FFmpeg
f_select.c
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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/imgutils.h"
30 #include "libavutil/internal.h"
31 #include "libavutil/opt.h"
32 #include "libavutil/pixdesc.h"
33 #include "avfilter.h"
34 #include "audio.h"
35 #include "formats.h"
36 #include "internal.h"
37 #include "video.h"
38 #include "scene_sad.h"
39 
40 static const char *const var_names[] = {
41  "TB", ///< timebase
42 
43  "pts", ///< original pts in the file of the frame
44  "start_pts", ///< first PTS in the stream, expressed in TB units
45  "prev_pts", ///< previous frame PTS
46  "prev_selected_pts", ///< previous selected frame PTS
47 
48  "t", ///< timestamp expressed in seconds
49  "start_t", ///< first PTS in the stream, expressed in seconds
50  "prev_t", ///< previous frame time
51  "prev_selected_t", ///< previously selected time
52 
53  "pict_type", ///< the type of picture in the movie
54  "I",
55  "P",
56  "B",
57  "S",
58  "SI",
59  "SP",
60  "BI",
61  "PICT_TYPE_I",
62  "PICT_TYPE_P",
63  "PICT_TYPE_B",
64  "PICT_TYPE_S",
65  "PICT_TYPE_SI",
66  "PICT_TYPE_SP",
67  "PICT_TYPE_BI",
68 
69  "interlace_type", ///< the frame interlace type
70  "PROGRESSIVE",
71  "TOPFIRST",
72  "BOTTOMFIRST",
73 
74  "consumed_samples_n",///< number of samples consumed by the filter (only audio)
75  "samples_n", ///< number of samples in the current frame (only audio)
76  "sample_rate", ///< sample rate (only audio)
77 
78  "n", ///< frame number (starting from zero)
79  "selected_n", ///< selected frame number (starting from zero)
80  "prev_selected_n", ///< number of the last selected frame
81 
82  "key", ///< tell if the frame is a key frame
83  "pos", ///< original position in the file of the frame
84 
85  "scene",
86 
87  "concatdec_select", ///< frame is within the interval set by the concat demuxer
88 
89  NULL
90 };
91 
92 enum var_name {
94 
99 
104 
120 
125 
129 
133 
136 
138 
140 
142 };
143 
144 typedef struct SelectContext {
145  const AVClass *class;
146  char *expr_str;
149  int bitdepth;
151  ptrdiff_t width[4];
152  ptrdiff_t height[4];
153  int do_scene_detect; ///< 1 if the expression requires scene detection variables, 0 otherwise
154  ff_scene_sad_fn sad; ///< Sum of the absolute difference function (scene detect only)
155  double prev_mafd; ///< previous MAFD (scene detect only)
156  AVFrame *prev_picref; ///< previous frame (scene detect only)
157  double select;
158  int select_out; ///< mark the selected output pad index
160 } SelectContext;
161 
162 #define OFFSET(x) offsetof(SelectContext, x)
163 #define DEFINE_OPTIONS(filt_name, FLAGS) \
164 static const AVOption filt_name##_options[] = { \
165  { "expr", "set an expression to use for selecting frames", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "1" }, .flags=FLAGS }, \
166  { "e", "set an expression to use for selecting frames", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "1" }, .flags=FLAGS }, \
167  { "outputs", "set the number of outputs", OFFSET(nb_outputs), AV_OPT_TYPE_INT, {.i64 = 1}, 1, INT_MAX, .flags=FLAGS }, \
168  { "n", "set the number of outputs", OFFSET(nb_outputs), AV_OPT_TYPE_INT, {.i64 = 1}, 1, INT_MAX, .flags=FLAGS }, \
169  { NULL } \
170 }
171 
172 static int request_frame(AVFilterLink *outlink);
173 
175 {
176  SelectContext *select = ctx->priv;
177  int i, ret;
178 
