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avf_showspectrum.c
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1 /*
2  * Copyright (c) 2012-2013 Clément Bœsch
3  * Copyright (c) 2013 Rudolf Polzer <divverent@xonotic.org>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * audio to spectrum (video) transmedia filter, based on ffplay rdft showmode
25  * (by Michael Niedermayer) and lavfi/avf_showwaves (by Stefano Sabatini).
26  */
27 
28 #include <math.h>
29 
30 #include "libavcodec/avfft.h"
31 #include "libavutil/avassert.h"
33 #include "libavutil/opt.h"
34 #include "avfilter.h"
35 #include "internal.h"
36 
42 
43 typedef struct {
44  const AVClass *class;
45  int w, h;
50  int sliding; ///< 1 if sliding mode, 0 otherwise
51  enum DisplayMode mode; ///< channel display mode
52  enum ColorMode color_mode; ///< display color scheme
54  float saturation; ///< color saturation multiplier
55  int xpos; ///< x position (current column)
56  RDFTContext *rdft; ///< Real Discrete Fourier Transform context
57  int rdft_bits; ///< number of bits (RDFT window size = 1<<rdft_bits)
58  FFTSample **rdft_data; ///< bins holder for each (displayed) channels
59  float *window_func_lut; ///< Window function LUT
61  float *combine_buffer; ///< color combining buffer (3 * h items)
63 
64 #define OFFSET(x) offsetof(ShowSpectrumContext, x)
65 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
66 
67 static const AVOption showspectrum_options[] = {
68  { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x512"}, 0, 0, FLAGS },
69  { "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x512"}, 0, 0, FLAGS },
70  { "slide", "set sliding mode", OFFSET(sliding), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NB_SLIDES, FLAGS, "slide" },
71  { "replace", "replace old columns with new", 0, AV_OPT_TYPE_CONST, {.i64=REPLACE}, 0, 0, FLAGS, "slide" },
72  { "scroll", "scroll from right to left", 0, AV_OPT_TYPE_CONST, {.i64=SCROLL}, 0, 0, FLAGS, "slide" },
73  { "fullframe", "return full frames", 0, AV_OPT_TYPE_CONST, {.i64=FULLFRAME}, 0, 0, FLAGS, "slide" },
74  { "mode", "set channel display mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=COMBINED}, COMBINED, NB_MODES-1, FLAGS, "mode" },
75  { "combined", "combined mode", 0, AV_OPT_TYPE_CONST, {.i64=COMBINED}, 0, 0, FLAGS, "mode" },
76  { "separate", "separate mode", 0, AV_OPT_TYPE_CONST, {.i64=SEPARATE}, 0, 0, FLAGS, "mode" },
77  { "color", "set channel coloring", OFFSET(color_mode), AV_OPT_TYPE_INT, {.i64=CHANNEL}, CHANNEL, NB_CLMODES-1, FLAGS, "color" },
78  { "channel", "separate color for each channel", 0, AV_OPT_TYPE_CONST, {.i64=CHANNEL}, 0, 0, FLAGS, "color" },
79  { "intensity", "intensity based coloring", 0, AV_OPT_TYPE_CONST, {.i64=INTENSITY}, 0, 0, FLAGS, "color" },
80  { "scale", "set display scale", OFFSET(scale), AV_OPT_TYPE_INT, {.i64=SQRT}, LINEAR, NB_SCALES-1, FLAGS, "scale" },
81  { "sqrt", "square root", 0, AV_OPT_TYPE_CONST, {.i64=SQRT}, 0, 0, FLAGS, "scale" },
82  { "cbrt", "cubic root", 0, AV_OPT_TYPE_CONST, {.i64=CBRT}, 0, 0, FLAGS, "scale" },
83  { "log", "logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=LOG}, 0, 0, FLAGS, "scale" },
84  { "lin", "linear", 0, AV_OPT_TYPE_CONST, {.i64=LINEAR}, 0, 0, FLAGS, "scale" },
85  { "saturation", "color saturation multiplier", OFFSET(saturation), AV_OPT_TYPE_FLOAT, {.dbl = 1}, -10, 10, FLAGS },
