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00028 #include "avcodec.h"
00029 #include "dsputil.h"
00030
00031 #ifndef CONFIG_RESAMPLE_HP
00032 #define FILTER_SHIFT 15
00033
00034 #define FELEM int16_t
00035 #define FELEM2 int32_t
00036 #define FELEML int64_t
00037 #define FELEM_MAX INT16_MAX
00038 #define FELEM_MIN INT16_MIN
00039 #define WINDOW_TYPE 9
00040 #elif !defined(CONFIG_RESAMPLE_AUDIOPHILE_KIDDY_MODE)
00041 #define FILTER_SHIFT 30
00042
00043 #define FELEM int32_t
00044 #define FELEM2 int64_t
00045 #define FELEML int64_t
00046 #define FELEM_MAX INT32_MAX
00047 #define FELEM_MIN INT32_MIN
00048 #define WINDOW_TYPE 12
00049 #else
00050 #define FILTER_SHIFT 0
00051
00052 #define FELEM double
00053 #define FELEM2 double
00054 #define FELEML double
00055 #define WINDOW_TYPE 24
00056 #endif
00057
00058
00059 typedef struct AVResampleContext{
00060 FELEM *filter_bank;
00061 int filter_length;
00062 int ideal_dst_incr;
00063 int dst_incr;
00064 int index;
00065 int frac;
00066 int src_incr;
00067 int compensation_distance;
00068 int phase_shift;
00069 int phase_mask;
00070 int linear;
00071 }AVResampleContext;
00072
00076 static double bessel(double x){
00077 double v=1;
00078 double t=1;
00079 int i;
00080
00081 x= x*x/4;
00082 for(i=1; i<50; i++){
00083 t *= x/(i*i);
00084 v += t;
00085 }
00086 return v;
00087 }
00088
00095 void av_build_filter(FELEM *filter, double factor, int tap_count, int phase_count, int scale, int type){
00096 int ph, i;
00097 double x, y, w, tab[tap_count];
00098 const int center= (tap_count-1)/2;
00099
00100
00101 if (factor > 1.0)
00102 factor = 1.0;
00103
00104 for(ph=0;ph<phase_count;ph++) {
00105 double norm = 0;
00106 for(i=0;i<tap_count;i++) {
00107 x = M_PI * ((double)(i - center) - (double)ph / phase_count) * factor;
00108 if (x == 0) y = 1.0;
00109 else y = sin(x) / x;
00110 switch(type){
00111 case 0:{
00112 const float d= -0.5;
00113 x = fabs(((double)(i - center) - (double)ph / phase_count) * factor);
00114 if(x<1.0) y= 1 - 3*x*x + 2*x*x*x + d*( -x*x + x*x*x);
00115 else y= d*(-4 + 8*x - 5*x*x + x*x*x);
00116 break;}
00117 case 1:
00118 w = 2.0*x / (factor*tap_count) + M_PI;
00119 y *= 0.3635819 - 0.4891775 * cos(w) + 0.1365995 * cos(2*w) - 0.0106411 * cos(3*w);
00120 break;
00121 default:
00122 w = 2.0*x / (factor*tap_count*M_PI);
00123 y *= bessel(type*sqrt(FFMAX(1-w*w, 0)));
00124 break;
00125 }
00126
00127 tab[i] = y;
00128 norm += y;
00129 }
00130
00131
00132 for(i=0;i<tap_count;i++) {
00133 #ifdef CONFIG_RESAMPLE_AUDIOPHILE_KIDDY_MODE
00134 filter[ph * tap_count + i] = tab[i] / norm;
00135 #else
00136 filter[ph * tap_count + i] = av_clip(lrintf(tab[i] * scale / norm), FELEM_MIN, FELEM_MAX);
00137 #endif
00138 }
00139 }
00140 #if 0
00141 {
00142 #define LEN 1024
00143 int j,k;
00144 double sine[LEN + tap_count];
00145 double filtered[LEN];
00146 double maxff=-2, minff=2, maxsf=-2, minsf=2;
00147 for(i=0; i<LEN; i++){
00148 double ss=0, sf=0, ff=0;
00149 for(j=0; j<LEN+tap_count; j++)
00150 sine[j]= cos(i*j*M_PI/LEN);
00151 for(j=0; j<LEN; j++){
00152 double sum=0;
00153 ph=0;
00154 for(k=0; k<tap_count; k++)
00155 sum += filter[ph * tap_count + k] * sine[k+j];
00156 filtered[j]= sum / (1<<FILTER_SHIFT);
00157 ss+= sine[j + center] * sine[j + center];
00158 ff+= filtered[j] * filtered[j];
00159 sf+= sine[j + center] * filtered[j];
00160 }
00161 ss= sqrt(2*ss/LEN);
00162 ff= sqrt(2*ff/LEN);
00163 sf= 2*sf/LEN;
00164 maxff= FFMAX(maxff, ff);
00165 minff= FFMIN(minff, ff);
00166 maxsf= FFMAX(maxsf, sf);
00167 minsf= FFMIN(minsf, sf);
00168 if(i%11==0){
00169 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);
00170 minff=minsf= 2;
00171 maxff=maxsf= -2;
00172 }
00173 }
00174 }
00175 #endif
00176 }
00177
00178 AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_size, int phase_shift, int linear, double cutoff){
00179 AVResampleContext *c= av_mallocz(sizeof(AVResampleContext));
00180 double factor= FFMIN(out_rate * cutoff / in_rate, 1.0);
00181 int phase_count= 1<<phase_shift;
00182
00183 c->phase_shift= phase_shift;
00184 c->phase_mask= phase_count-1;
00185 c->linear= linear;
00186
00187 c->filter_length= FFMAX((int)ceil(filter_size/factor), 1);