179  if ((ret = av_expr_parse(&select->expr, select->expr_str,
180  var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) {
181  av_log(ctx, AV_LOG_ERROR, "Error while parsing expression '%s'\n",
182  select->expr_str);
183  return ret;
184  }
185  select->do_scene_detect = !!strstr(select->expr_str, "scene");
186 
187  for (i = 0; i < select->nb_outputs; i++) {
188  AVFilterPad pad = { 0 };
189 
190  pad.name = av_asprintf("output%d", i);
191  if (!pad.name)
192  return AVERROR(ENOMEM);
193  pad.type = ctx->filter->inputs[0].type;
195  if ((ret = ff_insert_outpad(ctx, i, &pad)) < 0) {
196  av_freep(&pad.name);
197  return ret;
198  }
199  }
200 
201  return 0;
202 }
203 
204 #define INTERLACE_TYPE_P 0
205 #define INTERLACE_TYPE_T 1
206 #define INTERLACE_TYPE_B 2
207 
209 {
210  SelectContext *select = inlink->dst->priv;
212  int is_yuv = !(desc->flags & AV_PIX_FMT_FLAG_RGB) &&
213  (desc->flags & AV_PIX_FMT_FLAG_PLANAR) &&
214  desc->nb_components >= 3;
215 
216  select->bitdepth = desc->comp[0].depth;
217  select->nb_planes = is_yuv ? 1 : av_pix_fmt_count_planes(inlink->format);
218 
219  for (int plane = 0; plane < select->nb_planes; plane++) {
220  ptrdiff_t line_size = av_image_get_linesize(inlink->format, inlink->w, plane);
221  int vsub = desc->log2_chroma_h;
222 
223  select->width[plane] = line_size >> (select->bitdepth > 8);
224  select->height[plane] = plane == 1 || plane == 2 ? AV_CEIL_RSHIFT(inlink->h, vsub) : inlink->h;
225  }
226 
227  select->var_values[VAR_N] = 0.0;
228  select->var_values[VAR_SELECTED_N] = 0.0;
229 
230  select->var_values[VAR_TB] = av_q2d(inlink->time_base);
231 
232  select->var_values[VAR_PREV_PTS] = NAN;
235  select->var_values[VAR_PREV_T] = NAN;
236  select->var_values[VAR_START_PTS] = NAN;
237  select->var_values[VAR_START_T] = NAN;
238 
251 
255 
256  select->var_values[VAR_PICT_TYPE] = NAN;
257  select->var_values[VAR_INTERLACE_TYPE] = NAN;
258  select->var_values[VAR_SCENE] = NAN;
260  select->var_values[VAR_SAMPLES_N] = NAN;
261 
262  select->var_values[VAR_SAMPLE_RATE] =
263  inlink->type == AVMEDIA_TYPE_AUDIO ? inlink->sample_rate : NAN;
264 
265  if (CONFIG_SELECT_FILTER && select->do_scene_detect) {
266  select->sad = ff_scene_sad_get_fn(select->bitdepth == 8 ? 8 : 16);
267  if (!select->sad)
268  return AVERROR(EINVAL);
269  }
270  return 0;
271 }
272 
274 {
275  double ret = 0;
276  SelectContext *select = ctx->priv;
277  AVFrame *prev_picref = select->prev_picref;
278 
279  if (prev_picref &&
280  frame->height == prev_picref->height &&
281  frame->width == prev_picref->width) {
282  uint64_t sad = 0;
283  double mafd, diff;
284  uint64_t count = 0;
285 
286  for (int plane = 0; plane < select->nb_planes; plane++) {
287  uint64_t plane_sad;
288  select->sad(prev_picref->data[plane], prev_picref->linesize[plane],
289  frame->data[plane], frame->linesize[plane],
290  select->width[plane], select->height[plane], &plane_sad);
291  sad += plane_sad;
292  count += select->width[plane] * select->height[plane];
293  }
294 
295  emms_c();
296  mafd = (double)sad / count / (1ULL << (select->bitdepth - 8));
297  diff = fabs(mafd - select->prev_mafd);
298  ret = av_clipf(FFMIN(mafd, diff) / 100., 0, 1);
299  select->prev_mafd = mafd;
300  av_frame_free(&prev_picref);
301  }
302  select->prev_picref = av_frame_clone(frame);
303  return ret;
304 }
305 
