FFmpeg: libavfilter/f_select.c Source File

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libavfilter

f_select.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

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 */

21 /**

22 * @file

23 * filter for selecting which frame passes in the filterchain

24 */

26 #include "libavutil/avstring.h"

27 #include "libavutil/eval.h"

28 #include "libavutil/fifo.h"

29 #include "libavutil/internal.h"

30 #include "libavutil/opt.h"

31 #include "libavutil/pixelutils.h"

32 #include "avfilter.h"

33 #include "audio.h"

34 #include "formats.h"

35 #include "internal.h"

36 #include "video.h"

38 static const char *const var_names[] = {

39 "TB", ///< timebase

41 "pts", ///< original pts in the file of the frame

42 "start_pts", ///< first PTS in the stream, expressed in TB units

43 "prev_pts", ///< previous frame PTS

44 "prev_selected_pts", ///< previous selected frame PTS

46 "t", ///< timestamp expressed in seconds

47 "start_t", ///< first PTS in the stream, expressed in seconds

48 "prev_t", ///< previous frame time

49 "prev_selected_t", ///< previously selected time

51 "pict_type", ///< the type of picture in the movie

52 "I",

53 "P",

54 "B",

55 "S",

56 "SI",

57 "SP",

58 "BI",

59 "PICT_TYPE_I",

60 "PICT_TYPE_P",

61 "PICT_TYPE_B",

62 "PICT_TYPE_S",

63 "PICT_TYPE_SI",

64 "PICT_TYPE_SP",

65 "PICT_TYPE_BI",

67 "interlace_type", ///< the frame interlace type

68 "PROGRESSIVE",

69 "TOPFIRST",

70 "BOTTOMFIRST",

72 "consumed_samples_n",///< number of samples consumed by the filter (only audio)

73 "samples_n", ///< number of samples in the current frame (only audio)

74 "sample_rate", ///< sample rate (only audio)

76 "n", ///< frame number (starting from zero)

77 "selected_n", ///< selected frame number (starting from zero)

78 "prev_selected_n", ///< number of the last selected frame

80 "key", ///< tell if the frame is a key frame

81 "pos", ///< original position in the file of the frame

83 "scene",

85 NULL

86 };

88 enum var_name {

89 VAR_TB,

91 VAR_PTS,

92 VAR_START_PTS,

93 VAR_PREV_PTS,

94 VAR_PREV_SELECTED_PTS,

96 VAR_T,

97 VAR_START_T,

98 VAR_PREV_T,

99 VAR_PREV_SELECTED_T,

100

101 VAR_PICT_TYPE,

102 VAR_I,

103 VAR_P,

104 VAR_B,

105 VAR_S,

106 VAR_SI,

107 VAR_SP,

108 VAR_BI,

109 VAR_PICT_TYPE_I,

110 VAR_PICT_TYPE_P,

111 VAR_PICT_TYPE_B,

112 VAR_PICT_TYPE_S,

113 VAR_PICT_TYPE_SI,

114 VAR_PICT_TYPE_SP,

115 VAR_PICT_TYPE_BI,

116

117 VAR_INTERLACE_TYPE,

118 VAR_INTERLACE_TYPE_P,

119 VAR_INTERLACE_TYPE_T,

120 VAR_INTERLACE_TYPE_B,

121

122 VAR_CONSUMED_SAMPLES_N,

123 VAR_SAMPLES_N,

124 VAR_SAMPLE_RATE,

125

126 VAR_N,

127 VAR_SELECTED_N,

128 VAR_PREV_SELECTED_N,

129

130 VAR_KEY,

131 VAR_POS,

132

133 VAR_SCENE,

134

135 VAR_VARS_NB

136 };

137

138 typedef struct SelectContext {

139 const AVClass *class;

140 char *expr_str;

141 AVExpr *expr;

142 double var_values[VAR_VARS_NB];

143 int do_scene_detect; ///< 1 if the expression requires scene detection variables, 0 otherwise

144 av_pixelutils_sad_fn sad; ///< Sum of the absolute difference function (scene detect only)

145 double prev_mafd; ///< previous MAFD (scene detect only)

146 AVFrame *prev_picref; ///< previous frame (scene detect only)

147 double select;

148 int select_out; ///< mark the selected output pad index

149 int nb_outputs;

150 } SelectContext;

151

152 #define OFFSET(x) offsetof(SelectContext, x)

153 #define DEFINE_OPTIONS(filt_name, FLAGS) \

154 static const AVOption filt_name##_options[] = { \

155 { "expr", "set an expression to use for selecting frames", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "1" }, .flags=FLAGS }, \

156 { "e", "set an expression to use for selecting frames", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "1" }, .flags=FLAGS }, \

