FFmpeg: libavfilter/avf_showspectrum.c Source File

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libavfilter

avf_showspectrum.c

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1 /*

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 */

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 */

28 #include <math.h>

30 #include "libavcodec/avfft.h"

31 #include "libavutil/avassert.h"

32 #include "libavutil/channel_layout.h"

33 #include "libavutil/opt.h"

34 #include "avfilter.h"

35 #include "internal.h"

37 enum DisplayMode { COMBINED, SEPARATE, NB_MODES };

38 enum DisplayScale { LINEAR, SQRT, CBRT, LOG, NB_SCALES };

39 enum ColorMode { CHANNEL, INTENSITY, NB_CLMODES };

41 typedef struct {

42 const AVClass *class;

43 int w, h;

44 AVFrame *outpicref;

45 int req_fullfilled;

46 int nb_display_channels;

47 int channel_height;

48 int sliding; ///< 1 if sliding mode, 0 otherwise

49 enum DisplayMode mode; ///< channel display mode

50 enum ColorMode color_mode; ///< display color scheme

51 enum DisplayScale scale;

52 float saturation; ///< color saturation multiplier

53 int xpos; ///< x position (current column)

54 RDFTContext *rdft; ///< Real Discrete Fourier Transform context

55 int rdft_bits; ///< number of bits (RDFT window size = 1<<rdft_bits)

56 FFTSample **rdft_data; ///< bins holder for each (displayed) channels

57 int filled; ///< number of samples (per channel) filled in current rdft_buffer

58 int consumed; ///< number of samples (per channel) consumed from the input frame

59 float *window_func_lut; ///< Window function LUT

60 float *combine_buffer; ///< color combining buffer (3 * h items)

61 } ShowSpectrumContext;

63 #define OFFSET(x) offsetof(ShowSpectrumContext, x)

64 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

66 static const AVOption showspectrum_options[] = {

67 { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x512"}, 0, 0, FLAGS },

68 { "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x512"}, 0, 0, FLAGS },

69 { "slide", "set sliding mode", OFFSET(sliding), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },

70 { "mode", "set channel display mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=COMBINED}, COMBINED, NB_MODES-1, FLAGS, "mode" },

71 { "combined", "combined mode", 0, AV_OPT_TYPE_CONST, {.i64=COMBINED}, 0, 0, FLAGS, "mode" },

72 { "separate", "separate mode", 0, AV_OPT_TYPE_CONST, {.i64=SEPARATE}, 0, 0, FLAGS, "mode" },

73 { "color", "set channel coloring", OFFSET(color_mode), AV_OPT_TYPE_INT, {.i64=CHANNEL}, CHANNEL, NB_CLMODES-1, FLAGS, "color" },

74 { "channel", "separate color for each channel", 0, AV_OPT_TYPE_CONST, {.i64=CHANNEL}, 0, 0, FLAGS, "color" },

75 { "intensity", "intensity based coloring", 0, AV_OPT_TYPE_CONST, {.i64=INTENSITY}, 0, 0, FLAGS, "color" },

76 { "scale", "set display scale", OFFSET(scale), AV_OPT_TYPE_INT, {.i64=SQRT}, LINEAR, NB_SCALES-1, FLAGS, "scale" },

77 { "sqrt", "square root", 0, AV_OPT_TYPE_CONST, {.i64=SQRT}, 0, 0, FLAGS, "scale" },

78 { "cbrt", "cubic root", 0, AV_OPT_TYPE_CONST, {.i64=CBRT}, 0, 0, FLAGS, "scale" },

79 { "log", "logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=LOG}, 0, 0, FLAGS, "scale" },

80 { "lin", "linear", 0, AV_OPT_TYPE_CONST, {.i64=LINEAR}, 0, 0, FLAGS, "scale" },

81 { "saturation", "color saturation multiplier", OFFSET(saturation), AV_OPT_TYPE_FLOAT, {.dbl = 1}, -10, 10, FLAGS },