86  { "win_func", "set window function", OFFSET(win_func), AV_OPT_TYPE_INT, {.i64 = WFUNC_HANN}, 0, NB_WFUNC-1, FLAGS, "win_func" },
87  { "hann", "Hann window", 0, AV_OPT_TYPE_CONST, {.i64 = WFUNC_HANN}, 0, 0, FLAGS, "win_func" },
88  { "hamming", "Hamming window", 0, AV_OPT_TYPE_CONST, {.i64 = WFUNC_HAMMING}, 0, 0, FLAGS, "win_func" },
89  { "blackman", "Blackman window", 0, AV_OPT_TYPE_CONST, {.i64 = WFUNC_BLACKMAN}, 0, 0, FLAGS, "win_func" },
90  { NULL }
91 };
92 
93 AVFILTER_DEFINE_CLASS(showspectrum);
94 
95 static const struct {
96  float a, y, u, v;
98  { 0, 0, 0, 0 },
99  { 0.13, .03587126228984074, .1573300977624594, -.02548747583751842 },
100  { 0.30, .18572281794568020, .1772436246393981, .17475554840414750 },
101  { 0.60, .28184980583656130, -.1593064119945782, .47132074554608920 },
102  { 0.73, .65830621175547810, -.3716070802232764, .24352759331252930 },
103  { 0.78, .76318535758242900, -.4307467689263783, .16866496622310430 },
104  { 0.91, .95336363636363640, -.2045454545454546, .03313636363636363 },
105  { 1, 1, 0, 0 }
106 };
107 
108 static av_cold void uninit(AVFilterContext *ctx)
109 {
110  ShowSpectrumContext *s = ctx->priv;
111  int i;
112 
114  av_rdft_end(s->rdft);
115  for (i = 0; i < s->nb_display_channels; i++)
116  av_freep(&s->rdft_data[i]);
117  av_freep(&s->rdft_data);
120 }
121 
123 {
124  AVFilterFormats *formats = NULL;
126  AVFilterLink *inlink = ctx->inputs[0];
127  AVFilterLink *outlink = ctx->outputs[0];
129  static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_NONE };
130 
131  /* set input audio formats */
132  formats = ff_make_format_list(sample_fmts);
133  if (!formats)
134  return AVERROR(ENOMEM);
135  ff_formats_ref(formats, &inlink->out_formats);
136 
137  layouts = ff_all_channel_layouts();
138  if (!layouts)
139  return AVERROR(ENOMEM);
140  ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts);
141 
142  formats = ff_all_samplerates();
143  if (!formats)
144  return AVERROR(ENOMEM);
145  ff_formats_ref(formats, &inlink->out_samplerates);
146 
147  /* set output video format */
148  formats = ff_make_format_list(pix_fmts);
149  if (!formats)
150  return AVERROR(ENOMEM);
151  ff_formats_ref(formats, &outlink->in_formats);
152 
153  return 0;
154 }
155 
156 static int config_output(AVFilterLink *outlink)
157 {
158  AVFilterContext *ctx = outlink->src;
159  AVFilterLink *inlink = ctx->inputs[0];
160  ShowSpectrumContext *s = ctx->priv;
161  int i, rdft_bits, win_size, h;
162 
163  outlink->w = s->w;
164  outlink->h = s->h;
165 
166  h = (s->mode == COMBINED) ? outlink->h : outlink->h / inlink->channels;
167  s->channel_height = h;
168 
169  /* RDFT window size (precision) according to the requested output frame height */
170  for (rdft_bits = 1; 1 << rdft_bits < 2 * h; rdft_bits++);
171  win_size = 1 << rdft_bits;
172 
173  /* (re-)configuration if the video output changed (or first init) */
174  if (rdft_bits != s->rdft_bits) {
175  size_t rdft_size, rdft_listsize;
176  AVFrame *outpicref;
177 
178  av_rdft_end(s->rdft);
179  s->rdft = av_rdft_init(rdft_bits, DFT_R2C);
180  if (!s->rdft) {
181  av_log(ctx, AV_LOG_ERROR, "Unable to create RDFT context. "
182  "The window size might be too high.\n");
183  return AVERROR(EINVAL);
184  }
185  s->rdft_bits = rdft_bits;
186 
187  /* RDFT buffers: x2 for each (display) channel buffer.
