diff options
author | Paul B Mahol <onemda@gmail.com> | 2013-09-26 13:41:53 +0400 |
---|---|---|
committer | Paul B Mahol <onemda@gmail.com> | 2013-10-21 23:56:55 +0400 |
commit | c9660999b9a76541cc0ccee1e572f4ee1540d8c5 (patch) | |
tree | 5613fed043ae0f29b8a8cff7112ba59cce263edf /libavfilter/af_replaygain.c | |
parent | 2f9422d951dcbcad68303bed12461388a4e4b8a7 (diff) |
avfilter: replaygain scanner
Signed-off-by: Paul B Mahol <onemda@gmail.com>
Diffstat (limited to 'libavfilter/af_replaygain.c')
-rw-r--r-- | libavfilter/af_replaygain.c | 613 |
1 files changed, 613 insertions, 0 deletions
diff --git a/libavfilter/af_replaygain.c b/libavfilter/af_replaygain.c new file mode 100644 index 0000000000..886840b07e --- /dev/null +++ b/libavfilter/af_replaygain.c @@ -0,0 +1,613 @@ +/* + * Copyright (c) 1998 - 2009 Conifer Software + * + * This file is part of FFmpeg. + * + * FFmpeg 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. + * + * FFmpeg 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 FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * ReplayGain scanner + */ + +#include "libavutil/avassert.h" +#include "libavutil/channel_layout.h" +#include "audio.h" +#include "avfilter.h" +#include "internal.h" + +#define HISTOGRAM_SLOTS 12000 +#define BUTTER_ORDER 2 +#define YULE_ORDER 10 + +typedef struct ReplayGainFreqInfo { + int sample_rate; + double BYule[YULE_ORDER + 1]; + double AYule[YULE_ORDER + 1]; + double BButter[BUTTER_ORDER + 1]; + double AButter[BUTTER_ORDER + 1]; +} ReplayGainFreqInfo; + +static const ReplayGainFreqInfo freqinfos[] = +{ + { + 192000, + { 0.01184742123123, -0.04631092400086, 0.06584226961238, + -0.02165588522478, -0.05656260778952, 0.08607493592760, + -0.03375544339786, -0.04216579932754, 0.06416711490648, + -0.03444708260844, 0.00697275872241 }, + { 1.00000000000000, -5.24727318348167, 10.60821585192244, + -8.74127665810413, -1.33906071371683, 8.07972882096606, + -5.46179918950847, 0.54318070652536, 0.87450969224280, + -0.34656083539754, 0.03034796843589 }, + { 0.99653501465135, -1.99307002930271, 0.99653501465135 }, + { 1.00000000000000, -1.99305802314321, 0.99308203546221 }, + }, + { + 176400, + { 0.00268568524529, -0.00852379426080, 0.00852704191347, + 0.00146116310295, -0.00950855828762, 0.00625449515499, + 0.00116183868722, -0.00362461417136, 0.00203961000134, + -0.00050664587933, 0.00004327455427 }, + { 1.00000000000000, -5.57512782763045, 12.44291056065794, + -12.87462799681221, 3.08554846961576, 6.62493459880692, + -7.07662766313248, 2.51175542736441, 0.06731510802735, + -0.24567753819213, 0.03961404162376 }, + { 0.99622916581118, -1.99245833162236, 0.99622916581118 }, + { 1.00000000000000, -1.99244411238133, 0.99247255086339 }, + }, + { + 144000, + { 0.00639682359450, -0.02556437970955, 0.04230854400938, + -0.03722462201267, 0.01718514827295, 0.00610592243009, + -0.03065965747365, 0.04345745003539, -0.03298592681309, + 0.01320937236809, -0.00220304127757 }, + { 1.00000000000000, -6.14814623523425, 15.80002457141566, + -20.78487587686937, 11.98848552310315, 3.36462015062606, + -10.22419868359470, 