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af_afade.c
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1 /*
2  * Copyright (c) 2013 Paul B Mahol
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  * fade audio filter
24  */
25 
26 #include "libavutil/opt.h"
27 #include "audio.h"
28 #include "avfilter.h"
29 #include "internal.h"
30 
31 typedef struct {
32  const AVClass *class;
33  int type;
34  int curve;
35  int nb_samples;
36  int64_t start_sample;
37  int64_t duration;
38  int64_t start_time;
39 
40  void (*fade_samples)(uint8_t **dst, uint8_t * const *src,
41  int nb_samples, int channels, int direction,
42  int64_t start, int range, int curve);
43 } AudioFadeContext;
44 
45 enum CurveType { TRI, QSIN, ESIN, HSIN, LOG, PAR, QUA, CUB, SQU, CBR };
46 
47 #define OFFSET(x) offsetof(AudioFadeContext, x)
48 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
49 
50 static const AVOption afade_options[] = {
51  { "type", "set the fade direction", OFFSET(type), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 1, FLAGS, "type" },
52  { "t", "set the fade direction", OFFSET(type), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 1, FLAGS, "type" },
53  { "in", "fade-in", 0, AV_OPT_TYPE_CONST, {.i64 = 0 }, 0, 0, FLAGS, "type" },
54  { "out", "fade-out", 0, AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, FLAGS, "type" },
55  { "start_sample", "set number of first sample to start fading", OFFSET(start_sample), AV_OPT_TYPE_INT64, {.i64 = 0 }, 0, INT64_MAX, FLAGS },
56  { "ss", "set number of first sample to start fading", OFFSET(start_sample), AV_OPT_TYPE_INT64, {.i64 = 0 }, 0, INT64_MAX, FLAGS },
57  { "nb_samples", "set number of samples for fade duration", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 44100}, 1, INT32_MAX, FLAGS },
58  { "ns", "set number of samples for fade duration", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 44100}, 1, INT32_MAX, FLAGS },
59  { "start_time", "set time to start fading", OFFSET(start_time), AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT32_MAX, FLAGS },
60  { "st", "set time to start fading", OFFSET(start_time), AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT32_MAX, FLAGS },
61  { "duration", "set fade duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT32_MAX, FLAGS },
62  { "d", "set fade duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT32_MAX, FLAGS },
63  { "curve", "set fade curve type", OFFSET(curve), AV_OPT_TYPE_INT, {.i64 = TRI }, TRI, CBR, FLAGS, "curve" },
64  { "c", "set fade curve type", OFFSET(curve), AV_OPT_TYPE_INT, {.i64 = TRI }, TRI, CBR, FLAGS, "curve" },
65  { "tri", "linear slope", 0, AV_OPT_TYPE_CONST, {.i64 = TRI }, 0, 0, FLAGS, "curve" },
66  { "qsin", "quarter of sine wave", 0, AV_OPT_TYPE_CONST, {.i64 = QSIN }, 0, 0, FLAGS, "curve" },
67  { "esin", "exponential sine wave", 0, AV_OPT_TYPE_CONST, {.i64 = ESIN }, 0, 0, FLAGS, "curve" },
68  { "hsin", "half of sine wave", 0, AV_OPT_TYPE_CONST, {.i64 = HSIN }, 0, 0, FLAGS, "curve" },
69  { "log", "logarithmic", 0, AV_OPT_TYPE_CONST, {.i64 = LOG }, 0, 0, FLAGS, "curve" },
70  { "par", "inverted parabola", 0, AV_OPT_TYPE_CONST, {.i64 = PAR }, 0, 0, FLAGS, "curve" },
71  { "qua", "quadratic", 0, AV_OPT_TYPE_CONST, {.i64 = QUA }, 0, 0, FLAGS, "curve" },
72  { "cub", "cubic", 0, AV_OPT_TYPE_CONST, {.i64 = CUB }, 0, 0, FLAGS, "curve" },