188  * Note: we use free and malloc instead of a realloc-like function to
189  * make sure the buffer is aligned in memory for the FFT functions. */
190  for (i = 0; i < s->nb_display_channels; i++)
191  av_freep(&s->rdft_data[i]);
192  av_freep(&s->rdft_data);
193  s->nb_display_channels = inlink->channels;
194 
195  if (av_size_mult(sizeof(*s->rdft_data),
196  s->nb_display_channels, &rdft_listsize) < 0)
197  return AVERROR(EINVAL);
198  if (av_size_mult(sizeof(**s->rdft_data),
199  win_size, &rdft_size) < 0)
200  return AVERROR(EINVAL);
201  s->rdft_data = av_malloc(rdft_listsize);
202  if (!s->rdft_data)
203  return AVERROR(ENOMEM);
204  for (i = 0; i < s->nb_display_channels; i++) {
205  s->rdft_data[i] = av_malloc(rdft_size);
206  if (!s->rdft_data[i])
207  return AVERROR(ENOMEM);
208  }
209 
210  /* pre-calc windowing function */
211  s->window_func_lut =
212  av_realloc_f(s->window_func_lut, win_size,
213  sizeof(*s->window_func_lut));
214  if (!s->window_func_lut)
215  return AVERROR(ENOMEM);
216  switch (s->win_func) {
217  case WFUNC_NONE:
218  for (i = 0; i < win_size; i++)
219  s->window_func_lut[i] = 1.;
220  break;
221  case WFUNC_HANN:
222  for (i = 0; i < win_size; i++)
223  s->window_func_lut[i] = .5f * (1 - cos(2*M_PI*i / (win_size-1)));
224  break;
225  case WFUNC_HAMMING:
226  for (i = 0; i < win_size; i++)
227  s->window_func_lut[i] = .54f - .46f * cos(2*M_PI*i / (win_size-1));
228  break;
229  case WFUNC_BLACKMAN: {
230  for (i = 0; i < win_size; i++)
231  s->window_func_lut[i] = .42f - .5f*cos(2*M_PI*i / (win_size-1)) + .08f*cos(4*M_PI*i / (win_size-1));
232  break;
233  }
234  default:
235  av_assert0(0);
236  }
237 
238  /* prepare the initial picref buffer (black frame) */
240  s->outpicref = outpicref =
241  ff_get_video_buffer(outlink, outlink->w, outlink->h);
242  if (!outpicref)
243  return AVERROR(ENOMEM);
244  outlink->sample_aspect_ratio = (AVRational){1,1};
245  for (i = 0; i < outlink->h; i++) {
246  memset(outpicref->data[0] + i * outpicref->linesize[0], 0, outlink->w);
247  memset(outpicref->data[1] + i * outpicref->linesize[1], 128, outlink->w);
248  memset(outpicref->data[2] + i * outpicref->linesize[2], 128, outlink->w);
249  }
250  }
251 
252  if (s->xpos >= outlink->w)
253  s->xpos = 0;
254 
255  outlink->frame_rate = av_make_q(inlink->sample_rate, win_size);
256  if (s->sliding == FULLFRAME)
257  outlink->frame_rate.den *= outlink->w;
258 
259  inlink->min_samples = inlink->max_samples = inlink->partial_buf_size =
260  win_size;
261 
262  s->combine_buffer =
263  av_realloc_f(s->combine_buffer, outlink->h * 3,
264  sizeof(*s->combine_buffer));
265 
266  av_log(ctx, AV_LOG_VERBOSE, "s:%dx%d RDFT window size:%d\n",
267  s->w, s->h, win_size);
268  return 0;
269 }
270 
271 static int request_frame(AVFilterLink *outlink)
272 {
273  ShowSpectrumContext *s = outlink->src->priv;
274  AVFilterLink *inlink = outlink->src->inputs[0];
275  unsigned i;
276  int ret;
277 
278  s->req_fullfilled = 0;
279  do {
280  ret = ff_request_frame(inlink);
281  if (ret == AVERROR_EOF && s->sliding == FULLFRAME && s->xpos > 0 &&
282  s->outpicref) {
283  for (i = 0; i < outlink->h; i++) {
284  memset(s->outpicref->data[0] + i * s->outpicref->linesize[0] + s->xpos, 0, outlink->w - s->xpos);
285  memset(s->outpicref->data[1] + i * s->outpicref->linesize[1] + s->xpos, 128, outlink->w - s->xpos);
286  memset(s->outpicref->data[2] + i * s->outpicref->linesize[2] + s->xpos, 128, outlink->w - s->xpos);
