FFmpeg
af_vibrato.c
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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/mem.h"
22 #include "libavutil/opt.h"
23 #include "avfilter.h"
24 #include "internal.h"
25 #include "audio.h"
26 #include "generate_wave_table.h"
27 
28 typedef struct VibratoContext {
29  const AVClass *class;
30  double freq;
31  double depth;
32  int channels;
33 
34  double **buf;
35  int buf_index;
36  int buf_size;
37 
38  double *wave_table;
42 
43 #define OFFSET(x) offsetof(VibratoContext, x)
44 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
45 
46 static const AVOption vibrato_options[] = {
47  { "f", "set frequency in hertz", OFFSET(freq), AV_OPT_TYPE_DOUBLE, {.dbl = 5.0}, 0.1, 20000.0, FLAGS },
48  { "d", "set depth as percentage", OFFSET(depth), AV_OPT_TYPE_DOUBLE, {.dbl = 0.5}, 0.00, 1.0, FLAGS },
49  { NULL }
50 };
51 
52 AVFILTER_DEFINE_CLASS(vibrato);
53 
55 {
56  AVFilterContext *ctx = inlink->dst;
57  VibratoContext *s = ctx->priv;
58  const int wave_table_size = s->wave_table_size;
59  const double *wave_table = s->wave_table;
60  AVFilterLink *outlink = ctx->outputs[0];
61  const int channels = s->channels;
62  const int buf_size = s->buf_size;
63  const double depth = s->depth;
64  int wave_table_index = s->wave_table_index;
65  int buf_index = s->buf_index;
66  AVFrame *out;
67  const double *src;
68  double *dst;
69 
70  if (av_frame_is_writable(in)) {
71  out = in;
72  } else {
73  out = ff_get_audio_buffer(outlink, in->nb_samples);
74  if (!out) {
75  av_frame_free(&in);
76  return AVERROR(ENOMEM);
77  }
79  }
80 
81  for (int n = 0; n < in->nb_samples; n++) {
82  int samp1_index, samp2_index;
83  double integer, decimal;
84  decimal = modf(depth * wave_table[wave_table_index], &integer);
85 
86  wave_table_index++;
87  if (wave_table_index >= wave_table_size)
88  wave_table_index -= wave_table_size;
89 
90  samp1_index = buf_index + integer;
91  if (samp1_index >= buf_size)
92  samp1_index -= buf_size;
93  samp2_index = samp1_index + 1;
94  if (samp2_index >= buf_size)
95  samp2_index -= buf_size;
96 
97  for (int c = 0; c < channels; c++) {
98  double *buf, this_samp;
99 
100  src = (const double *)in->extended_data[c];
101  dst = (double *)out->extended_data[c];
102  buf = s->buf[c];
103 
104  this_samp = src[n];
105  dst[n] = buf[samp1_index] + (decimal * (buf[samp2_index] - buf[samp1_index]));
106  buf[buf_index] = this_samp;
107  }
108  buf_index++;
109  if (buf_index >= buf_size)
110  buf_index -= buf_size;
111  }
112 
113  s->wave_table_index = wave_table_index;
114  s->buf_index = buf_index;
115  if (in != out)
116  av_frame_free(&in);
117 
118  return ff_filter_frame(outlink, out);
119 }
120 
122 {
123  VibratoContext *s = ctx->priv;
124  int c;
125 
126  av_freep(&s->wave_table);
127  for (c = 0; c < s->channels; c++)
128  av_freep(&s->buf[c]);
129  av_freep(&s->buf);
130 }
131 
133 {
134  int c;
135  AVFilterContext *ctx = inlink->dst;
136  VibratoContext *s = ctx->priv;
137 
138  s->buf = av_calloc(inlink->ch_layout.nb_channels, sizeof(*s->buf));
139  if (!s->buf)
140  return AVERROR(ENOMEM);
141  s->channels = inlink->ch_layout.nb_channels;
142  s->buf_size = lrint(inlink->sample_rate * 0.005 + 0.5);
143  for (c = 0; c < s->channels; c++) {
144  s->buf[c] = av_malloc_array(s->buf_size, sizeof(*s->buf[c]));
145  if (!s->buf[c])
146  return AVERROR(ENOMEM);
147  }
148  s->buf_index = 0;
149 
150  s->wave_table_size = lrint(inlink->sample_rate / s->freq + 0.5);
151  s->wave_table = av_malloc_array(s->wave_table_size, sizeof(*s->wave_table));
152  if (!s->wave_table)
153  return AVERROR(ENOMEM);
154  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);
155  s->wave_table_index = 0;
156 
157  return 0;
158 }
159 
161  {
162  .name = "default",
163  .type = AVMEDIA_TYPE_AUDIO,
164  .config_props = config_input,
165  .filter_frame = filter_frame,
166  },
167 };
168 
170  .name = "vibrato",
171  .description = NULL_IF_CONFIG_SMALL("Apply vibrato effect."),
172  .priv_size = sizeof(VibratoContext),
173  .priv_class = &vibrato_class,
174  .uninit = uninit,
179 };
ff_get_audio_buffer
AVFrame * ff_get_audio_buffer(AVFilterLink *link, int nb_samples)
Request an audio samples buffer with a specific set of permissions.
