1/* 2 * Copyright (c) 2011 Stefano Sabatini 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 */ 20 21/** 22 * @file 23 * filter for selecting which frame passes in the filterchain 24 */ 25 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 "avfilter.h" 32#include "audio.h" 33#include "formats.h" 34#include "internal.h" 35#include "video.h" 36 37#if CONFIG_AVCODEC 38#include "libavcodec/dsputil.h" 39#endif 40 41static const char *const var_names[] = { 42 "TB", ///< timebase 43 44 "pts", ///< original pts in the file of the frame 45 "start_pts", ///< first PTS in the stream, expressed in TB units 46 "prev_pts", ///< previous frame PTS 47 "prev_selected_pts", ///< previous selected frame PTS 48 49 "t", ///< first PTS in seconds 50 "start_t", ///< first PTS in the stream, expressed in seconds 51 "prev_t", ///< previous frame time 52 "prev_selected_t", ///< previously selected time 53 54 "pict_type", ///< the type of picture in the movie 55 "I", 56 "P", 57 "B", 58 "S", 59 "SI", 60 "SP", 61 "BI", 62 "PICT_TYPE_I", 63 "PICT_TYPE_P", 64 "PICT_TYPE_B", 65 "PICT_TYPE_S", 66 "PICT_TYPE_SI", 67 "PICT_TYPE_SP", 68 "PICT_TYPE_BI", 69 70 "interlace_type", ///< the frame interlace type 71 "PROGRESSIVE", 72 "TOPFIRST", 73 "BOTTOMFIRST", 74 75 "consumed_samples_n",///< number of samples consumed by the filter (only audio) 76 "samples_n", ///< number of samples in the current frame (only audio) 77 "sample_rate", ///< sample rate (only audio) 78 79 "n", ///< frame number (starting from zero) 80 "selected_n", ///< selected frame number (starting from zero) 81 "prev_selected_n", ///< number of the last selected frame 82 83 "key", ///< tell if the frame is a key frame 84 "pos", ///< original position in the file of the frame 85 86 "scene", 87 88 NULL 89}; 90 91enum var_name { 92 VAR_TB, 93 94 VAR_PTS, 95 VAR_START_PTS, 96 VAR_PREV_PTS, 97 VAR_PREV_SELECTED_PTS, 98 99 VAR_T, 100 VAR_START_T, 101 VAR_PREV_T, 102 VAR_PREV_SELECTED_T, 103 104 VAR_PICT_TYPE, 105 VAR_I, 106 VAR_P, 107 VAR_B, 108 VAR_S, 109 VAR_SI, 110 VAR_SP, 111 VAR_BI, 112 VAR_PICT_TYPE_I, 113 VAR_PICT_TYPE_P, 114 VAR_PICT_TYPE_B, 115 VAR_PICT_TYPE_S, 116 VAR_PICT_TYPE_SI, 117 VAR_PICT_TYPE_SP, 118 VAR_PICT_TYPE_BI, 119 120 VAR_INTERLACE_TYPE, 121 VAR_INTERLACE_TYPE_P, 122 VAR_INTERLACE_TYPE_T, 123 VAR_INTERLACE_TYPE_B, 124 125 VAR_CONSUMED_SAMPLES_N, 126 VAR_SAMPLES_N, 127 VAR_SAMPLE_RATE, 128 129 VAR_N, 130 VAR_SELECTED_N, 131 VAR_PREV_SELECTED_N, 132 133 VAR_KEY, 134 VAR_POS, 135 136 VAR_SCENE, 137 138 VAR_VARS_NB 139}; 140 141typedef struct SelectContext { 142 const AVClass *class; 143 char *expr_str; 144 AVExpr *expr; 145 double var_values[VAR_VARS_NB]; 146 int do_scene_detect; ///< 1 if the expression requires scene detection variables, 0 otherwise 147#if CONFIG_AVCODEC 148 AVCodecContext *avctx; ///< codec context required for the DSPContext (scene detect only) 149 DSPContext c; ///< context providing optimized SAD methods (scene detect only) 150 double prev_mafd; ///< previous MAFD (scene detect only) 151#endif 152 AVFrame *prev_picref; ///< previous frame (scene