00188 c->filter_bank= av_mallocz(c->filter_length*(phase_count+1)*sizeof(FELEM));
00189 av_build_filter(c->filter_bank, factor, c->filter_length, phase_count, 1<<FILTER_SHIFT, WINDOW_TYPE);
00190 memcpy(&c->filter_bank[c->filter_length*phase_count+1], c->filter_bank, (c->filter_length-1)*sizeof(FELEM));
00191 c->filter_bank[c->filter_length*phase_count]= c->filter_bank[c->filter_length - 1];
00192
00193 if(!av_reduce(&c->src_incr, &c->dst_incr, out_rate, in_rate * (int64_t)phase_count, INT32_MAX/2))
00194 return NULL;
00195 c->ideal_dst_incr= c->dst_incr;
00196
00197 c->index= -phase_count*((c->filter_length-1)/2);
00198
00199 return c;
00200 }
00201
00202 void av_resample_close(AVResampleContext *c){
00203 av_freep(&c->filter_bank);
00204 av_freep(&c);
00205 }
00206
00207 void av_resample_compensate(AVResampleContext *c, int sample_delta, int compensation_distance){
00208
00209 c->compensation_distance= compensation_distance;
00210 c->dst_incr = c->ideal_dst_incr - c->ideal_dst_incr * (int64_t)sample_delta / compensation_distance;
00211 }
00212
00213 int av_resample(AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx){
00214 int dst_index, i;
00215 int index= c->index;
00216 int frac= c->frac;
00217 int dst_incr_frac= c->dst_incr % c->src_incr;
00218 int dst_incr= c->dst_incr / c->src_incr;
00219 int compensation_distance= c->compensation_distance;
00220
00221 if(compensation_distance == 0 && c->filter_length == 1 && c->phase_shift==0){
00222 int64_t index2= ((int64_t)index)<<32;
00223 int64_t incr= (1LL<<32) * c->dst_incr / c->src_incr;
00224 dst_size= FFMIN(dst_size, (src_size-1-index) * (int64_t)c->src_incr / c->dst_incr);
00225
00226 for(dst_index=0; dst_index < dst_size; dst_index++){
00227 dst[dst_index] = src[index2>>32];
00228 index2 += incr;
00229 }
00230 index += dst_index * dst_incr;
00231 index += (frac + dst_index * (int64_t)dst_incr_frac) / c->src_incr;
00232 frac = (frac + dst_index * (int64_t)dst_incr_frac) % c->src_incr;
00233 }else{
00234 for(dst_index=0; dst_index < dst_size; dst_index++){
00235 FELEM *filter= c->filter_bank + c->filter_length*(index & c->phase_mask);
00236 int sample_index= index >> c->phase_shift;
00237 FELEM2 val=0;
00238
00239 if(sample_index < 0){
00240 for(i=0; i<c->filter_length; i++)
00241 val += src[FFABS(sample_index + i) % src_size] * filter[i];
00242 }else if(sample_index + c->filter_length > src_size){
00243 break;
00244 }else if(c->linear){
00245 FELEM2 v2=0;
00246 for(i=0; i<c->filter_length; i++){
00247 val += src[sample_index + i] * (FELEM2)filter[i];
00248 v2 += src[sample_index + i] * (FELEM2)filter[i + c->filter_length];
00249 }
00250 val+=(v2-val)*(FELEML)frac / c->src_incr;
00251 }else{
00252 for(i=0; i<c->filter_length; i++){
00253 val += src[sample_index + i] * (FELEM2)filter[i];
00254 }
00255 }
00256
00257 #ifdef CONFIG_RESAMPLE_AUDIOPHILE_KIDDY_MODE
00258 dst[dst_index] = av_clip_int16(lrintf(val));
00259 #else
00260 val = (val + (1<<(FILTER_SHIFT-1)))>>FILTER_SHIFT;
00261 dst[dst_index] = (unsigned)(val + 32768) > 65535 ? (val>>31) ^ 32767 : val;
00262 #endif
00263
00264 frac += dst_incr_frac;
00265 index += dst_incr;
00266 if(frac >= c->src_incr){
00267 frac -= c->src_incr;
00268 index++;
00269 }
00270
00271 if(dst_index + 1 == compensation_distance){
00272 compensation_distance= 0;
00273 dst_incr_frac= c->ideal_dst_incr % c->src_incr;
00274 dst_incr= c->ideal_dst_incr / c->src_incr;
00275 }
00276 }
00277 }
00278 *consumed= FFMAX(index, 0) >> c->phase_shift;
00279 if(index>=0) index &= c->phase_mask;
00280
00281 if(compensation_distance){
00282 compensation_distance -= dst_index;
00283 assert(compensation_distance > 0);
00284 }
00285 if(update_ctx){
00286 c->frac= frac;
00287 c->index= index;
00288 c->dst_incr= dst_incr_frac + c->src_incr*dst_incr;
00289 c->compensation_distance= compensation_distance;
00290 }
00291 #if 0
00292 if(update_ctx && !c->compensation_distance){
00293 #undef rand
00294 av_resample_compensate(c, rand() % (8000*2) - 8000, 8000*2);
00295 av_log(NULL, AV_LOG_DEBUG, "%d %d %d\n", c->dst_incr, c->ideal_dst_incr, c->compensation_distance);
00296 }
00297 #endif
00298
00299 return dst_index;
00300 }