1 /*
2 * ReplayGainAnalysis - analyzes input samples and give the recommended dB change
3 * Copyright (C) 2001 David Robinson and Glen Sawyer
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * concept and filter values by David Robinson (David@Robinson.org)
20 * -- blame him if you think the idea is flawed
21 * original coding by Glen Sawyer (glensawyer@hotmail.com)
22 * -- blame him if you think this runs too slowly, or the coding is otherwise flawed
23 *
24 * lots of code improvements by Frank Klemm ( http://www.uni-jena.de/~pfk/mpp/ )
25 * -- credit him for all the _good_ programming ;)
26 *
27 * minor cosmetic tweaks to integrate with FLAC by Josh Coalson
28 *
29 *
30 * For an explanation of the concepts and the basic algorithms involved, go to:
31 * http://www.replaygain.org/
32 */
33
34 /*
35 * Here's the deal. Call
36 *
37 * InitGainAnalysis ( long samplefreq );
38 *
39 * to initialize everything. Call
40 *
41 * AnalyzeSamples ( const flac_float_t* left_samples,
42 * const flac_float_t* right_samples,
43 * size_t num_samples,
44 * int num_channels );
45 *
46 * as many times as you want, with as many or as few samples as you want.
47 * If mono, pass the sample buffer in through left_samples, leave
48 * right_samples NULL, and make sure num_channels = 1.
49 *
50 * GetTitleGain()
51 *
52 * will return the recommended dB level change for all samples analyzed
53 * SINCE THE LAST TIME you called GetTitleGain() OR InitGainAnalysis().
54 *
55 * GetAlbumGain()
56 *
57 * will return the recommended dB level change for all samples analyzed
58 * since InitGainAnalysis() was called and finalized with GetTitleGain().
59 *
60 * Pseudo-code to process an album:
61 *
62 * flac_float_t l_samples [4096];
63 * flac_float_t r_samples [4096];
64 * size_t num_samples;
65 * uint32_t num_songs;
66 * uint32_t i;
67 *
68 * InitGainAnalysis ( 44100 );
69 * for ( i = 1; i <= num_songs; i++ ) {
70 * while ( ( num_samples = getSongSamples ( song[i], left_samples, right_samples ) ) > 0 )
71 * AnalyzeSamples ( left_samples, right_samples, num_samples, 2 );
72 * fprintf ("Recommended dB change for song %2d: %+6.2f dB\n", i, GetTitleGain() );
73 * }
74 * fprintf ("Recommended dB change for whole album: %+6.2f dB\n", GetAlbumGain() );
75 */
76
77 /*
78 * So here's the main source of potential code confusion:
79 *
80 * The filters applied to the incoming samples are IIR filters,
81 * meaning they rely on up to <filter order> number of previous samples
82 * AND up to <filter order> number of previous filtered samples.
83 *
84 * I set up the AnalyzeSamples routine to minimize memory usage and interface
85 * complexity. The speed isn't compromised too much (I don't think), but the
86 * internal complexity is higher than it should be for such a relatively
87 * simple routine.
88 *
89 * Optimization/clarity suggestions are welcome.
