| 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 | |
| 36 | typedef 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 | |
| 44 | static 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 | |
| 308 | typedef 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 | |
| 322 | static 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 | |
| 341 | static 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 | */ |
| 370 | static 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 | */ |
| 397 | static 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 | */ |
| 413 | static 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 | */ |
| 462 | static 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 | */ |
| 529 | static 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 | |
| 547 | static 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 | |
| 578 | static 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 | |
| 587 | static 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 | |
| 597 | static const AVFilterPad replaygain_outputs[] = { |
| 598 | { |
| 599 | .name = "default", |
| 600 | .type = AVMEDIA_TYPE_AUDIO, |
| 601 | }, |
| 602 | { NULL } |
| 603 | }; |
| 604 | |
| 605 | AVFilter 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 | }; |