FFmpeg
af_tremolo.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/opt.h"
22 #include "avfilter.h"
23 #include "internal.h"
24 #include "audio.h"
25 
26 typedef struct TremoloContext {
27  const AVClass *class;
28  double freq;
29  double depth;
30  double *table;
32  int index;
34 
35 #define OFFSET(x) offsetof(TremoloContext, x)
36 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
37 
38 static const AVOption tremolo_options[] = {
39  { "f", "set frequency in hertz", OFFSET(freq), AV_OPT_TYPE_DOUBLE, {.dbl = 5.0}, 0.1, 20000.0, FLAGS },
40  { "d", "set depth as percentage", OFFSET(depth), AV_OPT_TYPE_DOUBLE, {.dbl = 0.5}, 0.0, 1.0, FLAGS },
41  { NULL }
42 };
43 
44 AVFILTER_DEFINE_CLASS(tremolo);
45 
47 {
48  AVFilterContext *ctx = inlink->dst;
49  AVFilterLink *outlink = ctx->outputs[0];
50  TremoloContext *s = ctx->priv;
51  const double *src = (const double *)in->data[0];
52  const int channels = inlink->channels;
53  const int nb_samples = in->nb_samples;
54  AVFrame *out;
55  double *dst;
56  int n, c;
57 
58  if (av_frame_is_writable(in)) {
59  out = in;
60  } else {
61  out = ff_get_audio_buffer(outlink, in->nb_samples);
62  if (!out) {
63  av_frame_free(&in);
64  return AVERROR(ENOMEM);
65  }
67  }
68  dst = (double *)out->data[0];
69 
70  for (n = 0; n < nb_samples; n++) {
71  for (c = 0; c < channels; c++)
72  dst[c] = src[c] * s->table[s->index];
73  dst += channels;
74  src += channels;
75  s->index++;
76  if (s->index >= s->table_size)
77  s->index = 0;
78  }
79 
80  if (in != out)
81  av_frame_free(&in);
82 
83  return ff_filter_frame(outlink, out);
84 }
85 
87 {
90  static const enum AVSampleFormat sample_fmts[] = {
93  };
94  int ret;
95 
96  layouts = ff_all_channel_counts();
97  if (!layouts)
98  return AVERROR(ENOMEM);
99  ret = ff_set_common_channel_layouts(ctx, layouts);
100  if (ret < 0)
101  return ret;
102 
103  formats = ff_make_format_list(sample_fmts);
104  if (!formats)
105  return AVERROR(ENOMEM);
106  ret = ff_set_common_formats(ctx, formats);
107  if (ret < 0)
108  return ret;
109 
110  formats = ff_all_samplerates();
111  if (!formats)
112  return AVERROR(ENOMEM);
113  return ff_set_common_samplerates(ctx, formats);
114 }
115 
117 {
118  TremoloContext *s = ctx->priv;
119  av_freep(&s->table);
120 }
121 
123 {
124  AVFilterContext *ctx = inlink->dst;
125  TremoloContext *s = ctx->priv;
126  const double offset = 1. - s->depth / 2.;
127  int i;
128 
129  s->table_size = inlink->sample_rate / s->freq;
130  s->table = av_malloc_array(s->table_size, sizeof(*s->table));
131  if (!s->table)
132  return AVERROR(ENOMEM);
133 
134  for (i = 0; i < s->table_size; i++) {
135  double env = s->freq * i / inlink->sample_rate;
136  env = sin(2 * M_PI * fmod(env + 0.25, 1.0));
137  s->table[i] = env * (1 - fabs(offset)) + offset;
138  }
139 
140  s->index = 0;
141 
142  return 0;
143 }
144 
146  {
147  .name = "default",
148  .type = AVMEDIA_TYPE_AUDIO,
149  .config_props = config_input,
150  .filter_frame = filter_frame,
151  },
152  { NULL }
153 };
154 
156  {
157  .name = "default",
158  .type = AVMEDIA_TYPE_AUDIO,
159  },
160  { NULL }
161 };
162 
164  .name = "tremolo",
165  .description = NULL_IF_CONFIG_SMALL("Apply tremolo effect."),
166  .priv_size = sizeof(TremoloContext),
167  .priv_class = &tremolo_class,
168  .uninit = uninit,
170  .inputs = avfilter_af_tremolo_inputs,
171  .outputs = avfilter_af_tremolo_outputs,
172 };
#define NULL
Definition: coverity.c:32
int ff_set_common_channel_layouts(AVFilterContext *ctx, AVFilterChannelLayouts *layouts)
A helper for query_formats() which sets all links to the same list of channel layouts/sample rates...