306 static double get_concatdec_select(AVFrame *frame, int64_t pts)
307 {
308  AVDictionary *metadata = frame->metadata;
309  AVDictionaryEntry *start_time_entry = av_dict_get(metadata, "lavf.concatdec.start_time", NULL, 0);
310  AVDictionaryEntry *duration_entry = av_dict_get(metadata, "lavf.concatdec.duration", NULL, 0);
311  if (start_time_entry) {
312  int64_t start_time = strtoll(start_time_entry->value, NULL, 10);
313  if (pts >= start_time) {
314  if (duration_entry) {
315  int64_t duration = strtoll(duration_entry->value, NULL, 10);
316  if (pts < start_time + duration)
317  return -1;
318  else
319  return 0;
320  }
321  return -1;
322  }
323  return 0;
324  }
325  return NAN;
326 }
327 
329 {
330  SelectContext *select = ctx->priv;
331  AVFilterLink *inlink = ctx->inputs[0];
332  double res;
333 
334  if (isnan(select->var_values[VAR_START_PTS]))
335  select->var_values[VAR_START_PTS] = TS2D(frame->pts);
336  if (isnan(select->var_values[VAR_START_T]))
337  select->var_values[VAR_START_T] = TS2D(frame->pts) * av_q2d(inlink->time_base);
338 
339  select->var_values[VAR_N ] = inlink->frame_count_out;
340  select->var_values[VAR_PTS] = TS2D(frame->pts);
341  select->var_values[VAR_T ] = TS2D(frame->pts) * av_q2d(inlink->time_base);
342  select->var_values[VAR_POS] = frame->pkt_pos == -1 ? NAN : frame->pkt_pos;
343  select->var_values[VAR_KEY] = frame->key_frame;
345 
346  switch (inlink->type) {
347  case AVMEDIA_TYPE_AUDIO:
348  select->var_values[VAR_SAMPLES_N] = frame->nb_samples;
349  break;
350 
351  case AVMEDIA_TYPE_VIDEO:
352  select->var_values[VAR_INTERLACE_TYPE] =
355  select->var_values[VAR_PICT_TYPE] = frame->pict_type;
356  if (select->do_scene_detect) {
357  char buf[32];
358  select->var_values[VAR_SCENE] = get_scene_score(ctx, frame);
359  // TODO: document metadata
360  snprintf(buf, sizeof(buf), "%f", select->var_values[VAR_SCENE]);
361  av_dict_set(&frame->metadata, "lavfi.scene_score", buf, 0);
362  }
363  break;
364  }
365 
366  select->select = res = av_expr_eval(select->expr, select->var_values, NULL);
367  av_log(inlink->dst, AV_LOG_DEBUG,
368  "n:%f pts:%f t:%f key:%d",
369  select->var_values[VAR_N],
370  select->var_values[VAR_PTS],
371  select->var_values[VAR_T],
372  frame->key_frame);
373 
374  switch (inlink->type) {
375  case AVMEDIA_TYPE_VIDEO:
376  av_log(inlink->dst, AV_LOG_DEBUG, " interlace_type:%c pict_type:%c scene:%f",
377  (!frame->interlaced_frame) ? 'P' :
378  frame->top_field_first ? 'T' : 'B',
380  select->var_values[VAR_SCENE]);
381  break;
382  case AVMEDIA_TYPE_AUDIO:
383  av_log(inlink->dst, AV_LOG_DEBUG, " samples_n:%d consumed_samples_n:%f",
384  frame->nb_samples,
386  break;
387  }
388 
389  if (res == 0) {
390  select->select_out = -1; /* drop */
391  } else if (isnan(res) || res < 0) {
392  select->select_out = 0; /* first output */
393  } else {
394  select->select_out = FFMIN(ceilf(res)-1, select->nb_outputs-1); /* other outputs */
395  }
396 
397  av_log(inlink->dst, AV_LOG_DEBUG, " -> select:%f select_out:%d\n", res, select->select_out);
398 
399  if (res) {
400  select->var_values[VAR_PREV_SELECTED_N] = select->var_values[VAR_N];
402  select->var_values[VAR_PREV_SELECTED_T] = select->var_values[VAR_T];
403  select->var_values[VAR_SELECTED_N] += 1.0;
404  if (inlink->type == AVMEDIA_TYPE_AUDIO)
405  select->var_values[VAR_CONSUMED_SAMPLES_N] += frame->nb_samples;
406  }
407 
