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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 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
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