detect only) 153 double select; 154 int select_out; ///< mark the selected output pad index 155 int nb_outputs; 156} SelectContext; 157 158#define OFFSET(x) offsetof(SelectContext, x) 159#define DEFINE_OPTIONS(filt_name, FLAGS) \ 160static const AVOption filt_name##_options[] = { \ 161 { "expr", "set an expression to use for selecting frames", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "1" }, .flags=FLAGS }, \ 162 { "e", "set an expression to use for selecting frames", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "1" }, .flags=FLAGS }, \ 163 { "outputs", "set the number of outputs", OFFSET(nb_outputs), AV_OPT_TYPE_INT, {.i64 = 1}, 1, INT_MAX, .flags=FLAGS }, \ 164 { "n", "set the number of outputs", OFFSET(nb_outputs), AV_OPT_TYPE_INT, {.i64 = 1}, 1, INT_MAX, .flags=FLAGS }, \ 165 { NULL } \ 166} 167 168static int request_frame(AVFilterLink *outlink); 169 170static av_cold int init(AVFilterContext *ctx) 171{ 172 SelectContext *select = ctx->priv; 173 int i, ret; 174 175 if ((ret = av_expr_parse(&select->expr, select->expr_str, 176 var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) { 177 av_log(ctx, AV_LOG_ERROR, "Error while parsing expression '%s'\n", 178 select->expr_str); 179 return ret; 180 } 181 select->do_scene_detect = !!strstr(select->expr_str, "scene"); 182 183 for (i = 0; i < select->nb_outputs; i++) { 184 AVFilterPad pad = { 0 }; 185 186 pad.name = av_asprintf("output%d", i); 187 if (!pad.name) 188 return AVERROR(ENOMEM); 189 pad.type = ctx->filter->inputs[0].type; 190 pad.request_frame = request_frame; 191 ff_insert_outpad(ctx, i, &pad); 192 } 193 194 return 0; 195} 196 197#define INTERLACE_TYPE_P 0 198#define INTERLACE_TYPE_T 1 199#define INTERLACE_TYPE_B 2 200 201static int config_input(AVFilterLink *inlink) 202{ 203 SelectContext *select = inlink->dst->priv; 204 205 select->var_values[VAR_N] = 0.0; 206 select->var_values[VAR_SELECTED_N] = 0.0; 207 208 select->var_values[VAR_TB] = av_q2d(inlink->time_base); 209 210 select->var_values[VAR_PREV_PTS] = NAN; 211 select->var_values[VAR_PREV_SELECTED_PTS] = NAN; 212 select->var_values[VAR_PREV_SELECTED_T] = NAN; 213 select->var_values[VAR_PREV_T] = NAN; 214 select->var_values[VAR_START_PTS] = NAN; 215 select->var_values[VAR_START_T] = NAN; 216 217 select->var_values[VAR_I] = AV_PICTURE_TYPE_I; 218 select->var_values[VAR_P] = AV_PICTURE_TYPE_P; 219 select->var_values[VAR_B] = AV_PICTURE_TYPE_B; 220 select->var_values[VAR_SI] = AV_PICTURE_TYPE_SI; 221 select->var_values[VAR_SP] = AV_PICTURE_TYPE_SP; 222 select->var_values[VAR_BI] = AV_PICTURE_TYPE_BI; 223 select->var_values[VAR_PICT_TYPE_I] = AV_PICTURE_TYPE_I; 224 select->var_values[VAR_PICT_TYPE_P] = AV_PICTURE_TYPE_P; 225 select->var_values[VAR_PICT_TYPE_B] = AV_PICTURE_TYPE_B; 226 select->var_values[VAR_PICT_TYPE_SI] = AV_PICTURE_TYPE_SI; 227 select->var_values[VAR_PICT_TYPE_SP] = AV_PICTURE_TYPE_SP; 228 select->var_values[VAR_PICT_TYPE_BI] = AV_PICTURE_TYPE_BI; 229 230 select->var_values[VAR_INTERLACE_TYPE_P] = INTERLACE_TYPE_P; 231 select->var_values[VAR_INTERLACE_TYPE_T] = INTERLACE_TYPE_T; 