resample: replace VLA with malloc/free
[libav.git] / libavcodec / resample2.c
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1/*
2 * audio resampling
3 * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
4 *
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5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
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8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
b78e7197 10 * version 2.1 of the License, or (at your option) any later version.
aaaf1635 11 *
b78e7197 12 * FFmpeg is distributed in the hope that it will be useful,
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13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
b78e7197 18 * License along with FFmpeg; if not, write to the Free Software
5509bffa 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
aaaf1635 20 */
115329f1 21
aaaf1635 22/**
ba87f080 23 * @file
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24 * audio resampling
25 * @author Michael Niedermayer <michaelni@gmx.at>
26 */
27
28#include "avcodec.h"
1ac31760 29#include "dsputil.h"
aaaf1635 30
c252b26d 31#ifndef CONFIG_RESAMPLE_HP
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32#define FILTER_SHIFT 15
33
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34#define FELEM int16_t
35#define FELEM2 int32_t
55fc0eb1 36#define FELEML int64_t
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37#define FELEM_MAX INT16_MAX
38#define FELEM_MIN INT16_MIN
14f887ef 39#define WINDOW_TYPE 9
55fc0eb1 40#elif !defined(CONFIG_RESAMPLE_AUDIOPHILE_KIDDY_MODE)
d6fead90 41#define FILTER_SHIFT 30
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42
43#define FELEM int32_t
44#define FELEM2 int64_t
55fc0eb1 45#define FELEML int64_t
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46#define FELEM_MAX INT32_MAX
47#define FELEM_MIN INT32_MIN
14f887ef 48#define WINDOW_TYPE 12
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49#else
50#define FILTER_SHIFT 0
51
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52#define FELEM double
53#define FELEM2 double
54#define FELEML double
55fc0eb1 55#define WINDOW_TYPE 24
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56#endif
57
58
aaaf1635 59typedef struct AVResampleContext{
6d69a653 60 const AVClass *av_class;
51a88020 61 FELEM *filter_bank;
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62 int filter_length;
63 int ideal_dst_incr;
64 int dst_incr;
65 int index;
66 int frac;
67 int src_incr;
68 int compensation_distance;
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69 int phase_shift;
70 int phase_mask;
71 int linear;
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72}AVResampleContext;
73
74/**
75 * 0th order modified bessel function of the first kind.
76 */
7b49ce2e 77static double bessel(double x){
aaaf1635 78 double v=1;
2efcf292 79 double lastv=0;
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80 double t=1;
81 int i;
115329f1 82
50df67d3 83 x= x*x/4;
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84 for(i=1; v != lastv; i++){
85 lastv=v;
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86 t *= x/(i*i);
87 v += t;
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88 }
89 return v;
90}
91
92/**
93 * builds a polyphase filterbank.
94 * @param factor resampling factor
95 * @param scale wanted sum of coefficients for each filter
20cf58c3 96 * @param type 0->cubic, 1->blackman nuttall windowed sinc, 2..16->kaiser windowed sinc beta=2..16
080ce907 97 * @return 0 on success, negative on error
aaaf1635 98 */
080ce907 99static int build_filter(FELEM *filter, double factor, int tap_count, int phase_count, int scale, int type){
0339fab8 100 int ph, i;
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101 double x, y, w;
102 double *tab = av_malloc(tap_count * sizeof(*tab));
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103 const int center= (tap_count-1)/2;
104
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105 if (!tab)
106 return AVERROR(ENOMEM);
107
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108 /* if upsampling, only need to interpolate, no filter */
109 if (factor > 1.0)
110 factor = 1.0;
111
112 for(ph=0;ph<phase_count;ph++) {
113 double norm = 0;
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114 for(i=0;i<tap_count;i++) {
115 x = M_PI * ((double)(i - center) - (double)ph / phase_count) * factor;
