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vf_fps.c
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1 /*
2  * Copyright 2007 Bobby Bingham
3  * Copyright 2012 Robert Nagy <ronag89 gmail com>
4  * Copyright 2012 Anton Khirnov <anton khirnov net>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * a filter enforcing given constant framerate
26  */
27 
28 #include <float.h>
29 #include <stdint.h>
30 
31 #include "libavutil/common.h"
32 #include "libavutil/fifo.h"
33 #include "libavutil/mathematics.h"
34 #include "libavutil/opt.h"
35 #include "libavutil/parseutils.h"
36 
37 #include "avfilter.h"
38 #include "internal.h"
39 #include "video.h"
40 
41 typedef struct FPSContext {
42  const AVClass *class;
43 
44  AVFifoBuffer *fifo; ///< store frames until we get two successive timestamps
45 
46  /* timestamps in input timebase */
47  int64_t first_pts; ///< pts of the first frame that arrived on this filter
48 
49  double start_time; ///< pts, in seconds, of the expected first frame
50 
51  AVRational framerate; ///< target framerate
52  int rounding; ///< AVRounding method for timestamps
53 
54  /* statistics */
55  int frames_in; ///< number of frames on input
56  int frames_out; ///< number of frames on output
57  int dup; ///< number of frames duplicated
58  int drop; ///< number of framed dropped
59 } FPSContext;
60 
61 #define OFFSET(x) offsetof(FPSContext, x)
62 #define V AV_OPT_FLAG_VIDEO_PARAM
63 #define F AV_OPT_FLAG_FILTERING_PARAM
64 static const AVOption fps_options[] = {
65  { "fps", "A string describing desired output framerate", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, { .str = "25" }, 0, INT_MAX, V|F },
66  { "start_time", "Assume the first PTS should be this value.", OFFSET(start_time), AV_OPT_TYPE_DOUBLE, { .dbl = DBL_MAX}, -DBL_MAX, DBL_MAX, V },
67  { "round", "set rounding method for timestamps", OFFSET(rounding), AV_OPT_TYPE_INT, { .i64 = AV_ROUND_NEAR_INF }, 0, 5, V|F, "round" },
68  { "zero", "round towards 0", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_ZERO }, 0, 5, V|F, "round" },
69  { "inf", "round away from 0", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_INF }, 0, 5, V|F, "round" },
70  { "down", "round towards -infty", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_DOWN }, 0, 5, V|F, "round" },
71  { "up", "round towards +infty", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_UP }, 0, 5, V|F, "round" },
72  { "near", "round to nearest", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_NEAR_INF }, 0, 5, V|F, "round" },
73  { NULL }
74 };
75 
77 
79 {
80  FPSContext *s = ctx->priv;
81 
82  if (!(s->fifo = av_fifo_alloc_array(2, sizeof(AVFrame*))))
83  return AVERROR(ENOMEM);
84 
86 
87  av_log(ctx, AV_LOG_VERBOSE, "fps=%d/%d\n", s->framerate.num, s->framerate.den);
88  return 0;
89 }
90 
91 static void flush_fifo(AVFifoBuffer *fifo)
92 {
93  while (av_fifo_size(fifo)) {
94  AVFrame *tmp;
95  av_fifo_generic_read(fifo, &tmp, sizeof(tmp), NULL);
96  av_frame_free(&tmp);
97  }
98 }
99 
101 {
102  FPSContext *s = ctx->priv;
103  if (s->fifo) {
104  s->drop += av_fifo_size(s->fifo) / sizeof(AVFrame*);
105  flush_fifo(s->fifo);
106  av_fifo_freep(&s->fifo);
107  }
108 
109  av_log(ctx, AV_LOG_VERBOSE, "%d frames in, %d frames out; %d frames dropped, "