232 select->var_values[VAR_INTERLACE_TYPE_B] = INTERLACE_TYPE_B; 233 234 select->var_values[VAR_PICT_TYPE] = NAN; 235 select->var_values[VAR_INTERLACE_TYPE] = NAN; 236 select->var_values[VAR_SCENE] = NAN; 237 select->var_values[VAR_CONSUMED_SAMPLES_N] = NAN; 238 select->var_values[VAR_SAMPLES_N] = NAN; 239 240 select->var_values[VAR_SAMPLE_RATE] = 241 inlink->type == AVMEDIA_TYPE_AUDIO ? inlink->sample_rate : NAN; 242 243#if CONFIG_AVCODEC 244 if (select->do_scene_detect) { 245 select->avctx = avcodec_alloc_context3(NULL); 246 if (!select->avctx) 247 return AVERROR(ENOMEM); 248 avpriv_dsputil_init(&select->c, select->avctx); 249 } 250#endif 251 return 0; 252} 253 254#if CONFIG_AVCODEC 255static double get_scene_score(AVFilterContext *ctx, AVFrame *frame) 256{ 257 double ret = 0; 258 SelectContext *select = ctx->priv; 259 AVFrame *prev_picref = select->prev_picref; 260 261 if (prev_picref && 262 frame->height == prev_picref->height && 263 frame->width == prev_picref->width && 264 frame->linesize[0] == prev_picref->linesize[0]) { 265 int x, y, nb_sad = 0; 266 int64_t sad = 0; 267 double mafd, diff; 268 uint8_t *p1 = frame->data[0]; 269 uint8_t *p2 = prev_picref->data[0]; 270 const int linesize = frame->linesize[0]; 271 272 for (y = 0; y < frame->height - 8; y += 8) { 273 for (x = 0; x < frame->width*3 - 8; x += 8) { 274 sad += select->c.sad[1](NULL, p1 + x, p2 + x, 275 linesize, 8); 276 nb_sad += 8 * 8; 277 } 278 p1 += 8 * linesize; 279 p2 += 8 * linesize; 280 } 281 emms_c(); 282 mafd = nb_sad ? (double)sad / nb_sad : 0; 283 diff = fabs(mafd - select->prev_mafd); 284 ret = av_clipf(FFMIN(mafd, diff) / 100., 0, 1); 285 select->prev_mafd = mafd; 286 av_frame_free(&prev_picref); 287 } 288 select->prev_picref = av_frame_clone(frame); 289 return ret; 290} 291#endif 292 293#define D2TS(d) (isnan(d) ? AV_NOPTS_VALUE : (int64_t)(d)) 294#define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts)) 295 296static void select_frame(AVFilterContext *ctx, AVFrame *frame) 297{ 298 SelectContext *select = ctx->priv; 299 AVFilterLink *inlink = ctx->inputs[0]; 300 double res; 301 302 if (isnan(select->var_values[VAR_START_PTS])) 303 select->var_values[VAR_START_PTS] = TS2D(frame->pts); 304 if (isnan(select->var_values[VAR_START_T])) 305 select->var_values[VAR_START_T] = TS2D(frame->pts) * av_q2d(inlink->time_base); 306 307 select->var_values[VAR_N ] = inlink->frame_count; 308 select->var_values[VAR_PTS] = TS2D(frame->pts); 309 select->var_values[VAR_T ] = TS2D(frame->pts) * av_q2d(inlink->time_base); 310 select->var_values[VAR_POS] = av_frame_get_pkt_pos(frame) == -1 ? NAN : av_frame_get_pkt_pos(frame); 311 312 switch (inlink->type) { 313 case AVMEDIA_TYPE_AUDIO: 314 select->var_values[VAR_SAMPLES_N] = frame->nb_samples; 315 break; 316 317 case AVMEDIA_TYPE_VIDEO: 318 select->var_values[VAR_INTERLACE_TYPE] = 319 !frame->interlaced_frame ? INTERLACE_TYPE_P : 320 frame->top_field_first ? INTERLACE_TYPE_T : INTERLACE_TYPE_B; 321 select->var_values[VAR_PICT_TYPE] = frame->pict_type; 322#if CONFIG_AVCODEC 323 if (select->do_scene_detect) { 