FFmpeg: libavfilter/f_ebur128.c Source File

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libavfilter

f_ebur128.c

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1 /*

3 *

4 * This file is part of FFmpeg.

5 *

6 * FFmpeg is free software; you can redistribute it and/or modify

7 * it under the terms of the GNU General Public License as published by

8 * the Free Software Foundation; either version 2 of the License, or

9 * (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

14 * GNU General Public License for more details.

15 *

16 * You should have received a copy of the GNU General Public License along

17 * with FFmpeg; if not, write to the Free Software Foundation, Inc.,

18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

19 */

21 /**

22 * @file

23 * EBU R.128 implementation

24 * @see http://tech.ebu.ch/loudness

25 * @see https://www.youtube.com/watch?v=iuEtQqC-Sqo "EBU R128 Introduction - Florian Camerer"

26 * @todo True Peak

27 * @todo implement start/stop/reset through filter command injection

28 * @todo support other frequencies to avoid resampling

29 */

31 #include <math.h>

33 #include "libavutil/avassert.h"

34 #include "libavutil/avstring.h"

35 #include "libavutil/channel_layout.h"

36 #include "libavutil/dict.h"

37 #include "libavutil/xga_font_data.h"

38 #include "libavutil/opt.h"

39 #include "libavutil/timestamp.h"

40 #include "audio.h"

41 #include "avfilter.h"

42 #include "formats.h"

43 #include "internal.h"

45 #define MAX_CHANNELS 63

47 /* pre-filter coefficients */

48 #define PRE_B0 1.53512485958697

49 #define PRE_B1 -2.69169618940638

50 #define PRE_B2 1.19839281085285

51 #define PRE_A1 -1.69065929318241

52 #define PRE_A2 0.73248077421585

54 /* RLB-filter coefficients */

55 #define RLB_B0 1.0

56 #define RLB_B1 -2.0

57 #define RLB_B2 1.0

58 #define RLB_A1 -1.99004745483398

59 #define RLB_A2 0.99007225036621

61 #define ABS_THRES -70 ///< silence gate: we discard anything below this absolute (LUFS) threshold

62 #define ABS_UP_THRES 10 ///< upper loud limit to consider (ABS_THRES being the minimum)

63 #define HIST_GRAIN 100 ///< defines histogram precision

64 #define HIST_SIZE ((ABS_UP_THRES - ABS_THRES) * HIST_GRAIN + 1)

66 /**

67 * A histogram is an array of HIST_SIZE hist_entry storing all the energies

68 * recorded (with an accuracy of 1/HIST_GRAIN) of the loudnesses from ABS_THRES

69 * (at 0) to ABS_UP_THRES (at HIST_SIZE-1).

70 * This fixed-size system avoids the need of a list of energies growing

71 * infinitely over the time and is thus more scalable.

72 */

73 struct hist_entry {

74 int count; ///< how many times the corresponding value occurred

75 double energy; ///< E = 10^((L + 0.691) / 10)

76 double loudness; ///< L = -0.691 + 10 * log10(E)

77 };

79 struct integrator {

80 double *cache[MAX_CHANNELS]; ///< window of filtered samples (N ms)

81 int cache_pos; ///< focus on the last added bin in the cache array

82 double sum[MAX_CHANNELS]; ///< sum of the last N ms filtered samples (cache content)

83 int filled; ///< 1 if the cache is completely filled, 0 otherwise

84 double rel_threshold; ///< relative threshold

85 double sum_kept_powers; ///< sum of the powers (weighted sums) above absolute threshold

86 int nb_kept_powers; ///< number of sum above absolute threshold

87 struct hist_entry *histogram; ///< histogram of the powers, used to compute LRA and I

88 };

90 struct rect { int x, y, w, h; };

92 typedef struct {

93 const AVClass *class; ///< AVClass context for log and options purpose

95 /* video */

96 int do_video; ///< 1 if video output enabled, 0 otherwise

97 int w, h; ///< size of the video output

98 struct rect text; ///< rectangle for the LU legend on the left

99 struct rect graph; ///< rectangle for the main graph in the center

100 struct rect gauge; ///< rectangle for the gauge on the right

101 AVFrame *outpicref; ///< output picture reference, updated regularly

102 int meter; ///< select a EBU mode between +9 and +18

103 int scale_range; ///< the range of LU values according to the meter

104 int y_zero_lu; ///< the y value (pixel position) for 0 LU

105 int *y_line_ref; ///< y reference values for drawing the LU lines in the graph and the gauge

106

107 /* audio */

108 int nb_channels; ///< number of channels in the input

109 double *ch_weighting; ///< channel weighting mapping

110 int sample_count; ///< sample count used for refresh frequency, reset at refresh

111

112 /* Filter caches.

