44static const ReplayGainFreqInfo freqinfos[] = 45{ 46 { 47 192000, 48 { 0.01184742123123, -0.04631092400086, 0.06584226961238, 49 -0.02165588522478, -0.05656260778952, 0.08607493592760, 50 -0.03375544339786, -0.04216579932754, 0.06416711490648, 51 -0.03444708260844, 0.00697275872241 }, 52 { 1.00000000000000, -5.24727318348167, 10.60821585192244, 53 -8.74127665810413, -1.33906071371683, 8.07972882096606, 54 -5.46179918950847, 0.54318070652536, 0.87450969224280, 55 -0.34656083539754, 0.03034796843589 }, 56 { 0.99653501465135, -1.99307002930271, 0.99653501465135 }, 57 { 1.00000000000000, -1.99305802314321, 0.99308203546221 }, 58 }, 59 { 60 176400, 61 { 0.00268568524529, -0.00852379426080, 0.00852704191347, 62 0.00146116310295, -0.00950855828762, 0.00625449515499, 63 0.00116183868722, -0.00362461417136, 0.00203961000134, 64 -0.00050664587933, 0.00004327455427 }, 65 { 1.00000000000000, -5.57512782763045, 12.44291056065794, 66 -12.87462799681221, 3.08554846961576, 6.62493459880692, 67 -7.07662766313248, 2.51175542736441, 0.06731510802735, 68 -0.24567753819213, 0.03961404162376 }, 69 { 0.99622916581118, -1.99245833162236, 0.99622916581118 }, 70 { 1.00000000000000, -1.99244411238133, 0.99247255086339 }, 71 }, 72 { 73 144000, 74 { 0.00639682359450, -0.02556437970955, 0.04230854400938, 75 -0.03722462201267, 0.01718514827295, 0.00610592243009, 76 -0.03065965747365, 0.04345745003539, -0.03298592681309, 77 0.01320937236809, -0.00220304127757 }, 78 { 1.00000000000000, -6.14814623523425, 15.80002457141566, 79 -20.78487587686937, 11.98848552310315, 3.36462015062606, 80 -10.22419868359470, 6.65599702146473, -1.67141861110485, 81 -0.05417956536718, 0.07374767867406 }, 82 { 0.99538268958706, -1.99076537917413, 0.99538268958706 }, 83 { 1.00000000000000, -1.99074405950505, 0.99078669884321 }, 84 }, 85 { 86 128000, 87 { 0.00553120584305, -0.02112620545016, 0.03549076243117, 88 -0.03362498312306, 0.01425867248183, 0.01344686928787, 89 -0.03392770787836, 0.03464136459530, -0.02039116051549, 90 0.00667420794705, -0.00093763762995 }, 91 { 1.00000000000000, -6.14581710839925, 16.04785903675838, 92 -22.19089131407749, 15.24756471580286, -0.52001440400238, 93 -8.00488641699940, 6.60916094768855, -2.37856022810923, 94 0.33106947986101, 0.00459820832036 }, 95 { 0.99480702681278, -1.98961405362557, 0.99480702681278 }, 96 { 1.00000000000000, -1.98958708647324, 0.98964102077790 }, 97 }, 98 { 99 112000, 100 { 0.00528778718259, -0.01893240907245, 0.03185982561867, 101 -0.02926260297838, 0.00715743034072, 0.01985743355827, 102 -0.03222614850941, 0.02565681978192, -0.01210662313473, 103 0.00325436284541, -0.00044173593001 }, 104 { 1.00000000000000, -6.24932108456288, 17.42344320538476, 105 -27.86819709054896, 26.79087344681326,-13.43711081485123, 106 -0.66023612948173, 6.03658091814935, -4.24926577030310, 107 1.40829268709186, -0.19480852628112 }, 108 { 0.99406737810867, -1.98813475621734, 0.99406737810867 }, 109 { 1.00000000000000, -1.98809955990514, 0.98816995252954 }, 110 }, 111 { 112 96000, 113 { 0.00588138296683, -0.01613559730421, 