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path: root/libavfilter/af_vibrato.c (plain)
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1/*
2 * Copyright (c) 2015 Kyle Swanson <k@ylo.ph>.
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include "libavutil/opt.h"
22#include "avfilter.h"
23#include "internal.h"
24#include "audio.h"
25#include "generate_wave_table.h"
26
27typedef struct VibratoContext {
28 const AVClass *class;
29 double freq;
30 double depth;
31 int channels;
32
33 double **buf;
34 int buf_index;
35 int buf_size;
36
37 double *wave_table;
38 int wave_table_index;
39 int wave_table_size;
40} VibratoContext;
41
42#define OFFSET(x) offsetof(VibratoContext, x)
43#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
44
45static const AVOption vibrato_options[] = {
46 { "f", "set frequency in hertz", OFFSET(freq), AV_OPT_TYPE_DOUBLE, {.dbl = 5.0}, 0.1, 20000.0, FLAGS },
47 { "d", "set depth as percentage", OFFSET(depth), AV_OPT_TYPE_DOUBLE, {.dbl = 0.5}, 0.00, 1.0, FLAGS },
48 { NULL }
49};
50
51AVFILTER_DEFINE_CLASS(vibrato);
52
53static int filter_frame(AVFilterLink *inlink, AVFrame *in)
54{
55 AVFilterContext *ctx = inlink->dst;
56 VibratoContext *s = ctx->priv;
57 AVFilterLink *outlink = ctx->outputs[0];
58 AVFrame *out;
59 int n, c;
60 const double *src;
61 double *dst;
62
63 if (av_frame_is_writable(in)) {
64 out = in;
65 } else {
66 out = ff_get_audio_buffer(inlink, in->nb_samples);
67 if (!out) {
68 av_frame_free(&in);
69 return AVERROR(ENOMEM);
70 }
71 av_frame_copy_props(out, in);
72 }
73
74
75 for (n = 0; n < in->nb_samples; n++) {
76 double integer, decimal;
77 decimal = modf(s->depth * s->wave_table[s->wave_table_index], &integer);
78
79 s->wave_table_index++;
80 if (s->wave_table_index >= s->wave_table_size)
81 s->wave_table_index -= s->wave_table_size;
82
83 for (c = 0; c < inlink->channels; c++) {
84 int samp1_index, samp2_index;
85 double *buf;
86 double this_samp;
87
88 src = (const double *)in->extended_data[c];
89 dst = (double *)out->extended_data[c];
90 buf = s->buf[c];
91
92 samp1_index = s->buf_index + integer;
93 if (samp1_index >= s->buf_size)
94 samp1_index -= s->buf_size;
95 samp2_index = samp1_index + 1;
96 if (samp2_index >= s->buf_size)
97 samp2_index -= s->buf_size;
98
99 this_samp = src[n];
100 dst[n] = buf[samp1_index] + (decimal * (buf[samp2_index] - buf[samp1_index]));
101 buf[s->buf_index] = this_samp;
102 }
103 s->buf_index++;
104 if (s->buf_index >= s->buf_size)
105 s->buf_index -= s->buf_size;
106 }
107
108 if (in != out)
109 av_frame_free(&in);
110
111 return ff_filter_frame(outlink, out);
112}
113
114static int query_formats(AVFilterContext *ctx)
115{
116 AVFilterFormats *formats;
117 AVFilterChannelLayouts *layouts;
118 static const enum AVSampleFormat sample_fmts[] = {
119 AV_SAMPLE_FMT_DBLP,
120 AV_SAMPLE_FMT_NONE
121 };
122 int ret;
123
124 layouts = ff_all_channel_counts();
125 if (!layouts)
126 return AVERROR(ENOMEM);
127 ret = ff_set_common_channel_layouts(ctx, layouts);
128 if (ret < 0)
129 return ret;
130
131 formats = ff_make_format_list(sample_fmts);
132 if (!formats)
133 return AVERROR(ENOMEM);
134 ret = ff_set_common_formats(ctx, formats);
135 if (ret < 0)
136 return ret;
137
138 formats = ff_all_samplerates();
139 if (!formats)
140 return AVERROR(ENOMEM);
141 return ff_set_common_samplerates(ctx, formats);
142}
143
144static av_cold void uninit(AVFilterContext *ctx)
145{
146 VibratoContext *s = ctx->priv;
147 int c;
148
149 av_freep(&s->wave_table);
150 for (c = 0; c < s->channels; c++)
151 av_freep(&s->buf[c]);
152 av_freep(&s->buf);
153}
154
155static int config_input(AVFilterLink *inlink)
156{
157 int c;
158 AVFilterContext *ctx = inlink->dst;
159 VibratoContext *s = ctx->priv;
160 s->channels = inlink->channels;
161
162 s->buf = av_calloc(inlink->channels, sizeof(*s->buf));
163 if (!s->buf)
164 return AVERROR(ENOMEM);
165 s->buf_size = inlink->sample_rate * 0.005;
166 for (c = 0; c < s->channels; c++) {
167 s->buf[c] = av_malloc_array(s->buf_size, sizeof(*s->buf[c]));
168 if (!s->buf[c])
169 return AVERROR(ENOMEM);
170 }
171 s->buf_index = 0;
172
173 s->wave_table_size = inlink->sample_rate / s->freq;
174 s->wave_table = av_malloc_array(s->wave_table_size, sizeof(*s->wave_table));
175 if (!s->wave_table)
176 return AVERROR(ENOMEM);
177 ff_generate_wave_table(WAVE_SIN, AV_SAMPLE_FMT_DBL, s->wave_table, s->wave_table_size, 0.0, s->buf_size - 1, 3.0 * M_PI_2);
178 s->wave_table_index = 0;
179
180 return 0;
181}
182
183static const AVFilterPad avfilter_af_vibrato_inputs[] = {
184 {
185 .name = "default",
186 .type = AVMEDIA_TYPE_AUDIO,
187 .config_props = config_input,
188 .filter_frame = filter_frame,
189 },
190 { NULL }
191};
192
193static const AVFilterPad avfilter_af_vibrato_outputs[] = {
194 {
195 .name = "default",
196 .type = AVMEDIA_TYPE_AUDIO,
197 },
198 { NULL }
199};
200
201AVFilter ff_af_vibrato = {
202 .name = "vibrato",
203 .description = NULL_IF_CONFIG_SMALL("Apply vibrato effect."),
204 .priv_size = sizeof(VibratoContext),
205 .priv_class = &vibrato_class,
206 .uninit = uninit,
207 .query_formats = query_formats,
208 .inputs = avfilter_af_vibrato_inputs,
209 .outputs = avfilter_af_vibrato_outputs,
210};
211
generated by cgit at 2024-05-17 02:05:15 (GMT)