FFmpeg: libavfilter/af_agate.c Source File

FFmpeg
af_agate.c
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1 /*
2  * Copyright (C) 2001-2010 Krzysztof Foltman, Markus Schmidt, Thor Harald Johansen, Damien Zammit
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 /**
22  * @file
23  * Audio (Sidechain) Gate filter
24  */
25 
26 #include "config_components.h"
27 
28 #include "libavutil/audio_fifo.h"
29 #include "libavutil/channel_layout.h"
30 #include "libavutil/opt.h"
31 #include "avfilter.h"
32 #include "audio.h"
33 #include "filters.h"
34 #include "formats.h"
35 #include "hermite.h"
36 
37  typedef struct AudioGateContext {
38   const AVClass *class;
39 
40   double level_in;
41   double level_sc;
42   double attack;
43   double release;
44   double threshold;
45   double ratio;
46   double knee;
47   double makeup;
48   double range;
49   int link;
50   int detection;
51   int mode;
52 
53   double thres;
54   double knee_start;
55   double knee_stop;
56   double lin_knee_start;
57   double lin_knee_stop;
58   double lin_slope;
59   double attack_coeff;
60   double release_coeff;
61 
62   AVAudioFifo *fifo[2];
63   int64_t pts;
64 } AudioGateContext;
65 
66  #define OFFSET(x) offsetof(AudioGateContext, x)
67  #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
68 
69  static const AVOption options[] = {
70  { "level_in", "set input level", OFFSET(level_in), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.015625, 64, A },
71  { "mode", "set mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, A, "mode" },
72  { "downward",0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A, "mode" },
73  { "upward", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A, "mode" },
74  { "range", "set max gain reduction", OFFSET(range), AV_OPT_TYPE_DOUBLE, {.dbl=0.06125}, 0, 1, A },
75  { "threshold", "set threshold", OFFSET(threshold), AV_OPT_TYPE_DOUBLE, {.dbl=0.125}, 0, 1, A },
76  { "ratio", "set ratio", OFFSET(ratio), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 1, 9000, A },
77  { "attack", "set attack", OFFSET(attack), AV_OPT_TYPE_DOUBLE, {.dbl=20}, 0.01, 9000, A },
78  { "release", "set release", OFFSET(release), AV_OPT_TYPE_DOUBLE, {.dbl=250}, 0.01, 9000, A },
79  { "makeup", "set makeup gain", OFFSET(makeup), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 1, 64, A },
80  { "knee", "set knee", OFFSET(knee), AV_OPT_TYPE_DOUBLE, {.dbl=2.828427125}, 1, 8, A },
81  { "detection", "set detection", OFFSET(detection), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, A, "detection" },
82  { "peak", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A, "detection" },
83  { "rms", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A, "detection" },
84  { "link", "set link", OFFSET(link), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, A, "link" },
85  { "average", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, A, "link" },
86  { "maximum", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, A, "link" },
87  { "level_sc", "set sidechain gain", OFFSET(level_sc), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.015625, 64, A },
88  { NULL }
89 };
90 
91 AVFILTER_DEFINE_CLASS_EXT(agate_sidechaingate, "agate/sidechaingate", options);
92 
93  static int agate_config_input(AVFilterLink *inlink)
94 {
95  AVFilterContext *ctx = inlink->dst;
96  AudioGateContext *s = ctx->priv;
97  double lin_threshold = s->threshold;
98  double lin_knee_sqrt = sqrt(s->knee);
99 
100  if (s->detection)