0.02184798954216, 114 -0.01742490405317, 0.00464635643780, 0.01117772513205, 115 -0.02123865824368, 0.01959354413350, -0.01079720643523, 116 0.00352183686289, -0.00063124341421 }, 117 { 1.00000000000000, -5.97808823642008, 16.21362507964068, 118 -25.72923730652599, 25.40470663139513,-14.66166287771134, 119 2.81597484359752, 2.51447125969733, -2.23575306985286, 120 0.75788151036791, -0.10078025199029 }, 121 { 0.99308203517541, -1.98616407035082, 0.99308203517541 }, 122 { 1.00000000000000, -1.98611621154089, 0.98621192916075 }, 123 }, 124 { 125 88200, 126 { 0.02667482047416, -0.11377479336097, 0.23063167910965, 127 -0.30726477945593, 0.33188520686529, -0.33862680249063, 128 0.31807161531340, -0.23730796929880, 0.12273894790371, 129 -0.03840017967282, 0.00549673387936 }, 130 { 1.00000000000000, -6.31836451657302, 18.31351310801799, 131 -31.88210014815921, 36.53792146976740,-28.23393036467559, 132 14.24725258227189, -4.04670980012854, 0.18865757280515, 133 0.25420333563908, -0.06012333531065 }, 134 { 0.99247255046129, -1.98494510092259, 0.99247255046129 }, 135 { 1.00000000000000, -1.98488843762335, 0.98500176422183 }, 136 }, 137 { 138 64000, 139 { 0.02613056568174, -0.08128786488109, 0.14937282347325, 140 -0.21695711675126, 0.25010286673402, -0.23162283619278, 141 0.17424041833052, -0.10299599216680, 0.04258696481981, 142 -0.00977952936493, 0.00105325558889 }, 143 { 1.00000000000000, -5.73625477092119, 16.15249794355035, 144 -29.68654912464508, 39.55706155674083,-39.82524556246253, 145 30.50605345013009,-17.43051772821245, 7.05154573908017, 146 -1.80783839720514, 0.22127840210813 }, 147 { 0.98964101933472, -1.97928203866944, 0.98964101933472 }, 148 { 1.00000000000000, -1.97917472731009, 0.97938935002880 }, 149 }, 150 { 151 56000, 152 { 0.03144914734085, -0.06151729206963, 0.08066788708145, 153 -0.09737939921516, 0.08943210803999, -0.06989984672010, 154 0.04926972841044, -0.03161257848451, 0.01456837493506, 155 -0.00316015108496, 0.00132807215875 }, 156 { 1.00000000000000, -4.87377313090032, 12.03922160140209, 157 -20.10151118381395, 25.10388534415171,-24.29065560815903, 158 18.27158469090663,-10.45249552560593, 4.30319491872003, 159 -1.13716992070185, 0.14510733527035 }, 160 { 0.98816995007392, -1.97633990014784, 0.98816995007392 }, 161 { 1.00000000000000, -1.97619994516973, 0.97647985512594 }, 162 }, 163 { 164 48000, 165 { 0.03857599435200, -0.02160367184185, -0.00123395316851, 166 -0.00009291677959, -0.01655260341619, 0.02161526843274, 167 -0.02074045215285, 0.00594298065125, 0.00306428023191, 168 0.00012025322027, 0.00288463683916 }, 169 { 1.00000000000000, -3.84664617118067, 7.81501653005538, 170 -11.34170355132042, 13.05504219327545,-12.28759895145294, 171 9.48293806319790, -5.87257861775999, 2.75465861874613, 172 -0.86984376593551, 0.13919314567432 }, 173 { 0.98621192462708, -1.97242384925416, 0.98621192462708 }, 174 { 1.00000000000000, -1.97223372919527, 0.97261396931306 }, 175 }, 176 { 177 44100, 178 { 0.05418656406430, -0.02911007808948, -0.00848709379851, 179 -0.00851165645469, -0.00834990904936, 0.02245293253339, 180 -0.02596338512915, 0.01624864962975, -0.00240879051584, 181 0.00674613682247, -0.00187763777362 }, 182 { 1.00000000000000, -3.47845948550071, 6.36317777566148, 183 -8.54751527471874, 9.47693607801280, -8.81498681370155, 184 6.85401540936998, -4.39470996079559, 2.19611684890774, 185 -0.75104302451432, 0.13149317958808 }, 186 { 0.98500175787242, -1.97000351574484, 0.98500175787242 }, 187 { 1.00000000000000, -1.96977855582618, 0.97022847566350 }, 188 }, 189 { 190 37800, 191 { 0.08717879977844, -0.01000374016172, -0.06265852122368, 192 -0.01119328800950, -0.00114279372960, 0.02081333954769, 193 -0.01603261863207, 0.01936763028546, 0.00760044736442, 194 -0.00303979112271, -0.00075088605788 }, 195 { 1.00000000000000, -2.62816311472146, 3.53734535817992, 196 -3.81003448678921, 3.91291636730132, -3.53518605896288, 197 2.71356866157873, -1.86723311846592, 1.12075382367659, 198 -0.48574086886890, 0.11330544663849 }, 199 { 0.98252400815195, -1.96504801630391, 0.98252400815195 }, 200 { 1.00000000000000, -1.96474258269041, 0.96535344991740 }, 201 }, 202 { 203 32000, 204 { 0.15457299681924, -0.09331049056315, -0.06247880153653, 205 0.02163541888798, -0.05588393329856, 0.04781476674921, 206 0.00222312597743, 0.03174092540049, -0.01390589421898, 207 0.00651420667831, -0.00881362733839 }, 208 { 1.00000000000000, -2.37898834973084, 2.84868151156327, 209 -2.64577170229825, 2.23697657451713, -1.67148153367602, 210 1.00595954808547, -0.45953458054983, 0.16378164858596, 211 -0.05032077717131, 0.02347897407020 }, 212 { 0.97938932735214, -1.95877865470428, 0.97938932735214 }, 213 { 1.00000000000000, -1.95835380975398, 0.95920349965459 }, 214 }, 215 { 216 24000, 217 { 0.30296907319327, -0.22613988682123, -0.08587323730772, 218 0.03282930172664, -0.00915702933434, -0.02364141202522, 219 -0.00584456039913, 0.06276101321749, -0.00000828086748, 220 0.00205861885564, -0.02950134983287 }, 221 { 1.00000000000000, -1.61273165137247, 1.07977492259970, 222 -0.25656257754070, -0.16276719120440, -0.22638893773906, 223 0.39120800788284, -0.22138138954925, 0.04500235387352, 224 0.02005851806501, 0.00302439095741 }, 225 { 0.97531843204928, -1.95063686409857, 0.97531843204928 }, 226 { 1.00000000000000, -1.95002759149878, 0.95124613669835 }, 227 }, 228 { 229 22050, 230 { 0.33642304856132, -0.25572241425570, -0.11828570177555, 231 0.11921148675203, -0.07834489609479, -0.00469977914380, 232 -0.00589500224440, 0.05724228140351, 0.00832043980773, 233 -0.01635381384540, -0.01760176568150 }, 234 { 1.00000000000000, -1.49858979367799, 0.87350271418188, 235 0.12205022308084, -0.80774944671438, 0.47854794562326, 236 -0.12453458140019, -0.04067510197014, 0.08333755284107, 237 -0.04237348025746, 0.02977207319925 }, 238 { 0.97316523498161, -1.94633046996323, 0.97316523498161 }, 239 { 1.00000000000000, -1.94561023566527, 0.94705070426118 }, 240 }, 241 { 242 18900, 243 { 0.38524531015142, -0.27682212062067, -0.09980181488805, 244 0.09951486755646, -0.08934020156622, -0.00322369330199, 