157 { "outputs", "set the number of outputs", OFFSET(nb_outputs), AV_OPT_TYPE_INT, {.i64 = 1}, 1, INT_MAX, .flags=FLAGS }, \

158 { "n", "set the number of outputs", OFFSET(nb_outputs), AV_OPT_TYPE_INT, {.i64 = 1}, 1, INT_MAX, .flags=FLAGS }, \

159 { NULL } \

160 }

161

162 static int request_frame(AVFilterLink *outlink);

163

164 static av_cold int init(AVFilterContext *ctx)

165 {

166 SelectContext *select = ctx->priv;

167 int i, ret;

168

169 if ((ret = av_expr_parse(&select->expr, select->expr_str,

170 var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) {

171 av_log(ctx, AV_LOG_ERROR, "Error while parsing expression '%s'\n",

172 select->expr_str);

173 return ret;

174 }

175 select->do_scene_detect = !!strstr(select->expr_str, "scene");

176

177 for (i = 0; i < select->nb_outputs; i++) {

178 AVFilterPad pad = { 0 };

179

180 pad.name = av_asprintf("output%d", i);

181 if (!pad.name)

182 return AVERROR(ENOMEM);

183 pad.type = ctx->filter->inputs[0].type;

184 pad.request_frame = request_frame;

185 ff_insert_outpad(ctx, i, &pad);

186 }

187

188 return 0;

189 }

190

191 #define INTERLACE_TYPE_P 0

192 #define INTERLACE_TYPE_T 1

193 #define INTERLACE_TYPE_B 2

194

195 static int config_input(AVFilterLink *inlink)

196 {

197 SelectContext *select = inlink->dst->priv;

198

199 select->var_values[VAR_N] = 0.0;

200 select->var_values[VAR_SELECTED_N] = 0.0;

201

202 select->var_values[VAR_TB] = av_q2d(inlink->time_base);

203

204 select->var_values[VAR_PREV_PTS] = NAN;

205 select->var_values[VAR_PREV_SELECTED_PTS] = NAN;

206 select->var_values[VAR_PREV_SELECTED_T] = NAN;

207 select->var_values[VAR_PREV_T] = NAN;

208 select->var_values[VAR_START_PTS] = NAN;

209 select->var_values[VAR_START_T] = NAN;

210

211 select->var_values[VAR_I] = AV_PICTURE_TYPE_I;

212 select->var_values[VAR_P] = AV_PICTURE_TYPE_P;

213 select->var_values[VAR_B] = AV_PICTURE_TYPE_B;

214 select->var_values[VAR_SI] = AV_PICTURE_TYPE_SI;

215 select->var_values[VAR_SP] = AV_PICTURE_TYPE_SP;

216 select->var_values[VAR_BI] = AV_PICTURE_TYPE_BI;

217 select->var_values[VAR_PICT_TYPE_I] = AV_PICTURE_TYPE_I;

218 select->var_values[VAR_PICT_TYPE_P] = AV_PICTURE_TYPE_P;

219 select->var_values[VAR_PICT_TYPE_B] = AV_PICTURE_TYPE_B;

220 select->var_values[VAR_PICT_TYPE_SI] = AV_PICTURE_TYPE_SI;

221 select->var_values[VAR_PICT_TYPE_SP] = AV_PICTURE_TYPE_SP;

222 select->var_values[VAR_PICT_TYPE_BI] = AV_PICTURE_TYPE_BI;

223

224 select->var_values[VAR_INTERLACE_TYPE_P] = INTERLACE_TYPE_P;

225 select->var_values[VAR_INTERLACE_TYPE_T] = INTERLACE_TYPE_T;

226 select->var_values[VAR_INTERLACE_TYPE_B] = INTERLACE_TYPE_B;

227

228 select->var_values[VAR_PICT_TYPE] = NAN;

229 select->var_values[VAR_INTERLACE_TYPE] = NAN;

230 select->var_values[VAR_SCENE] = NAN;

231 select->var_values[VAR_CONSUMED_SAMPLES_N] = NAN;

232 select->var_values[VAR_SAMPLES_N] = NAN;

233

234 select->var_values[VAR_SAMPLE_RATE] =

235 inlink->type == AVMEDIA_TYPE_AUDIO ? inlink->sample_rate : NAN;

236

237 if (select->do_scene_detect) {

238 select->sad = av_pixelutils_get_sad_fn(3, 3, 2, select); // 8x8 both sources aligned

239 if (!select->sad)

240 return AVERROR(EINVAL);

241 }

242 return 0;

243 }

244

245 static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)

246 {

247 double ret = 0;

248 SelectContext *select = ctx->priv;

249 AVFrame *prev_picref = select->prev_picref;

250

251 if (prev_picref &&

252 frame->height == prev_picref->height &&

253 frame->width == prev_picref->width) {

254 int x, y, nb_sad = 0;