101  lin_threshold *= lin_threshold;
102 
103  s->attack_coeff = FFMIN(1., 1. / (s->attack * inlink->sample_rate / 4000.));
104  s->release_coeff = FFMIN(1., 1. / (s->release * inlink->sample_rate / 4000.));
105  s->lin_knee_stop = lin_threshold * lin_knee_sqrt;
106  s->lin_knee_start = lin_threshold / lin_knee_sqrt;
107  s->thres = log(lin_threshold);
108  s->knee_start = log(s->lin_knee_start);
109  s->knee_stop = log(s->lin_knee_stop);
110 
111  return 0;
112 }
113 
114 // A fake infinity value (because real infinity may break some hosts)
115  #define FAKE_INFINITY (65536.0 * 65536.0)
116 
117 // Check for infinity (with appropriate-ish tolerance)
118  #define IS_FAKE_INFINITY(value) (fabs(value-FAKE_INFINITY) < 1.0)
119 
120  static double output_gain(double lin_slope, double ratio, double thres,
121  double knee, double knee_start, double knee_stop,
122  double range, int mode)
123 {
124  double slope = log(lin_slope);
125  double tratio = ratio;
126  double gain = 0.;
127  double delta = 0.;
128 
129  if (IS_FAKE_INFINITY(ratio))
130  tratio = 1000.;
131  gain = (slope - thres) * tratio + thres;
132  delta = tratio;
133 
134  if (mode) {
135  if (knee > 1. && slope < knee_stop)
136  gain = hermite_interpolation(slope, knee_stop, knee_start, ((knee_stop - thres) * tratio + thres), knee_start, delta, 1.);
137  } else {
138  if (knee > 1. && slope > knee_start)
139  gain = hermite_interpolation(slope, knee_start, knee_stop, ((knee_start - thres) * tratio + thres), knee_stop, delta, 1.);
140  }
141  return FFMAX(range, exp(gain - slope));
142 }
143 
144  static void gate(AudioGateContext *s,
145  const double *src, double *dst, const double *scsrc,
146  int nb_samples, double level_in, double level_sc,
147  AVFilterLink *inlink, AVFilterLink *sclink)
148 {
149  AVFilterContext *ctx = inlink->dst;
150  const double makeup = s->makeup;
151  const double attack_coeff = s->attack_coeff;
152  const double release_coeff = s->release_coeff;
153  int n, c;
154 
155  for (n = 0; n < nb_samples; n++, src += inlink->ch_layout.nb_channels, dst += inlink->ch_layout.nb_channels, scsrc += sclink->ch_layout.nb_channels) {
156  double abs_sample = fabs(scsrc[0] * level_sc), gain = 1.0;
157  double factor;
158  int detected;
159 
160  if (s->link == 1) {
161  for (c = 1; c < sclink->ch_layout.nb_channels; c++)
162  abs_sample = FFMAX(fabs(scsrc[c] * level_sc), abs_sample);
163  } else {
164  for (c = 1; c < sclink->ch_layout.nb_channels; c++)
165  abs_sample += fabs(scsrc[c] * level_sc);
166 
167  abs_sample /= sclink->ch_layout.nb_channels;
168  }
169 
170  if (s->detection)
171  abs_sample *= abs_sample;
172 
173  s->lin_slope += (abs_sample - s->lin_slope) * (abs_sample > s->lin_slope ? attack_coeff : release_coeff);
174 
175  if (s->mode)
176  detected = s->lin_slope > s->lin_knee_start;
177  else
178  detected = s->lin_slope < s->lin_knee_stop;
179 
180  if (s->lin_slope > 0.0 && detected)
181  gain = output_gain(s->lin_slope, s->ratio, s->thres,
182  s->knee, s->knee_start, s->knee_stop,
183  s->range, s->mode);
184 
185  factor = ctx->is_disabled ? 1.f : level_in * gain * makeup;
186  for (c = 0; c < inlink->ch_layout.nb_channels; c++)
187  dst[c] = src[c] * factor;
188  }
189 }
190 
191 #if CONFIG_AGATE_FILTER
192 
193 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
194 {
195  const double *src = (const double *)in->data[0];
196  AVFilterContext *ctx = inlink->dst;
197  AVFilterLink *outlink = ctx->outputs[0];
198  AudioGateContext *s = ctx->priv;
199  AVFrame *out;