113 * The mult by 3 in the following is for X[i], X[i-1] and X[i-2] */

114 double x[MAX_CHANNELS * 3]; ///< 3 input samples cache for each channel

115 double y[MAX_CHANNELS * 3]; ///< 3 pre-filter samples cache for each channel

116 double z[MAX_CHANNELS * 3]; ///< 3 RLB-filter samples cache for each channel

117

118 #define I400_BINS (48000 * 4 / 10)

119 #define I3000_BINS (48000 * 3)

120 struct integrator i400; ///< 400ms integrator, used for Momentary loudness (M), and Integrated loudness (I)

121 struct integrator i3000; ///< 3s integrator, used for Short term loudness (S), and Loudness Range (LRA)

122

123 /* I and LRA specific */

124 double integrated_loudness; ///< integrated loudness in LUFS (I)

125 double loudness_range; ///< loudness range in LU (LRA)

126 double lra_low, lra_high; ///< low and high LRA values

127

128 /* misc */

129 int loglevel; ///< log level for frame logging

130 int metadata; ///< whether or not to inject loudness results in frames

131 } EBUR128Context;

132

133 #define OFFSET(x) offsetof(EBUR128Context, x)

134 #define A AV_OPT_FLAG_AUDIO_PARAM

135 #define V AV_OPT_FLAG_VIDEO_PARAM

136 #define F AV_OPT_FLAG_FILTERING_PARAM

137 static const AVOption ebur128_options[] = {

138 { "video", "set video output", OFFSET(do_video), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, V|F },

139 { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x480"}, 0, 0, V|F },

140 { "meter", "set scale meter (+9 to +18)", OFFSET(meter), AV_OPT_TYPE_INT, {.i64 = 9}, 9, 18, V|F },

141 { "framelog", "force frame logging level", OFFSET(loglevel), AV_OPT_TYPE_INT, {.i64 = -1}, INT_MIN, INT_MAX, A|V|F, "level" },

142 { "info", "information logging level", 0, AV_OPT_TYPE_CONST, {.i64 = AV_LOG_INFO}, INT_MIN, INT_MAX, A|V|F, "level" },

143 { "verbose", "verbose logging level", 0, AV_OPT_TYPE_CONST, {.i64 = AV_LOG_VERBOSE}, INT_MIN, INT_MAX, A|V|F, "level" },

144 { "metadata", "inject metadata in the filtergraph", OFFSET(metadata), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, A|V|F },

145 { NULL }

146 };

147

148 AVFILTER_DEFINE_CLASS(ebur128);

149

150 static const uint8_t graph_colors[] = {

151 0xdd, 0x66, 0x66, // value above 0LU non reached

152 0x66, 0x66, 0xdd, // value below 0LU non reached

153 0x96, 0x33, 0x33, // value above 0LU reached

154 0x33, 0x33, 0x96, // value below 0LU reached

155 0xdd, 0x96, 0x96, // value above 0LU line non reached

156 0x96, 0x96, 0xdd, // value below 0LU line non reached

157 0xdd, 0x33, 0x33, // value above 0LU line reached

158 0x33, 0x33, 0xdd, // value below 0LU line reached

159 };

160

161 static const uint8_t *get_graph_color(const EBUR128Context *ebur128, int v, int y)

162 {

163 const int below0 = y > ebur128->y_zero_lu;

164 const int reached = y >= v;

165 const int line = ebur128->y_line_ref[y] || y == ebur128->y_zero_lu;

166 const int colorid = 4*line + 2*reached + below0;

167 return graph_colors + 3*colorid;

168 }

169

170 static inline int lu_to_y(const EBUR128Context *ebur128, double v)

171 {

172 v += 2 * ebur128->meter; // make it in range [0;...]

173 v = av_clipf(v, 0, ebur128->scale_range); // make sure it's in the graph scale

174 v = ebur128->scale_range - v; // invert value (y=0 is on top)

175 return v * ebur128->graph.h / ebur128->scale_range; // rescale from scale range to px height

176 }

177

178 #define FONT8 0

179 #define FONT16 1

180

181 static const uint8_t font_colors[] = {

182 0xdd, 0xdd, 0x00,

183 0x00, 0x96, 0x96,

184 };

185

186 static void drawtext(AVFrame *pic, int x, int y, int ftid, const uint8_t *color, const char *fmt, ...)

