yading@11: /*
yading@11:  * audio resampling
yading@11:  * Copyright (c) 2004-2012 Michael Niedermayer <michaelni@gmx.at>
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: /**
yading@11:  * @file
yading@11:  * audio resampling
yading@11:  * @author Michael Niedermayer <michaelni@gmx.at>
yading@11:  */
yading@11: 
yading@11: #include "libavutil/log.h"
yading@11: #include "libavutil/avassert.h"
yading@11: #include "swresample_internal.h"
yading@11: 
yading@11: 
yading@11: typedef struct ResampleContext {
yading@11:     const AVClass *av_class;
yading@11:     uint8_t *filter_bank;
yading@11:     int filter_length;
yading@11:     int filter_alloc;
yading@11:     int ideal_dst_incr;
yading@11:     int dst_incr;
yading@11:     int index;
yading@11:     int frac;
yading@11:     int src_incr;
yading@11:     int compensation_distance;
yading@11:     int phase_shift;
yading@11:     int phase_mask;
yading@11:     int linear;
yading@11:     enum SwrFilterType filter_type;
yading@11:     int kaiser_beta;
yading@11:     double factor;
yading@11:     enum AVSampleFormat format;
yading@11:     int felem_size;
yading@11:     int filter_shift;
yading@11: } ResampleContext;
yading@11: 
yading@11: /**
yading@11:  * 0th order modified bessel function of the first kind.
yading@11:  */
yading@11: static double bessel(double x){
yading@11:     double v=1;
yading@11:     double lastv=0;
yading@11:     double t=1;
yading@11:     int i;
yading@11:     static const double inv[100]={
yading@11:  1.0/( 1* 1), 1.0/( 2* 2), 1.0/( 3* 3), 1.0/( 4* 4), 1.0/( 5* 5), 1.0/( 6* 6), 1.0/( 7* 7), 1.0/( 8* 8), 1.0/( 9* 9), 1.0/(10*10),
yading@11:  1.0/(11*11), 1.0/(12*12), 1.0/(13*13), 1.0/(14*14), 1.0/(15*15), 1.0/(16*16), 1.0/(17*17), 1.0/(18*18), 1.0/(19*19), 1.0/(20*20),
yading@11:  1.0/(21*21), 1.0/(22*22), 1.0/(23*23), 1.0/(24*24), 1.0/(25*25), 1.0/(26*26), 1.0/(27*27), 1.0/(28*28), 1.0/(29*29), 1.0/(30*30),
yading@11:  1.0/(31*31), 1.0/(32*32), 1.0/(33*33), 1.0/(34*34), 1.0/(35*35), 1.0/(36*36), 1.0/(37*37), 1.0/(38*38), 1.0/(39*39), 1.0/(40*40),
yading@11:  1.0/(41*41), 1.0/(42*42), 1.0/(43*43), 1.0/(44*44), 1.0/(45*45), 1.0/(46*46), 1.0/(47*47), 1.0/(48*48), 1.0/(49*49), 1.0/(50*50),
yading@11:  1.0/(51*51), 1.0/(52*52), 1.0/(53*53), 1.0/(54*54), 1.0/(55*55), 1.0/(56*56), 1.0/(57*57), 1.0/(58*58), 1.0/(59*59), 1.0/(60*60),
yading@11:  1.0/(61*61), 1.0/(62*62), 1.0/(63*63), 1.0/(64*64), 1.0/(65*65), 1.0/(66*66), 1.0/(67*67), 1.0/(68*68), 1.0/(69*69), 1.0/(70*70),
yading@11:  1.0/(71*71), 1.0/(72*72), 1.0/(73*73), 1.0/(74*74), 1.0/(75*75), 1.0/(76*76), 1.0/(77*77), 1.0/(78*78), 1.0/(79*79), 1.0/(80*80),
yading@11:  1.0/(81*81), 1.0/(82*82), 1.0/(83*83), 1.0/(84*84), 1.0/(85*85), 1.0/(86*86), 1.0/(87*87), 1.0/(88*88), 1.0/(89*89), 1.0/(90*90),
yading@11:  1.0/(91*91), 1.0/(92*92), 1.0/(93*93), 1.0/(94*94), 1.0/(95*95), 1.0/(96*96), 1.0/(97*97), 1.0/(98*98), 1.0/(99*99), 1.0/(10000)
yading@11:     };
yading@11: 
yading@11:     x= x*x/4;
yading@11:     for(i=0; v != lastv; i++){
yading@11:         lastv=v;
yading@11:         t *= x*inv[i];
yading@11:         v += t;
yading@11:         av_assert2(i<99);
yading@11:     }
yading@11:     return v;
yading@11: }
yading@11: 
yading@11: /**
yading@11:  * builds a polyphase filterbank.