6.65599702146473, -1.67141861110485, + -0.05417956536718, 0.07374767867406 }, + { 0.99538268958706, -1.99076537917413, 0.99538268958706 }, + { 1.00000000000000, -1.99074405950505, 0.99078669884321 }, + }, + { + 128000, + { 0.00553120584305, -0.02112620545016, 0.03549076243117, + -0.03362498312306, 0.01425867248183, 0.01344686928787, + -0.03392770787836, 0.03464136459530, -0.02039116051549, + 0.00667420794705, -0.00093763762995 }, + { 1.00000000000000, -6.14581710839925, 16.04785903675838, + -22.19089131407749, 15.24756471580286, -0.52001440400238, + -8.00488641699940, 6.60916094768855, -2.37856022810923, + 0.33106947986101, 0.00459820832036 }, + { 0.99480702681278, -1.98961405362557, 0.99480702681278 }, + { 1.00000000000000, -1.98958708647324, 0.98964102077790 }, + }, + { + 112000, + { 0.00528778718259, -0.01893240907245, 0.03185982561867, + -0.02926260297838, 0.00715743034072, 0.01985743355827, + -0.03222614850941, 0.02565681978192, -0.01210662313473, + 0.00325436284541, -0.00044173593001 }, + { 1.00000000000000, -6.24932108456288, 17.42344320538476, + -27.86819709054896, 26.79087344681326,-13.43711081485123, + -0.66023612948173, 6.03658091814935, -4.24926577030310, + 1.40829268709186, -0.19480852628112 }, + { 0.99406737810867, -1.98813475621734, 0.99406737810867 }, + { 1.00000000000000, -1.98809955990514, 0.98816995252954 }, + }, + { + 96000, + { 0.00588138296683, -0.01613559730421, 0.02184798954216, + -0.01742490405317, 0.00464635643780, 0.01117772513205, + -0.02123865824368, 0.01959354413350, -0.01079720643523, + 0.00352183686289, -0.00063124341421 }, + { 1.00000000000000, -5.97808823642008, 16.21362507964068, + -25.72923730652599, 25.40470663139513,-14.66166287771134, + 2.81597484359752, 2.51447125969733, -2.23575306985286, + 0.75788151036791, -0.10078025199029 }, + { 0.99308203517541, -1.98616407035082, 0.99308203517541 }, + { 1.00000000000000, -1.98611621154089, 0.98621192916075 }, + }, + { + 88200, + { 0.02667482047416, -0.11377479336097, 0.23063167910965, + -0.30726477945593, 0.33188520686529, -0.33862680249063, + 0.31807161531340, -0.23730796929880, 0.12273894790371, + -0.03840017967282, 0.00549673387936 }, + { 1.00000000000000, -6.31836451657302, 18.31351310801799, + -31.88210014815921, 36.53792146976740,-28.23393036467559, + 14.24725258227189, -4.04670980012854, 0.18865757280515, + 0.25420333563908, -0.06012333531065 }, + { 0.99247255046129, -1.98494510092259, 0.99247255046129 }, + { 1.00000000000000, -1.98488843762335, 0.98500176422183 }, + }, + { + 64000, + { 0.02613056568174, -0.08128786488109, 0.14937282347325, + -0.21695711675126, 0.25010286673402, -0.23162283619278, + 0.17424041833052, -0.10299599216680, 0.04258696481981, + -0.00977952936493, 0.00105325558889 }, + { 1.00000000000000, -5.73625477092119, 16.15249794355035, + -29.68654912464508, 39.55706155674083,-39.82524556246253, + 30.50605345013009,-17.43051772821245, 7.05154573908017, + -1.80783839720514, 0.22127840210813 }, + { 0.98964101933472, -1.97928203866944, 0.98964101933472 }, + { 1.00000000000000, -1.97917472731009, 0.97938935002880 }, + }, + { + 56000, + { 