187 {

188 int i;

189 char buf[128] = {0};

190 const uint8_t *font;

191 int font_height;

192 va_list vl;

193

194 if (ftid == FONT16) font = avpriv_vga16_font, font_height = 16;

195 else if (ftid == FONT8) font = avpriv_cga_font, font_height = 8;

196 else return;

197

198 va_start(vl, fmt);

199 vsnprintf(buf, sizeof(buf), fmt, vl);

200 va_end(vl);

201

202 for (i = 0; buf[i]; i++) {

203 int char_y, mask;

204 uint8_t *p = pic->data[0] + y*pic->linesize[0] + (x + i*8)*3;

205

206 for (char_y = 0; char_y < font_height; char_y++) {

207 for (mask = 0x80; mask; mask >>= 1) {

208 if (font[buf[i] * font_height + char_y] & mask)

209 memcpy(p, color, 3);

210 else

211 memcpy(p, "\x00\x00\x00", 3);

212 p += 3;

213 }

214 p += pic->linesize[0] - 8*3;

215 }

216 }

217 }

218

219 static void drawline(AVFrame *pic, int x, int y, int len, int step)

220 {

221 int i;

222 uint8_t *p = pic->data[0] + y*pic->linesize[0] + x*3;

223

224 for (i = 0; i < len; i++) {

225 memcpy(p, "\x00\xff\x00", 3);

226 p += step;

227 }

228 }

229

230 static int config_video_output(AVFilterLink *outlink)

231 {

232 int i, x, y;

233 uint8_t *p;

234 AVFilterContext *ctx = outlink->src;

235 EBUR128Context *ebur128 = ctx->priv;

236 AVFrame *outpicref;

237

238 /* check if there is enough space to represent everything decently */

239 if (ebur128->w < 640 || ebur128->h < 480) {

240 av_log(ctx, AV_LOG_ERROR, "Video size %dx%d is too small, "

241 "minimum size is 640x480\n", ebur128->w, ebur128->h);

242 return AVERROR(EINVAL);

243 }

244 outlink->w = ebur128->w;

245 outlink->h = ebur128->h;

246

247 #define PAD 8

248

249 /* configure text area position and size */

250 ebur128->text.x = PAD;

251 ebur128->text.y = 40;

252 ebur128->text.w = 3 * 8; // 3 characters

253 ebur128->text.h = ebur128->h - PAD - ebur128->text.y;

254

255 /* configure gauge position and size */

256 ebur128->gauge.w = 20;

257 ebur128->gauge.h = ebur128->text.h;

258 ebur128->gauge.x = ebur128->w - PAD - ebur128->gauge.w;

259 ebur128->gauge.y = ebur128->text.y;

260

261 /* configure graph position and size */

262 ebur128->graph.x = ebur128->text.x + ebur128->text.w + PAD;

263 ebur128->graph.y = ebur128->gauge.y;

264 ebur128->graph.w = ebur128->gauge.x - ebur128->graph.x - PAD;

265 ebur128->graph.h = ebur128->gauge.h;

266

267 /* graph and gauge share the LU-to-pixel code */

268 av_assert0(ebur128->graph.h == ebur128->gauge.h);

269

270 /* prepare the initial picref buffer */

271 av_frame_free(&ebur128->outpicref);

272 ebur128->outpicref = outpicref =

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

274 if (!outpicref)

275 return AVERROR(ENOMEM);

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

277

278 /* init y references values (to draw LU lines) */

279 ebur128->y_line_ref = av_calloc(ebur128->graph.h + 1, sizeof(*ebur128->y_line_ref));

280 if (!ebur128->y_line_ref)

281 return AVERROR(ENOMEM);

282

283 /* black background */

284 memset(outpicref->data[0], 0, ebur128->h * outpicref->linesize[0]);

285

286 /* draw LU legends */

287 drawtext(outpicref, PAD, PAD+16, FONT8, font_colors+3, " LU");

288 for (i = ebur128->meter; i >= -ebur128->meter * 2; i--) {

289 y = lu_to_y(ebur128, i);

290 x = PAD + (i < 10 && i > -10) * 8;