408  select->var_values[VAR_PREV_PTS] = select->var_values[VAR_PTS];
409  select->var_values[VAR_PREV_T] = select->var_values[VAR_T];
410 }
411 
413 {
414  AVFilterContext *ctx = inlink->dst;
415  SelectContext *select = ctx->priv;
416 
417  select_frame(ctx, frame);
418  if (select->select)
419  return ff_filter_frame(ctx->outputs[select->select_out], frame);
420 
421  av_frame_free(&frame);
422  return 0;
423 }
424 
425 static int request_frame(AVFilterLink *outlink)
426 {
427  AVFilterLink *inlink = outlink->src->inputs[0];
428  int ret = ff_request_frame(inlink);
429  return ret;
430 }
431 
433 {
434  SelectContext *select = ctx->priv;
435  int i;
436 
437  av_expr_free(select->expr);
438  select->expr = NULL;
439 
440  for (i = 0; i < ctx->nb_outputs; i++)
441  av_freep(&ctx->output_pads[i].name);
442 
443  if (select->do_scene_detect) {
444  av_frame_free(&select->prev_picref);
445  }
446 }
447 
448 #if CONFIG_ASELECT_FILTER
449 
451 AVFILTER_DEFINE_CLASS(aselect);
452 
453 static 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 
469 static 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 
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,
488 };
489 #endif /* CONFIG_ASELECT_FILTER */
490 
491 #if CONFIG_SELECT_FILTER
492 
493 static int query_formats(AVFilterContext *ctx)
494 {
495  SelectContext *select = ctx->priv;
496 
497  if (!select->do_scene_detect) {
498  return ff_default_query_formats(ctx);
499  } else {
500  int ret;
501  static const enum AVPixelFormat pix_fmts[] = {
508  };
509  AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
510 
511  if (!fmts_list)
512  return AVERROR(ENOMEM);
513  ret = ff_set_common_formats(ctx, fmts_list);
514  if (ret < 0)
515  return ret;
516  }
517  return 0;
518 }
519 
522 
523 static av_cold int select_init(AVFilterContext *ctx)
524 {
525  int ret;
526 
527  if ((ret = init(ctx)) < 0)
528  return ret;
529 
530  return 0;
531 }
532 
533 static const AVFilterPad avfilter_vf_select_inputs[] = {
534  {
535  .name = "default",
536  .type = AVMEDIA_TYPE_VIDEO,
537  .config_props = config_input,
538  .filter_frame = filter_frame,
539  },
540  { NULL }
541 };
542 
544  .name = "select",
545  .description = NULL_IF_CONFIG_SMALL("Select video frames to pass in output."),
546  .init = select_init,
547  .uninit = uninit,
548  .query_formats = query_formats,
549  .priv_size = sizeof(SelectContext),
550  .priv_class = &select_class,
551  .inputs = avfilter_vf_select_inputs,
553 };
554 #endif /* CONFIG_SELECT_FILTER */
#define NULL
Definition: coverity.c:32
void(* ff_scene_sad_fn)(SCENE_SAD_PARAMS)
Definition: scene_sad.h:34
int av_image_get_linesize(enum AVPixelFormat pix_fmt, int width, int plane)
Compute the size of an image line with format pix_fmt and width width for the plane plane...
Definition: imgutils.c:76
BI type.
Definition: avutil.h:280
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2573
This structure describes decoded (raw) audio or video data.
Definition: frame.h:308
int64_t pkt_pos
reordered pos from the last AVPacket that has been input into the decoder
Definition: frame.h:579
const char * desc
Definition: libsvtav1.c:79
static av_cold void uninit(AVFilterContext *ctx)
Definition: f_select.c:432
misc image utilities
int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2613
Main libavfilter public API header.
packed RGB 8:8:8, 24bpp, RGBRGB...