110  "%d frames duplicated.\n", s->frames_in, s->frames_out, s->drop, s->dup);
111 }
112 
113 static int config_props(AVFilterLink* link)
114 {
115  FPSContext *s = link->src->priv;
116 
117  link->time_base = av_inv_q(s->framerate);
118  link->frame_rate= s->framerate;
119  link->w = link->src->inputs[0]->w;
120  link->h = link->src->inputs[0]->h;
121 
122  return 0;
123 }
124 
125 static int request_frame(AVFilterLink *outlink)
126 {
127  AVFilterContext *ctx = outlink->src;
128  FPSContext *s = ctx->priv;
129  int ret;
130 
131  ret = ff_request_frame(ctx->inputs[0]);
132 
133  /* flush the fifo */
134  if (ret == AVERROR_EOF && av_fifo_size(s->fifo)) {
135  int i;
136  for (i = 0; av_fifo_size(s->fifo); i++) {
137  AVFrame *buf;
138 
139  av_fifo_generic_read(s->fifo, &buf, sizeof(buf), NULL);
140  buf->pts = av_rescale_q(s->first_pts, ctx->inputs[0]->time_base,
141  outlink->time_base) + s->frames_out;
142 
143  if ((ret = ff_filter_frame(outlink, buf)) < 0)
144  return ret;
145 
146  s->frames_out++;
147  }
148  return 0;
149  }
150 
151  return ret;
152 }
153 
155 {
156  int ret;
157 
158  if (!av_fifo_space(fifo) &&
159  (ret = av_fifo_realloc2(fifo, 2*av_fifo_size(fifo)))) {
160  av_frame_free(&buf);
161  return ret;
162  }
163 
164  av_fifo_generic_write(fifo, &buf, sizeof(buf), NULL);
165  return 0;
166 }
167 
168 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
169 {
170  AVFilterContext *ctx = inlink->dst;
171  FPSContext *s = ctx->priv;
172  AVFilterLink *outlink = ctx->outputs[0];
173  int64_t delta;
174  int i, ret;
175 
176  s->frames_in++;
177  /* discard frames until we get the first timestamp */
178  if (s->first_pts == AV_NOPTS_VALUE) {
179  if (buf->pts != AV_NOPTS_VALUE) {
180  ret = write_to_fifo(s->fifo, buf);
181  if (ret < 0)
182  return ret;
183 
184  if (s->start_time != DBL_MAX && s->start_time != AV_NOPTS_VALUE) {
185  double first_pts = s->start_time * AV_TIME_BASE;
186  first_pts = FFMIN(FFMAX(first_pts, INT64_MIN), INT64_MAX);
187  s->first_pts = av_rescale_q(first_pts, AV_TIME_BASE_Q,
188  inlink->time_base);
189  av_log(ctx, AV_LOG_VERBOSE, "Set first pts to (in:%"PRId64" out:%"PRId64")\n",
190  s->first_pts, av_rescale_q(first_pts, AV_TIME_BASE_Q,
191  outlink->time_base));
192  } else {
193  s->first_pts = buf->pts;
194  }
195  } else {
196  av_log(ctx, AV_LOG_WARNING, "Discarding initial frame(s) with no "
197  "timestamp.\n");
198  av_frame_free(&buf);
199  s->drop++;
200  }
201  return 0;
202  }
203 
204  /* now wait for the next timestamp */
205  if (buf->pts == AV_NOPTS_VALUE || av_fifo_size(s->fifo) <= 0) {
206  return write_to_fifo(s->fifo, buf);
207  }
208 
209  /* number of output frames */
210  delta = av_rescale_q_rnd(buf->pts - s->first_pts, inlink->time_base,
211  outlink->time_base, s->rounding) - s->frames_out ;
212 
213  if (delta < 1) {
214  /* drop everything buffered except the last */
215  int drop = av_fifo_size(s->fifo)/sizeof(AVFrame*);
216 
217  av_log(ctx, AV_LOG_DEBUG, "Dropping %d frame(s).\n", drop);
218  s->drop += drop;
219 
220  flush_fifo(s->fifo);
221  ret = write_to_fifo(s->fifo, buf);
222 
223  return ret;
224  }
225 
226  /* can output >= 1 frames */
227  for (i = 0; i < delta; i++) {
228  AVFrame *buf_out;