82 { NULL }

83 };

85 AVFILTER_DEFINE_CLASS(showspectrum);

87 static const struct {

88 float a, y, u, v;

89 } intensity_color_table[] = {

90 { 0, 0, 0, 0 },

91 { 0.13, .03587126228984074, .1573300977624594, -.02548747583751842 },

92 { 0.30, .18572281794568020, .1772436246393981, .17475554840414750 },

93 { 0.60, .28184980583656130, -.1593064119945782, .47132074554608920 },

94 { 0.73, .65830621175547810, -.3716070802232764, .24352759331252930 },

95 { 0.78, .76318535758242900, -.4307467689263783, .16866496622310430 },

96 { 0.91, .95336363636363640, -.2045454545454546, .03313636363636363 },

97 { 1, 1, 0, 0 }

98 };

100 static av_cold void uninit(AVFilterContext *ctx)

101 {

102 ShowSpectrumContext *s = ctx->priv;

103 int i;

104

105 av_freep(&s->combine_buffer);

106 av_rdft_end(s->rdft);

107 for (i = 0; i < s->nb_display_channels; i++)

108 av_freep(&s->rdft_data[i]);

109 av_freep(&s->rdft_data);

110 av_freep(&s->window_func_lut);

111 av_frame_free(&s->outpicref);

112 }

113

114 static int query_formats(AVFilterContext *ctx)

115 {

116 AVFilterFormats *formats = NULL;

117 AVFilterChannelLayouts *layouts = NULL;

118 AVFilterLink *inlink = ctx->inputs[0];

119 AVFilterLink *outlink = ctx->outputs[0];

120 static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_S16P, AV_SAMPLE_FMT_NONE };

121 static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_NONE };

122

123 /* set input audio formats */

124 formats = ff_make_format_list(sample_fmts);

125 if (!formats)

126 return AVERROR(ENOMEM);

127 ff_formats_ref(formats, &inlink->out_formats);

128

129 layouts = ff_all_channel_layouts();

130 if (!layouts)

131 return AVERROR(ENOMEM);

132 ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts);

133

134 formats = ff_all_samplerates();

135 if (!formats)

136 return AVERROR(ENOMEM);

137 ff_formats_ref(formats, &inlink->out_samplerates);

138

139 /* set output video format */

140 formats = ff_make_format_list(pix_fmts);

141 if (!formats)

142 return AVERROR(ENOMEM);

143 ff_formats_ref(formats, &outlink->in_formats);

144

145 return 0;

146 }

147

148 static int config_output(AVFilterLink *outlink)

149 {

150 AVFilterContext *ctx = outlink->src;

151 AVFilterLink *inlink = ctx->inputs[0];

152 ShowSpectrumContext *s = ctx->priv;

153 int i, rdft_bits, win_size, h;

154

155 outlink->w = s->w;

156 outlink->h = s->h;

157

158 h = (s->mode == COMBINED) ? outlink->h : outlink->h / inlink->channels;

159 s->channel_height = h;

160

161 /* RDFT window size (precision) according to the requested output frame height */

162 for (rdft_bits = 1; 1 << rdft_bits < 2 * h; rdft_bits++);

163 win_size = 1 << rdft_bits;

164

165 /* (re-)configuration if the video output changed (or first init) */

166 if (rdft_bits != s->rdft_bits) {

167 size_t rdft_size, rdft_listsize;

168 AVFrame *outpicref;

169

170 av_rdft_end(s->rdft);

171 s->rdft = av_rdft_init(rdft_bits, DFT_R2C);

172 s->rdft_bits = rdft_bits;

173

174 /* RDFT buffers: x2 for each (display) channel buffer.