yading@11:  * @param factor resampling factor
yading@11:  * @param scale wanted sum of coefficients for each filter
yading@11:  * @param filter_type  filter type
yading@11:  * @param kaiser_beta  kaiser window beta
yading@11:  * @return 0 on success, negative on error
yading@11:  */
yading@11: static int build_filter(ResampleContext *c, void *filter, double factor, int tap_count, int alloc, int phase_count, int scale,
yading@11:                         int filter_type, int kaiser_beta){
yading@11:     int ph, i;
yading@11:     double x, y, w;
yading@11:     double *tab = av_malloc(tap_count * sizeof(*tab));
yading@11:     const int center= (tap_count-1)/2;
yading@11: 
yading@11:     if (!tab)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     /* if upsampling, only need to interpolate, no filter */
yading@11:     if (factor > 1.0)
yading@11:         factor = 1.0;
yading@11: 
yading@11:     for(ph=0;ph<phase_count;ph++) {
yading@11:         double norm = 0;
yading@11:         for(i=0;i<tap_count;i++) {
yading@11:             x = M_PI * ((double)(i - center) - (double)ph / phase_count) * factor;
yading@11:             if (x == 0) y = 1.0;
yading@11:             else        y = sin(x) / x;
yading@11:             switch(filter_type){
yading@11:             case SWR_FILTER_TYPE_CUBIC:{
yading@11:                 const float d= -0.5; //first order derivative = -0.5
yading@11:                 x = fabs(((double)(i - center) - (double)ph / phase_count) * factor);
yading@11:                 if(x<1.0) y= 1 - 3*x*x + 2*x*x*x + d*(            -x*x + x*x*x);
yading@11:                 else      y=                       d*(-4 + 8*x - 5*x*x + x*x*x);
yading@11:                 break;}
yading@11:             case SWR_FILTER_TYPE_BLACKMAN_NUTTALL:
yading@11:                 w = 2.0*x / (factor*tap_count) + M_PI;
yading@11:                 y *= 0.3635819 - 0.4891775 * cos(w) + 0.1365995 * cos(2*w) - 0.0106411 * cos(3*w);
yading@11:                 break;
yading@11:             case SWR_FILTER_TYPE_KAISER:
yading@11:                 w = 2.0*x / (factor*tap_count*M_PI);
yading@11:                 y *= bessel(kaiser_beta*sqrt(FFMAX(1-w*w, 0)));
yading@11:                 break;
yading@11:             default:
yading@11:                 av_assert0(0);
yading@11:             }
yading@11: 
yading@11:             tab[i] = y;
yading@11:             norm += y;
yading@11:         }
yading@11: 
yading@11:         /* normalize so that an uniform color remains the same */
yading@11:         switch(c->format){
yading@11:         case AV_SAMPLE_FMT_S16P:
yading@11:             for(i=0;i<tap_count;i++)
yading@11:                 ((int16_t*)filter)[ph * alloc + i] = av_clip(lrintf(tab[i] * scale / norm), INT16_MIN, INT16_MAX);
yading@11:             break;
yading@11:         case AV_SAMPLE_FMT_S32P:
yading@11:             for(i=0;i<tap_count;i++)
yading@11:                 ((int32_t*)filter)[ph * alloc + i] = av_clipl_int32(llrint(tab[i] * scale / norm));
yading@11:             break;
yading@11:         case AV_SAMPLE_FMT_FLTP:
yading@11:             for(i=0;i<tap_count;i++)
yading@11:                 ((float*)filter)[ph * alloc + i] = tab[i] * scale / norm;
yading@11:             break;
yading@11:         case AV_SAMPLE_FMT_DBLP:
yading@11:             for(i=0;i<tap_count;i++)
yading@11:                 ((double*)filter)[ph * alloc + i] = tab[i] * scale / norm;
