2 * audio resampling with soxr
3 * Copyright (c) 2012 Rob Sykes <robs@users.sourceforge.net>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * audio resampling with soxr
27 #include "libavutil/log.h"
28 #include "swresample_internal.h"
32 static struct ResampleContext *create(struct ResampleContext *c, int out_rate, int in_rate, int filter_size, int phase_shift, int linear,
33 double cutoff, enum AVSampleFormat format, enum SwrFilterType filter_type, int kaiser_beta, double precision, int cheby){
36 soxr_datatype_t type =
37 format == AV_SAMPLE_FMT_S16P? SOXR_INT16_S :
38 format == AV_SAMPLE_FMT_S16 ? SOXR_INT16_I :
39 format == AV_SAMPLE_FMT_S32P? SOXR_INT32_S :
40 format == AV_SAMPLE_FMT_S32 ? SOXR_INT32_I :
41 format == AV_SAMPLE_FMT_FLTP? SOXR_FLOAT32_S :
42 format == AV_SAMPLE_FMT_FLT ? SOXR_FLOAT32_I :
43 format == AV_SAMPLE_FMT_DBLP? SOXR_FLOAT64_S :
44 format == AV_SAMPLE_FMT_DBL ? SOXR_FLOAT64_I : (soxr_datatype_t)-1;
46 soxr_io_spec_t io_spec = soxr_io_spec(type, type);
48 soxr_quality_spec_t q_spec = soxr_quality_spec((int)((precision-2)/4), (SOXR_HI_PREC_CLOCK|SOXR_ROLLOFF_NONE)*!!cheby);
49 q_spec.precision = linear? 0 : precision;
50 q_spec.bw_pc = cutoff? FFMAX(FFMIN(cutoff,.995),.8)*100 : q_spec.bw_pc;
52 soxr_delete((soxr_t)c);
53 c = (struct ResampleContext *)
54 soxr_create(in_rate, out_rate, 0, &error, &io_spec, &q_spec, 0);
56 av_log(NULL, AV_LOG_ERROR, "soxr_create: %s\n", error);
60 static void destroy(struct ResampleContext * *c){
61 soxr_delete((soxr_t)*c);
65 static int flush(struct SwrContext *s){
66 soxr_process((soxr_t)s->resample, NULL, 0, NULL, NULL, 0, NULL);
71 struct ResampleContext * c, AudioData *dst, int dst_size,
72 AudioData *src, int src_size, int *consumed){
74 soxr_error_t error = soxr_set_error((soxr_t)c, soxr_set_num_channels((soxr_t)c, src->ch_count));
75 error = soxr_process((soxr_t)c, src->ch, (size_t)src_size,
76 &idone, dst->ch, (size_t)dst_size, &odone);
77 *consumed = (int)idone;
78 return error? -1 : odone;
81 static int64_t get_delay(struct SwrContext *s, int64_t base){
82 double delay_s = soxr_delay((soxr_t)s->resample) / s->out_sample_rate;
83 return (int64_t)(delay_s * base + .5);
86 struct Resampler const soxr_resampler={
87 create, destroy, process, flush, NULL /* set_compensation */, get_delay,