200  double *dst;
201 
202  if (av_frame_is_writable(in)) {
203  out = in;
204  } else {
205  out = ff_get_audio_buffer(outlink, in->nb_samples);
206  if (!out) {
207  av_frame_free(&in);
208  return AVERROR(ENOMEM);
209  }
210  av_frame_copy_props(out, in);
211  }
212  dst = (double *)out->data[0];
213 
214  gate(s, src, dst, src, in->nb_samples,
215  s->level_in, s->level_in, inlink, inlink);
216 
217  if (out != in)
218  av_frame_free(&in);
219  return ff_filter_frame(outlink, out);
220 }
221 
222 static const AVFilterPad inputs[] = {
223  {
224  .name = "default",
225  .type = AVMEDIA_TYPE_AUDIO,
226  .filter_frame = filter_frame,
227  .config_props = agate_config_input,
228  },
229 };
230 
231 static const AVFilterPad outputs[] = {
232  {
233  .name = "default",
234  .type = AVMEDIA_TYPE_AUDIO,
235  },
236 };
237 
238 const AVFilter ff_af_agate = {
239  .name = "agate",
240  .description = NULL_IF_CONFIG_SMALL("Audio gate."),
241  .priv_class = &agate_sidechaingate_class,
242  .priv_size = sizeof(AudioGateContext),
243  FILTER_INPUTS(inputs),
244  FILTER_OUTPUTS(outputs),
245  FILTER_SINGLE_SAMPLEFMT(AV_SAMPLE_FMT_DBL),
246  .process_command = ff_filter_process_command,
247  .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
248 };
249 
250 #endif /* CONFIG_AGATE_FILTER */
251 
252 #if CONFIG_SIDECHAINGATE_FILTER
253 
254 static int activate(AVFilterContext *ctx)
255 {
256  AudioGateContext *s = ctx->priv;
257  AVFrame *out = NULL, *in[2] = { NULL };
258  int ret, i, nb_samples;
259  double *dst;
260 
261  FF_FILTER_FORWARD_STATUS_BACK_ALL(ctx->outputs[0], ctx);
262  if ((ret = ff_inlink_consume_frame(ctx->inputs[0], &in[0])) > 0) {
263  av_audio_fifo_write(s->fifo[0], (void **)in[0]->extended_data,
264  in[0]->nb_samples);
265  av_frame_free(&in[0]);
266  }
267  if (ret < 0)
268  return ret;
269  if ((ret = ff_inlink_consume_frame(ctx->inputs[1], &in[1])) > 0) {
270  av_audio_fifo_write(s->fifo[1], (void **)in[1]->extended_data,
271  in[1]->nb_samples);
272  av_frame_free(&in[1]);
273  }
274  if (ret < 0)
275  return ret;
276 
277  nb_samples = FFMIN(av_audio_fifo_size(s->fifo[0]), av_audio_fifo_size(s->fifo[1]));
278  if (nb_samples) {
279  out = ff_get_audio_buffer(ctx->outputs[0], nb_samples);
280  if (!out)
281  return AVERROR(ENOMEM);
282  for (i = 0; i < 2; i++) {
283  in[i] = ff_get_audio_buffer(ctx->inputs[i], nb_samples);
284  if (!in[i]) {
285  av_frame_free(&in[0]);
286  av_frame_free(&in[1]);
287  av_frame_free(&out);
288  return AVERROR(ENOMEM);
289  }
290  av_audio_fifo_read(s->fifo[i], (void **)in[i]->data, nb_samples);
291  }
292 
293  dst = (double *)out->data[0];
294  out->pts = s->pts;
295  s->pts += av_rescale_q(nb_samples, (AVRational){1, ctx->outputs[0]->sample_rate}, ctx->outputs[0]->time_base);
296 
297  gate(s, (double *)in[0]->data[0], dst,
298  (double *)in[1]->data[0], nb_samples,
299  s->level_in, s->level_sc,
300  ctx->inputs[0], ctx->inputs[1]);
301 
302  av_frame_free(&in[0]);
303  av_frame_free(&in[1]);
304 
305  ret = ff_filter_frame(ctx->outputs[0], out);
306  if (ret < 0)
307  return ret;
308  }
309  FF_FILTER_FORWARD_STATUS(ctx->inputs[0], ctx->outputs[0]);
310  FF_FILTER_FORWARD_STATUS(ctx->inputs[1], ctx->outputs[0]);
311  if (ff_outlink_frame_wanted(ctx->outputs[0])) {
312  if (!av_audio_fifo_size(s->fifo[0]))
313  ff_inlink_request_frame(ctx->inputs[0]);
314  if (!av_audio_fifo_size(s->fifo[1]))
315  ff_inlink_request_frame(ctx->inputs[1]);
316  }
317  return 0;
318 }
319 