175 * Note: we use free and malloc instead of a realloc-like function to

176 * make sure the buffer is aligned in memory for the FFT functions. */

177 for (i = 0; i < s->nb_display_channels; i++)

178 av_freep(&s->rdft_data[i]);

179 av_freep(&s->rdft_data);

180 s->nb_display_channels = inlink->channels;

181

182 if (av_size_mult(sizeof(*s->rdft_data),

183 s->nb_display_channels, &rdft_listsize) < 0)

184 return AVERROR(EINVAL);

185 if (av_size_mult(sizeof(**s->rdft_data),

186 win_size, &rdft_size) < 0)

187 return AVERROR(EINVAL);

188 s->rdft_data = av_malloc(rdft_listsize);

189 if (!s->rdft_data)

190 return AVERROR(ENOMEM);

191 for (i = 0; i < s->nb_display_channels; i++) {

192 s->rdft_data[i] = av_malloc(rdft_size);

193 if (!s->rdft_data[i])

194 return AVERROR(ENOMEM);

195 }

196 s->filled = 0;

197

198 /* pre-calc windowing function (hann here) */

199 s->window_func_lut =

200 av_realloc_f(s->window_func_lut, win_size,

201 sizeof(*s->window_func_lut));

202 if (!s->window_func_lut)

203 return AVERROR(ENOMEM);

204 for (i = 0; i < win_size; i++)

205 s->window_func_lut[i] = .5f * (1 - cos(2*M_PI*i / (win_size-1)));

206

207 /* prepare the initial picref buffer (black frame) */

208 av_frame_free(&s->outpicref);

209 s->outpicref = outpicref =

210 ff_get_video_buffer(outlink, outlink->w, outlink->h);

211 if (!outpicref)

212 return AVERROR(ENOMEM);

213 outlink->sample_aspect_ratio = (AVRational){1,1};

214 for (i = 0; i < outlink->h; i++) {

215 memset(outpicref->data[0] + i * outpicref->linesize[0], 0, outlink->w);

216 memset(outpicref->data[1] + i * outpicref->linesize[1], 128, outlink->w);

217 memset(outpicref->data[2] + i * outpicref->linesize[2], 128, outlink->w);

218 }

219 }

220

221 if (s->xpos >= outlink->w)

222 s->xpos = 0;

223

224 s->combine_buffer =

225 av_realloc_f(s->combine_buffer, outlink->h * 3,

226 sizeof(*s->combine_buffer));

227

228 av_log(ctx, AV_LOG_VERBOSE, "s:%dx%d RDFT window size:%d\n",

229 s->w, s->h, win_size);

230 return 0;

231 }

232

233 inline static int push_frame(AVFilterLink *outlink)

234 {

235 ShowSpectrumContext *s = outlink->src->priv;

236

237 s->xpos++;

238 if (s->xpos >= outlink->w)

239 s->xpos = 0;

240 s->filled = 0;

241 s->req_fullfilled = 1;

242

243 return ff_filter_frame(outlink, av_frame_clone(s->outpicref));

244 }

245

246 static int request_frame(AVFilterLink *outlink)

247 {

248 ShowSpectrumContext *s = outlink->src->priv;

249 AVFilterLink *inlink = outlink->src->inputs[0];

250 int ret;

251

252 s->req_fullfilled = 0;

253 do {

254 ret = ff_request_frame(inlink);

255 } while (!s->req_fullfilled && ret >= 0);

256

257 if (ret == AVERROR_EOF && s->outpicref)

258 push_frame(outlink);

259 return ret;

260 }

261

262 static int plot_spectrum_column(AVFilterLink *inlink, AVFrame *insamples, int nb_samples)

263 {

264 int ret;

265 AVFilterContext *ctx = inlink->dst;

266 AVFilterLink *outlink = ctx->outputs[0];

267 ShowSpectrumContext *s = ctx->priv;

268 AVFrame *outpicref = s->outpicref;

269

270 /* nb_freq contains the power of two superior or equal to the output image

271 * height (or half the RDFT window size) */

272 const int nb_freq = 1 << (s->rdft_bits - 1);

273 const int win_size = nb_freq << 1;

274 const double w = 1. / (sqrt(nb_freq) * 32768.);