324 char buf[32]; 325 select->var_values[VAR_SCENE] = get_scene_score(ctx, frame); 326 // TODO: document metadata 327 snprintf(buf, sizeof(buf), "%f", select->var_values[VAR_SCENE]); 328 av_dict_set(avpriv_frame_get_metadatap(frame), "lavfi.scene_score", buf, 0); 329 } 330#endif 331 break; 332 } 333 334 select->select = res = av_expr_eval(select->expr, select->var_values, NULL); 335 av_log(inlink->dst, AV_LOG_DEBUG, 336 "n:%f pts:%f t:%f key:%d", 337 select->var_values[VAR_N], 338 select->var_values[VAR_PTS], 339 select->var_values[VAR_T], 340 (int)select->var_values[VAR_KEY]); 341 342 switch (inlink->type) { 343 case AVMEDIA_TYPE_VIDEO: 344 av_log(inlink->dst, AV_LOG_DEBUG, " interlace_type:%c pict_type:%c scene:%f", 345 select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_P ? 'P' : 346 select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_T ? 'T' : 347 select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_B ? 'B' : '?', 348 av_get_picture_type_char(select->var_values[VAR_PICT_TYPE]), 349 select->var_values[VAR_SCENE]); 350 break; 351 case AVMEDIA_TYPE_AUDIO: 352 av_log(inlink->dst, AV_LOG_DEBUG, " samples_n:%d consumed_samples_n:%d", 353 (int)select->var_values[VAR_SAMPLES_N], 354 (int)select->var_values[VAR_CONSUMED_SAMPLES_N]); 355 break; 356 } 357 358 if (res == 0) { 359 select->select_out = -1; /* drop */ 360 } else if (isnan(res) || res < 0) { 361 select->select_out = 0; /* first output */ 362 } else { 363 select->select_out = FFMIN(ceilf(res)-1, select->nb_outputs-1); /* other outputs */ 364 } 365 366 av_log(inlink->dst, AV_LOG_DEBUG, " -> select:%f select_out:%d\n", res, select->select_out); 367 368 if (res) { 369 select->var_values[VAR_PREV_SELECTED_N] = select->var_values[VAR_N]; 370 select->var_values[VAR_PREV_SELECTED_PTS] = select->var_values[VAR_PTS]; 371 select->var_values[VAR_PREV_SELECTED_T] = select->var_values[VAR_T]; 372 select->var_values[VAR_SELECTED_N] += 1.0; 373 if (inlink->type == AVMEDIA_TYPE_AUDIO) 374 select->var_values[VAR_CONSUMED_SAMPLES_N] += frame->nb_samples; 375 } 376 377 select->var_values[VAR_PREV_PTS] = select->var_values[VAR_PTS]; 378 select->var_values[VAR_PREV_T] = select->var_values[VAR_T]; 379} 380 381static int filter_frame(AVFilterLink *inlink, AVFrame *frame) 382{ 383 AVFilterContext *ctx = inlink->dst; 384 SelectContext *select = ctx->priv; 385 386 select_frame(ctx, frame); 387 if (select->select) 388 return ff_filter_frame(ctx->outputs[select->select_out], frame); 389 390 av_frame_free(&frame); 391 return 0; 392} 393 394static int request_frame(AVFilterLink *outlink) 395{ 396 AVFilterContext *ctx = outlink->src; 397 SelectContext *select = ctx->priv; 398 AVFilterLink *inlink = outlink->src->inputs[0]; 399 int out_no = FF_OUTLINK_IDX(outlink); 400 401 do { 402 int ret = ff_request_frame(inlink); 403 if (ret < 0) 404 return ret; 405 } while (select->select_out != out_no); 406 407 return 0; 408} 409 410static av_cold void uninit(AVFilterContext *ctx) 411{ 412 SelectContext *select = ctx->priv; 413 int i; 414 415 av_expr_free(select->expr); 