1/*
2 * audio resampling with soxr
3 * Copyright (c) 2012 Rob Sykes <robs@users.sourceforge.net>
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22/**
23 * @file
24 * audio resampling with soxr
25 */
26
27#include "libavutil/log.h"
28#include "swresample_internal.h"
29
30#include <soxr.h>
31
32static 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, double kaiser_beta, double precision, int cheby, int exact_rational){
34    soxr_error_t error;
35
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;
45
46    soxr_io_spec_t io_spec = soxr_io_spec(type, type);
47
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 = precision;
50#if !defined SOXR_VERSION /* Deprecated @ March 2013: */
51    q_spec.bw_pc = cutoff? FFMAX(FFMIN(cutoff,.995),.8)*100 : q_spec.bw_pc;
52#else
53    q_spec.passband_end = cutoff? FFMAX(FFMIN(cutoff,.995),.8) : q_spec.passband_end;
54#endif
55
56    soxr_delete((soxr_t)c);
57    c = (struct ResampleContext *)
58        soxr_create(in_rate, out_rate, 0, &error, &io_spec, &q_spec, 0);
59    if (!c)
60        av_log(NULL, AV_LOG_ERROR, "soxr_create: %s\n", error);
61    return c;
62}
63
64static void destroy(struct ResampleContext * *c){
65    soxr_delete((soxr_t)*c);
66    *c = NULL;
67}
68
69static int flush(struct SwrContext *s){
70    s->delayed_samples_fixup = soxr_delay((soxr_t)s->resample);
71
72    soxr_process((soxr_t)s->resample, NULL, 0, NULL, NULL, 0, NULL);
73
74    {
75        float f;
76        size_t idone, odone;
77        soxr_process((soxr_t)s->resample, &f, 0, &idone, &f, 0, &odone);
78        s->delayed_samples_fixup -= soxr_delay((soxr_t)s->resample);
79    }
80
81    return 0;
82}
83
84static int process(
85        struct ResampleContext * c, AudioData *dst, int dst_size,
86        AudioData *src, int src_size, int *consumed){
87    size_t idone, odone;
88    soxr_error_t error = soxr_set_error((soxr_t)c, soxr_set_num_channels((soxr_t)c, src->ch_count));
89    if (!error)
90        error = soxr_process((soxr_t)c, src->ch, (size_t)src_size,
91                             &idone, dst->ch, (size_t)dst_size, &odone);
92    else
93        idone = 0;
94
95    *consumed = (int)idone;
96    return error? -1 : odone;
97}
98
99static int64_t get_delay(struct SwrContext *s, int64_t base){
100    double delayed_samples = soxr_delay((soxr_t)s->resample);
101    double delay_s;
102
103    if (s->flushed)
104        delayed_samples += s->delayed_samples_fixup;
105
106    delay_s = delayed_samples / s->out_sample_rate;
107
108    return (int64_t)(delay_s * base + .5);
109}
110
111static int invert_initial_buffer(struct ResampleContext *c, AudioData *dst, const AudioData *src,
112                                 int in_count, int *out_idx, int *out_sz){
113    return 0;
114}
115
116static int64_t get_out_samples(struct SwrContext *s, int in_samples){
117    double out_samples = (double)s->out_sample_rate / s->in_sample_rate * in_samples;
118    double delayed_samples = soxr_delay((soxr_t)s->resample);
119
120    if (s->flushed)
121        delayed_samples += s->delayed_samples_fixup;
122
123    return (int64_t)(out_samples + delayed_samples + 1 + .5);
124}
125
126struct Resampler const swri_soxr_resampler={
127    create, destroy, process, flush, NULL /* set_compensation */, get_delay,
128    invert_initial_buffer, get_out_samples
129};
130
131