0.03144914734085, -0.06151729206963, 0.08066788708145, + -0.09737939921516, 0.08943210803999, -0.06989984672010, + 0.04926972841044, -0.03161257848451, 0.01456837493506, + -0.00316015108496, 0.00132807215875 }, + { 1.00000000000000, -4.87377313090032, 12.03922160140209, + -20.10151118381395, 25.10388534415171,-24.29065560815903, + 18.27158469090663,-10.45249552560593, 4.30319491872003, + -1.13716992070185, 0.14510733527035 }, + { 0.98816995007392, -1.97633990014784, 0.98816995007392 }, + { 1.00000000000000, -1.97619994516973, 0.97647985512594 }, + }, + { + 48000, + { 0.03857599435200, -0.02160367184185, -0.00123395316851, + -0.00009291677959, -0.01655260341619, 0.02161526843274, + -0.02074045215285, 0.00594298065125, 0.00306428023191, + 0.00012025322027, 0.00288463683916 }, + { 1.00000000000000, -3.84664617118067, 7.81501653005538, + -11.34170355132042, 13.05504219327545,-12.28759895145294, + 9.48293806319790, -5.87257861775999, 2.75465861874613, + -0.86984376593551, 0.13919314567432 }, + { 0.98621192462708, -1.97242384925416, 0.98621192462708 }, + { 1.00000000000000, -1.97223372919527, 0.97261396931306 }, + }, + { + 44100, + { 0.05418656406430, -0.02911007808948, -0.00848709379851, + -0.00851165645469, -0.00834990904936, 0.02245293253339, + -0.02596338512915, 0.01624864962975, -0.00240879051584, + 0.00674613682247, -0.00187763777362 }, + { 1.00000000000000, -3.47845948550071, 6.36317777566148, + -8.54751527471874, 9.47693607801280, -8.81498681370155, + 6.85401540936998, -4.39470996079559, 2.19611684890774, + -0.75104302451432, 0.13149317958808 }, + { 0.98500175787242, -1.97000351574484, 0.98500175787242 }, + { 1.00000000000000, -1.96977855582618, 0.97022847566350 }, + }, + { + 37800, + { 0.08717879977844, -0.01000374016172, -0.06265852122368, + -0.01119328800950, -0.00114279372960, 0.02081333954769, + -0.01603261863207, 0.01936763028546, 0.00760044736442, + -0.00303979112271, -0.00075088605788 }, + { 1.00000000000000, -2.62816311472146, 3.53734535817992, + -3.81003448678921, 3.91291636730132, -3.53518605896288, + 2.71356866157873, -1.86723311846592, 1.12075382367659, + -0.48574086886890, 0.11330544663849 }, + { 0.98252400815195, -1.96504801630391, 0.98252400815195 }, + { 1.00000000000000, -1.96474258269041, 0.96535344991740 }, + }, + { + 32000, + { 0.15457299681924, -0.09331049056315, -0.06247880153653, + 0.02163541888798, -0.05588393329856, 0.04781476674921, + 0.00222312597743, 0.03174092540049, -0.01390589421898, + 0.00651420667831, -0.00881362733839 }, + { 1.00000000000000, -2.37898834973084, 2.84868151156327, + -2.64577170229825, 2.23697657451713, -1.67148153367602, + 1.00595954808547, -0.45953458054983, 0.16378164858596, + -0.05032077717131, 0.02347897407020 }, + { 0.97938932735214, -1.95877865470428, 0.97938932735214 }, + { 1.00000000000000, -1.95835380975398, 0.95920349965459 }, + }, + { + 24000, + { 0.30296907319327, -0.22613988682123, -0.08587323730772, + 0.03282930172664, -0.00915702933434, -0.02364141202522, + -0.00584456039913, 0.06276101321749, -0.00000828086748, + 0.00205861885564, -0.02950134983287 }, + { 1.00000000000000, -1.61273165137247, 