416 select->expr = NULL; 417 418 for (i = 0; i < ctx->nb_outputs; i++) 419 av_freep(&ctx->output_pads[i].name); 420 421#if CONFIG_AVCODEC 422 if (select->do_scene_detect) { 423 av_frame_free(&select->prev_picref); 424 if (select->avctx) { 425 avcodec_close(select->avctx); 426 av_freep(&select->avctx); 427 } 428 } 429#endif 430} 431 432static int query_formats(AVFilterContext *ctx) 433{ 434 SelectContext *select = ctx->priv; 435 436 if (!select->do_scene_detect) { 437 return ff_default_query_formats(ctx); 438 } else { 439 static const enum AVPixelFormat pix_fmts[] = { 440 AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24, 441 AV_PIX_FMT_NONE 442 }; 443 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); 444 } 445 return 0; 446} 447 448#if CONFIG_ASELECT_FILTER 449 450DEFINE_OPTIONS(aselect, AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM); 451AVFILTER_DEFINE_CLASS(aselect); 452 453static av_cold int aselect_init(AVFilterContext *ctx) 454{ 455 SelectContext *select = ctx->priv; 456 int ret; 457 458 if ((ret = init(ctx)) < 0) 459 return ret; 460 461 if (select->do_scene_detect) { 462 av_log(ctx, AV_LOG_ERROR, "Scene detection is ignored in aselect filter\n"); 463 return AVERROR(EINVAL); 464 } 465 466 return 0; 467} 468 469static const AVFilterPad avfilter_af_aselect_inputs[] = { 470 { 471 .name = "default", 472 .type = AVMEDIA_TYPE_AUDIO, 473 .config_props = config_input, 474 .filter_frame = filter_frame, 475 }, 476 { NULL } 477}; 478 479AVFilter ff_af_aselect = { 480 .name = "aselect", 481 .description = NULL_IF_CONFIG_SMALL("Select audio frames to pass in output."), 482 .init = aselect_init, 483 .uninit = uninit, 484 .priv_size = sizeof(SelectContext), 485 .inputs = avfilter_af_aselect_inputs, 486 .priv_class = &aselect_class, 487 .flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS, 488}; 489#endif /* CONFIG_ASELECT_FILTER */ 490 491#if CONFIG_SELECT_FILTER 492 493DEFINE_OPTIONS(select, AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM); 494AVFILTER_DEFINE_CLASS(select); 495 496static av_cold int select_init(AVFilterContext *ctx) 497{ 498 SelectContext *select = ctx->priv; 499 int ret; 500 501 if ((ret = init(ctx)) < 0) 502 return ret; 503 504 if (select->do_scene_detect && !CONFIG_AVCODEC) { 505 av_log(ctx, AV_LOG_ERROR, "Scene detection is not available without libavcodec.\n"); 506 return AVERROR(EINVAL); 507 } 508 509 return 0; 510} 511 512static const AVFilterPad avfilter_vf_select_inputs[] = { 513 { 514 .name = "default", 515 .type = AVMEDIA_TYPE_VIDEO, 516 .config_props = config_input, 517 .filter_frame = filter_frame, 518 }, 519 { NULL } 520}; 521 522AVFilter ff_vf_select = { 523 .name = "select", 524 .description = NULL_IF_CONFIG_SMALL("Select video frames to pass in output."), 525 .init = select_init, 526 .uninit = uninit, 527 .query_formats = query_formats, 528 .priv_size = sizeof(SelectContext), 529 .priv_class = &select_class, 530 .inputs = avfilter_vf_select_inputs, 531 .flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS, 532}; 533#endif /* CONFIG_SELECT_FILTER */ 534