291 ebur128->y_line_ref[y] = i;

292 y -= 4; // -4 to center vertically

293 drawtext(outpicref, x, y + ebur128->graph.y, FONT8, font_colors+3,

294 "%c%d", i < 0 ? '-' : i > 0 ? '+' : ' ', FFABS(i));

295 }

296

297 /* draw graph */

298 ebur128->y_zero_lu = lu_to_y(ebur128, 0);

299 p = outpicref->data[0] + ebur128->graph.y * outpicref->linesize[0]

300 + ebur128->graph.x * 3;

301 for (y = 0; y < ebur128->graph.h; y++) {

302 const uint8_t *c = get_graph_color(ebur128, INT_MAX, y);

303

304 for (x = 0; x < ebur128->graph.w; x++)

305 memcpy(p + x*3, c, 3);

306 p += outpicref->linesize[0];

307 }

308

309 /* draw fancy rectangles around the graph and the gauge */

310 #define DRAW_RECT(r) do { \

311 drawline(outpicref, r.x, r.y - 1, r.w, 3); \

312 drawline(outpicref, r.x, r.y + r.h, r.w, 3); \

313 drawline(outpicref, r.x - 1, r.y, r.h, outpicref->linesize[0]); \

314 drawline(outpicref, r.x + r.w, r.y, r.h, outpicref->linesize[0]); \

315 } while (0)

316 DRAW_RECT(ebur128->graph);

317 DRAW_RECT(ebur128->gauge);

318

319 outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;

320

321 return 0;

322 }

323

324 static int config_audio_input(AVFilterLink *inlink)

325 {

326 AVFilterContext *ctx = inlink->dst;

327 EBUR128Context *ebur128 = ctx->priv;

328

329 /* force 100ms framing in case of metadata injection: the frames must have

330 * a granularity of the window overlap to be accurately exploited */

331 if (ebur128->metadata)

332 inlink->min_samples =

333 inlink->max_samples =

334 inlink->partial_buf_size = inlink->sample_rate / 10;

335 return 0;

336 }

337

338 static int config_audio_output(AVFilterLink *outlink)

339 {

340 int i;

341 int idx_bitposn = 0;

342 AVFilterContext *ctx = outlink->src;

343 EBUR128Context *ebur128 = ctx->priv;

344 const int nb_channels = av_get_channel_layout_nb_channels(outlink->channel_layout);

345

346 #define BACK_MASK (AV_CH_BACK_LEFT |AV_CH_BACK_CENTER |AV_CH_BACK_RIGHT| \

347 AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_CENTER|AV_CH_TOP_BACK_RIGHT| \

348 AV_CH_SIDE_LEFT |AV_CH_SIDE_RIGHT| \

349 AV_CH_SURROUND_DIRECT_LEFT |AV_CH_SURROUND_DIRECT_RIGHT)

350

351 ebur128->nb_channels = nb_channels;

352 ebur128->ch_weighting = av_calloc(nb_channels, sizeof(*ebur128->ch_weighting));

353 if (!ebur128->ch_weighting)

354 return AVERROR(ENOMEM);

355

356 for (i = 0; i < nb_channels; i++) {

357

358 /* find the next bit that is set starting from the right */

359 while ((outlink->channel_layout & 1ULL<<idx_bitposn) == 0 && idx_bitposn < 63)

360 idx_bitposn++;

361

362 /* channel weighting */

363 if ((1ULL<<idx_bitposn & AV_CH_LOW_FREQUENCY) ||

364 (1ULL<<idx_bitposn & AV_CH_LOW_FREQUENCY_2)) {

365 ebur128->ch_weighting[i] = 0;

366 } else if (1ULL<<idx_bitposn & BACK_MASK) {

367 ebur128->ch_weighting[i] = 1.41;

368 } else {

369 ebur128->ch_weighting[i] = 1.0;

370 }

371

372 idx_bitposn++;

373

374 if (!ebur128->ch_weighting[i])

375 continue;

376

377 /* bins buffer for the two integration window (400ms and 3s) */

378 ebur128->i400.cache[i] = av_calloc(I400_BINS, sizeof(*ebur128->i400.cache[0]));

379 ebur128->i3000.cache[i] = av_calloc(I3000_BINS, sizeof(*ebur128->i3000.cache[0]));

380 if (!ebur128->i400.cache[i] || !ebur128->i3000.cache[i])

381 return AVERROR(ENOMEM);

382 }

383

384 outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;

385

386 return 0;

387 }

388

389 #define ENERGY(loudness) (pow(10, ((loudness) + 0.691) / 10.))