1.07977492259970, + -0.25656257754070, -0.16276719120440, -0.22638893773906, + 0.39120800788284, -0.22138138954925, 0.04500235387352, + 0.02005851806501, 0.00302439095741 }, + { 0.97531843204928, -1.95063686409857, 0.97531843204928 }, + { 1.00000000000000, -1.95002759149878, 0.95124613669835 }, + }, + { + 22050, + { 0.33642304856132, -0.25572241425570, -0.11828570177555, + 0.11921148675203, -0.07834489609479, -0.00469977914380, + -0.00589500224440, 0.05724228140351, 0.00832043980773, + -0.01635381384540, -0.01760176568150 }, + { 1.00000000000000, -1.49858979367799, 0.87350271418188, + 0.12205022308084, -0.80774944671438, 0.47854794562326, + -0.12453458140019, -0.04067510197014, 0.08333755284107, + -0.04237348025746, 0.02977207319925 }, + { 0.97316523498161, -1.94633046996323, 0.97316523498161 }, + { 1.00000000000000, -1.94561023566527, 0.94705070426118 }, + }, + { + 18900, + { 0.38524531015142, -0.27682212062067, -0.09980181488805, + 0.09951486755646, -0.08934020156622, -0.00322369330199, + -0.00110329090689, 0.03784509844682, 0.01683906213303, + -0.01147039862572, -0.01941767987192 }, + { 1.00000000000000, -1.29708918404534, 0.90399339674203, + -0.29613799017877, -0.42326645916207, 0.37934887402200, + -0.37919795944938, 0.23410283284785, -0.03892971758879, + 0.00403009552351, 0.03640166626278 }, + { 0.96535326815829, -1.93070653631658, 0.96535326815829 }, + { 1.00000000000000, -1.92950577983524, 0.93190729279793 }, + }, + { + 16000, + { 0.44915256608450, -0.14351757464547, -0.22784394429749, + -0.01419140100551, 0.04078262797139, -0.12398163381748, + 0.04097565135648, 0.10478503600251, -0.01863887810927, + -0.03193428438915, 0.00541907748707 }, + { 1.00000000000000, -0.62820619233671, 0.29661783706366, + -0.37256372942400, 0.00213767857124, -0.42029820170918, + 0.22199650564824, 0.00613424350682, 0.06747620744683, + 0.05784820375801, 0.03222754072173 }, + { 0.96454515552826, -1.92909031105652, 0.96454515552826 }, + { 1.00000000000000, -1.92783286977036, 0.93034775234268 }, + }, + { + 12000, + { 0.56619470757641, -0.75464456939302, 0.16242137742230, + 0.16744243493672, -0.18901604199609, 0.30931782841830, + -0.27562961986224, 0.00647310677246, 0.08647503780351, + -0.03788984554840, -0.00588215443421 }, + { 1.00000000000000, -1.04800335126349, 0.29156311971249, + -0.26806001042947, 0.00819999645858, 0.45054734505008, + -0.33032403314006, 0.06739368333110, -0.04784254229033, + 0.01639907836189, 0.01807364323573 }, + { 0.96009142950541, -1.92018285901082, 0.96009142950541 }, + { 1.00000000000000, -1.91858953033784, 0.92177618768381 }, + }, + { + 11025, + { 0.58100494960553, -0.53174909058578, -0.14289799034253, + 0.17520704835522, 0.02377945217615, 0.15558449135573, + -0.25344790059353, 0.01628462406333, 0.06920467763959, + -0.03721611395801, -0.00749618797172 }, + { 1.00000000000000, -0.51035327095184, -0.31863563325245, + -0.20256413484477, 0.14728154134330, 0.38952639978999, + -0.23313271880868, -0.05246019024463, -0.02505961724053, + 0.02442357316099, 0.01818801111503 }, + { 0.95856916599601, -1.91713833199203, 0.95856916599601 }, + { 