90 */
91
92 #ifdef HAVE_CONFIG_H
93 # include <config.h>
94 #endif
95
96 #include <stdio.h>
97 #include <stdlib.h>
98 #include <string.h>
99 #include <math.h>
100 #include "share/alloc.h"
101 #include "share/compat.h"
102 #include "share/replaygain_analysis.h"
103
104 flac_float_t ReplayGainReferenceLoudness = 89.0; /* in dB SPL */
105
106 #define YULE_ORDER 10
107 #define BUTTER_ORDER 2
108 #define RMS_PERCENTILE 0.95 /* percentile which is louder than the proposed level */
109 #define RMS_WINDOW_TIME 50 /* Time slice size [ms] */
110 #define STEPS_per_dB 100. /* Table entries per dB */
111 #define MAX_dB 120. /* Table entries for 0...MAX_dB (normal max. values are 70...80 dB) */
112
113 #define MAX_ORDER (BUTTER_ORDER > YULE_ORDER ? BUTTER_ORDER : YULE_ORDER)
114 #define PINK_REF 64.82 /* 298640883795 */ /* calibration value */
115
116 static flac_float_t linprebuf [MAX_ORDER * 2];
117 static flac_float_t* linpre; /* left input samples, with pre-buffer */
118 static flac_float_t* lstepbuf;
119 static flac_float_t* lstep; /* left "first step" (i.e. post first filter) samples */
120 static flac_float_t* loutbuf;
121 static flac_float_t* lout; /* left "out" (i.e. post second filter) samples */
122 static flac_float_t rinprebuf [MAX_ORDER * 2];
123 static flac_float_t* rinpre; /* right input samples ... */
124 static flac_float_t* rstepbuf;
125 static flac_float_t* rstep;
126 static flac_float_t* routbuf;
127 static flac_float_t* rout;
128 static uint32_t sampleWindow; /* number of samples required to reach number of milliseconds required for RMS window */
129 static uint64_t totsamp;
130 static double lsum;
131 static double rsum;
132 #if 0
133 static uint32_t A [(size_t)(STEPS_per_dB * MAX_dB)];
134 static uint32_t B [(size_t)(STEPS_per_dB * MAX_dB)];
135 #else
136 /* [JEC] Solaris Forte compiler doesn't like float calc in array indices */
137 static uint32_t A [120 * 100];
138 static uint32_t B [120 * 100];
139 #endif
140
141 #ifdef _MSC_VER
142 #pragma warning ( disable : 4305 )
143 #endif
144
145 struct ReplayGainFilter {
146 long rate;
147 uint32_t downsample;
148 flac_float_t BYule[YULE_ORDER+1];
149 flac_float_t AYule[YULE_ORDER+1];
150 flac_float_t BButter[BUTTER_ORDER+1];
151 flac_float_t AButter[BUTTER_ORDER+1];
152 };
153
154 static struct ReplayGainFilter *replaygainfilter;
155
156 static const struct ReplayGainFilter ReplayGainFilters[] = {
157
158 {
159 48000, 0, /* ORIGINAL */
160 { 0.03857599435200, -0.02160367184185, -0.00123395316851, -0.00009291677959, -0.01655260341619, 0.02161526843274, -0.02074045215285, 0.00594298065125, 0.00306428023191, 0.00012025322027, 0.00288463683916 },
161 { 1.00000000000000, -3.84664617118067, 7.81501653005538, -11.34170355132042, 13.05504219327545, -12.28759895145294, 9.48293806319790, -5.87257861775999, 2.75465861874613, -0.86984376593551, 0.13919314567432 },
162 { 0.98621192462708, -1.97242384925416, 0.98621192462708 },
163 { 1.00000000000000, -1.97223372919527, 0.97261396931306 },
164 },
165
166 {
167 44100, 0, /* ORIGINAL */
168 { 0.05418656406430, -0.02911007808948, -0.00848709379851, -0.00851165645469, -0.00834990904936, 0.02245293253339, -0.02596338512915, 0.01624864962975, -0.00240879051584, 0.00674613682247, -0.00187763777362 },