390 #define LOUDNESS(energy) (-0.691 + 10 * log10(energy))

391

392 static struct hist_entry *get_histogram(void)

393 {

394 int i;

395 struct hist_entry *h = av_calloc(HIST_SIZE, sizeof(*h));

396

397 if (!h)

398 return NULL;

399 for (i = 0; i < HIST_SIZE; i++) {

400 h[i].loudness = i / (double)HIST_GRAIN + ABS_THRES;

401 h[i].energy = ENERGY(h[i].loudness);

402 }

403 return h;

404 }

405

406 static av_cold int init(AVFilterContext *ctx)

407 {

408 EBUR128Context *ebur128 = ctx->priv;

409 AVFilterPad pad;

410

411 if (ebur128->loglevel != AV_LOG_INFO &&

412 ebur128->loglevel != AV_LOG_VERBOSE) {

413 if (ebur128->do_video || ebur128->metadata)

414 ebur128->loglevel = AV_LOG_VERBOSE;

415 else

416 ebur128->loglevel = AV_LOG_INFO;

417 }

418

419 // if meter is +9 scale, scale range is from -18 LU to +9 LU (or 3*9)

420 // if meter is +18 scale, scale range is from -36 LU to +18 LU (or 3*18)

421 ebur128->scale_range = 3 * ebur128->meter;

422

423 ebur128->i400.histogram = get_histogram();

424 ebur128->i3000.histogram = get_histogram();

425 if (!ebur128->i400.histogram || !ebur128->i3000.histogram)

426 return AVERROR(ENOMEM);

427

428 ebur128->integrated_loudness = ABS_THRES;

429 ebur128->loudness_range = 0;

430

431 /* insert output pads */

432 if (ebur128->do_video) {

433 pad = (AVFilterPad){

434 .name = av_strdup("out0"),

435 .type = AVMEDIA_TYPE_VIDEO,

436 .config_props = config_video_output,

437 };

438 if (!pad.name)

439 return AVERROR(ENOMEM);

440 ff_insert_outpad(ctx, 0, &pad);

441 }

442 pad = (AVFilterPad){

443 .name = av_asprintf("out%d", ebur128->do_video),

444 .type = AVMEDIA_TYPE_AUDIO,

445 .config_props = config_audio_output,

446 };

447 if (!pad.name)

448 return AVERROR(ENOMEM);

449 ff_insert_outpad(ctx, ebur128->do_video, &pad);

450

451 /* summary */

452 av_log(ctx, AV_LOG_VERBOSE, "EBU +%d scale\n", ebur128->meter);

453

454 return 0;

455 }

456

457 #define HIST_POS(power) (int)(((power) - ABS_THRES) * HIST_GRAIN)

458

459 /* loudness and power should be set such as loudness = -0.691 +

460 * 10*log10(power), we just avoid doing that calculus two times */

461 static int gate_update(struct integrator *integ, double power,

462 double loudness, int gate_thres)

463 {

464 int ipower;

465 double relative_threshold;

466 int gate_hist_pos;

467

468 /* update powers histograms by incrementing current power count */

469 ipower = av_clip(HIST_POS(loudness), 0, HIST_SIZE - 1);

470 integ->histogram[ipower].count++;

471

472 /* compute relative threshold and get its position in the histogram */

473 integ->sum_kept_powers += power;

474 integ->nb_kept_powers++;

475 relative_threshold = integ->sum_kept_powers / integ->nb_kept_powers;

476 if (!relative_threshold)

477 relative_threshold = 1e-12;

478 integ->rel_threshold = LOUDNESS(relative_threshold) + gate_thres;

479 gate_hist_pos = av_clip(HIST_POS(integ->rel_threshold), 0, HIST_SIZE - 1);

480

481 return gate_hist_pos;

482 }

483

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

485 {

486 int i, ch, idx_insample;

487 AVFilterContext *ctx = inlink->dst;

488 EBUR128Context *ebur128 = ctx->priv;

489 const int nb_channels = ebur128->nb_channels;

490 const int nb_samples = insamples->nb_samples;

491 const double *samples = (double *)insamples->data[0];

