/* * audio resampling * Copyright (c) 2004-2012 Michael Niedermayer <michaelni@gmx.at> * * 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 * audio resampling * @author Michael Niedermayer <michaelni@gmx.at> */ #if defined(TEMPLATE_RESAMPLE_DBL) #    define RENAME(N) N ## _double#    define FILTER_SHIFT 0#    define DELEM  double#    define FELEM  double#    define FELEM2 double#    define FOFFSET 0#    define OUT(d, v) d = v #elif    defined(TEMPLATE_RESAMPLE_FLT) #    define RENAME(N) N ## _float#    define FILTER_SHIFT 0#    define DELEM  float#    define FELEM  float#    define FELEM2 float#    define FOFFSET 0#    define OUT(d, v) d = v #elif defined(TEMPLATE_RESAMPLE_S32) #    define RENAME(N) N ## _int32#    define FILTER_SHIFT 30#    define DELEM  int32_t#    define FELEM  int32_t#    define FELEM2 int64_t#    define FELEM_MAX INT32_MAX#    define FELEM_MIN INT32_MIN#    define FOFFSET (1<<(FILTER_SHIFT-1))#    define OUT(d, v) (d) = av_clipl_int32((v)>>FILTER_SHIFT) #elif    defined(TEMPLATE_RESAMPLE_S16) #    define RENAME(N) N ## _int16#    define FILTER_SHIFT 15#    define DELEM  int16_t#    define FELEM  int16_t#    define FELEM2 int32_t#    define FELEML int64_t#    define FELEM_MAX INT16_MAX#    define FELEM_MIN INT16_MIN#    define FOFFSET (1<<(FILTER_SHIFT-1))#    define OUT(d, v) (d) = av_clip_int16((v)>>FILTER_SHIFT) #endif static void RENAME(resample_one)(void *dest, const void *source,                                 int dst_size, int64_t index2, int64_t incr){    DELEM *dst = dest;    const DELEM *src = source;    int dst_index;     for (dst_index = 0; dst_index < dst_size; dst_index++) {        dst[dst_index] = src[index2 >> 32];        index2 += incr;    }} static int RENAME(resample_common)(ResampleContext *c,                                   void *dest, const void *source,                                   int n, int update_ctx){    DELEM *dst = dest;    const DELEM *src = source;    int dst_index;    int index= c->index;    int frac= c->frac;    int sample_index = 0;     while (index >= c->phase_count) {        sample_index++;        index -= c->phase_count;    }     for (dst_index = 0; dst_index < n; dst_index++) {        FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index;         FELEM2 val = FOFFSET;        FELEM2 val2= 0;        int i;        for (i = 0; i + 1 < c->filter_length; i+=2) {            val  += src[sample_index + i    ] * (FELEM2)filter[i    ];            val2 += src[sample_index + i + 1] * (FELEM2)filter[i + 1];        }        if (i < c->filter_length)            val  += src[sample_index + i    ] * (FELEM2)filter[i    ];#ifdef FELEML        OUT(dst[dst_index], val + (FELEML)val2);#else        OUT(dst[dst_index], val + val2);#endif         frac  += c->dst_incr_mod;        index += c->dst_incr_div;        if (frac >= c->src_incr) {            frac -= c->src_incr;            index++;        }         while (index >= c->phase_count) {            sample_index++;            index -= c->phase_count;        }    }     if(update_ctx){        c->frac= frac;        c->index= index;    }     return sample_index;} static int RENAME(resample_linear)(ResampleContext *c,                                   void *dest, const void *source,                                   int n, int update_ctx){    DELEM *dst = dest;    const DELEM *src = source;    int dst_index;    int index= c->index;    int frac= c->frac;    int sample_index = 0;#if FILTER_SHIFT == 0    double inv_src_incr = 1.0 / c->src_incr;#endif     while (index >= c->phase_count) {        sample_index++;        index -= c->phase_count;    }     for (dst_index = 0; dst_index < n; dst_index++) {        FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index;        FELEM2 val = FOFFSET, v2 = FOFFSET;         int i;        for (i = 0; i < c->filter_length; i++) {            val += src[sample_index + i] * (FELEM2)filter[i];            v2  += src[sample_index + i] * (FELEM2)filter[i + c->filter_alloc];        }#ifdef FELEML        val += (v2 - val) * (FELEML) frac / c->src_incr;#else#    if FILTER_SHIFT == 0        val += (v2 - val) * inv_src_incr * frac;#    else        val += (v2 - val) / c->src_incr * frac;#    endif#endif        OUT(dst[dst_index], val);         frac += c->dst_incr_mod;        index += c->dst_incr_div;        if (frac >= c->src_incr) {            frac -= c->src_incr;            index++;        }         while (index >= c->phase_count) {            sample_index++;            index -= c->phase_count;        }    }     if(update_ctx){        c->frac= frac;        c->index= index;    }     return sample_index;} #undef RENAME#undef FILTER_SHIFT#undef DELEM#undef FELEM#undef FELEM2#undef FELEML#undef FELEM_MAX#undef FELEM_MIN#undef OUT#undef FOFFSET