275

276 int ch, plane, n, y;

277 const int start = s->filled;

278 const int add_samples = FFMIN(win_size - start, nb_samples);

279

280 /* fill RDFT input with the number of samples available */

281 for (ch = 0; ch < s->nb_display_channels; ch++) {

282 const int16_t *p = (int16_t *)insamples->extended_data[ch];

283

284 p += s->consumed;

285 for (n = 0; n < add_samples; n++)

286 s->rdft_data[ch][start + n] = p[n] * s->window_func_lut[start + n];

287 }

288 s->filled += add_samples;

289

290 /* complete RDFT window size? */

291 if (s->filled == win_size) {

292

293 /* channel height */

294 int h = s->channel_height;

295

296 /* run RDFT on each samples set */

297 for (ch = 0; ch < s->nb_display_channels; ch++)

298 av_rdft_calc(s->rdft, s->rdft_data[ch]);

299

300 /* fill a new spectrum column */

301 #define RE(y, ch) s->rdft_data[ch][2 * y + 0]

302 #define IM(y, ch) s->rdft_data[ch][2 * y + 1]

303 #define MAGNITUDE(y, ch) hypot(RE(y, ch), IM(y, ch))

304

305 /* initialize buffer for combining to black */

306 for (y = 0; y < outlink->h; y++) {

307 s->combine_buffer[3 * y ] = 0;

308 s->combine_buffer[3 * y + 1] = 127.5;

309 s->combine_buffer[3 * y + 2] = 127.5;

310 }

311

312 for (ch = 0; ch < s->nb_display_channels; ch++) {

313 float yf, uf, vf;

314

315 /* decide color range */

316 switch (s->mode) {

317 case COMBINED:

318 // reduce range by channel count

319 yf = 256.0f / s->nb_display_channels;

320 switch (s->color_mode) {

321 case INTENSITY:

322 uf = yf;

323 vf = yf;

324 break;

325 case CHANNEL:

326 /* adjust saturation for mixed UV coloring */

327 /* this factor is correct for infinite channels, an approximation otherwise */

328 uf = yf * M_PI;

329 vf = yf * M_PI;

330 break;

331 default:

332 av_assert0(0);

333 }

334 break;

335 case SEPARATE:

336 // full range

337 yf = 256.0f;

338 uf = 256.0f;

339 vf = 256.0f;

340 break;

341 default:

342 av_assert0(0);

343 }

344

345 if (s->color_mode == CHANNEL) {

346 if (s->nb_display_channels > 1) {

347 uf *= 0.5 * sin((2 * M_PI * ch) / s->nb_display_channels);

348 vf *= 0.5 * cos((2 * M_PI * ch) / s->nb_display_channels);

349 } else {

350 uf = 0.0f;

351 vf = 0.0f;

352 }

353 }

354 uf *= s->saturation;

355 vf *= s->saturation;

356

357 /* draw the channel */

358 for (y = 0; y < h; y++) {

359 int row = (s->mode == COMBINED) ? y : ch * h + y;

360 float *out = &s->combine_buffer[3 * row];

361

362 /* get magnitude */

363 float a = w * MAGNITUDE(y, ch);

364

365 /* apply scale */

366 switch (s->scale) {

367 case LINEAR:

368 break;

369 case SQRT:

370 a = sqrt(a);

371 break;

372 case CBRT:

373 a = cbrt(a);

374 break;

375 case LOG:

376 a = 1 - log(FFMAX(FFMIN(1, a), 1e-6)) / log(1e-6); // zero = -120dBFS

377 break;

378 default:

379 av_assert0(0);

380 }

381

382 if (s->color_mode == INTENSITY) {

383 float y, u, v;

384 int i;

385

386 for (i = 1; i < sizeof(intensity_color_table) / sizeof(*intensity_color_table) - 1; i++)

387 if (intensity_color_table[i].a >= a)

388 break;