169 { 1.00000000000000, -3.47845948550071, 6.36317777566148, -8.54751527471874, 9.47693607801280, -8.81498681370155, 6.85401540936998, -4.39470996079559, 2.19611684890774, -0.75104302451432, 0.13149317958808 },
170 { 0.98500175787242, -1.97000351574484, 0.98500175787242 },
171 { 1.00000000000000, -1.96977855582618, 0.97022847566350 },
172 },
173
174 {
175 37800, 0,
176 { 0.10296717174470, -0.04877975583256, -0.02878009075237, -0.03519509188311, 0.02888717172493, -0.00609872684844, 0.00209851217112, 0.00911704668543, 0.01154404718589, -0.00630293688700, 0.00107527155228 },
177 { 1.00000000000000, -2.64848054923531, 3.58406058405771, -3.83794914179161, 3.90142345804575, -3.50179818637243, 2.67085284083076, -1.82581142372418, 1.09530368139801, -0.47689017820395, 0.11171431535905 },
178 { 0.98252400815195, -1.96504801630391, 0.98252400815195 },
179 { 1.00000000000000, -1.96474258269041, 0.96535344991740 },
180 },
181
182 {
183 36000, 0,
184 { 0.11572297028613, -0.04120916051252, -0.04977731768022, -0.01047308680426, 0.00750863219157, 0.00055507694408, 0.00140344192886, 0.01286095246036, 0.00998223033885, -0.00725013810661, 0.00326503346879 },
185 { 1.00000000000000, -2.43606802820871, 3.01907406973844, -2.90372016038192, 2.67947188094303, -2.17606479220391, 1.44912956803015, -0.87785765549050, 0.53592202672557, -0.26469344817509, 0.07495878059717 },
186 { 0.98165826840326, -1.96331653680652, 0.98165826840326 },
187 { 1.00000000000000, -1.96298008938934, 0.96365298422371 },
188 },
189
190 {
191 32000, 0, /* ORIGINAL */
192 { 0.15457299681924, -0.09331049056315, -0.06247880153653, 0.02163541888798, -0.05588393329856, 0.04781476674921, 0.00222312597743, 0.03174092540049, -0.01390589421898, 0.00651420667831, -0.00881362733839 },
193 { 1.00000000000000, -2.37898834973084, 2.84868151156327, -2.64577170229825, 2.23697657451713, -1.67148153367602, 1.00595954808547, -0.45953458054983, 0.16378164858596, -0.05032077717131, 0.02347897407020 },
194 { 0.97938932735214, -1.95877865470428, 0.97938932735214 },
195 { 1.00000000000000, -1.95835380975398, 0.95920349965459 },
196 },
197
198 {
199 28000, 0,
200 { 0.23882392323383, -0.22007791534089, -0.06014581950332, 0.05004458058021, -0.03293111254977, 0.02348678189717, 0.04290549799671, -0.00938141862174, 0.00015095146303, -0.00712601540885, -0.00626520210162 },
201 { 1.00000000000000, -2.06894080899139, 1.76944699577212, -0.81404732584187, 0.25418286850232, -0.30340791669762, 0.35616884070937, -0.14967310591258, -0.07024154183279, 0.11078404345174, -0.03551838002425 },
202 { 0.97647981663949, -1.95295963327897, 0.97647981663949 },
203 { 1.00000000000000, -1.95240635772520, 0.95351290883275 },
204
205 },
206
207 {
208 24000, 0, /* ORIGINAL */
209 { 0.30296907319327, -0.22613988682123, -0.08587323730772, 0.03282930172664, -0.00915702933434, -0.02364141202522, -0.00584456039913, 0.06276101321749, -0.00000828086748, 0.00205861885564, -0.02950134983287 },
210 { 1.00000000000000, -1.61273165137247, 1.07977492259970, -0.25656257754070, -0.16276719120440, -0.22638893773906, 0.39120800788284, -0.22138138954925, 0.04500235387352, 0.02005851806501, 0.00302439095741 },
211 { 0.97531843204928, -1.95063686409857, 0.97531843204928 },
212 { 1.00000000000000, -1.95002759149878, 0.95124613669835 },
213 },
214
215 {
216 22050, 0, /* ORIGINAL */