287  }
288  ret = ff_filter_frame(outlink, s->outpicref);
289  s->outpicref = NULL;
290  s->req_fullfilled = 1;
291  }
292  } while (!s->req_fullfilled && ret >= 0);
293 
294  return ret;
295 }
296 
297 static int plot_spectrum_column(AVFilterLink *inlink, AVFrame *insamples)
298 {
299  int ret;
300  AVFilterContext *ctx = inlink->dst;
301  AVFilterLink *outlink = ctx->outputs[0];
302  ShowSpectrumContext *s = ctx->priv;
303  AVFrame *outpicref = s->outpicref;
304 
305  /* nb_freq contains the power of two superior or equal to the output image
306  * height (or half the RDFT window size) */
307  const int nb_freq = 1 << (s->rdft_bits - 1);
308  const int win_size = nb_freq << 1;
309  const double w = 1. / (sqrt(nb_freq) * 32768.);
310  int h = s->channel_height;
311 
312  int ch, plane, n, y;
313 
314  av_assert0(insamples->nb_samples == win_size);
315 
316  /* fill RDFT input with the number of samples available */
317  for (ch = 0; ch < s->nb_display_channels; ch++) {
318  const int16_t *p = (int16_t *)insamples->extended_data[ch];
319 
320  for (n = 0; n < win_size; n++)
321  s->rdft_data[ch][n] = p[n] * s->window_func_lut[n];
322  }
323 
324  /* TODO reindent */
325 
326  /* run RDFT on each samples set */
327  for (ch = 0; ch < s->nb_display_channels; ch++)
328  av_rdft_calc(s->rdft, s->rdft_data[ch]);
329 
330  /* fill a new spectrum column */
331 #define RE(y, ch) s->rdft_data[ch][2 * (y) + 0]
332 #define IM(y, ch) s->rdft_data[ch][2 * (y) + 1]
333 #define MAGNITUDE(y, ch) hypot(RE(y, ch), IM(y, ch))
334 
335  /* initialize buffer for combining to black */
336  for (y = 0; y < outlink->h; y++) {
337  s->combine_buffer[3 * y ] = 0;
338  s->combine_buffer[3 * y + 1] = 127.5;
339  s->combine_buffer[3 * y + 2] = 127.5;
340  }
341 
342  for (ch = 0; ch < s->nb_display_channels; ch++) {
343  float yf, uf, vf;
344 
345  /* decide color range */
346  switch (s->mode) {
347  case COMBINED:
348  // reduce range by channel count
349  yf = 256.0f / s->nb_display_channels;
350  switch (s->color_mode) {
351  case INTENSITY:
352  uf = yf;
353  vf = yf;
354  break;
355  case CHANNEL:
356  /* adjust saturation for mixed UV coloring */
357  /* this factor is correct for infinite channels, an approximation otherwise */
358  uf = yf * M_PI;
359  vf = yf * M_PI;
360  break;
361  default:
362  av_assert0(0);
363  }
364  break;
365  case SEPARATE:
366  // full range
367  yf = 256.0f;
368  uf = 256.0f;
369  vf = 256.0f;
370  break;
371  default:
372  av_assert0(0);
373  }
374 
375  if (s->color_mode == CHANNEL) {
376  if (s->nb_display_channels > 1) {
377  uf *= 0.5 * sin((2 * M_PI * ch) / s->nb_display_channels);
378  vf *= 0.5 * cos((2 * M_PI * ch) / s->nb_display_channels);
379  } else {
380  uf = 0.0f;
381  vf = 0.0f;
382  }
383  }
384  uf *= s->saturation;
385  vf *= s->saturation;
386 
387  /* draw the channel */
388  for (y = 0; y < h; y++) {
389  int row = (s->mode == COMBINED) ? y : ch * h + y;
390  float *out = &s->combine_buffer[3 * row];
391 
392  /* get magnitude */
393  float a = w * MAGNITUDE(y, ch);
394 
395  /* apply scale */
396  switch (s->scale) {
397  case LINEAR:
398  break;
399  case SQRT:
400  a = sqrt(a);
401  break;
402  case CBRT:
403  a = cbrt(a);
404  break;
405  case LOG:
406  a = 1 - log(FFMAX(FFMIN(1, a), 1e-6)) / log(1e-6); // zero = -120dBFS
407  break;
408  default:
409  av_assert0(0);
410  }
411 