320 static int scquery_formats(AVFilterContext *ctx)
321 {
322  static const enum AVSampleFormat sample_fmts[] = {
323  AV_SAMPLE_FMT_DBL,
324  AV_SAMPLE_FMT_NONE
325  };
326  int ret = ff_channel_layouts_ref(ff_all_channel_counts(),
327  &ctx->inputs[1]->outcfg.channel_layouts);
328  if (ret < 0)
329  return ret;
330 
331  /* This will link the channel properties of the main input and the output;
332  * it won't touch the second input as its channel_layouts is already set. */
333  if ((ret = ff_set_common_all_channel_counts(ctx)) < 0)
334  return ret;
335 
336  if ((ret = ff_set_common_formats_from_list(ctx, sample_fmts)) < 0)
337  return ret;
338 
339  return ff_set_common_all_samplerates(ctx);
340 }
341 
342 static int scconfig_output(AVFilterLink *outlink)
343 {
344  AVFilterContext *ctx = outlink->src;
345  AudioGateContext *s = ctx->priv;
346 
347  outlink->time_base = ctx->inputs[0]->time_base;
348 
349  s->fifo[0] = av_audio_fifo_alloc(ctx->inputs[0]->format, ctx->inputs[0]->ch_layout.nb_channels, 1024);
350  s->fifo[1] = av_audio_fifo_alloc(ctx->inputs[1]->format, ctx->inputs[1]->ch_layout.nb_channels, 1024);
351  if (!s->fifo[0] || !s->fifo[1])
352  return AVERROR(ENOMEM);
353 
354 
355  agate_config_input(ctx->inputs[0]);
356 
357  return 0;
358 }
359 
360 static av_cold void uninit(AVFilterContext *ctx)
361 {
362  AudioGateContext *s = ctx->priv;
363 
364  av_audio_fifo_free(s->fifo[0]);
365  av_audio_fifo_free(s->fifo[1]);
366 }
367 
368 static const AVFilterPad sidechaingate_inputs[] = {
369  {
370  .name = "main",
371  .type = AVMEDIA_TYPE_AUDIO,
372  },{
373  .name = "sidechain",
374  .type = AVMEDIA_TYPE_AUDIO,
375  },
376 };
377 
378 static const AVFilterPad sidechaingate_outputs[] = {
379  {
380  .name = "default",
381  .type = AVMEDIA_TYPE_AUDIO,
382  .config_props = scconfig_output,
383  },
384 };
385 
386 const AVFilter ff_af_sidechaingate = {
387  .name = "sidechaingate",
388  .description = NULL_IF_CONFIG_SMALL("Audio sidechain gate."),
389  .priv_class = &agate_sidechaingate_class,
390  .priv_size = sizeof(AudioGateContext),
391  .activate = activate,
392  .uninit = uninit,
393  FILTER_INPUTS(sidechaingate_inputs),
394  FILTER_OUTPUTS(sidechaingate_outputs),
395  FILTER_QUERY_FUNC(scquery_formats),
396  .process_command = ff_filter_process_command,
397  .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
398 };
399 #endif /* CONFIG_SIDECHAINGATE_FILTER */
AudioGateContext::lin_slope
double lin_slope
Definition: af_agate.c:58
av_audio_fifo_free
void av_audio_fifo_free(AVAudioFifo *af)
Free an AVAudioFifo.
Definition: audio_fifo.c:48
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:100
AudioGateContext::range
double range
Definition: af_agate.c:48
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
AudioGateContext::attack
double attack
Definition: af_agate.c:42
out
FILE * out
Definition: movenc.c:54
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:999
sample_fmts
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:947
ff_channel_layouts_ref
int ff_channel_layouts_ref(AVFilterChannelLayouts *f, AVFilterChannelLayouts **ref)
Add *ref as a new reference to f.
Definition: formats.c:591
FILTER_SINGLE_SAMPLEFMT
#define FILTER_SINGLE_SAMPLEFMT(sample_fmt_)
Definition: internal.h:183
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:111
ff_all_channel_counts
AVFilterChannelLayouts * ff_all_channel_counts(void)
Construct an AVFilterChannelLayouts coding for any channel layout, with known or unknown disposition.