217 { 0.33642304856132, -0.25572241425570, -0.11828570177555, 0.11921148675203, -0.07834489609479, -0.00469977914380, -0.00589500224440, 0.05724228140351, 0.00832043980773, -0.01635381384540, -0.01760176568150 },
218 { 1.00000000000000, -1.49858979367799, 0.87350271418188, 0.12205022308084, -0.80774944671438, 0.47854794562326, -0.12453458140019, -0.04067510197014, 0.08333755284107, -0.04237348025746, 0.02977207319925 },
219 { 0.97316523498161, -1.94633046996323, 0.97316523498161 },
220 { 1.00000000000000, -1.94561023566527, 0.94705070426118 },
221 },
222
223 {
224 18900, 0,
225 { 0.38412657295385, -0.44533729608120, 0.20426638066221, -0.28031676047946, 0.31484202614802, -0.26078311203207, 0.12925201224848, -0.01141164696062, 0.03036522115769, -0.03776339305406, 0.00692036603586 },
226 { 1.00000000000000, -1.74403915585708, 1.96686095832499, -2.10081452941881, 1.90753918182846, -1.83814263754422, 1.36971352214969, -0.77883609116398, 0.39266422457649, -0.12529383592986, 0.05424760697665 },
227 { 0.96535326815829, -1.93070653631658, 0.96535326815829 },
228 { 1.00000000000000, -1.92950577983524, 0.93190729279793 },
229 },
230
231 {
232 16000, 0, /* ORIGINAL */
233 { 0.44915256608450, -0.14351757464547, -0.22784394429749, -0.01419140100551, 0.04078262797139, -0.12398163381748, 0.04097565135648, 0.10478503600251, -0.01863887810927, -0.03193428438915, 0.00541907748707 },
234 { 1.00000000000000, -0.62820619233671, 0.29661783706366, -0.37256372942400, 0.00213767857124, -0.42029820170918, 0.22199650564824, 0.00613424350682, 0.06747620744683, 0.05784820375801, 0.03222754072173 },
235 { 0.96454515552826, -1.92909031105652, 0.96454515552826 },
236 { 1.00000000000000, -1.92783286977036, 0.93034775234268 },
237 },
238
239 {
240 12000, 0, /* ORIGINAL */
241 { 0.56619470757641, -0.75464456939302, 0.16242137742230, 0.16744243493672, -0.18901604199609, 0.30931782841830, -0.27562961986224, 0.00647310677246, 0.08647503780351, -0.03788984554840, -0.00588215443421 },
242 { 1.00000000000000, -1.04800335126349, 0.29156311971249, -0.26806001042947, 0.00819999645858, 0.45054734505008, -0.33032403314006, 0.06739368333110, -0.04784254229033, 0.01639907836189, 0.01807364323573 },
243 { 0.96009142950541, -1.92018285901082, 0.96009142950541 },
244 { 1.00000000000000, -1.91858953033784, 0.92177618768381 },
245 },
246
247 {
248 11025, 0, /* ORIGINAL */
249 { 0.58100494960553, -0.53174909058578, -0.14289799034253, 0.17520704835522, 0.02377945217615, 0.15558449135573, -0.25344790059353, 0.01628462406333, 0.06920467763959, -0.03721611395801, -0.00749618797172 },
250 { 1.00000000000000, -0.51035327095184, -0.31863563325245, -0.20256413484477, 0.14728154134330, 0.38952639978999, -0.23313271880868, -0.05246019024463, -0.02505961724053, 0.02442357316099, 0.01818801111503 },
251 { 0.95856916599601, -1.91713833199203, 0.95856916599601 },
252 { 1.00000000000000, -1.91542108074780, 0.91885558323625 },
253 },
254
255 {
256 8000, 0, /* ORIGINAL */
257 { 0.53648789255105, -0.42163034350696, -0.00275953611929, 0.04267842219415, -0.10214864179676, 0.14590772289388, -0.02459864859345, -0.11202315195388, -0.04060034127000, 0.04788665548180, -0.02217936801134 },
258 { 1.00000000000000, -0.25049871956020, -0.43193942311114, -0.03424681017675, -0.04678328784242, 0.26408300200955, 0.15113130533216, -0.17556493366449, -0.18823009262115, 0.05477720428674, 0.04704409688120 },