116 if (x == 0) y = 1.0;
117 else y = sin(x) / x;
118 switch(type){
119 case 0:{
120 const float d= -0.5; //first order derivative = -0.5
121 x = fabs(((double)(i - center) - (double)ph / phase_count) * factor);
122 if(x<1.0) y= 1 - 3*x*x + 2*x*x*x + d*( -x*x + x*x*x);
123 else y= d*(-4 + 8*x - 5*x*x + x*x*x);
124 break;}
125 case 1:
126 w = 2.0*x / (factor*tap_count) + M_PI;
127 y *= 0.3635819 - 0.4891775 * cos(w) + 0.1365995 * cos(2*w) - 0.0106411 * cos(3*w);
128 break;
20cf58c3 129 default:
aaaf1635 130 w = 2.0*x / (factor*tap_count*M_PI);
20cf58c3 131 y *= bessel(type*sqrt(FFMAX(1-w*w, 0)));
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132 break;
133 }
134
135 tab[i] = y;
136 norm += y;
137 }
138
139 /* normalize so that an uniform color remains the same */
140 for(i=0;i<tap_count;i++) {
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141#ifdef CONFIG_RESAMPLE_AUDIOPHILE_KIDDY_MODE
142 filter[ph * tap_count + i] = tab[i] / norm;
143#else
144 filter[ph * tap_count + i] = av_clip(lrintf(tab[i] * scale / norm), FELEM_MIN, FELEM_MAX);
145#endif
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146 }
147 }
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148#if 0
149 {
150#define LEN 1024
151 int j,k;
152 double sine[LEN + tap_count];
153 double filtered[LEN];
154 double maxff=-2, minff=2, maxsf=-2, minsf=2;
155 for(i=0; i<LEN; i++){
156 double ss=0, sf=0, ff=0;
157 for(j=0; j<LEN+tap_count; j++)
158 sine[j]= cos(i*j*M_PI/LEN);
159 for(j=0; j<LEN; j++){
160 double sum=0;
161 ph=0;
162 for(k=0; k<tap_count; k++)
163 sum += filter[ph * tap_count + k] * sine[k+j];
164 filtered[j]= sum / (1<<FILTER_SHIFT);
165 ss+= sine[j + center] * sine[j + center];
166 ff+= filtered[j] * filtered[j];
167 sf+= sine[j + center] * filtered[j];
168 }
169 ss= sqrt(2*ss/LEN);
170 ff= sqrt(2*ff/LEN);
171 sf= 2*sf/LEN;
172 maxff= FFMAX(maxff, ff);
173 minff= FFMIN(minff, ff);
174 maxsf= FFMAX(maxsf, sf);
175 minsf= FFMIN(minsf, sf);
176 if(i%11==0){
55fc0eb1 177 av_log(NULL, AV_LOG_ERROR, "i:%4d ss:%f ff:%13.6e-%13.6e sf:%13.6e-%13.6e\n", i, ss, maxff, minff, maxsf, minsf);
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178 minff=minsf= 2;
179 maxff=maxsf= -2;
180 }
181 }
182 }
183#endif
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184
185 av_free(tab);
186 return 0;
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187}
188
6e225de2 189AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_size, int phase_shift, int linear, double cutoff){
aaaf1635 190 AVResampleContext *c= av_mallocz(sizeof(AVResampleContext));
6e225de2 191 double factor= FFMIN(out_rate * cutoff / in_rate, 1.0);
ed861c6b 192 int phase_count= 1<<phase_shift;
115329f1 193
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194 if (!c)
195 return NULL;
196
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197 c->phase_shift= phase_shift;
198 c->phase_mask= phase_count-1;
199 c->linear= linear;
aaaf1635 200
f0ff20a1 201 c->filter_length= FFMAX((int)ceil(filter_size/factor), 1);
ed861c6b 202 c->filter_bank= av_mallocz(c->filter_length*(phase_count+1)*sizeof(FELEM));
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203 if (!c->filter_bank)
204 goto error;
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205 if (build_filter(c->filter_bank, factor, c->filter_length, phase_count, 1<<FILTER_SHIFT, WINDOW_TYPE))
206 goto error;
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207 memcpy(&c->filter_bank[c->filter_length*phase_count+1], c->filter_bank, (c->filter_length-1)*sizeof(FELEM));
208 c->filter_bank[c->filter_length*phase_count]= c->filter_bank[c->filter_length - 1];
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209
210 c->src_incr= out_rate;
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211 c->ideal_dst_incr= c->dst_incr= in_rate * phase_count;
212 c->index= -phase_count*((c->filter_length-1)/2);
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213
214 return c;
a426016c 215error:
080ce907 216 av_free(c->filter_bank);
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217 av_free(c);
218 return NULL;
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219}
220
221void av_resample_close(AVResampleContext *c){
222 av_freep(&c->filter_bank);
223 av_freep(&c);
224}
225
226void av_resample_compensate(AVResampleContext *c, int sample_delta, int compensation_distance){