245 -0.00110329090689, 0.03784509844682, 0.01683906213303, 246 -0.01147039862572, -0.01941767987192 }, 247 { 1.00000000000000, -1.29708918404534, 0.90399339674203, 248 -0.29613799017877, -0.42326645916207, 0.37934887402200, 249 -0.37919795944938, 0.23410283284785, -0.03892971758879, 250 0.00403009552351, 0.03640166626278 }, 251 { 0.96535326815829, -1.93070653631658, 0.96535326815829 }, 252 { 1.00000000000000, -1.92950577983524, 0.93190729279793 }, 253 }, 254 { 255 16000, 256 { 0.44915256608450, -0.14351757464547, -0.22784394429749, 257 -0.01419140100551, 0.04078262797139, -0.12398163381748, 258 0.04097565135648, 0.10478503600251, -0.01863887810927, 259 -0.03193428438915, 0.00541907748707 }, 260 { 1.00000000000000, -0.62820619233671, 0.29661783706366, 261 -0.37256372942400, 0.00213767857124, -0.42029820170918, 262 0.22199650564824, 0.00613424350682, 0.06747620744683, 263 0.05784820375801, 0.03222754072173 }, 264 { 0.96454515552826, -1.92909031105652, 0.96454515552826 }, 265 { 1.00000000000000, -1.92783286977036, 0.93034775234268 }, 266 }, 267 { 268 12000, 269 { 0.56619470757641, -0.75464456939302, 0.16242137742230, 270 0.16744243493672, -0.18901604199609, 0.30931782841830, 271 -0.27562961986224, 0.00647310677246, 0.08647503780351, 272 -0.03788984554840, -0.00588215443421 }, 273 { 1.00000000000000, -1.04800335126349, 0.29156311971249, 274 -0.26806001042947, 0.00819999645858, 0.45054734505008, 275 -0.33032403314006, 0.06739368333110, -0.04784254229033, 276 0.01639907836189, 0.01807364323573 }, 277 { 0.96009142950541, -1.92018285901082, 0.96009142950541 }, 278 { 1.00000000000000, -1.91858953033784, 0.92177618768381 }, 279 }, 280 { 281 11025, 282 { 0.58100494960553, -0.53174909058578, -0.14289799034253, 283 0.17520704835522, 0.02377945217615, 0.15558449135573, 284 -0.25344790059353, 0.01628462406333, 0.06920467763959, 285 -0.03721611395801, -0.00749618797172 }, 286 { 1.00000000000000, -0.51035327095184, -0.31863563325245, 287 -0.20256413484477, 0.14728154134330, 0.38952639978999, 288 -0.23313271880868, -0.05246019024463, -0.02505961724053, 289 0.02442357316099, 0.01818801111503 }, 290 { 0.95856916599601, -1.91713833199203, 0.95856916599601 }, 291 { 1.00000000000000, -1.91542108074780, 0.91885558323625 }, 292 }, 293 { 294 8000, 295 { 0.53648789255105, -0.42163034350696, -0.00275953611929, 296 0.04267842219415, -0.10214864179676, 0.14590772289388, 297 -0.02459864859345, -0.11202315195388, -0.04060034127000, 298 0.04788665548180, -0.02217936801134 }, 299 { 1.00000000000000, -0.25049871956020, -0.43193942311114, 300 -0.03424681017675, -0.04678328784242, 0.26408300200955, 301 0.15113130533216, -0.17556493366449, -0.18823009262115, 302 0.05477720428674, 0.04704409688120 }, 303 { 0.94597685600279, -1.89195371200558, 0.94597685600279 }, 304 { 1.00000000000000, -1.88903307939452, 0.89487434461664 }, 305 }, 306}; 307 308typedef struct ReplayGainContext { 309 uint32_t histogram[HISTOGRAM_SLOTS]; 310 float peak; 311 int yule_hist_i, butter_hist_i; 312 const double *yule_coeff_a; 313 const double *yule_coeff_b; 