259 { 0.94597685600279, -1.89195371200558, 0.94597685600279 },
260 { 1.00000000000000, -1.88903307939452, 0.89487434461664 },
261 },
262
263 };
264
265 #ifdef _MSC_VER
266 #pragma warning ( default : 4305 )
267 #endif
268
269 /* When calling this procedure, make sure that ip[-order] and op[-order] point to real data! */
270
271 static void
filter(const flac_float_t * input,flac_float_t * output,size_t nSamples,const flac_float_t * a,const flac_float_t * b,size_t order,uint32_t downsample)272 filter ( const flac_float_t* input, flac_float_t* output, size_t nSamples, const flac_float_t* a, const flac_float_t* b, size_t order, uint32_t downsample )
273 {
274 double y;
275 size_t i;
276 size_t k;
277
278 const flac_float_t* input_head = input;
279 const flac_float_t* input_tail;
280
281 flac_float_t* output_head = output;
282 flac_float_t* output_tail;
283
284 for ( i = 0; i < nSamples; i++, input_head += downsample, ++output_head ) {
285
286 input_tail = input_head;
287 output_tail = output_head;
288
289 y = *input_head * b[0];
290
291 for ( k = 1; k <= order; k++ ) {
292 input_tail -= downsample;
293 --output_tail;
294 y += *input_tail * b[k] - *output_tail * a[k];
295 }
296
297 output[i] = (flac_float_t)y;
298 }
299 }
300
301 /* returns a INIT_GAIN_ANALYSIS_OK if successful, INIT_GAIN_ANALYSIS_ERROR if not */
302
303 static struct ReplayGainFilter*
CreateGainFilter(long samplefreq)304 CreateGainFilter ( long samplefreq )
305 {
306 uint32_t i;
307 long maxrate = 0;
308 uint32_t downsample = 1;
309 struct ReplayGainFilter* gainfilter = malloc(sizeof(*gainfilter));
310
311 if ( !gainfilter )
312 return 0;
313
314 while (1) {
315 for ( i = 0; i < sizeof(ReplayGainFilters)/sizeof(ReplayGainFilters[0]); ++i ) {
316 if (maxrate < ReplayGainFilters[i].rate)
317 maxrate = ReplayGainFilters[i].rate;
318
319 if ( ReplayGainFilters[i].rate == samplefreq ) {
320 *gainfilter = ReplayGainFilters[i];
321 gainfilter->downsample = downsample;
322 return gainfilter;
323 }
324 }
325
326 if (samplefreq < maxrate)
327 break;
328
329 while (samplefreq > maxrate) {
330 downsample *= 2;
331 samplefreq /= 2;
332 }
333 }
334
335 free(gainfilter);
336
337 return 0;
338 }
339
340 static void*
ReallocateWindowBuffer(uint32_t window_size,flac_float_t ** window_buffer)341 ReallocateWindowBuffer(uint32_t window_size, flac_float_t **window_buffer)
342 {
343 *window_buffer = safe_realloc_(*window_buffer, sizeof(**window_buffer) * (window_size + MAX_ORDER));
344 return *window_buffer;
345 }
346
347 static int
ResetSampleFrequency(long samplefreq)348 ResetSampleFrequency ( long samplefreq ) {
349 int i;
350
351 free(replaygainfilter);
352
353 replaygainfilter = CreateGainFilter( samplefreq );
354
355 if ( ! replaygainfilter)
356 return INIT_GAIN_ANALYSIS_ERROR;
357
358 sampleWindow =
359 (replaygainfilter->rate * RMS_WINDOW_TIME + 1000-1) / 1000;
360
361 if ( ! ReallocateWindowBuffer(sampleWindow, &lstepbuf) ||
362 ! ReallocateWindowBuffer(sampleWindow, &rstepbuf) ||
363 ! ReallocateWindowBuffer(sampleWindow, &loutbuf) ||
364 ! ReallocateWindowBuffer(sampleWindow, &routbuf) ) {
365
366 return INIT_GAIN_ANALYSIS_ERROR;
367 }
368
369 /* zero out initial values */
370 for ( i = 0; i < MAX_ORDER; i++ )