1.00000000000000, -1.91542108074780, 0.91885558323625 }, + }, + { + 8000, + { 0.53648789255105, -0.42163034350696, -0.00275953611929, + 0.04267842219415, -0.10214864179676, 0.14590772289388, + -0.02459864859345, -0.11202315195388, -0.04060034127000, + 0.04788665548180, -0.02217936801134 }, + { 1.00000000000000, -0.25049871956020, -0.43193942311114, + -0.03424681017675, -0.04678328784242, 0.26408300200955, + 0.15113130533216, -0.17556493366449, -0.18823009262115, + 0.05477720428674, 0.04704409688120 }, + { 0.94597685600279, -1.89195371200558, 0.94597685600279 }, + { 1.00000000000000, -1.88903307939452, 0.89487434461664 }, + }, +}; + +typedef struct ReplayGainContext { + uint32_t histogram[HISTOGRAM_SLOTS]; + float peak; + int yule_hist_i, butter_hist_i; + const double *yule_coeff_a; + const double *yule_coeff_b; + const double *butter_coeff_a; + const double *butter_coeff_b; + float yule_hist_a[256]; + float yule_hist_b[256]; + float butter_hist_a[256]; + float butter_hist_b[256]; +} ReplayGainContext; + +static int query_formats(AVFilterContext *ctx) +{ + AVFilterFormats *formats = NULL; + AVFilterChannelLayouts *layout = NULL; + int i; + + ff_add_format(&formats, AV_SAMPLE_FMT_FLT); + ff_set_common_formats(ctx, formats); + ff_add_channel_layout(&layout, AV_CH_LAYOUT_STEREO); + ff_set_common_channel_layouts(ctx, layout); + + formats = NULL; + for (i = 0; i < FF_ARRAY_ELEMS(freqinfos); i++) + ff_add_format(&formats, freqinfos[i].sample_rate); + ff_set_common_samplerates(ctx, formats); + + return 0; +} + +static int config_input(AVFilterLink *inlink) +{ + AVFilterContext *ctx = inlink->dst; + ReplayGainContext *s = ctx->priv; + int i; + + for (i = 0; i < FF_ARRAY_ELEMS(freqinfos); i++) { + if (freqinfos[i].sample_rate == inlink->sample_rate) + break; + } + av_assert0(i < FF_ARRAY_ELEMS(freqinfos)); + + s->yule_coeff_a = freqinfos[i].AYule; + s->yule_coeff_b = freqinfos[i].BYule; + s->butter_coeff_a = freqinfos[i].AButter; + s->butter_coeff_b = freqinfos[i].BButter; + + s->yule_hist_i = 20; + s->butter_hist_i = 4; + inlink->partial_buf_size = + inlink->min_samples = + inlink->max_samples = inlink->sample_rate / 20; + + return 0; +} + +/* + * Update largest absolute sample value. + */ +static void calc_stereo_peak(const float *samples, int nb_samples, + float *peak_p) +{ + float peak = 0.0; + + while (nb_samples--) { + if (samples[0] > peak) + peak = samples[0]; + else if (-samples[0] > peak) + peak = -samples[0]; + + if (samples[1] > peak) + peak = samples[1]; + else if (-samples[1] > peak) + peak = -samples[1]; + + samples += 2; + } + + *peak_p = FFMAX(peak, *peak_p); +} + +/* + * Calculate stereo RMS level. Minimum value is about -100 dB for + * digital silence. The 90 dB offset is to compensate for the + * normalized float range and 3 dB is for stereo samples. + */ +static double calc_stereo_rms(const float *samples, int nb_samples) +{ + int count = nb_samples; + double sum = 1e-16; + + while (count--) { + sum += samples[0] * samples[0] + samples[1] * samples[1]; + samples += 2; + } + + return 10 * log10 (sum / nb_samples) + 90.0 - 3.0; +} + +/* + * Optimized