Definition: audio.c:97
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
out
FILE * out
Definition: movenc.c:55
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1015
VibratoContext::wave_table
double * wave_table
Definition: af_vibrato.c:38
FILTER_SINGLE_SAMPLEFMT
#define FILTER_SINGLE_SAMPLEFMT(sample_fmt_)
Definition: internal.h:175
inlink
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
Definition: filter_design.txt:212
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:160
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:375
M_PI_2
#define M_PI_2
Definition: mathematics.h:73
VibratoContext::freq
double freq
Definition: af_vibrato.c:30
AVOption
AVOption.
Definition: opt.h:346
integer
int integer
Definition: swresample_internal.h:37
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:170
VibratoContext
Definition: af_vibrato.c:28
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: af_vibrato.c:54
uninit
static av_cold void uninit(AVFilterContext *ctx)
Definition: af_vibrato.c:121
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:33
lrint
#define lrint
Definition: tablegen.h:53
av_cold
#define av_cold
Definition: attributes.h:90
avfilter_af_vibrato_inputs
static const AVFilterPad avfilter_af_vibrato_inputs[]
Definition: af_vibrato.c:160
s
#define s(width, name)
Definition: cbs_vp9.c:198
AV_OPT_TYPE_DOUBLE
@ AV_OPT_TYPE_DOUBLE
Definition: opt.h:237
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
ctx
AVFormatContext * ctx
Definition: movenc.c:49
channels
channels
Definition: aptx.h:31
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:182
WAVE_SIN
@ WAVE_SIN
Definition: generate_wave_table.h:25
ff_af_vibrato
const AVFilter ff_af_vibrato
Definition: af_vibrato.c:169
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
VibratoContext::buf
double ** buf
Definition: af_vibrato.c:34
NULL
#define NULL
Definition: coverity.c:32
av_frame_copy_props
int av_frame_copy_props(AVFrame *dst, const AVFrame *src)
Copy only "metadata" fields from src to dst.
Definition: frame.c:709
VibratoContext::wave_table_size
int wave_table_size
Definition: af_vibrato.c:40
config_input
static int config_input(AVFilterLink *inlink)
Definition: af_vibrato.c:132
ff_audio_default_filterpad
const AVFilterPad ff_audio_default_filterpad[1]
An AVFilterPad array whose only entry has name "default" and is of type AVMEDIA_TYPE_AUDIO.
Definition: audio.c:33
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(vibrato)
FLAGS
#define FLAGS
Definition: af_vibrato.c:44
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
ff_generate_wave_table
void ff_generate_wave_table(enum WaveType wave_type, enum AVSampleFormat sample_fmt, void *table, int table_size, double min, double max, double phase)
Definition: generate_wave_table.c:24
VibratoContext::buf_index
int buf_index
Definition: af_vibrato.c:35
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:94
av_frame_is_writable
int av_frame_is_writable(AVFrame *frame)
Check if the frame data is writable.
Definition: frame.c:645
vibrato_options
static const AVOption vibrato_options[]
Definition: af_vibrato.c:46
VibratoContext::depth
double depth
Definition: af_vibrato.c:31
internal.h
AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
#define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
Some filters support a generic "enable" expression option that can be used to enable or disable a fil...
Definition: avfilter.h:147
AVFrame::nb_samples
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:455
AVFrame::extended_data
uint8_t ** extended_data
pointers to the data planes/channels.
Definition: frame.h:436
av_malloc_array
#define av_malloc_array(a, b)
Definition: tableprint_vlc.h:31
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:39
av_calloc
void * av_calloc(size_t nmemb, size_t size)
Definition: mem.c:264
AVFilter
Filter definition.
Definition: avfilter.h:166
VibratoContext::buf_size
int buf_size
Definition: af_vibrato.c:36
generate_wave_table.h
avfilter.h
AV_SAMPLE_FMT_DBLP
@ AV_SAMPLE_FMT_DBLP
double, planar
Definition: samplefmt.h:67
AVFilterContext
An instance of a filter.
Definition: avfilter.h:407
mem.h
audio.h
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:183
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
VibratoContext::wave_table_index
int wave_table_index
Definition: af_vibrato.c:39
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
VibratoContext::channels
int channels
Definition: af_vibrato.c:32
AV_SAMPLE_FMT_DBL
@ AV_SAMPLE_FMT_DBL
double
Definition: samplefmt.h:61
OFFSET
#define OFFSET(x)
Definition: af_vibrato.c:43