314 const double *butter_coeff_a; 315 const double *butter_coeff_b; 316 float yule_hist_a[256]; 317 float yule_hist_b[256]; 318 float butter_hist_a[256]; 319 float butter_hist_b[256]; 320} ReplayGainContext; 321 322static int query_formats(AVFilterContext *ctx) 323{ 324 AVFilterFormats *formats = NULL; 325 AVFilterChannelLayouts *layout = NULL; 326 int i; 327 328 ff_add_format(&formats, AV_SAMPLE_FMT_FLT); 329 ff_set_common_formats(ctx, formats); 330 ff_add_channel_layout(&layout, AV_CH_LAYOUT_STEREO); 331 ff_set_common_channel_layouts(ctx, layout); 332 333 formats = NULL; 334 for (i = 0; i < FF_ARRAY_ELEMS(freqinfos); i++) 335 ff_add_format(&formats, freqinfos[i].sample_rate); 336 ff_set_common_samplerates(ctx, formats); 337 338 return 0; 339} 340 341static int config_input(AVFilterLink *inlink) 342{ 343 AVFilterContext *ctx = inlink->dst; 344 ReplayGainContext *s = ctx->priv; 345 int i; 346 347 for (i = 0; i < FF_ARRAY_ELEMS(freqinfos); i++) { 348 if (freqinfos[i].sample_rate == inlink->sample_rate) 349 break; 350 } 351 av_assert0(i < FF_ARRAY_ELEMS(freqinfos)); 352 353 s->yule_coeff_a = freqinfos[i].AYule; 354 s->yule_coeff_b = freqinfos[i].BYule; 355 s->butter_coeff_a = freqinfos[i].AButter; 356 s->butter_coeff_b = freqinfos[i].BButter; 357 358 s->yule_hist_i = 20; 359 s->butter_hist_i = 4; 360 inlink->partial_buf_size = 361 inlink->min_samples = 362 inlink->max_samples = inlink->sample_rate / 20; 363 364 return 0; 365} 366 367/* 368 * Update largest absolute sample value. 369 */ 370static void calc_stereo_peak(const float *samples, int nb_samples, 371 float *peak_p) 372{ 373 float peak = 0.0; 374 375 while (nb_samples--) { 376 if (samples[0] > peak) 377 peak = samples[0]; 378 else if (-samples[0] > peak) 379 peak = -samples[0]; 380 381 if (samples[1] > peak) 382 peak = samples[1]; 383 else if (-samples[1] > peak) 384 peak = -samples[1]; 385 386 samples += 2; 387 } 388 389 *peak_p = FFMAX(peak, *peak_p); 390} 391 392/* 393 * Calculate stereo RMS level. Minimum value is about -100 dB for 394 * digital silence. The 90 dB offset is to compensate for the 395 * normalized float range and 3 dB is for stereo samples. 396 */ 397static double calc_stereo_rms(const float *samples, int nb_samples) 398{ 399 int count = nb_samples; 400 double sum = 1e-16; 401 402 while (count--) { 403 sum += samples[0] * samples[0] + samples[1] * samples[1]; 404 samples += 2; 405 } 406 407 return 10 * log10 (sum / nb_samples) + 90.0 - 3.0; 408} 409 410/* 411 * Optimized implementation of 2nd-order IIR stereo filter. 412 */ 413static void butter_filter_stereo_samples(ReplayGainContext *s, 414 float *samples, int nb_samples) 415{ 416 const double *coeff_a = s->butter_coeff_a; 417 const double *coeff_b = s->butter_coeff_b; 418 float *hist_a = s->butter_hist_a; 419 float *hist_b = s->butter_hist_b; 420 double left, right; 421 int i, j; 422 423 i = s->butter_hist_i; 424 425 // If filter history is very small magnitude, clear it completely 426 // to prevent denormals from rattling around in there forever 427 // (slowing us down). 