255 int64_t sad = 0;

256 double mafd, diff;

257 uint8_t *p1 = frame->data[0];

258 uint8_t *p2 = prev_picref->data[0];

259 const int p1_linesize = frame->linesize[0];

260 const int p2_linesize = prev_picref->linesize[0];

261

262 for (y = 0; y < frame->height - 7; y += 8) {

263 for (x = 0; x < frame->width*3 - 7; x += 8) {

264 sad += select->sad(p1 + x, p1_linesize, p2 + x, p2_linesize);

265 nb_sad += 8 * 8;

266 }

267 p1 += 8 * p1_linesize;

268 p2 += 8 * p2_linesize;

269 }

270 emms_c();

271 mafd = nb_sad ? (double)sad / nb_sad : 0;

272 diff = fabs(mafd - select->prev_mafd);

273 ret = av_clipf(FFMIN(mafd, diff) / 100., 0, 1);

274 select->prev_mafd = mafd;

275 av_frame_free(&prev_picref);

276 }

277 select->prev_picref = av_frame_clone(frame);

278 return ret;

279 }

280

281 #define D2TS(d) (isnan(d) ? AV_NOPTS_VALUE : (int64_t)(d))

282 #define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts))

283

284 static void select_frame(AVFilterContext *ctx, AVFrame *frame)

285 {

286 SelectContext *select = ctx->priv;

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

288 double res;

289

290 if (isnan(select->var_values[VAR_START_PTS]))

291 select->var_values[VAR_START_PTS] = TS2D(frame->pts);

292 if (isnan(select->var_values[VAR_START_T]))

293 select->var_values[VAR_START_T] = TS2D(frame->pts) * av_q2d(inlink->time_base);

294

295 select->var_values[VAR_N ] = inlink->frame_count;

296 select->var_values[VAR_PTS] = TS2D(frame->pts);

297 select->var_values[VAR_T ] = TS2D(frame->pts) * av_q2d(inlink->time_base);

298 select->var_values[VAR_POS] = av_frame_get_pkt_pos(frame) == -1 ? NAN : av_frame_get_pkt_pos(frame);

299 select->var_values[VAR_KEY] = frame->key_frame;

300

301 switch (inlink->type) {

302 case AVMEDIA_TYPE_AUDIO:

303 select->var_values[VAR_SAMPLES_N] = frame->nb_samples;

304 break;

305

306 case AVMEDIA_TYPE_VIDEO:

307 select->var_values[VAR_INTERLACE_TYPE] =

308 !frame->interlaced_frame ? INTERLACE_TYPE_P :

309 frame->top_field_first ? INTERLACE_TYPE_T : INTERLACE_TYPE_B;

310 select->var_values[VAR_PICT_TYPE] = frame->pict_type;

311 if (select->do_scene_detect) {

312 char buf[32];

313 select->var_values[VAR_SCENE] = get_scene_score(ctx, frame);

314 // TODO: document metadata

315 snprintf(buf, sizeof(buf), "%f", select->var_values[VAR_SCENE]);

316 av_dict_set(avpriv_frame_get_metadatap(frame), "lavfi.scene_score", buf, 0);

317 }

318 break;

319 }

320

321 select->select = res = av_expr_eval(select->expr, select->var_values, NULL);

322 av_log(inlink->dst, AV_LOG_DEBUG,

323 "n:%f pts:%f t:%f key:%d",

324 select->var_values[VAR_N],

325 select->var_values[VAR_PTS],

326 select->var_values[VAR_T],

327 frame->key_frame);

328

329 switch (inlink->type) {

330 case AVMEDIA_TYPE_VIDEO:

331 av_log(inlink->dst, AV_LOG_DEBUG, " interlace_type:%c pict_type:%c scene:%f",

332 (!frame->interlaced_frame) ? 'P' :

333 frame->top_field_first ? 'T' : 'B',

334 av_get_picture_type_char(frame->pict_type),

335 select->var_values[VAR_SCENE]);

336 break;

337 case AVMEDIA_TYPE_AUDIO:

338 av_log(inlink->dst, AV_LOG_DEBUG, " samples_n:%d consumed_samples_n:%f",

339 frame->nb_samples,

340 select->var_values[VAR_CONSUMED_SAMPLES_N]);

341 break;

342 }

343

344 if (res == 0) {

345 select->select_out = -1; /* drop */

346 } else if (isnan(res) || res < 0) {

347 select->select_out = 0; /* first output */

348 } else {

349 select->select_out = FFMIN(ceilf(res)-1, select->nb_outputs-1); /* other outputs */

350 }

351

352 av_log(inlink->dst, AV_LOG_DEBUG, " -> select:%f select_out:%d\n", res, select->select_out);