yading@11:             break;
yading@11:         }
yading@11:     }
yading@11: #if 0
yading@11:     {
yading@11: #define LEN 1024
yading@11:         int j,k;
yading@11:         double sine[LEN + tap_count];
yading@11:         double filtered[LEN];
yading@11:         double maxff=-2, minff=2, maxsf=-2, minsf=2;
yading@11:         for(i=0; i<LEN; i++){
yading@11:             double ss=0, sf=0, ff=0;
yading@11:             for(j=0; j<LEN+tap_count; j++)
yading@11:                 sine[j]= cos(i*j*M_PI/LEN);
yading@11:             for(j=0; j<LEN; j++){
yading@11:                 double sum=0;
yading@11:                 ph=0;
yading@11:                 for(k=0; k<tap_count; k++)
yading@11:                     sum += filter[ph * tap_count + k] * sine[k+j];
yading@11:                 filtered[j]= sum / (1<<FILTER_SHIFT);
yading@11:                 ss+= sine[j + center] * sine[j + center];
yading@11:                 ff+= filtered[j] * filtered[j];
yading@11:                 sf+= sine[j + center] * filtered[j];
yading@11:             }
yading@11:             ss= sqrt(2*ss/LEN);
yading@11:             ff= sqrt(2*ff/LEN);
yading@11:             sf= 2*sf/LEN;
yading@11:             maxff= FFMAX(maxff, ff);
yading@11:             minff= FFMIN(minff, ff);
yading@11:             maxsf= FFMAX(maxsf, sf);
yading@11:             minsf= FFMIN(minsf, sf);
yading@11:             if(i%11==0){
yading@11:                 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);
yading@11:                 minff=minsf= 2;
yading@11:                 maxff=maxsf= -2;
yading@11:             }
yading@11:         }
yading@11:     }
yading@11: #endif
yading@11: 
yading@11:     av_free(tab);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static ResampleContext *resample_init(ResampleContext *c, int out_rate, int in_rate, int filter_size, int phase_shift, int linear,
yading@11:                                     double cutoff0, enum AVSampleFormat format, enum SwrFilterType filter_type, int kaiser_beta,
yading@11:                                     double precision, int cheby){
yading@11:     double cutoff = cutoff0? cutoff0 : 0.97;
yading@11:     double factor= FFMIN(out_rate * cutoff / in_rate, 1.0);
yading@11:     int phase_count= 1<<phase_shift;
yading@11: 
yading@11:     if (!c || c->phase_shift != phase_shift || c->linear!=linear || c->factor != factor
yading@11:            || c->filter_length != FFMAX((int)ceil(filter_size/factor), 1) || c->format != format
yading@11:            || c->filter_type != filter_type || c->kaiser_beta != kaiser_beta) {
yading@11:         c = av_mallocz(sizeof(*c));
yading@11:         if (!c)
yading@11:             return NULL;
yading@11: 
yading@11:         c->format= format;
yading@11: 
yading@11:         c->felem_size= av_get_bytes_per_sample(c->format);
yading@11: 
yading@11:         switch(c->format){
yading@11:         case AV_SAMPLE_FMT_S16P:
yading@11:             c->filter_shift = 15;
yading@11:             break;
yading@11:         case AV_SAMPLE_FMT_S32P:
yading@11:             c->filter_shift = 30;
yading@11:             break;
yading@11:         case AV_SAMPLE_FMT_FLTP:
yading@11:         case AV_SAMPLE_FMT_DBLP:
yading@11:             c->filter_shift = 0;
yading@11:             break;
yading@11:         default:
yading@11:             av_log(NULL, AV_LOG_ERROR, "Unsupported sample format\n");
yading@11:             av_assert0(0);