Definition: formats.c:566
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
AudioGateContext::level_in
double level_in
Definition: af_agate.c:40
AudioGateContext::knee
double knee
Definition: af_agate.c:46
AVOption
AVOption.
Definition: opt.h:251
AudioGateContext::ratio
double ratio
Definition: af_agate.c:45
FILTER_QUERY_FUNC
#define FILTER_QUERY_FUNC(func)
Definition: internal.h:167
data
const char data[16]
Definition: mxf.c:143
ff_set_common_all_samplerates
int ff_set_common_all_samplerates(AVFilterContext *ctx)
Equivalent to ff_set_common_samplerates(ctx, ff_all_samplerates())
Definition: formats.c:739
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:175
ff_af_agate
const AVFilter ff_af_agate
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:300
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:346
formats.h
AVFILTER_DEFINE_CLASS_EXT
AVFILTER_DEFINE_CLASS_EXT(agate_sidechaingate, "agate/sidechaingate", options)
ff_inlink_consume_frame
int ff_inlink_consume_frame(AVFilterLink *link, AVFrame **rframe)
Take a frame from the link's FIFO and update the link's stats.
Definition: avfilter.c:1394
AudioGateContext::knee_start
double knee_start
Definition: af_agate.c:54
FF_FILTER_FORWARD_STATUS_BACK_ALL
#define FF_FILTER_FORWARD_STATUS_BACK_ALL(outlink, filter)
Forward the status on an output link to all input links.
Definition: filters.h:212
AVAudioFifo
Context for an Audio FIFO Buffer.
Definition: audio_fifo.c:37
AudioGateContext::makeup
double makeup
Definition: af_agate.c:47
AudioGateContext::lin_knee_start
double lin_knee_start
Definition: af_agate.c:56
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:49
av_cold
#define av_cold
Definition: attributes.h:90
ff_inlink_request_frame
void ff_inlink_request_frame(AVFilterLink *link)
Mark that a frame is wanted on the link.
Definition: avfilter.c:1511
s
#define s(width, name)
Definition: cbs_vp9.c:256
AudioGateContext::mode
int mode
Definition: af_agate.c:51
hermite_interpolation
static double hermite_interpolation(double x, double x0, double x1, double p0, double p1, double m0, double m1)
Definition: hermite.h:22
av_audio_fifo_write
int av_audio_fifo_write(AVAudioFifo *af, void **data, int nb_samples)
Write data to an AVAudioFifo.
Definition: audio_fifo.c:119
AV_OPT_TYPE_DOUBLE
@ AV_OPT_TYPE_DOUBLE
Definition: opt.h:227
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AudioGateContext::release
double release
Definition: af_agate.c:43
ff_set_common_formats_from_list
int ff_set_common_formats_from_list(AVFilterContext *ctx, const int *fmts)
Equivalent to ff_set_common_formats(ctx, ff_make_format_list(fmts))
Definition: formats.c:755
outputs
static const AVFilterPad outputs[]
Definition: af_acontrast.c:172
filters.h
ctx
AVFormatContext * ctx
Definition: movenc.c:48
av_rescale_q
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:142
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:190
link
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 link
Definition: filter_design.txt:23
if
if(ret)
Definition: filter_design.txt:179
output_gain
static double output_gain(double lin_slope, double ratio, double thres, double knee, double knee_start, double knee_stop, double range, int mode)
Definition: af_agate.c:120
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
fabs
static __device__ float fabs(float a)
Definition: cuda_runtime.h:182
NULL
#define NULL
Definition: coverity.c:32
A
#define A
Definition: af_agate.c:67
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:596
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
av_audio_fifo_alloc
AVAudioFifo * av_audio_fifo_alloc(enum AVSampleFormat sample_fmt, int channels, int nb_samples)
Allocate an AVAudioFifo.