492 AVFrame *pic = ebur128->outpicref;

493

494 for (idx_insample = 0; idx_insample < nb_samples; idx_insample++) {

495 const int bin_id_400 = ebur128->i400.cache_pos;

496 const int bin_id_3000 = ebur128->i3000.cache_pos;

497

498 #define MOVE_TO_NEXT_CACHED_ENTRY(time) do { \

499 ebur128->i##time.cache_pos++; \

500 if (ebur128->i##time.cache_pos == I##time##_BINS) { \

501 ebur128->i##time.filled = 1; \

502 ebur128->i##time.cache_pos = 0; \

503 } \

504 } while (0)

505

506 MOVE_TO_NEXT_CACHED_ENTRY(400);

507 MOVE_TO_NEXT_CACHED_ENTRY(3000);

508

509 for (ch = 0; ch < nb_channels; ch++) {

510 double bin;

511

512 ebur128->x[ch * 3] = *samples++; // set X[i]

513

514 if (!ebur128->ch_weighting[ch])

515 continue;

516

517 /* Y[i] = X[i]*b0 + X[i-1]*b1 + X[i-2]*b2 - Y[i-1]*a1 - Y[i-2]*a2 */

518 #define FILTER(Y, X, name) do { \

519 double *dst = ebur128->Y + ch*3; \

520 double *src = ebur128->X + ch*3; \

521 dst[2] = dst[1]; \

522 dst[1] = dst[0]; \

523 dst[0] = src[0]*name##_B0 + src[1]*name##_B1 + src[2]*name##_B2 \

524 - dst[1]*name##_A1 - dst[2]*name##_A2; \

525 } while (0)

526

527 // TODO: merge both filters in one?

528 FILTER(y, x, PRE); // apply pre-filter

529 ebur128->x[ch * 3 + 2] = ebur128->x[ch * 3 + 1];

530 ebur128->x[ch * 3 + 1] = ebur128->x[ch * 3 ];

531 FILTER(z, y, RLB); // apply RLB-filter

532

533 bin = ebur128->z[ch * 3] * ebur128->z[ch * 3];

534

535 /* add the new value, and limit the sum to the cache size (400ms or 3s)

536 * by removing the oldest one */

537 ebur128->i400.sum [ch] = ebur128->i400.sum [ch] + bin - ebur128->i400.cache [ch][bin_id_400];

538 ebur128->i3000.sum[ch] = ebur128->i3000.sum[ch] + bin - ebur128->i3000.cache[ch][bin_id_3000];

539

540 /* override old cache entry with the new value */

541 ebur128->i400.cache [ch][bin_id_400 ] = bin;

542 ebur128->i3000.cache[ch][bin_id_3000] = bin;

543 }

544

545 /* For integrated loudness, gating blocks are 400ms long with 75%

546 * overlap (see BS.1770-2 p5), so a re-computation is needed each 100ms

547 * (4800 samples at 48kHz). */

548 if (++ebur128->sample_count == 4800) {

549 double loudness_400, loudness_3000;

550 double power_400 = 1e-12, power_3000 = 1e-12;

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

552 const int64_t pts = insamples->pts +

553 av_rescale_q(idx_insample, (AVRational){ 1, inlink->sample_rate },

554 outlink->time_base);

555

556 ebur128->sample_count = 0;

557

558 #define COMPUTE_LOUDNESS(m, time) do { \

559 if (ebur128->i##time.filled) { \

560 /* weighting sum of the last <time> ms */ \

561 for (ch = 0; ch < nb_channels; ch++) \

562 power_##time += ebur128->ch_weighting[ch] * ebur128->i##time.sum[ch]; \

563 power_##time /= I##time##_BINS; \

564 } \

565 loudness_##time = LOUDNESS(power_##time); \

566 } while (0)

567

568 COMPUTE_LOUDNESS(M, 400);

569 COMPUTE_LOUDNESS(S, 3000);

570

571 /* Integrated loudness */

572 #define I_GATE_THRES -10 // initially defined to -8 LU in the first EBU standard

573

574 if (loudness_400 >= ABS_THRES) {

575 double integrated_sum = 0;

576 int nb_integrated = 0;

577 int gate_hist_pos = gate_update(&ebur128->i400, power_400,

578 loudness_400, I_GATE_THRES);

579

580 /* compute integrated loudness by summing the histogram values

581 * above the relative threshold */

582 for (i = gate_hist_pos; i < HIST_SIZE; i++) {

583 const int nb_v = ebur128->i400.histogram[i].count;