yading@11:         }
yading@11: 
yading@11:         c->phase_shift   = phase_shift;
yading@11:         c->phase_mask    = phase_count - 1;
yading@11:         c->linear        = linear;
yading@11:         c->factor        = factor;
yading@11:         c->filter_length = FFMAX((int)ceil(filter_size/factor), 1);
yading@11:         c->filter_alloc  = FFALIGN(c->filter_length, 8);
yading@11:         c->filter_bank   = av_calloc(c->filter_alloc, (phase_count+1)*c->felem_size);
yading@11:         c->filter_type   = filter_type;
yading@11:         c->kaiser_beta   = kaiser_beta;
yading@11:         if (!c->filter_bank)
yading@11:             goto error;
yading@11:         if (build_filter(c, (void*)c->filter_bank, factor, c->filter_length, c->filter_alloc, phase_count, 1<<c->filter_shift, filter_type, kaiser_beta))
yading@11:             goto error;
yading@11:         memcpy(c->filter_bank + (c->filter_alloc*phase_count+1)*c->felem_size, c->filter_bank, (c->filter_alloc-1)*c->felem_size);
yading@11:         memcpy(c->filter_bank + (c->filter_alloc*phase_count  )*c->felem_size, c->filter_bank + (c->filter_alloc - 1)*c->felem_size, c->felem_size);
yading@11:     }
yading@11: 
yading@11:     c->compensation_distance= 0;
yading@11:     if(!av_reduce(&c->src_incr, &c->dst_incr, out_rate, in_rate * (int64_t)phase_count, INT32_MAX/2))
yading@11:         goto error;
yading@11:     c->ideal_dst_incr= c->dst_incr;
yading@11: 
yading@11:     c->index= -phase_count*((c->filter_length-1)/2);
yading@11:     c->frac= 0;
yading@11: 
yading@11:     return c;
yading@11: error:
yading@11:     av_free(c->filter_bank);
yading@11:     av_free(c);
yading@11:     return NULL;
yading@11: }
yading@11: 
yading@11: static void resample_free(ResampleContext **c){
yading@11:     if(!*c)
yading@11:         return;
yading@11:     av_freep(&(*c)->filter_bank);
yading@11:     av_freep(c);
yading@11: }
yading@11: 
yading@11: static int set_compensation(ResampleContext *c, int sample_delta, int compensation_distance){
yading@11:     c->compensation_distance= compensation_distance;
yading@11:     if (compensation_distance)
yading@11:         c->dst_incr = c->ideal_dst_incr - c->ideal_dst_incr * (int64_t)sample_delta / compensation_distance;
yading@11:     else
yading@11:         c->dst_incr = c->ideal_dst_incr;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: #define TEMPLATE_RESAMPLE_S16
yading@11: #include "resample_template.c"
yading@11: #undef TEMPLATE_RESAMPLE_S16
yading@11: 
yading@11: #define TEMPLATE_RESAMPLE_S32
yading@11: #include "resample_template.c"
yading@11: #undef TEMPLATE_RESAMPLE_S32
yading@11: 
yading@11: #define TEMPLATE_RESAMPLE_FLT
yading@11: #include "resample_template.c"
yading@11: #undef TEMPLATE_RESAMPLE_FLT
yading@11: 
yading@11: #define TEMPLATE_RESAMPLE_DBL
yading@11: #include "resample_template.c"
yading@11: #undef TEMPLATE_RESAMPLE_DBL
yading@11: 
yading@11: // XXX FIXME the whole C loop should be written in asm so this x86 specific code here isnt needed
yading@11: #if HAVE_MMXEXT_INLINE
yading@11: 
yading@11: #include "x86/resample_mmx.h"
yading@11: 
yading@11: #define TEMPLATE_RESAMPLE_S16_MMX2
yading@11: #include "resample_template.c"
yading@11: #undef TEMPLATE_RESAMPLE_S16_MMX2
yading@11: 
yading@11: #if HAVE_SSSE3_INLINE
yading@11: #define TEMPLATE_RESAMPLE_S16_SSSE3
yading@11: #include "resample_template.c"
yading@11: #undef TEMPLATE_RESAMPLE_S16_SSSE3