Definition: pixfmt.h:68
ff_scene_sad_fn ff_scene_sad_get_fn(int depth)
Definition: scene_sad.c:59
#define AV_OPT_FLAG_AUDIO_PARAM
Definition: opt.h:280
#define INTERLACE_TYPE_P
Definition: f_select.c:204
enum AVMediaType type
AVFilterPad type.
Definition: internal.h:65
int av_expr_parse(AVExpr **expr, const char *s, const char *const *const_names, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), int log_offset, void *log_ctx)
Parse an expression.
Definition: eval.c:685
static double get_concatdec_select(AVFrame *frame, int64_t pts)
Definition: f_select.c:306
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:287
Switching Intra.
Definition: avutil.h:278
const char * name
Pad name.
Definition: internal.h:60
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:347
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1091
AVFilterPad * output_pads
array of output pads
Definition: avfilter.h:350
static int64_t start_time
Definition: ffplay.c:332
AVComponentDescriptor comp[4]
Parameters that describe how pixels are packed.
Definition: pixdesc.h:117
#define av_cold
Definition: attributes.h:88
ff_scene_sad_fn sad
Sum of the absolute difference function (scene detect only)
Definition: f_select.c:154
AVOptions.
static void select_frame(AVFilterContext *ctx, AVFrame *frame)
Definition: f_select.c:328
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:401
Definition: eval.c:157
int nb_outputs
Definition: f_select.c:159
#define INTERLACE_TYPE_T
Definition: f_select.c:205
int64_t duration
Definition: movenc.c:63
packed ABGR 8:8:8:8, 32bpp, ABGRABGR...
Definition: pixfmt.h:94
char * expr_str
Definition: f_select.c:146
AVDictionaryEntry * av_dict_get(const AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags)
Get a dictionary entry with matching key.
Definition: dict.c:40
static double av_q2d(AVRational a)
Convert an AVRational to a double.
Definition: rational.h:104
char av_get_picture_type_char(enum AVPictureType pict_type)
Return a single letter to describe the given picture type pict_type.
Definition: utils.c:88
planar YUV 4:2:2, 16bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV422P and setting col...
Definition: pixfmt.h:79
AVDictionary * metadata
metadata.
Definition: frame.h:594
int interlaced_frame
The content of the picture is interlaced.
Definition: frame.h:455
#define AVFILTER_FLAG_DYNAMIC_OUTPUTS
The number of the filter outputs is not determined just by AVFilter.outputs.
Definition: avfilter.h:112
#define av_log(a,...)
AVFilter ff_vf_select
A filter pad used for either input or output.
Definition: internal.h:54
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:142
Scene SAD functions.
int width
Definition: frame.h:366
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
int ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
A helper for query_formats() which sets all links to the same list of formats.
Definition: formats.c:588
uint8_t log2_chroma_h
Amount to shift the luma height right to find the chroma height.
Definition: pixdesc.h:101
#define AV_OPT_FLAG_FILTERING_PARAM
a generic parameter which can be set by the user for filtering
Definition: opt.h:294
double var_values[VAR_VARS_NB]
Definition: f_select.c:148
#define AV_PIX_FMT_FLAG_RGB
The pixel format contains RGB-like data (as opposed to YUV/grayscale).
Definition: pixdesc.h:148
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
unsigned nb_outputs
number of output pads
Definition: avfilter.h:352
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:153
packed BGRA 8:8:8:8, 32bpp, BGRABGRA...
Definition: pixfmt.h:95
void * priv
private data for use by the filter
Definition: avfilter.h:354
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:215
GLsizei count
Definition: opengl_enc.c:108
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
Definition: pixfmt.h:93
int select_out
mark the selected output pad index
Definition: f_select.c:158
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:70
char * av_asprintf(const char *fmt,...)
Definition: avstring.c:113
var_name
Definition: aeval.c:46
static int config_input(AVFilterLink *inlink)
Definition: f_select.c:208
common internal API header
uint64_t flags
Combination of AV_PIX_FMT_FLAG_...
Definition: pixdesc.h:106
uint8_t nb_components
The number of components each pixel has, (1-4)
Definition: pixdesc.h:83
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:391
#define NAN
Definition: mathematics.h:64
#define FFMIN(a, b)
Definition: common.h:96
planar YUV 4:2:0, 12bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV420P and setting col...