implementation of 2nd-order IIR stereo filter. + */ +static void butter_filter_stereo_samples(ReplayGainContext *s, + float *samples, int nb_samples) +{ + const double *coeff_a = s->butter_coeff_a; + const double *coeff_b = s->butter_coeff_b; + float *hist_a = s->butter_hist_a; + float *hist_b = s->butter_hist_b; + double left, right; + int i, j; + + i = s->butter_hist_i; + + // If filter history is very small magnitude, clear it completely + // to prevent denormals from rattling around in there forever + // (slowing us down). + + for (j = -4; j < 0; ++j) + if (fabs(hist_a[i + j]) > 1e-10 || fabs(hist_b[i + j]) > 1e-10) + break; + + if (!j) { + memset(s->butter_hist_a, 0, sizeof(s->butter_hist_a)); + memset(s->butter_hist_b, 0, sizeof(s->butter_hist_b)); + } + + while (nb_samples--) { + left = (hist_b[i ] = samples[0]) * coeff_b[0]; + right = (hist_b[i + 1] = samples[1]) * coeff_b[0]; + left += hist_b[i - 2] * coeff_b[1] - hist_a[i - 2] * coeff_a[1]; + right += hist_b[i - 1] * coeff_b[1] - hist_a[i - 1] * coeff_a[1]; + left += hist_b[i - 4] * coeff_b[2] - hist_a[i - 4] * coeff_a[2]; + right += hist_b[i - 3] * coeff_b[2] - hist_a[i - 3] * coeff_a[2]; + samples[0] = hist_a[i ] = (float) left; + samples[1] = hist_a[i + 1] = (float) right; + samples += 2; + + if ((i += 2) == 256) { + memcpy(hist_a, hist_a + 252, sizeof(*hist_a) * 4); + memcpy(hist_b, hist_b + 252, sizeof(*hist_b) * 4); + i = 4; + } + } + + s->butter_hist_i = i; +} + +/* + * Optimized implementation of 10th-order IIR stereo filter. + */ +static void yule_filter_stereo_samples(ReplayGainContext *s, const float *src, + float *dst, int nb_samples) +{ + const double *coeff_a = s->yule_coeff_a; + const double *coeff_b = s->yule_coeff_b; + float *hist_a = s->yule_hist_a; + float *hist_b = s->yule_hist_b; + double left, right; + int i, j; + + i = s->yule_hist_i; + + // If filter history is very small magnitude, clear it completely to + // prevent denormals from rattling around in there forever + // (slowing us down). + + for (j = -20; j < 0; ++j) + if (fabs(hist_a[i + j]) > 1e-10 || fabs(hist_b[i + j]) > 1e-10) + break; + + if (!j) { + memset(s->yule_hist_a, 0, sizeof(s->yule_hist_a)); + memset(s->yule_hist_b, 0, sizeof(s->yule_hist_b)); + } + + while (nb_samples--) { + left = (hist_b[i] = src[0]) * coeff_b[0]; + right = (hist_b[i + 1] = src[1]) * coeff_b[0]; + left += hist_b[i - 2] * coeff_b[ 1] - hist_a[i - 2] * coeff_a[1 ]; + right += hist_b[i - 1] * coeff_b[ 1] - hist_a[i - 1] * coeff_a[1 ]; + left += hist_b[i - 4] * coeff_b[ 2] - hist_a[i - 4] * coeff_a[2 ]; + right += hist_b[i - 3] * coeff_b[ 2] - hist_a[i - 3] * coeff_a[2 ]; + left += hist_b[i - 6] * coeff_b[ 3] - hist_a[i - 6] * coeff_a[3 ]; + right += hist_b[i - 5] * coeff_b[ 3] - hist_a[i - 5] * coeff_a[3 ]; + left += hist_b[i - 8] * coeff_b[ 4] - hist_a[i - 8] * coeff_a[4 ]; + right += hist_b[i - 7] * coeff_b[ 4] - hist_a[i - 7] * coeff_a[4 ]; + left += hist_b[i - 10] * coeff_b[ 5] - hist_a[i - 10] * coeff_a[5 ]; + right += hist_b[i - 9] * coeff_b[ 5] - hist_a[i - 9] * coeff_a[5 ]; + left += hist_b[i - 12] * coeff_b[ 