Definition: formats.c:581
This structure describes decoded (raw) audio or video data.
Definition: frame.h:300
AVOption.
Definition: opt.h:246
Main libavfilter public API header.
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:283
const char * name
Pad name.
Definition: internal.h:60
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1075
#define av_cold
Definition: attributes.h:82
AVOptions.
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
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
#define FLAGS
Definition: af_tremolo.c:36
#define OFFSET(x)
Definition: af_tremolo.c:35
static av_cold void uninit(AVFilterContext *ctx)
Definition: af_tremolo.c:116
channels
Definition: aptx.h:33
A filter pad used for either input or output.
Definition: internal.h:54
#define src
Definition: vp8dsp.c:254
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
int ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
A helper for query_formats() which sets all links to the same list of formats.
Definition: formats.c:600
AVFrame * ff_get_audio_buffer(AVFilterLink *link, int nb_samples)
Request an audio samples buffer with a specific set of permissions.
Definition: audio.c:86
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
void * priv
private data for use by the filter
Definition: avfilter.h:353
static const AVOption tremolo_options[]
Definition: af_tremolo.c:38
AVFormatContext * ctx
Definition: movenc.c:48
double * table
Definition: af_tremolo.c:30
#define s(width, name)
Definition: cbs_vp9.c:257
static int query_formats(AVFilterContext *ctx)
Definition: af_tremolo.c:86
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
double depth
Definition: af_tremolo.c:29
A list of supported channel layouts.
Definition: formats.h:85
if(ret)
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
int av_frame_is_writable(AVFrame *frame)
Check if the frame data is writable.
Definition: frame.c:595
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: af_tremolo.c:46
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several inputs
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(const int16_t *) pi >> 8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(const int32_t *) pi >> 24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31))))#define SET_CONV_FUNC_GROUP(ofmt, ifmt) static void set_generic_function(AudioConvert *ac){}void ff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, int sample_rate, int apply_map){AudioConvert *ac;int in_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) return NULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method!=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt) > 2){ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc){av_free(ac);return NULL;}return ac;}in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar){ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar?ac->channels:1;}else if(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;else ac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);return ac;}int ff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){int use_generic=1;int len=in->nb_samples;int p;if(ac->dc){av_log(ac->avr, AV_LOG_TRACE,"%d samples - audio_convert: %s to %s (dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));return ff_convert_dither(ac-> in
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
const char * name
Filter name.
Definition: avfilter.h:148
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:350
enum MovChannelLayoutTag * layouts
Definition: mov_chan.c:434
AVFilterFormats * ff_all_samplerates(void)
Definition: formats.c:425
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:314
static const AVFilterPad avfilter_af_tremolo_inputs[]
Definition: af_tremolo.c:145
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
static const AVFilterPad avfilter_af_tremolo_outputs[]
Definition: af_tremolo.c:155
AVFilter ff_af_tremolo
Definition: af_tremolo.c:163
AVFILTER_DEFINE_CLASS(tremolo)
A list of supported formats for one end of a filter link.
Definition: formats.h:64
An instance of a filter.
Definition: avfilter.h:338
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:701
FILE * out
Definition: movenc.c:54
#define av_freep(p)
#define M_PI
Definition: mathematics.h:52
#define av_malloc_array(a, b)
formats
Definition: signature.h:48
internal API functions
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
AVFilterChannelLayouts * ff_all_channel_counts(void)
Construct an AVFilterChannelLayouts coding for any channel layout, with known or unknown disposition...
Definition: formats.c:440
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:366
static int config_input(AVFilterLink *inlink)
Definition: af_tremolo.c:122
for(j=16;j >0;--j)
int ff_set_common_samplerates(AVFilterContext *ctx, AVFilterFormats *samplerates)
Definition: formats.c:588
int av_frame_copy_props(AVFrame *dst, const AVFrame *src)
Copy only "metadata" fields from src to dst.
Definition: frame.c:659