GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavfilter/af_extrastereo.c Lines: 31 38 81.6 %
Date: 2020-08-13 15:06:06 Branches: 9 18 50.0 %

Line Branch Exec Source
1
/*
2
 * Copyright (c) 2015 The FFmpeg Project
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/channel_layout.h"
22
#include "libavutil/opt.h"
23
#include "avfilter.h"
24
#include "audio.h"
25
#include "formats.h"
26
27
typedef struct ExtraStereoContext {
28
    const AVClass *class;
29
    float mult;
30
    int clip;
31
} ExtraStereoContext;
32
33
#define OFFSET(x) offsetof(ExtraStereoContext, x)
34
#define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
35
36
static const AVOption extrastereo_options[] = {
37
    { "m", "set the difference coefficient", OFFSET(mult), AV_OPT_TYPE_FLOAT, {.dbl=2.5}, -10, 10, A },
38
    { "c", "enable clipping",                OFFSET(clip), AV_OPT_TYPE_BOOL,  {.i64=1},     0,  1, A },
39
    { NULL }
40
};
41
42
AVFILTER_DEFINE_CLASS(extrastereo);
43
44
1
static int query_formats(AVFilterContext *ctx)
45
{
46
1
    AVFilterFormats *formats = NULL;
47
1
    AVFilterChannelLayouts *layout = NULL;
48
    int ret;
49
50

2
    if ((ret = ff_add_format                 (&formats, AV_SAMPLE_FMT_FLT  )) < 0 ||
51
2
        (ret = ff_set_common_formats         (ctx     , formats            )) < 0 ||
52
2
        (ret = ff_add_channel_layout         (&layout , AV_CH_LAYOUT_STEREO)) < 0 ||
53
1
        (ret = ff_set_common_channel_layouts (ctx     , layout             )) < 0)
54
        return ret;
55
56
1
    formats = ff_all_samplerates();
57
1
    return ff_set_common_samplerates(ctx, formats);
58
}
59
60
20
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
61
{
62
20
    AVFilterContext *ctx = inlink->dst;
63
20
    AVFilterLink *outlink = ctx->outputs[0];
64
20
    ExtraStereoContext *s = ctx->priv;
65
20
    const float *src = (const float *)in->data[0];
66
20
    const float mult = s->mult;
67
    AVFrame *out;
68
    float *dst;
69
    int n;
70
71
20
    if (av_frame_is_writable(in)) {
72
20
        out = in;
73
    } else {
74
        out = ff_get_audio_buffer(outlink, in->nb_samples);
75
        if (!out) {
76
            av_frame_free(&in);
77
            return AVERROR(ENOMEM);
78
        }
79
        av_frame_copy_props(out, in);
80
    }
81
20
    dst = (float *)out->data[0];
82
83
20500
    for (n = 0; n < in->nb_samples; n++) {
84
        float average, left, right;
85
86
20480
        left    = src[n * 2    ];
87
20480
        right   = src[n * 2 + 1];
88
20480
        average = (left + right) / 2.;
89
20480
        left    = average + mult * (left  - average);
90
20480
        right   = average + mult * (right - average);
91
92
20480
        if (s->clip) {
93
20480
            left  = av_clipf(left,  -1, 1);
94
20480
            right = av_clipf(right, -1, 1);
95
        }
96
97
20480
        dst[n * 2    ] = left;
98
20480
        dst[n * 2 + 1] = right;
99
    }
100
101
20
    if (out != in)
102
        av_frame_free(&in);
103
20
    return ff_filter_frame(outlink, out);
104
}
105
106
static const AVFilterPad inputs[] = {
107
    {
108
        .name         = "default",
109
        .type         = AVMEDIA_TYPE_AUDIO,
110
        .filter_frame = filter_frame,
111
    },
112
    { NULL }
113
};
114
115
static const AVFilterPad outputs[] = {
116
    {
117
        .name = "default",
118
        .type = AVMEDIA_TYPE_AUDIO,
119
    },
120
    { NULL }
121
};
122
123
AVFilter ff_af_extrastereo = {
124
    .name           = "extrastereo",
125
    .description    = NULL_IF_CONFIG_SMALL("Increase difference between stereo audio channels."),
126
    .query_formats  = query_formats,
127
    .priv_size      = sizeof(ExtraStereoContext),
128
    .priv_class     = &extrastereo_class,
129
    .inputs         = inputs,
130
    .outputs        = outputs,
131
    .flags          = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
132
    .process_command = ff_filter_process_command,
133
};