yading@11: #endif
yading@11: 
yading@11: #endif // HAVE_MMXEXT_INLINE
yading@11: 
yading@11: static int multiple_resample(ResampleContext *c, AudioData *dst, int dst_size, AudioData *src, int src_size, int *consumed){
yading@11:     int i, ret= -1;
yading@11:     int av_unused mm_flags = av_get_cpu_flags();
yading@11:     int need_emms= 0;
yading@11: 
yading@11:     for(i=0; i<dst->ch_count; i++){
yading@11: #if HAVE_MMXEXT_INLINE
yading@11: #if HAVE_SSSE3_INLINE
yading@11:              if(c->format == AV_SAMPLE_FMT_S16P && (mm_flags&AV_CPU_FLAG_SSSE3)) ret= swri_resample_int16_ssse3(c, (int16_t*)dst->ch[i], (const int16_t*)src->ch[i], consumed, src_size, dst_size, i+1==dst->ch_count);
yading@11:         else
yading@11: #endif
yading@11:              if(c->format == AV_SAMPLE_FMT_S16P && (mm_flags&AV_CPU_FLAG_MMX2 )){
yading@11:                  ret= swri_resample_int16_mmx2 (c, (int16_t*)dst->ch[i], (const int16_t*)src->ch[i], consumed, src_size, dst_size, i+1==dst->ch_count);
yading@11:                  need_emms= 1;
yading@11:              } else
yading@11: #endif
yading@11:              if(c->format == AV_SAMPLE_FMT_S16P) ret= swri_resample_int16(c, (int16_t*)dst->ch[i], (const int16_t*)src->ch[i], consumed, src_size, dst_size, i+1==dst->ch_count);
yading@11:         else if(c->format == AV_SAMPLE_FMT_S32P) ret= swri_resample_int32(c, (int32_t*)dst->ch[i], (const int32_t*)src->ch[i], consumed, src_size, dst_size, i+1==dst->ch_count);
yading@11:         else if(c->format == AV_SAMPLE_FMT_FLTP) ret= swri_resample_float(c, (float  *)dst->ch[i], (const float  *)src->ch[i], consumed, src_size, dst_size, i+1==dst->ch_count);
yading@11:         else if(c->format == AV_SAMPLE_FMT_DBLP) ret= swri_resample_double(c,(double *)dst->ch[i], (const double *)src->ch[i], consumed, src_size, dst_size, i+1==dst->ch_count);
yading@11:     }
yading@11:     if(need_emms)
yading@11:         emms_c();
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: static int64_t get_delay(struct SwrContext *s, int64_t base){
yading@11:     ResampleContext *c = s->resample;
yading@11:     int64_t num = s->in_buffer_count - (c->filter_length-1)/2;
yading@11:     num <<= c->phase_shift;
yading@11:     num -= c->index;
yading@11:     num *= c->src_incr;
yading@11:     num -= c->frac;
yading@11:     return av_rescale(num, base, s->in_sample_rate*(int64_t)c->src_incr << c->phase_shift);
yading@11: }
yading@11: 
yading@11: static int resample_flush(struct SwrContext *s) {
yading@11:     AudioData *a= &s->in_buffer;
yading@11:     int i, j, ret;
yading@11:     if((ret = swri_realloc_audio(a, s->in_buffer_index + 2*s->in_buffer_count)) < 0)
yading@11:         return ret;
yading@11:     av_assert0(a->planar);
yading@11:     for(i=0; i<a->ch_count; i++){
yading@11:         for(j=0; j<s->in_buffer_count; j++){
yading@11:             memcpy(a->ch[i] + (s->in_buffer_index+s->in_buffer_count+j  )*a->bps,
yading@11:                 a->ch[i] + (s->in_buffer_index+s->in_buffer_count-j-1)*a->bps, a->bps);
yading@11:         }
yading@11:     }
yading@11:     s->in_buffer_count += (s->in_buffer_count+1)/2;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: struct Resampler const swri_resampler={
yading@11:   resample_init,
yading@11:   resample_free,
yading@11:   multiple_resample,
yading@11:   resample_flush,
yading@11:   set_compensation,
yading@11:   get_delay,
yading@11: };