428 429 for (j = -4; j < 0; ++j) 430 if (fabs(hist_a[i + j]) > 1e-10 || fabs(hist_b[i + j]) > 1e-10) 431 break; 432 433 if (!j) { 434 memset(s->butter_hist_a, 0, sizeof(s->butter_hist_a)); 435 memset(s->butter_hist_b, 0, sizeof(s->butter_hist_b)); 436 } 437 438 while (nb_samples--) { 439 left = (hist_b[i ] = samples[0]) * coeff_b[0]; 440 right = (hist_b[i + 1] = samples[1]) * coeff_b[0]; 441 left += hist_b[i - 2] * coeff_b[1] - hist_a[i - 2] * coeff_a[1]; 442 right += hist_b[i - 1] * coeff_b[1] - hist_a[i - 1] * coeff_a[1]; 443 left += hist_b[i - 4] * coeff_b[2] - hist_a[i - 4] * coeff_a[2]; 444 right += hist_b[i - 3] * coeff_b[2] - hist_a[i - 3] * coeff_a[2]; 445 samples[0] = hist_a[i ] = (float) left; 446 samples[1] = hist_a[i + 1] = (float) right; 447 samples += 2; 448 449 if ((i += 2) == 256) { 450 memcpy(hist_a, hist_a + 252, sizeof(*hist_a) * 4); 451 memcpy(hist_b, hist_b + 252, sizeof(*hist_b) * 4); 452 i = 4; 453 } 454 } 455 456 s->butter_hist_i = i; 457} 458 459/* 460 * Optimized implementation of 10th-order IIR stereo filter. 461 */ 462static void yule_filter_stereo_samples(ReplayGainContext *s, const float *src, 463 float *dst, int nb_samples) 464{ 465 const double *coeff_a = s->yule_coeff_a; 466 const double *coeff_b = s->yule_coeff_b; 467 float *hist_a = s->yule_hist_a; 468 float *hist_b = s->yule_hist_b; 469 double left, right; 470 int i, j; 471 472 i = s->yule_hist_i; 473 474 // If filter history is very small magnitude, clear it completely to 475 // prevent denormals from rattling around in there forever 476 // (slowing us down). 477 478 for (j = -20; j < 0; ++j) 479 if (fabs(hist_a[i + j]) > 1e-10 || fabs(hist_b[i + j]) > 1e-10) 480 break; 481 482 if (!j) { 483 memset(s->yule_hist_a, 0, sizeof(s->yule_hist_a)); 484 memset(s->yule_hist_b, 0, sizeof(s->yule_hist_b)); 485 } 486 487 while (nb_samples--) { 488 left = (hist_b[i] = src[0]) * coeff_b[0]; 489 right = (hist_b[i + 1] = src[1]) * coeff_b[0]; 490 left += hist_b[i - 2] * coeff_b[ 1] - hist_a[i - 2] * coeff_a[1 ]; 491 right += hist_b[i - 1] * coeff_b[ 1] - hist_a[i - 1] * coeff_a[1 ]; 492 left += hist_b[i - 4] * coeff_b[ 2] - hist_a[i - 4] * coeff_a[2 ]; 493 right += hist_b[i - 3] * coeff_b[ 2] - hist_a[i - 3] * coeff_a[2 ]; 494 left += hist_b[i - 6] * coeff_b[ 3] - hist_a[i - 6] * coeff_a[3 ]; 495 right += hist_b[i - 5] * coeff_b[ 3] - hist_a[i - 5] * coeff_a[3 ]; 496 left += hist_b[i - 8] * coeff_b[ 4] - hist_a[i - 8] * coeff_a[4 ]; 497 right += hist_b[i - 7] * coeff_b[ 4] - hist_a[i - 7] * coeff_a[4 ]; 498 left += hist_b[i - 10] * coeff_b[ 5] - hist_a[i - 10] * coeff_a[5 ]; 499 right += hist_b[i - 9] * coeff_b[ 5] - hist_a[i - 9] * coeff_a[5 ]; 500 left += hist_b[i - 12] * coeff_b[ 6] - hist_a[i - 12] * coeff_a[6 ]; 501 right += hist_b[i - 11] * coeff_b[ 6] - hist_a[i - 11] * coeff_a[6 ]; 502 left += hist_b[i - 14] * coeff_b[ 7] - hist_a[i - 14] * coeff_a[7 ]; 503 right += hist_b[i - 13] * coeff_b[ 7] - hist_a[i - 13] * coeff_a[7 ]; 504 left += hist_b[i - 16] * coeff_b[ 8] - hist_a[i - 