08f7073a 227// sample_delta += (c->ideal_dst_incr - c->dst_incr)*(int64_t)c->compensation_distance / c->ideal_dst_incr;
aaaf1635 228 c->compensation_distance= compensation_distance;
08f7073a 229 c->dst_incr = c->ideal_dst_incr - c->ideal_dst_incr * (int64_t)sample_delta / compensation_distance;
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230}
231
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232int av_resample(AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx){
233 int dst_index, i;
234 int index= c->index;
235 int frac= c->frac;
236 int dst_incr_frac= c->dst_incr % c->src_incr;
237 int dst_incr= c->dst_incr / c->src_incr;
80e85288 238 int compensation_distance= c->compensation_distance;
53f0090d 239
6cb5dcb3 240 if(compensation_distance == 0 && c->filter_length == 1 && c->phase_shift==0){
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241 int64_t index2= ((int64_t)index)<<32;
242 int64_t incr= (1LL<<32) * c->dst_incr / c->src_incr;
243 dst_size= FFMIN(dst_size, (src_size-1-index) * (int64_t)c->src_incr / c->dst_incr);
115329f1 244
6cb5dcb3 245 for(dst_index=0; dst_index < dst_size; dst_index++){
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246 dst[dst_index] = src[index2>>32];
247 index2 += incr;
6cb5dcb3 248 }
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249 frac += dst_index * dst_incr_frac;
250 index += dst_index * dst_incr;
251 index += frac / c->src_incr;
252 frac %= c->src_incr;
6cb5dcb3 253 }else{
aaaf1635 254 for(dst_index=0; dst_index < dst_size; dst_index++){
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255 FELEM *filter= c->filter_bank + c->filter_length*(index & c->phase_mask);
256 int sample_index= index >> c->phase_shift;
51a88020 257 FELEM2 val=0;
115329f1 258
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259 if(sample_index < 0){
260 for(i=0; i<c->filter_length; i++)
c26abfa5 261 val += src[FFABS(sample_index + i) % src_size] * filter[i];
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262 }else if(sample_index + c->filter_length > src_size){
263 break;
ed861c6b 264 }else if(c->linear){
303bd95c 265 FELEM2 v2=0;
aaaf1635 266 for(i=0; i<c->filter_length; i++){
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267 val += src[sample_index + i] * (FELEM2)filter[i];
268 v2 += src[sample_index + i] * (FELEM2)filter[i + c->filter_length];
aaaf1635 269 }
303bd95c 270 val+=(v2-val)*(FELEML)frac / c->src_incr;
ed861c6b 271 }else{
aaaf1635 272 for(i=0; i<c->filter_length; i++){
51a88020 273 val += src[sample_index + i] * (FELEM2)filter[i];
aaaf1635 274 }
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275 }
276
55fc0eb1 277#ifdef CONFIG_RESAMPLE_AUDIOPHILE_KIDDY_MODE
aee481ce 278 dst[dst_index] = av_clip_int16(lrintf(val));
55fc0eb1 279#else
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280 val = (val + (1<<(FILTER_SHIFT-1)))>>FILTER_SHIFT;
281 dst[dst_index] = (unsigned)(val + 32768) > 65535 ? (val>>31) ^ 32767 : val;
55fc0eb1 282#endif
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283
284 frac += dst_incr_frac;
285 index += dst_incr;
286 if(frac >= c->src_incr){
287 frac -= c->src_incr;
288 index++;
289 }
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290
291 if(dst_index + 1 == compensation_distance){
292 compensation_distance= 0;
293 dst_incr_frac= c->ideal_dst_incr % c->src_incr;
294 dst_incr= c->ideal_dst_incr / c->src_incr;
295 }
aaaf1635 296 }
6cb5dcb3 297 }
ed861c6b 298 *consumed= FFMAX(index, 0) >> c->phase_shift;
4e255822 299 if(index>=0) index &= c->phase_mask;
b9d2085b 300
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301 if(compensation_distance){
302 compensation_distance -= dst_index;
303 assert(compensation_distance > 0);
304 }
aaaf1635 305 if(update_ctx){
aaaf1635 306 c->frac= frac;
b9d2085b 307 c->index= index;
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308 c->dst_incr= dst_incr_frac + c->src_incr*dst_incr;
309 c->compensation_distance= compensation_distance;
aaaf1635 310 }
115329f1 311#if 0
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312 if(update_ctx && !c->compensation_distance){
313#undef rand
314 av_resample_compensate(c, rand() % (8000*2) - 8000, 8000*2);
315av_log(NULL, AV_LOG_DEBUG, "%d %d %d\n", c->dst_incr, c->ideal_dst_incr, c->compensation_distance);
316 }
317#endif
115329f1 318
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319 return dst_index;
320}