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 };

40 enum WindowFunc { WFUNC_NONE, WFUNC_HANN, WFUNC_HAMMING, WFUNC_BLACKMAN, NB_WFUNC };

41 enum SlideMode { REPLACE, SCROLL, FULLFRAME, NB_SLIDES };

43 typedef struct {

44 const AVClass *class;

45 int w, h;

46 AVFrame *outpicref;

47 int req_fullfilled;

48 int nb_display_channels;

49 int channel_height;

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

51 int mode; ///< channel display mode

52 int color_mode; ///< display color scheme

53 int scale;

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

60 int win_func;

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

62 } ShowSpectrumContext;

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

65 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

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 };

93 AVFILTER_DEFINE_CLASS(showspectrum);

95 static const struct {

96 float a, y, u, v;

97 } intensity_color_table[] = {

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

113 av_freep(&s->combine_buffer);

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);

118 av_freep(&s->window_func_lut);

119 av_frame_free(&s->outpicref);

120 }

121

122 static int query_formats(AVFilterContext *ctx)

123 {

124 AVFilterFormats *formats = NULL;

125 AVFilterChannelLayouts *layouts = NULL;

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

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

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

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) */

239 av_frame_free(&s->outpicref);

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

504 static const AVFilterPad showspectrum_inputs[] = {

505 {

506 .name = "default",

507 .type = AVMEDIA_TYPE_AUDIO,

508 .filter_frame = filter_frame,

509 },

510 { NULL }

511 };

512

513 static const AVFilterPad showspectrum_outputs[] = {

514 {

515 .name = "default",

516 .type = AVMEDIA_TYPE_VIDEO,

517 .config_props = config_output,

518 .request_frame = request_frame,

519 },

520 { NULL }

521 };

522

523 AVFilter ff_avf_showspectrum = {

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 };

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