371 linprebuf[i] = lstepbuf[i] = loutbuf[i] = rinprebuf[i] = rstepbuf[i] = routbuf[i] = 0.;
372
373 lsum = 0.;
374 rsum = 0.;
375 totsamp = 0;
376
377 memset ( A, 0, sizeof(A) );
378
379 return INIT_GAIN_ANALYSIS_OK;
380 }
381
382 int
ValidGainFrequency(long samplefreq)383 ValidGainFrequency ( long samplefreq )
384 {
385 struct ReplayGainFilter* gainfilter = CreateGainFilter( samplefreq );
386
387 if (gainfilter == 0) {
388 return 0;
389 } else {
390 free(gainfilter);
391 return 1;
392 }
393 }
394
395 int
InitGainAnalysis(long samplefreq)396 InitGainAnalysis ( long samplefreq )
397 {
398 if (ResetSampleFrequency(samplefreq) != INIT_GAIN_ANALYSIS_OK) {
399 return INIT_GAIN_ANALYSIS_ERROR;
400 }
401
402 linpre = linprebuf + MAX_ORDER;
403 rinpre = rinprebuf + MAX_ORDER;
404 lstep = lstepbuf + MAX_ORDER;
405 rstep = rstepbuf + MAX_ORDER;
406 lout = loutbuf + MAX_ORDER;
407 rout = routbuf + MAX_ORDER;
408
409 memset ( B, 0, sizeof(B) );
410
411 return INIT_GAIN_ANALYSIS_OK;
412 }
413
414 /* returns GAIN_ANALYSIS_OK if successful, GAIN_ANALYSIS_ERROR if not */
415
416 int
AnalyzeSamples(const flac_float_t * left_samples,const flac_float_t * right_samples,size_t num_samples,int num_channels)417 AnalyzeSamples ( const flac_float_t* left_samples, const flac_float_t* right_samples, size_t num_samples, int num_channels )
418 {
419 uint32_t downsample = replaygainfilter->downsample;
420 const flac_float_t* curleft;
421 const flac_float_t* curright;
422 long prebufsamples;
423 long batchsamples;
424 long cursamples;
425 long cursamplepos;
426 int i;
427
428 num_samples /= downsample;
429
430 if ( num_samples == 0 )
431 return GAIN_ANALYSIS_OK;
432
433 cursamplepos = 0;
434 batchsamples = num_samples;
435
436 switch ( num_channels) {
437 case 1: right_samples = left_samples;
438 case 2: break;
439 default: return GAIN_ANALYSIS_ERROR;
440 }
441
442 prebufsamples = MAX_ORDER;
443 if ((size_t) prebufsamples > num_samples)
444 prebufsamples = num_samples;
445
446 for ( i = 0; i < prebufsamples; ++i ) {
447 linprebuf[i+MAX_ORDER] = left_samples [i * downsample];
448 rinprebuf[i+MAX_ORDER] = right_samples[i * downsample];
449 }
450
451 while ( batchsamples > 0 ) {
452 cursamples = batchsamples > (long)(sampleWindow-totsamp) ? (long)(sampleWindow - totsamp) : batchsamples;
453 if ( cursamplepos < MAX_ORDER ) {
454 downsample = 1;
455 curleft = linpre+cursamplepos;
456 curright = rinpre+cursamplepos;
457 if (cursamples > MAX_ORDER - cursamplepos )
458 cursamples = MAX_ORDER - cursamplepos;
459 }
460 else {
461 downsample = replaygainfilter->downsample;
462 curleft = left_samples + cursamplepos * downsample;
463 curright = right_samples + cursamplepos * downsample;
464 }
465
466 filter ( curleft , lstep + totsamp, cursamples, replaygainfilter->AYule, replaygainfilter->BYule, YULE_ORDER, downsample );
467 filter ( curright, rstep + totsamp, cursamples, replaygainfilter->AYule, replaygainfilter->BYule, YULE_ORDER, downsample );
468
469 filter ( lstep + totsamp, lout + totsamp, cursamples, replaygainfilter->AButter, replaygainfilter->BButter, BUTTER_ORDER, 1 );
470 filter ( rstep + totsamp, rout + totsamp, cursamples, replaygainfilter->AButter, replaygainfilter->BButter, BUTTER_ORDER, 1 );
471
472 for ( i = 0; i < cursamples; i++ ) { /* Get the squared values */
473 lsum += lout [totsamp+i] * lout [totsamp+i];
