path: root/libswresample/soxr_resample.c (plain)
blob: 8181c749b860b16781e35f8ac21832de81dc512c

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
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, 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
64	static void destroy(struct ResampleContext * *c){
65	soxr_delete((soxr_t)*c);
66	*c = NULL;
67	}
68
69	static 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
84	static 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
99	static 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
111	static 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
116	static 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
126	struct 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