73  { "squ", "square root", 0, AV_OPT_TYPE_CONST, {.i64 = SQU }, 0, 0, FLAGS, "curve" },
74  { "cbr", "cubic root", 0, AV_OPT_TYPE_CONST, {.i64 = CBR }, 0, 0, FLAGS, "curve" },
75  {NULL},
76 };
77 
78 AVFILTER_DEFINE_CLASS(afade);
79 
80 static av_cold int init(AVFilterContext *ctx)
81 {
82  AudioFadeContext *afade = ctx->priv;
83 
84  if (INT64_MAX - afade->nb_samples < afade->start_sample)
85  return AVERROR(EINVAL);
86 
87  return 0;
88 }
89 
90 static int query_formats(AVFilterContext *ctx)
91 {
92  AVFilterFormats *formats;
93  AVFilterChannelLayouts *layouts;
94  static const enum AVSampleFormat sample_fmts[] = {
95  AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S16P,
96  AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S32P,
97  AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_FLTP,
98  AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_DBLP,
99  AV_SAMPLE_FMT_NONE
100  };
101 
102  layouts = ff_all_channel_layouts();
103  if (!layouts)
104  return AVERROR(ENOMEM);
105  ff_set_common_channel_layouts(ctx, layouts);
106 
107  formats = ff_make_format_list(sample_fmts);
108  if (!formats)
109  return AVERROR(ENOMEM);
110  ff_set_common_formats(ctx, formats);
111 
112  formats = ff_all_samplerates();
113  if (!formats)
114  return AVERROR(ENOMEM);
115  ff_set_common_samplerates(ctx, formats);
116 
117  return 0;
118 }
119 
120 static double fade_gain(int curve, int64_t index, int range)
121 {
122  double gain;
123 
124  gain = FFMAX(0.0, FFMIN(1.0, 1.0 * index / range));
125 
126  switch (curve) {
127  case QSIN:
128  gain = sin(gain * M_PI / 2.0);
129  break;
130  case ESIN:
131  gain = 1.0 - cos(M_PI / 4.0 * (pow(2.0*gain - 1, 3) + 1));
132  break;
133  case HSIN:
134  gain = (1.0 - cos(gain * M_PI)) / 2.0;
135  break;
136  case LOG:
137  gain = pow(0.1, (1 - gain) * 5.0);
138  break;
139  case PAR:
140  gain = (1 - (1 - gain) * (1 - gain));
141  break;
142  case QUA:
143  gain *= gain;
144  break;
145  case CUB:
146  gain = gain * gain * gain;
147  break;
148  case SQU:
149  gain = sqrt(gain);
150  break;
151  case CBR:
152  gain = cbrt(gain);
153  break;
154  }
155 
156  return gain;
157 }
158 
159 #define FADE_PLANAR(name, type) \
160 static void fade_samples_## name ##p(uint8_t **dst, uint8_t * const *src, \
161  int nb_samples, int channels, int dir, \
162  int64_t start, int range, int curve) \
163 { \
164  int i, c; \
165  \
166  for (i = 0; i < nb_samples; i++) { \
167  double gain = fade_gain(curve, start + i * dir, range); \
168  for (c = 0; c < channels; c++) { \
169  type *d = (type *)dst[c]; \
170  const type *s = (type *)src[c]; \
171  \
172  d[i] = s[i] * gain; \
173  } \
174  } \
175 }
176 
177 #define FADE(name, type) \
178 static void fade_samples_## name (uint8_t **dst, uint8_t * const *src, \
179  int nb_samples, int channels, int dir, \
180  int64_t start, int range, int curve) \
181 { \
182  type *d = (type *)dst[0]; \
183  const type *s = (type *)src[0]; \
184  int i, c, k = 0; \
185  \
186  for (i = 0; i < nb_samples; i++) { \
187  double gain = fade_gain(curve, start + i * dir, range); \
188  for (c = 0; c < channels; c++, k++) \
189  d[k] = s[k] * gain; \
190  } \
191 }
192 
193 FADE_PLANAR(dbl, double)
194 FADE_PLANAR(flt, float)
195 FADE_PLANAR(s16, int16_t)
196 FADE_PLANAR(s32, int32_t)
197 
198 FADE(dbl, double)
199 FADE(flt, float)
200 FADE(s16, int16_t)
201 FADE(s32, int32_t)
202 
203 static int config_output(AVFilterLink *outlink)