Definition: pixfmt.h:78
AVFormatContext * ctx
Definition: movenc.c:48
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:69
ptrdiff_t width[4]
Definition: f_select.c:151
AVFrame * av_frame_clone(const AVFrame *src)
Create a new frame that references the same data as src.
Definition: frame.c:553
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: f_select.c:412
const AVFilterPad * inputs
List of inputs, terminated by a zeroed element.
Definition: avfilter.h:165
int ff_default_query_formats(AVFilterContext *ctx)
Definition: formats.c:594
void av_expr_free(AVExpr *e)
Free a parsed expression previously created with av_expr_parse().
Definition: eval.c:336
#define AV_TIME_BASE_Q
Internal time base represented as fractional value.
Definition: avutil.h:260
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:339
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:81
#define AV_OPT_FLAG_VIDEO_PARAM
Definition: opt.h:281
#define TS2D(ts)
Definition: internal.h:208
static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)
Definition: f_select.c:273
a very simple circular buffer FIFO implementation
double prev_mafd
previous MAFD (scene detect only)
Definition: f_select.c:155
AVFilter ff_af_aselect
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several inputs
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:70
#define AV_PIX_FMT_YUV420P10
Definition: pixfmt.h:399
Switching Predicted.
Definition: avutil.h:279
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:145
#define isnan(x)
Definition: libm.h:340
const char * name
Filter name.
Definition: avfilter.h:149
#define snprintf
Definition: snprintf.h:34
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:351
static enum AVPixelFormat pix_fmts[]
Definition: libkvazaar.c:300
static int64_t pts
static int request_frame(AVFilterLink *outlink)
Definition: f_select.c:425
#define flags(name, subs,...)
Definition: cbs_av1.c:560
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:322
int do_scene_detect
1 if the expression requires scene detection variables, 0 otherwise
Definition: f_select.c:153
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
AVFrame * prev_picref
previous frame (scene detect only)
Definition: f_select.c:156
#define DEFINE_OPTIONS(filt_name, FLAGS)
Definition: f_select.c:163
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
Y , 8bpp.
Definition: pixfmt.h:74
static int query_formats(AVFilterContext *ctx)
Definition: aeval.c:244
ptrdiff_t height[4]
Definition: f_select.c:152
static av_cold int init(AVFilterContext *ctx)
Definition: f_select.c:174
Bi-dir predicted.
Definition: avutil.h:276
static av_always_inline int diff(const uint32_t a, const uint32_t b)
char * value
Definition: dict.h:87
int top_field_first
If the content is interlaced, is top field displayed first.
Definition: frame.h:460
double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)
Evaluate a previously parsed expression.
Definition: eval.c:766
#define AVFILTER_DEFINE_CLASS(fname)
Definition: internal.h:288
AVExpr * expr
Definition: f_select.c:147
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:386
A list of supported formats for one end of a filter link.
Definition: formats.h:65
int(* request_frame)(AVFilterLink *link)
Frame request callback.
Definition: internal.h:102
An instance of a filter.
Definition: avfilter.h:339
static const char *const var_names[]
Definition: f_select.c:40
int height
Definition: frame.h:366
#define av_freep(p)
int ff_request_frame(AVFilterLink *link)
Request an input frame from the filter at the other end of the link.
Definition: avfilter.c:407
#define INTERLACE_TYPE_B
Definition: f_select.c:206
internal API functions
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
int depth
Number of bits in the component.
Definition: pixdesc.h:58
static int ff_insert_outpad(AVFilterContext *f, unsigned index, AVFilterPad *p)
Insert a new output pad for the filter.
Definition: internal.h:248
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
double select
Definition: f_select.c:157
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:374
#define AV_PIX_FMT_FLAG_PLANAR
At least one pixel component is not in the first data plane.
Definition: pixdesc.h:144
const AVFilter * filter
the AVFilter of which this is an instance
Definition: avfilter.h:342
int i
Definition: input.c:407
Predicted.
Definition: avutil.h:275
simple arithmetic expression evaluator
#define AV_CEIL_RSHIFT(a, b)
Definition: common.h:58