412  if (s->color_mode == INTENSITY) {
413  float y, u, v;
414  int i;
415 
416  for (i = 1; i < sizeof(intensity_color_table) / sizeof(*intensity_color_table) - 1; i++)
417  if (intensity_color_table[i].a >= a)
418  break;
419  // i now is the first item >= the color
420  // now we know to interpolate between item i - 1 and i
421  if (a <= intensity_color_table[i - 1].a) {
422  y = intensity_color_table[i - 1].y;
423  u = intensity_color_table[i - 1].u;
424  v = intensity_color_table[i - 1].v;
425  } else if (a >= intensity_color_table[i].a) {
426  y = intensity_color_table[i].y;
427  u = intensity_color_table[i].u;
428  v = intensity_color_table[i].v;
429  } else {
430  float start = intensity_color_table[i - 1].a;
431  float end = intensity_color_table[i].a;
432  float lerpfrac = (a - start) / (end - start);
433  y = intensity_color_table[i - 1].y * (1.0f - lerpfrac)
434  + intensity_color_table[i].y * lerpfrac;
435  u = intensity_color_table[i - 1].u * (1.0f - lerpfrac)
436  + intensity_color_table[i].u * lerpfrac;
437  v = intensity_color_table[i - 1].v * (1.0f - lerpfrac)
438  + intensity_color_table[i].v * lerpfrac;
439  }
440 
441  out[0] += y * yf;
442  out[1] += u * uf;
443  out[2] += v * vf;
444  } else {
445  out[0] += a * yf;
446  out[1] += a * uf;
447  out[2] += a * vf;
448  }
449  }
450  }
451 
452  /* copy to output */
453  if (s->sliding == SCROLL) {
454  for (plane = 0; plane < 3; plane++) {
455  for (y = 0; y < outlink->h; y++) {
456  uint8_t *p = outpicref->data[plane] +
457  y * outpicref->linesize[plane];
458  memmove(p, p + 1, outlink->w - 1);
459  }
460  }
461  s->xpos = outlink->w - 1;
462  }
463  for (plane = 0; plane < 3; plane++) {
464  uint8_t *p = outpicref->data[plane] +
465  (outlink->h - 1) * outpicref->linesize[plane] +
466  s->xpos;
467  for (y = 0; y < outlink->h; y++) {
468  *p = rint(FFMAX(0, FFMIN(s->combine_buffer[3 * y + plane], 255)));
469  p -= outpicref->linesize[plane];
470  }
471  }
472 
473  if (s->sliding != FULLFRAME || s->xpos == 0)
474  outpicref->pts = insamples->pts;
475 
476  s->xpos++;
477  if (s->xpos >= outlink->w)
478  s->xpos = 0;
479  if (s->sliding != FULLFRAME || s->xpos == 0) {
480  s->req_fullfilled = 1;
481  ret = ff_filter_frame(outlink, av_frame_clone(s->outpicref));
482  if (ret < 0)
483  return ret;
484  }
485 
486  return win_size;
487 }
488 
489 static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
490 {
491  AVFilterContext *ctx = inlink->dst;
492  ShowSpectrumContext *s = ctx->priv;
493  unsigned win_size = 1 << s->rdft_bits;
494  int ret = 0;
495 
496  av_assert0(insamples->nb_samples <= win_size);
497  if (insamples->nb_samples == win_size)
498  ret = plot_spectrum_column(inlink, insamples);
499 
500  av_frame_free(&insamples);
501  return ret;
502 }
503 
505  {
506  .name = "default",
507  .type = AVMEDIA_TYPE_AUDIO,
508  .filter_frame = filter_frame,
509  },
510  { NULL }
511 };
512 
514  {
515  .name = "default",
516  .type = AVMEDIA_TYPE_VIDEO,
517  .config_props = config_output,
518  .request_frame = request_frame,
519  },
520  { NULL }
521 };
522 
524  .name = "showspectrum",
525  .description = NULL_IF_CONFIG_SMALL("Convert input audio to a spectrum video output."),
526  .uninit = uninit,
527  .query_formats = query_formats,
528  .priv_size = sizeof(ShowSpectrumContext),
529  .inputs = showspectrum_inputs,
530  .outputs = showspectrum_outputs,
531  .priv_class = &showspectrum_class,
532 };