204 {
205  AVFilterContext *ctx = outlink->src;
206  AudioFadeContext *afade = ctx->priv;
207  AVFilterLink *inlink = ctx->inputs[0];
208 
209  switch (inlink->format) {
210  case AV_SAMPLE_FMT_DBL: afade->fade_samples = fade_samples_dbl; break;
211  case AV_SAMPLE_FMT_DBLP: afade->fade_samples = fade_samples_dblp; break;
212  case AV_SAMPLE_FMT_FLT: afade->fade_samples = fade_samples_flt; break;
213  case AV_SAMPLE_FMT_FLTP: afade->fade_samples = fade_samples_fltp; break;
214  case AV_SAMPLE_FMT_S16: afade->fade_samples = fade_samples_s16; break;
215  case AV_SAMPLE_FMT_S16P: afade->fade_samples = fade_samples_s16p; break;
216  case AV_SAMPLE_FMT_S32: afade->fade_samples = fade_samples_s32; break;
217  case AV_SAMPLE_FMT_S32P: afade->fade_samples = fade_samples_s32p; break;
218  }
219 
220  if (afade->duration)
221  afade->nb_samples = afade->duration * inlink->sample_rate / AV_TIME_BASE;
222  if (afade->start_time)
223  afade->start_sample = afade->start_time * inlink->sample_rate / AV_TIME_BASE;
224 
225  return 0;
226 }
227 
228 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
229 {
230  AudioFadeContext *afade = inlink->dst->priv;
231  AVFilterLink *outlink = inlink->dst->outputs[0];
232  int nb_samples = buf->nb_samples;
233  AVFrame *out_buf;
234  int64_t cur_sample = av_rescale_q(buf->pts, (AVRational){1, outlink->sample_rate}, outlink->time_base);
235 
236  if ((!afade->type && (afade->start_sample + afade->nb_samples < cur_sample)) ||
237  ( afade->type && (cur_sample + afade->nb_samples < afade->start_sample)))
238  return ff_filter_frame(outlink, buf);
239 
240  if (av_frame_is_writable(buf)) {
241  out_buf = buf;
242  } else {
243  out_buf = ff_get_audio_buffer(inlink, nb_samples);
244  if (!out_buf)
245  return AVERROR(ENOMEM);
246  av_frame_copy_props(out_buf, buf);
247  }
248 
249  if ((!afade->type && (cur_sample + nb_samples < afade->start_sample)) ||
250  ( afade->type && (afade->start_sample + afade->nb_samples < cur_sample))) {
251  av_samples_set_silence(out_buf->extended_data, 0, nb_samples,
252  av_frame_get_channels(out_buf), out_buf->format);
253  } else {
254  int64_t start;
255 
256  if (!afade->type)
257  start = cur_sample - afade->start_sample;
258  else
259  start = afade->start_sample + afade->nb_samples - cur_sample;
260 
261  afade->fade_samples(out_buf->extended_data, buf->extended_data,
262  nb_samples, av_frame_get_channels(buf),
263  afade->type ? -1 : 1, start,
264  afade->nb_samples, afade->curve);
265  }
266 
267  if (buf != out_buf)
268  av_frame_free(&buf);
269 
270  return ff_filter_frame(outlink, out_buf);
271 }
272 
273 static const AVFilterPad avfilter_af_afade_inputs[] = {
274  {
275  .name = "default",
276  .type = AVMEDIA_TYPE_AUDIO,
277  .filter_frame = filter_frame,
278  },
279  { NULL }
280 };
281 
282 static const AVFilterPad avfilter_af_afade_outputs[] = {
283  {
284  .name = "default",
285  .type = AVMEDIA_TYPE_AUDIO,
286  .config_props = config_output,
287  },
288  { NULL }
289 };
290 
291 AVFilter avfilter_af_afade = {
292  .name = "afade",
293  .description = NULL_IF_CONFIG_SMALL("Fade in/out input audio."),
294  .query_formats = query_formats,
295  .priv_size = sizeof(AudioFadeContext),
296  .init = init,
297  .inputs = avfilter_af_afade_inputs,
298  .outputs = avfilter_af_afade_outputs,
299  .priv_class = &afade_class,
300 };
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