584 nb_integrated += nb_v;

585 integrated_sum += nb_v * ebur128->i400.histogram[i].energy;

586 }

587 if (nb_integrated)

588 ebur128->integrated_loudness = LOUDNESS(integrated_sum / nb_integrated);

589 }

590

591 /* LRA */

592 #define LRA_GATE_THRES -20

593 #define LRA_LOWER_PRC 10

594 #define LRA_HIGHER_PRC 95

595

596 /* XXX: example code in EBU 3342 is ">=" but formula in BS.1770

597 * specs is ">" */

598 if (loudness_3000 >= ABS_THRES) {

599 int nb_powers = 0;

600 int gate_hist_pos = gate_update(&ebur128->i3000, power_3000,

601 loudness_3000, LRA_GATE_THRES);

602

603 for (i = gate_hist_pos; i < HIST_SIZE; i++)

604 nb_powers += ebur128->i3000.histogram[i].count;

605 if (nb_powers) {

606 int n, nb_pow;

607

608 /* get lower loudness to consider */

609 n = 0;

610 nb_pow = LRA_LOWER_PRC * nb_powers / 100. + 0.5;

611 for (i = gate_hist_pos; i < HIST_SIZE; i++) {

612 n += ebur128->i3000.histogram[i].count;

613 if (n >= nb_pow) {

614 ebur128->lra_low = ebur128->i3000.histogram[i].loudness;

615 break;

616 }

617 }

618

619 /* get higher loudness to consider */

620 n = nb_powers;

621 nb_pow = LRA_HIGHER_PRC * nb_powers / 100. + 0.5;

622 for (i = HIST_SIZE - 1; i >= 0; i--) {

623 n -= ebur128->i3000.histogram[i].count;

624 if (n < nb_pow) {

625 ebur128->lra_high = ebur128->i3000.histogram[i].loudness;

626 break;

627 }

628 }

629

630 // XXX: show low & high on the graph?

631 ebur128->loudness_range = ebur128->lra_high - ebur128->lra_low;

632 }

633 }

634

635 #define LOG_FMT "M:%6.1f S:%6.1f I:%6.1f LUFS LRA:%6.1f LU"

636

637 /* push one video frame */

638 if (ebur128->do_video) {

639 int x, y, ret;

640 uint8_t *p;

641

642 const int y_loudness_lu_graph = lu_to_y(ebur128, loudness_3000 + 23);

643 const int y_loudness_lu_gauge = lu_to_y(ebur128, loudness_400 + 23);

644

645 /* draw the graph using the short-term loudness */

646 p = pic->data[0] + ebur128->graph.y*pic->linesize[0] + ebur128->graph.x*3;

647 for (y = 0; y < ebur128->graph.h; y++) {

648 const uint8_t *c = get_graph_color(ebur128, y_loudness_lu_graph, y);

649

650 memmove(p, p + 3, (ebur128->graph.w - 1) * 3);

651 memcpy(p + (ebur128->graph.w - 1) * 3, c, 3);

652 p += pic->linesize[0];

653 }

654

655 /* draw the gauge using the momentary loudness */

656 p = pic->data[0] + ebur128->gauge.y*pic->linesize[0] + ebur128->gauge.x*3;

657 for (y = 0; y < ebur128->gauge.h; y++) {

658 const uint8_t *c = get_graph_color(ebur128, y_loudness_lu_gauge, y);

659

660 for (x = 0; x < ebur128->gauge.w; x++)

661 memcpy(p + x*3, c, 3);

662 p += pic->linesize[0];

663 }

664

665 /* draw textual info */

666 drawtext(pic, PAD, PAD - PAD/2, FONT16, font_colors,

667 LOG_FMT " ", // padding to erase trailing characters

668 loudness_400, loudness_3000,

669 ebur128->integrated_loudness, ebur128->loudness_range);

670

671 /* set pts and push frame */

672 pic->pts = pts;

673 ret = ff_filter_frame(outlink, av_frame_clone(pic));

674 if (ret < 0)

675 return ret;

676 }

677

678 if (ebur128->metadata) { /* happens only once per filter_frame call */

679 char metabuf[128];

680 #define SET_META(name, var) do { \

681 snprintf(metabuf, sizeof(metabuf), "%.3f", var); \

682 av_dict_set(&insamples->metadata, "lavfi.r128." name, metabuf, 0); \

683 } while (0)

