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/*
* 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 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 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 OUT(d, v) v = (v + (1<<(FILTER_SHIFT-1)))>>FILTER_SHIFT;\
d = (uint64_t)(v + 0x80000000) > 0xFFFFFFFF ? (v>>63) ^ 0x7FFFFFFF : v
#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 OUT(d, v) v = (v + (1<<(FILTER_SHIFT-1)))>>FILTER_SHIFT;\
d = (unsigned)(v + 32768) > 65535 ? (v>>31) ^ 32767 : v
#endif
static void RENAME(resample_one)(DELEM *dst, const DELEM *src,
int dst_size, int64_t index2, int64_t incr)
{
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,
DELEM *dst, const DELEM *src,
int n, int update_ctx)
{
int dst_index;
int index= c->index;
int frac= c->frac;
int sample_index = index >> c->phase_shift;
index &= c->phase_mask;
for (dst_index = 0; dst_index < n; dst_index++) {
FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index;
FELEM2 val=0;
int i;
for (i = 0; i < c->filter_length; i++) {
val += src[sample_index + i] * (FELEM2)filter[i];
}
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++;
}
sample_index += index >> c->phase_shift;
index &= c->phase_mask;
}
if(update_ctx){
c->frac= frac;
c->index= index;
}
return sample_index;
}
static int RENAME(resample_linear)(ResampleContext *c,
DELEM *dst, const DELEM *src,
int n, int update_ctx)
{
int dst_index;
int index= c->index;
int frac= c->frac;
int sample_index = index >> c->phase_shift;
#if FILTER_SHIFT == 0
double inv_src_incr = 1.0 / c->src_incr;
#endif
index &= c->phase_mask;
for (dst_index = 0; dst_index < n; dst_index++) {
FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index;
FELEM2 val=0, v2 = 0;
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++;
}
sample_index += index >> c->phase_shift;
index &= c->phase_mask;
}
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
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