FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavfilter/af_stereowiden.c
Date: 2026-09-27 18:38:33
Exec Total Coverage
Lines: 0 54 0.0%
Functions: 0 4 0.0%
Branches: 0 20 0.0%

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1 /*
2 * Copyright (C) 2012 VLC authors and VideoLAN
3 * Author : Sukrit Sangwan < sukritsangwan at gmail dot com >
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 #include "libavutil/channel_layout.h"
23 #include "libavutil/mem.h"
24 #include "libavutil/opt.h"
25 #include "avfilter.h"
26 #include "audio.h"
27 #include "filters.h"
28 #include "formats.h"
29
30 typedef struct StereoWidenContext {
31 const AVClass *class;
32
33 float delay;
34 float feedback;
35 float crossfeed;
36 float drymix;
37
38 float *buffer;
39 float *cur;
40 int length;
41 } StereoWidenContext;
42
43 #define OFFSET(x) offsetof(StereoWidenContext, x)
44 #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
45 #define AT AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
46
47 static const AVOption stereowiden_options[] = {
48 { "delay", "set delay time", OFFSET(delay), AV_OPT_TYPE_FLOAT, {.dbl=20}, 1, 100, A },
49 { "feedback", "set feedback gain", OFFSET(feedback), AV_OPT_TYPE_FLOAT, {.dbl=.3}, 0, 0.9, AT },
50 { "crossfeed", "set cross feed", OFFSET(crossfeed), AV_OPT_TYPE_FLOAT, {.dbl=.3}, 0, 0.8, AT },
51 { "drymix", "set dry-mix", OFFSET(drymix), AV_OPT_TYPE_FLOAT, {.dbl=.8}, 0, 1.0, AT },
52 { NULL }
53 };
54
55 AVFILTER_DEFINE_CLASS(stereowiden);
56
57 ✗ static int query_formats(const AVFilterContext *ctx,
58 AVFilterFormatsConfig **cfg_in,
59 AVFilterFormatsConfig **cfg_out)
60 {
61 static const enum AVSampleFormat formats[] = {
62 AV_SAMPLE_FMT_FLT,
63 AV_SAMPLE_FMT_NONE,
64 };
65 static const AVChannelLayout layouts[] = {
66 AV_CHANNEL_LAYOUT_STEREO,
67 { .nb_channels = 0 },
68 };
69
70 int ret;
71
72 ✗ ret = ff_set_sample_formats_from_list2(ctx, cfg_in, cfg_out, formats);
73 ✗ if (ret < 0)
74 ✗ return ret;
75
76 ✗ ret = ff_set_common_channel_layouts_from_list2(ctx, cfg_in, cfg_out, layouts);
77 ✗ if (ret < 0)
78 ✗ return ret;
79
80 ✗ return 0;
81 }
82
83 ✗ static int config_input(AVFilterLink *inlink)
84 {
85 ✗ AVFilterContext *ctx = inlink->dst;
86 ✗ StereoWidenContext *s = ctx->priv;
87
88 ✗ s->length = lrintf(s->delay * inlink->sample_rate / 1000);
89 ✗ s->length *= 2;
90 ✗ if (s->length == 0)
91 ✗ return AVERROR(EINVAL);
92 ✗ s->buffer = av_calloc(s->length, sizeof(*s->buffer));
93 ✗ if (!s->buffer)
94 ✗ return AVERROR(ENOMEM);
95 ✗ s->cur = s->buffer;
96
97 ✗ return 0;
98 }
99
100 ✗ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
101 {
102 ✗ AVFilterContext *ctx = inlink->dst;
103 ✗ AVFilterLink *outlink = ctx->outputs[0];
104 ✗ StereoWidenContext *s = ctx->priv;
105 ✗ const float *src = (const float *)in->data[0];
106 ✗ const float drymix = s->drymix;
107 ✗ const float crossfeed = s->crossfeed;
108 ✗ const float feedback = s->feedback;
109 AVFrame *out;
110 float *dst;
111 int n;
112
113 ✗ if (av_frame_is_writable(in)) {
114 ✗ out = in;
115 } else {
116 ✗ out = ff_get_audio_buffer(outlink, in->nb_samples);
117 ✗ if (!out) {
118 ✗ av_frame_free(&in);
119 ✗ return AVERROR(ENOMEM);
120 }
121 ✗ av_frame_copy_props(out, in);
122 }
123 ✗ dst = (float *)out->data[0];
124
125 ✗ for (n = 0; n < in->nb_samples; n++, src += 2, dst += 2, s->cur += 2) {
126 ✗ const float left = src[0], right = src[1];
127
128 ✗ if (s->cur == s->buffer + s->length)
129 ✗ s->cur = s->buffer;
130
131 ✗ if (ctx->is_disabled) {
132 ✗ dst[0] = left;
133 ✗ dst[1] = right;
134 } else {
135 ✗ dst[0] = drymix * left - crossfeed * right - feedback * s->cur[1];
136 ✗ dst[1] = drymix * right - crossfeed * left - feedback * s->cur[0];
137 }
138
139 ✗ s->cur[0] = left;
140 ✗ s->cur[1] = right;
141 }
142
143 ✗ if (out != in)
144 ✗ av_frame_free(&in);
145 ✗ return ff_filter_frame(outlink, out);
146 }
147
148 ✗ static av_cold void uninit(AVFilterContext *ctx)
149 {
150 ✗ StereoWidenContext *s = ctx->priv;
151
152 ✗ av_freep(&s->buffer);
153 ✗ }
154
155 static const AVFilterPad inputs[] = {
156 {
157 .name = "default",
158 .type = AVMEDIA_TYPE_AUDIO,
159 .filter_frame = filter_frame,
160 .config_props = config_input,
161 },
162 };
163
164 const FFFilter ff_af_stereowiden = {
165 .p.name = "stereowiden",
166 .p.description = NULL_IF_CONFIG_SMALL("Apply stereo widening effect."),
167 .p.priv_class = &stereowiden_class,
168 .p.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
169 .priv_size = sizeof(StereoWidenContext),
170 .uninit = uninit,
171 FILTER_INPUTS(inputs),
172 FILTER_OUTPUTS(ff_audio_default_filterpad),
173 FILTER_QUERY_FUNC2(query_formats),
174 .process_command = ff_filter_process_command,
175 };
176