229  av_fifo_generic_read(s->fifo, &buf_out, sizeof(buf_out), NULL);
230 
231  /* duplicate the frame if needed */
232  if (!av_fifo_size(s->fifo) && i < delta - 1) {
233  AVFrame *dup = av_frame_clone(buf_out);
234 
235  av_log(ctx, AV_LOG_DEBUG, "Duplicating frame.\n");
236  if (dup)
237  ret = write_to_fifo(s->fifo, dup);
238  else
239  ret = AVERROR(ENOMEM);
240 
241  if (ret < 0) {
242  av_frame_free(&buf_out);
243  av_frame_free(&buf);
244  return ret;
245  }
246 
247  s->dup++;
248  }
249 
250  buf_out->pts = av_rescale_q(s->first_pts, inlink->time_base,
251  outlink->time_base) + s->frames_out;
252 
253  if ((ret = ff_filter_frame(outlink, buf_out)) < 0) {
254  av_frame_free(&buf);
255  return ret;
256  }
257 
258  s->frames_out++;
259  }
260  flush_fifo(s->fifo);
261 
262  ret = write_to_fifo(s->fifo, buf);
263 
264  return ret;
265 }
266 
268  {
269  .name = "default",
270  .type = AVMEDIA_TYPE_VIDEO,
271  .filter_frame = filter_frame,
272  },
273  { NULL }
274 };
275 
277  {
278  .name = "default",
279  .type = AVMEDIA_TYPE_VIDEO,
280  .request_frame = request_frame,
281  .config_props = config_props
282  },
283  { NULL }
284 };
285 
287  .name = "fps",
288  .description = NULL_IF_CONFIG_SMALL("Force constant framerate."),
289  .init = init,
290  .uninit = uninit,
291  .priv_size = sizeof(FPSContext),
292  .priv_class = &fps_class,
293  .inputs = avfilter_vf_fps_inputs,
294  .outputs = avfilter_vf_fps_outputs,
295 };
int frames_out
number of frames on output
Definition: vf_fps.c:56
#define NULL
Definition: coverity.c:32
#define F
Definition: vf_fps.c:63
const char * s
Definition: avisynth_c.h:631
AVFifoBuffer * fifo
store frames until we get two successive timestamps
Definition: vf_fps.c:44
AVFilter ff_vf_fps
Definition: vf_fps.c:286
static const AVOption fps_options[]
Definition: vf_fps.c:64
This structure describes decoded (raw) audio or video data.
Definition: frame.h:180
AVOption.
Definition: opt.h:245
AVFormatContext * ctx
Definition: movenc-test.c:48
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
Main libavfilter public API header.
int num
numerator
Definition: rational.h:44
int drop
number of framed dropped
Definition: vf_fps.c:58
int64_t first_pts
pts of the first frame that arrived on this filter
Definition: vf_fps.c:47
int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int(*func)(void *, void *, int))
Feed data from a user-supplied callback to an AVFifoBuffer.
Definition: fifo.c:122
const char * name
Pad name.
Definition: internal.h:59
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:313
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1180
static int64_t start_time
Definition: ffplay.c:329
Round toward +infinity.
Definition: mathematics.h:74
#define av_cold
Definition: attributes.h:82
int frames_in
number of frames on input
Definition: vf_fps.c:55
float delta
AVOptions.
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:264
int av_fifo_space(const AVFifoBuffer *f)
Return the amount of space in bytes in the AVFifoBuffer, that is the amount of data you can write int...
Definition: fifo.c:82
#define AVERROR_EOF
End of file.
Definition: error.h:55
static av_cold int init(AVFilterContext *ctx)
Definition: vf_fps.c:78
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:192
#define av_log(a,...)