684 SET_META("M", loudness_400);

685 SET_META("S", loudness_3000);

686 SET_META("I", ebur128->integrated_loudness);

687 SET_META("LRA", ebur128->loudness_range);

688 SET_META("LRA.low", ebur128->lra_low);

689 SET_META("LRA.high", ebur128->lra_high);

690 }

691

692 av_log(ctx, ebur128->loglevel, "t: %-10s " LOG_FMT "\n",

693 av_ts2timestr(pts, &outlink->time_base),

694 loudness_400, loudness_3000,

695 ebur128->integrated_loudness, ebur128->loudness_range);

696 }

697 }

698

699 return ff_filter_frame(ctx->outputs[ebur128->do_video], insamples);

700 }

701

702 static int query_formats(AVFilterContext *ctx)

703 {

704 EBUR128Context *ebur128 = ctx->priv;

705 AVFilterFormats *formats;

706 AVFilterChannelLayouts *layouts;

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

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

709

710 static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_NONE };

711 static const int input_srate[] = {48000, -1}; // ITU-R BS.1770 provides coeff only for 48kHz

712 static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGB24, AV_PIX_FMT_NONE };

713

714 /* set optional output video format */

715 if (ebur128->do_video) {

716 formats = ff_make_format_list(pix_fmts);

717 if (!formats)

718 return AVERROR(ENOMEM);

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

720 outlink = ctx->outputs[1];

721 }

722

723 /* set input and output audio formats

724 * Note: ff_set_common_* functions are not used because they affect all the

725 * links, and thus break the video format negotiation */

726 formats = ff_make_format_list(sample_fmts);

727 if (!formats)

728 return AVERROR(ENOMEM);

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

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

731

732 layouts = ff_all_channel_layouts();

733 if (!layouts)

734 return AVERROR(ENOMEM);

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

736 ff_channel_layouts_ref(layouts, &outlink->in_channel_layouts);

737

738 formats = ff_make_format_list(input_srate);

739 if (!formats)

740 return AVERROR(ENOMEM);

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

742 ff_formats_ref(formats, &outlink->in_samplerates);

743

744 return 0;

745 }

746

747 static av_cold void uninit(AVFilterContext *ctx)

748 {

749 int i;

750 EBUR128Context *ebur128 = ctx->priv;

751

752 av_log(ctx, AV_LOG_INFO, "Summary:\n\n"

753 " Integrated loudness:\n"

754 " I: %5.1f LUFS\n"

755 " Threshold: %5.1f LUFS\n\n"

756 " Loudness range:\n"

757 " LRA: %5.1f LU\n"

758 " Threshold: %5.1f LUFS\n"

759 " LRA low: %5.1f LUFS\n"

760 " LRA high: %5.1f LUFS\n",

761 ebur128->integrated_loudness, ebur128->i400.rel_threshold,

762 ebur128->loudness_range, ebur128->i3000.rel_threshold,

763 ebur128->lra_low, ebur128->lra_high);

764

765 av_freep(&ebur128->y_line_ref);

766 av_freep(&ebur128->ch_weighting);

767 av_freep(&ebur128->i400.histogram);

768 av_freep(&ebur128->i3000.histogram);

769 for (i = 0; i < ebur128->nb_channels; i++) {

770 av_freep(&ebur128->i400.cache[i]);

771 av_freep(&ebur128->i3000.cache[i]);

772 }

773 for (i = 0; i < ctx->nb_outputs; i++)

774 av_freep(&ctx->output_pads[i].name);

775 av_frame_free(&ebur128->outpicref);

776 }

777

778 static const AVFilterPad ebur128_inputs[] = {

779 {

780 .name = "default",

781 .type = AVMEDIA_TYPE_AUDIO,

782 .filter_frame = filter_frame,

783 .config_props = config_audio_input,

784 },

785 { NULL }

786 };

787

788 AVFilter avfilter_af_ebur128 = {

789 .name = "ebur128",

790 .description = NULL_IF_CONFIG_SMALL("EBU R128 scanner."),

791 .priv_size = sizeof(EBUR128Context),

792 .init = init,

793 .uninit = uninit,

794 .query_formats = query_formats,

795 .inputs = ebur128_inputs,

796 .outputs = NULL,

797 .priv_class = &ebur128_class,

798 .flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS,

799 };

Generated on Sat Jan 25 2014 19:51:59 for FFmpeg by doxygen 1.8.2