6] - hist_a[i - 12] * coeff_a[6 ]; + right += hist_b[i - 11] * coeff_b[ 6] - hist_a[i - 11] * coeff_a[6 ]; + left += hist_b[i - 14] * coeff_b[ 7] - hist_a[i - 14] * coeff_a[7 ]; + right += hist_b[i - 13] * coeff_b[ 7] - hist_a[i - 13] * coeff_a[7 ]; + left += hist_b[i - 16] * coeff_b[ 8] - hist_a[i - 16] * coeff_a[8 ]; + right += hist_b[i - 15] * coeff_b[ 8] - hist_a[i - 15] * coeff_a[8 ]; + left += hist_b[i - 18] * coeff_b[ 9] - hist_a[i - 18] * coeff_a[9 ]; + right += hist_b[i - 17] * coeff_b[ 9] - hist_a[i - 17] * coeff_a[9 ]; + left += hist_b[i - 20] * coeff_b[10] - hist_a[i - 20] * coeff_a[10]; + right += hist_b[i - 19] * coeff_b[10] - hist_a[i - 19] * coeff_a[10]; + dst[0] = hist_a[i ] = (float)left; + dst[1] = hist_a[i + 1] = (float)right; + src += 2; + dst += 2; + + if ((i += 2) == 256) { + memcpy(hist_a, hist_a + 236, sizeof(*hist_a) * 20); + memcpy(hist_b, hist_b + 236, sizeof(*hist_b) * 20); + i = 20; + } + } + + s->yule_hist_i = i; +} + +/* + * Calculate the ReplayGain value from the specified loudness histogram; + * clip to -24 / +64 dB. + */ +static float calc_replaygain(uint32_t *histogram) +{ + uint32_t loud_count = 0, total_windows = 0; + float gain; + int i; + + for (i = 0; i < HISTOGRAM_SLOTS; i++) + total_windows += histogram [i]; + + while (i--) + if ((loud_count += histogram [i]) * 20 >= total_windows) + break; + + gain = (float)(64.54 - i / 100.0); + + return av_clipf(gain, -24.0, 64.0); +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *in) +{ + AVFilterContext *ctx = inlink->dst; + AVFilterLink *outlink = ctx->outputs[0]; + ReplayGainContext *s = ctx->priv; + uint32_t level; + AVFrame *out; + + out = ff_get_audio_buffer(inlink, in->nb_samples); + if (!out) { + av_frame_free(&in); + return AVERROR(ENOMEM); + } + + calc_stereo_peak((float *)in->data[0], + in->nb_samples, &s->peak); + yule_filter_stereo_samples(s, (const float *)in->data[0], + (float *)out->data[0], + out->nb_samples); + butter_filter_stereo_samples(s, (float *)out->data[0], + out->nb_samples); + level = (uint32_t)floor(100 * calc_stereo_rms((float *)out->data[0], + out->nb_samples)); + level = av_clip(level, 0, HISTOGRAM_SLOTS - 1); + + s->histogram[level]++; + + av_frame_free(&out); + return ff_filter_frame(outlink, in); +} + +static av_cold void uninit(AVFilterContext *ctx) +{ + ReplayGainContext *s = ctx->priv; + float gain = calc_replaygain(s->histogram); + + av_log(ctx, AV_LOG_INFO, "track_gain = %+.2f dB\n", gain); + av_log(ctx, AV_LOG_INFO, "track_peak = %.6f\n", s->peak); +} + +static const AVFilterPad replaygain_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .filter_frame = filter_frame, + .config_props = config_input, + }, + { NULL } +}; + +static const AVFilterPad replaygain_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + }, + { NULL } +}; + +AVFilter avfilter_af_replaygain = { + .name = "replaygain", + .description = NULL_IF_CONFIG_SMALL("ReplayGain scanner."), + .query_formats = query_formats, + .uninit = uninit, + .priv_size = sizeof(ReplayGainContext), + .inputs = replaygain_inputs, + .outputs = replaygain_outputs, +}; |