16] * coeff_a[8 ]; 505 right += hist_b[i - 15] * coeff_b[ 8] - hist_a[i - 15] * coeff_a[8 ]; 506 left += hist_b[i - 18] * coeff_b[ 9] - hist_a[i - 18] * coeff_a[9 ]; 507 right += hist_b[i - 17] * coeff_b[ 9] - hist_a[i - 17] * coeff_a[9 ]; 508 left += hist_b[i - 20] * coeff_b[10] - hist_a[i - 20] * coeff_a[10]; 509 right += hist_b[i - 19] * coeff_b[10] - hist_a[i - 19] * coeff_a[10]; 510 dst[0] = hist_a[i ] = (float)left; 511 dst[1] = hist_a[i + 1] = (float)right; 512 src += 2; 513 dst += 2; 514 515 if ((i += 2) == 256) { 516 memcpy(hist_a, hist_a + 236, sizeof(*hist_a) * 20); 517 memcpy(hist_b, hist_b + 236, sizeof(*hist_b) * 20); 518 i = 20; 519 } 520 } 521 522 s->yule_hist_i = i; 523} 524 525/* 526 * Calculate the ReplayGain value from the specified loudness histogram; 527 * clip to -24 / +64 dB. 528 */ 529static float calc_replaygain(uint32_t *histogram) 530{ 531 uint32_t loud_count = 0, total_windows = 0; 532 float gain; 533 int i; 534 535 for (i = 0; i < HISTOGRAM_SLOTS; i++) 536 total_windows += histogram [i]; 537 538 while (i--) 539 if ((loud_count += histogram [i]) * 20 >= total_windows) 540 break; 541 542 gain = (float)(64.54 - i / 100.0); 543 544 return av_clipf(gain, -24.0, 64.0); 545} 546 547static int filter_frame(AVFilterLink *inlink, AVFrame *in) 548{ 549 AVFilterContext *ctx = inlink->dst; 550 AVFilterLink *outlink = ctx->outputs[0]; 551 ReplayGainContext *s = ctx->priv; 552 uint32_t level; 553 AVFrame *out; 554 555 out = ff_get_audio_buffer(inlink, in->nb_samples); 556 if (!out) { 557 av_frame_free(&in); 558 return AVERROR(ENOMEM); 559 } 560 561 calc_stereo_peak((float *)in->data[0], 562 in->nb_samples, &s->peak); 563 yule_filter_stereo_samples(s, (const float *)in->data[0], 564 (float *)out->data[0], 565 out->nb_samples); 566 butter_filter_stereo_samples(s, (float *)out->data[0], 567 out->nb_samples); 568 level = (uint32_t)floor(100 * calc_stereo_rms((float *)out->data[0], 569 out->nb_samples)); 570 level = av_clip(level, 0, HISTOGRAM_SLOTS - 1); 571 572 s->histogram[level]++; 573 574 av_frame_free(&out); 575 return ff_filter_frame(outlink, in); 576} 577 578static av_cold void uninit(AVFilterContext *ctx) 579{ 580 ReplayGainContext *s = ctx->priv; 581 float gain = calc_replaygain(s->histogram); 582 583 av_log(ctx, AV_LOG_INFO, "track_gain = %+.2f dB\n", gain); 584 av_log(ctx, AV_LOG_INFO, "track_peak = %.6f\n", s->peak); 585} 586 587static const AVFilterPad replaygain_inputs[] = { 588 { 589 .name = "default", 590 .type = AVMEDIA_TYPE_AUDIO, 591 .filter_frame = filter_frame, 592 .config_props = config_input, 593 }, 594 { NULL } 595}; 596 597static const AVFilterPad replaygain_outputs[] = { 598 { 599 .name = "default", 600 .type = AVMEDIA_TYPE_AUDIO, 601 }, 602 { NULL } 603}; 604 605AVFilter ff_af_replaygain = { 606 .name = "replaygain", 607 .description = NULL_IF_CONFIG_SMALL("ReplayGain scanner."), 608 .query_formats = query_formats, 609 .uninit = uninit, 610 .priv_size = sizeof(ReplayGainContext), 611 .inputs = replaygain_inputs, 612 .outputs = replaygain_outputs, 613}; 614