353

354 if (res) {

355 select->var_values[VAR_PREV_SELECTED_N] = select->var_values[VAR_N];

356 select->var_values[VAR_PREV_SELECTED_PTS] = select->var_values[VAR_PTS];

357 select->var_values[VAR_PREV_SELECTED_T] = select->var_values[VAR_T];

358 select->var_values[VAR_SELECTED_N] += 1.0;

359 if (inlink->type == AVMEDIA_TYPE_AUDIO)

360 select->var_values[VAR_CONSUMED_SAMPLES_N] += frame->nb_samples;

361 }

362

363 select->var_values[VAR_PREV_PTS] = select->var_values[VAR_PTS];

364 select->var_values[VAR_PREV_T] = select->var_values[VAR_T];

365 }

366

367 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)

368 {

369 AVFilterContext *ctx = inlink->dst;

370 SelectContext *select = ctx->priv;

371

372 select_frame(ctx, frame);

373 if (select->select)

374 return ff_filter_frame(ctx->outputs[select->select_out], frame);

375

376 av_frame_free(&frame);

377 return 0;

378 }

379

380 static int request_frame(AVFilterLink *outlink)

381 {

382 AVFilterContext *ctx = outlink->src;

383 SelectContext *select = ctx->priv;

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

385 int out_no = FF_OUTLINK_IDX(outlink);

386

387 do {

388 int ret = ff_request_frame(inlink);

389 if (ret < 0)

390 return ret;

391 } while (select->select_out != out_no);

392

393 return 0;

394 }

395

396 static av_cold void uninit(AVFilterContext *ctx)

397 {

398 SelectContext *select = ctx->priv;

399 int i;

400

401 av_expr_free(select->expr);

402 select->expr = NULL;

403

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

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

406

407 if (select->do_scene_detect) {

408 av_frame_free(&select->prev_picref);

409 }

410 }

411

412 static int query_formats(AVFilterContext *ctx)

413 {

414 SelectContext *select = ctx->priv;

415

416 if (!select->do_scene_detect) {

417 return ff_default_query_formats(ctx);

418 } else {

419 static const enum AVPixelFormat pix_fmts[] = {

420 AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,

421 AV_PIX_FMT_NONE

422 };

423 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));

424 }

425 return 0;

426 }

427

428 #if CONFIG_ASELECT_FILTER

429

430 DEFINE_OPTIONS(aselect, AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM);

431 AVFILTER_DEFINE_CLASS(aselect);

432

433 static av_cold int aselect_init(AVFilterContext *ctx)

434 {

435 SelectContext *select = ctx->priv;

436 int ret;

437

438 if ((ret = init(ctx)) < 0)

439 return ret;

440

441 if (select->do_scene_detect) {

442 av_log(ctx, AV_LOG_ERROR, "Scene detection is ignored in aselect filter\n");

443 return AVERROR(EINVAL);

444 }

445

446 return 0;

447 }

448

449 static const AVFilterPad avfilter_af_aselect_inputs[] = {

450 {

451 .name = "default",

452 .type = AVMEDIA_TYPE_AUDIO,

453 .config_props = config_input,

454 .filter_frame = filter_frame,

455 },

456 { NULL }

457 };

458

459 AVFilter ff_af_aselect = {

460 .name = "aselect",

461 .description = NULL_IF_CONFIG_SMALL("Select audio frames to pass in output."),

462 .init = aselect_init,

463 .uninit = uninit,

464 .priv_size = sizeof(SelectContext),

465 .inputs = avfilter_af_aselect_inputs,

466 .priv_class = &aselect_class,

467 .flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS,

468 };

469 #endif /* CONFIG_ASELECT_FILTER */

470

471 #if CONFIG_SELECT_FILTER

472

473 DEFINE_OPTIONS(select, AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM);

474 AVFILTER_DEFINE_CLASS(select);

475

476 static av_cold int select_init(AVFilterContext *ctx)

477 {

478 int ret;

479

480 if ((ret = init(ctx)) < 0)

481 return ret;

482

483 return 0;

484 }

485

486 static const AVFilterPad avfilter_vf_select_inputs[] = {

487 {

488 .name = "default",

489 .type = AVMEDIA_TYPE_VIDEO,

490 .config_props = config_input,

491 .filter_frame = filter_frame,

492 },

493 { NULL }

494 };

495

496 AVFilter ff_vf_select = {

497 .name = "select",

498 .description = NULL_IF_CONFIG_SMALL("Select video frames to pass in output."),

499 .init = select_init,

500 .uninit = uninit,

501 .query_formats = query_formats,

502 .priv_size = sizeof(SelectContext),

503 .priv_class = &select_class,

504 .inputs = avfilter_vf_select_inputs,

505 .flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS,

506 };

507 #endif /* CONFIG_SELECT_FILTER */

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