389 // i now is the first item >= the color

390 // now we know to interpolate between item i - 1 and i

391 if (a <= intensity_color_table[i - 1].a) {

392 y = intensity_color_table[i - 1].y;

393 u = intensity_color_table[i - 1].u;

394 v = intensity_color_table[i - 1].v;

395 } else if (a >= intensity_color_table[i].a) {

396 y = intensity_color_table[i].y;

397 u = intensity_color_table[i].u;

398 v = intensity_color_table[i].v;

399 } else {

400 float start = intensity_color_table[i - 1].a;

401 float end = intensity_color_table[i].a;

402 float lerpfrac = (a - start) / (end - start);

403 y = intensity_color_table[i - 1].y * (1.0f - lerpfrac)

404 + intensity_color_table[i].y * lerpfrac;

405 u = intensity_color_table[i - 1].u * (1.0f - lerpfrac)

406 + intensity_color_table[i].u * lerpfrac;

407 v = intensity_color_table[i - 1].v * (1.0f - lerpfrac)

408 + intensity_color_table[i].v * lerpfrac;

409 }

410

411 out[0] += y * yf;

412 out[1] += u * uf;

413 out[2] += v * vf;

414 } else {

415 out[0] += a * yf;

416 out[1] += a * uf;

417 out[2] += a * vf;

418 }

419 }

420 }

421

422 /* copy to output */

423 if (s->sliding) {

424 for (plane = 0; plane < 3; plane++) {

425 for (y = 0; y < outlink->h; y++) {

426 uint8_t *p = outpicref->data[plane] +

427 y * outpicref->linesize[plane];

428 memmove(p, p + 1, outlink->w - 1);

429 }

430 }

431 s->xpos = outlink->w - 1;

432 }

433 for (plane = 0; plane < 3; plane++) {

434 uint8_t *p = outpicref->data[plane] +

435 (outlink->h - 1) * outpicref->linesize[plane] +

436 s->xpos;

437 for (y = 0; y < outlink->h; y++) {

438 *p = rint(FFMAX(0, FFMIN(s->combine_buffer[3 * y + plane], 255)));

439 p -= outpicref->linesize[plane];

440 }

441 }

442

443 outpicref->pts = insamples->pts +

444 av_rescale_q(s->consumed,

445 (AVRational){ 1, inlink->sample_rate },

446 outlink->time_base);

447 ret = push_frame(outlink);

448 if (ret < 0)

449 return ret;

450 }

451

452 return add_samples;

453 }

454

455 static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)

456 {

457 AVFilterContext *ctx = inlink->dst;

458 ShowSpectrumContext *s = ctx->priv;

459 int ret = 0, left_samples = insamples->nb_samples;

460

461 s->consumed = 0;

462 while (left_samples) {

463 int ret = plot_spectrum_column(inlink, insamples, left_samples);

464 if (ret < 0)

465 break;

466 s->consumed += ret;

467 left_samples -= ret;

468 }

469

470 av_frame_free(&insamples);

471 return ret;

472 }

473

474 static const AVFilterPad showspectrum_inputs[] = {

475 {

476 .name = "default",

477 .type = AVMEDIA_TYPE_AUDIO,

478 .filter_frame = filter_frame,

479 },

480 { NULL }

481 };

482

483 static const AVFilterPad showspectrum_outputs[] = {

484 {

485 .name = "default",

486 .type = AVMEDIA_TYPE_VIDEO,

487 .config_props = config_output,

488 .request_frame = request_frame,

489 },

490 { NULL }

491 };

492

493 AVFilter avfilter_avf_showspectrum = {

494 .name = "showspectrum",

495 .description = NULL_IF_CONFIG_SMALL("Convert input audio to a spectrum video output."),

496 .uninit = uninit,

497 .query_formats = query_formats,

498 .priv_size = sizeof(ShowSpectrumContext),

499 .inputs = showspectrum_inputs,

500 .outputs = showspectrum_outputs,

501 .priv_class = &showspectrum_class,

502 };

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