A filter pad used for either input or output.
Definition: internal.h:53
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
int dup
number of frames duplicated
Definition: vf_fps.c:57
static av_cold void uninit(AVFilterContext *ctx)
Definition: vf_fps.c:100
#define AVERROR(e)
Definition: error.h:43
Round away from zero.
Definition: mathematics.h:72
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:153
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
void * priv
private data for use by the filter
Definition: avfilter.h:320
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void(*func)(void *, void *, int))
Feed data from an AVFifoBuffer to a user-supplied callback.
Definition: fifo.c:213
static const AVFilterPad avfilter_vf_fps_inputs[]
Definition: vf_fps.c:267
Round to nearest and halfway cases away from zero.
Definition: mathematics.h:75
static int request_frame(AVFilterLink *outlink)
Definition: vf_fps.c:125
#define V
Definition: vf_fps.c:62
static const AVFilterPad avfilter_vf_fps_outputs[]
Definition: vf_fps.c:276
#define FFMAX(a, b)
Definition: common.h:94
#define OFFSET(x)
Definition: vf_fps.c:61
int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq, enum AVRounding rnd)
Rescale a 64-bit integer by 2 rational numbers with specified rounding.
Definition: mathematics.c:134
#define AV_TIME_BASE
Internal time base represented as integer.
Definition: avutil.h:246
#define FFMIN(a, b)
Definition: common.h:96
Round toward zero.
Definition: mathematics.h:71
static uint8_t tmp[8]
Definition: des-test.c:38
static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
Definition: vf_fps.c:168
static const AVFilterPad outputs[]
Definition: af_afftfilt.c:386
AVFrame * av_frame_clone(const AVFrame *src)
Create a new frame that references the same data as src.
Definition: frame.c:468
static const AVFilterPad inputs[]
Definition: af_afftfilt.c:376
int av_fifo_size(const AVFifoBuffer *f)
Return the amount of data in bytes in the AVFifoBuffer, that is the amount of data you can read from ...
Definition: fifo.c:77
#define AV_TIME_BASE_Q
Internal time base represented as fractional value.
Definition: avutil.h:252
int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size)
Resize an AVFifoBuffer.
Definition: fifo.c:87
a very simple circular buffer FIFO implementation
void * buf
Definition: avisynth_c.h:553
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:142
rational number numerator/denominator
Definition: rational.h:43
offset must point to AVRational
Definition: opt.h:235
const char * name
Filter name.
Definition: avfilter.h:146
misc parsing utilities
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:317
Round toward -infinity.
Definition: mathematics.h:73
AVFifoBuffer * av_fifo_alloc_array(size_t nmemb, size_t size)
Initialize an AVFifoBuffer.
Definition: fifo.c:49
static av_always_inline AVRational av_inv_q(AVRational q)
Invert a rational.
Definition: rational.h:133
AVFILTER_DEFINE_CLASS(fps)
common internal and external API header
AVRational framerate
target framerate
Definition: vf_fps.c:51
int den
denominator
Definition: rational.h:45
int rounding
AVRounding method for timestamps.
Definition: vf_fps.c:52
static int config_props(AVFilterLink *link)
Definition: vf_fps.c:113
static int write_to_fifo(AVFifoBuffer *fifo, AVFrame *buf)
Definition: vf_fps.c:154
An instance of a filter.
Definition: avfilter.h:305
void av_fifo_freep(AVFifoBuffer **f)
Free an AVFifoBuffer and reset pointer to NULL.
Definition: fifo.c:63
int ff_request_frame(AVFilterLink *link)
Request an input frame from the filter at the other end of the link.
Definition: avfilter.c:369
internal API functions
static void flush_fifo(AVFifoBuffer *fifo)
Definition: vf_fps.c:91
double start_time
pts, in seconds, of the expected first frame
Definition: vf_fps.c:49
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:240