Definition: audio_fifo.c:62
activate
filter_frame For filters that do not use the activate() callback
options
static const AVOption options[]
Definition: af_agate.c:69
AudioGateContext::thres
double thres
Definition: af_agate.c:53
filter_frame
static int filter_frame(DBEDecodeContext *s, AVFrame *frame)
Definition: dolby_e.c:1058
AudioGateContext
Definition: af_agate.c:37
inputs
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
Definition: filter_design.txt:243
ff_set_common_all_channel_counts
int ff_set_common_all_channel_counts(AVFilterContext *ctx)
Equivalent to ff_set_common_channel_layouts(ctx, ff_all_channel_counts())
Definition: formats.c:721
exp
int8_t exp
Definition: eval.c:72
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
AudioGateContext::attack_coeff
double attack_coeff
Definition: af_agate.c:59
OFFSET
#define OFFSET(x)
Definition: af_agate.c:66
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:117
AudioGateContext::level_sc
double level_sc
Definition: af_agate.c:41
hermite.h
AV_SAMPLE_FMT_NONE
@ AV_SAMPLE_FMT_NONE
Definition: samplefmt.h:56
av_frame_is_writable
int av_frame_is_writable(AVFrame *frame)
Check if the frame data is writable.
Definition: frame.c:523
AudioGateContext::lin_knee_stop
double lin_knee_stop
Definition: af_agate.c:57
ff_filter_process_command
int ff_filter_process_command(AVFilterContext *ctx, const char *cmd, const char *arg, char *res, int res_len, int flags)
Generic processing of user supplied commands that are set in the same way as the filter options.
Definition: avfilter.c:863
AudioGateContext::fifo
AVAudioFifo * fifo[2]
Definition: af_agate.c:62
av_audio_fifo_size
int av_audio_fifo_size(AVAudioFifo *af)
Get the current number of samples in the AVAudioFifo available for reading.
Definition: audio_fifo.c:221
IS_FAKE_INFINITY
#define IS_FAKE_INFINITY(value)
Definition: af_agate.c:118
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:152
av_audio_fifo_read
int av_audio_fifo_read(AVAudioFifo *af, void **data, int nb_samples)
Read data from an AVAudioFifo.
Definition: audio_fifo.c:174
AVFrame::nb_samples
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:405
AudioGateContext::release_coeff
double release_coeff
Definition: af_agate.c:60
AudioGateContext::pts
int64_t pts
Definition: af_agate.c:63
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
delta
float delta
Definition: vorbis_enc_data.h:430
AudioGateContext::knee_stop
double knee_stop
Definition: af_agate.c:55
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
audio_fifo.h
ff_af_sidechaingate
const AVFilter ff_af_sidechaingate
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:55
AudioGateContext::link
int link
Definition: af_agate.c:49
AudioGateContext::threshold
double threshold
Definition: af_agate.c:44
AVFilter
Filter definition.
Definition: avfilter.h:171
ret
ret
Definition: filter_design.txt:187
channel_layout.h
mode
mode
Definition: ebur128.h:83
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:225
avfilter.h
AVFilterContext
An instance of a filter.
Definition: avfilter.h:408
factor
static const int factor[16]
Definition: vf_pp7.c:76
audio.h
FF_FILTER_FORWARD_STATUS
FF_FILTER_FORWARD_STATUS(inlink, outlink)
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:191
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
gate
static void gate(AudioGateContext *s, const double *src, double *dst, const double *scsrc, int nb_samples, double level_in, double level_sc, AVFilterLink *inlink, AVFilterLink *sclink)
Definition: af_agate.c:144
AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL
#define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL
Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will have its filter_frame() c...
Definition: avfilter.h:160
AudioGateContext::detection
int detection
Definition: af_agate.c:50
uninit
static av_cold int uninit(AVCodecContext *avctx)
Definition: crystalhd.c:285
ff_outlink_frame_wanted
the definition of that something depends on the semantic of the filter The callback must examine the status of the filter s links and proceed accordingly The status of output links is stored in the status_in and status_out fields and tested by the ff_outlink_frame_wanted() function. If this function returns true
AV_SAMPLE_FMT_DBL
@ AV_SAMPLE_FMT_DBL
double
Definition: samplefmt.h:61
agate_config_input
static int agate_config_input(AVFilterLink *inlink)
Definition: af_agate.c:93
AV_OPT_TYPE_CONST
@ AV_OPT_TYPE_CONST
Definition: opt.h:234
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