474 rsum += rout [totsamp+i] * rout [totsamp+i];
475 }
476
477 batchsamples -= cursamples;
478 cursamplepos += cursamples;
479 totsamp += cursamples;
480 if ( totsamp == sampleWindow ) { /* Get the Root Mean Square (RMS) for this set of samples */
481 double val = STEPS_per_dB * 10. * log10 ( (lsum+rsum) / totsamp * 0.5 + 1.e-37 );
482 int ival = (int) val;
483 if ( ival < 0 ) ival = 0;
484 if ( ival >= (int)(sizeof(A)/sizeof(*A)) ) ival = (int)(sizeof(A)/sizeof(*A)) - 1;
485 A [ival]++;
486 lsum = rsum = 0.;
487 memmove ( loutbuf , loutbuf + totsamp, MAX_ORDER * sizeof(flac_float_t) );
488 memmove ( routbuf , routbuf + totsamp, MAX_ORDER * sizeof(flac_float_t) );
489 memmove ( lstepbuf, lstepbuf + totsamp, MAX_ORDER * sizeof(flac_float_t) );
490 memmove ( rstepbuf, rstepbuf + totsamp, MAX_ORDER * sizeof(flac_float_t) );
491 totsamp = 0;
492 }
493 if ( totsamp > sampleWindow ) /* somehow I really screwed up: Error in programming! Contact author about totsamp > sampleWindow */
494 return GAIN_ANALYSIS_ERROR;
495 }
496
497 if ( num_samples < MAX_ORDER ) {
498 memmove ( linprebuf, linprebuf + num_samples, (MAX_ORDER-num_samples) * sizeof(flac_float_t) );
499 memmove ( rinprebuf, rinprebuf + num_samples, (MAX_ORDER-num_samples) * sizeof(flac_float_t) );
500 memcpy ( linprebuf + MAX_ORDER - num_samples, left_samples, num_samples * sizeof(flac_float_t) );
501 memcpy ( rinprebuf + MAX_ORDER - num_samples, right_samples, num_samples * sizeof(flac_float_t) );
502 }
503 else {
504 downsample = replaygainfilter->downsample;
505
506 left_samples += (num_samples - MAX_ORDER) * downsample;
507 right_samples += (num_samples - MAX_ORDER) * downsample;
508
509 for ( i = 0; i < MAX_ORDER; ++i ) {
510 linprebuf[i] = left_samples [i * downsample];
511 rinprebuf[i] = right_samples[i * downsample];
512 }
513 }
514
515 return GAIN_ANALYSIS_OK;
516 }
517
518
519 static flac_float_t
analyzeResult(uint32_t * Array,size_t len)520 analyzeResult ( uint32_t* Array, size_t len )
521 {
522 uint32_t elems;
523 int32_t upper;
524 size_t i;
525
526 elems = 0;
527 for ( i = 0; i < len; i++ )
528 elems += Array[i];
529 if ( elems == 0 )
530 return GAIN_NOT_ENOUGH_SAMPLES;
531
532 /* workaround for GCC bug #61423: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61423 */
533 #if 0
534 upper = (int32_t) ceil (elems * (1. - RMS_PERCENTILE));
535 #else
536 upper = (int32_t) (elems / 20 + ((elems % 20) ? 1 : 0));
537 #endif
538 for ( i = len; i-- > 0; ) {
539 if ( (upper -= Array[i]) <= 0 )
540 break;
541 }
542
543 return (flac_float_t) ((flac_float_t)PINK_REF - (flac_float_t)i / (flac_float_t)STEPS_per_dB);
544 }
545
546
547 flac_float_t
GetTitleGain(void)548 GetTitleGain ( void )
549 {
550 flac_float_t retval;
551 uint32_t i;
552
553 retval = analyzeResult ( A, sizeof(A)/sizeof(*A) );
554
555 for ( i = 0; i < sizeof(A)/sizeof(*A); i++ ) {
556 B[i] += A[i];
557 A[i] = 0;
558 }
559
560 for ( i = 0; i < MAX_ORDER; i++ )
561 linprebuf[i] = lstepbuf[i] = loutbuf[i] = rinprebuf[i] = rstepbuf[i] = routbuf[i] = 0.f;
562
563 totsamp = 0;
564 lsum = rsum = 0.;
565 return retval;
566 }
567
568
569 flac_float_t
GetAlbumGain(void)570 GetAlbumGain ( void )
571 {
572 return analyzeResult ( B, sizeof(B)/sizeof(*B) );
573 }
574
575 /* end of replaygain_analysis.c */
576