FFmpeg  4.2.1
f_realtime.c
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1 /*
2  * Copyright (c) 2015 Nicolas George
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 License
8  * 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
14  * GNU Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public License
17  * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "libavutil/opt.h"
22 #include "libavutil/time.h"
23 #include "avfilter.h"
24 #include "internal.h"
25 #include <float.h>
26 
27 typedef struct RealtimeContext {
28  const AVClass *class;
29  int64_t delta;
30  int64_t limit;
31  double speed;
32  unsigned inited;
34 
35 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
36 {
37  AVFilterContext *ctx = inlink->dst;
38  RealtimeContext *s = ctx->priv;
39 
40  if (frame->pts != AV_NOPTS_VALUE) {
41  int64_t pts = av_rescale_q(frame->pts, inlink->time_base, AV_TIME_BASE_Q) / s->speed;
42  int64_t now = av_gettime_relative();
43  int64_t sleep = pts - now + s->delta;
44  if (!s->inited) {
45  s->inited = 1;
46  sleep = 0;
47  s->delta = now - pts;
48  }
49  if (FFABS(sleep) > s->limit / s->speed) {
51  "time discontinuity detected: %"PRIi64" us, resetting\n",
52  sleep);
53  sleep = 0;
54  s->delta = now - pts;
55  }
56  if (sleep > 0) {
57  av_log(ctx, AV_LOG_DEBUG, "sleeping %"PRIi64" us\n", sleep);
58  for (; sleep > 600000000; sleep -= 600000000)
59  av_usleep(600000000);
60  av_usleep(sleep);
61  }
62  }
63  return ff_filter_frame(inlink->dst->outputs[0], frame);
64 }
65 
66 #define OFFSET(x) offsetof(RealtimeContext, x)
67 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
68 static const AVOption options[] = {
69  { "limit", "sleep time limit", OFFSET(limit), AV_OPT_TYPE_DURATION, { .i64 = 2000000 }, 0, INT64_MAX, FLAGS },
70  { "speed", "speed factor", OFFSET(speed), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, DBL_MIN, DBL_MAX, FLAGS },
71  { NULL }
72 };
73 
74 #if CONFIG_REALTIME_FILTER
75 #define realtime_options options
76 AVFILTER_DEFINE_CLASS(realtime);
77 
78 static const AVFilterPad avfilter_vf_realtime_inputs[] = {
79  {
80  .name = "default",
81  .type = AVMEDIA_TYPE_VIDEO,
82  .filter_frame = filter_frame,
83  },
84  { NULL }
85 };
86 
87 static const AVFilterPad avfilter_vf_realtime_outputs[] = {
88  {
89  .name = "default",
90  .type = AVMEDIA_TYPE_VIDEO,
91  },
92  { NULL }
93 };
94 
96  .name = "realtime",
97  .description = NULL_IF_CONFIG_SMALL("Slow down filtering to match realtime."),
98  .priv_size = sizeof(RealtimeContext),
99  .priv_class = &realtime_class,
100  .inputs = avfilter_vf_realtime_inputs,
101  .outputs = avfilter_vf_realtime_outputs,
102 };
103 #endif /* CONFIG_REALTIME_FILTER */
104 
105 #if CONFIG_AREALTIME_FILTER
106 
107 #define arealtime_options options
108 AVFILTER_DEFINE_CLASS(arealtime);
109 
110 static const AVFilterPad arealtime_inputs[] = {
111  {
112  .name = "default",
113  .type = AVMEDIA_TYPE_AUDIO,
114  .filter_frame = filter_frame,
115  },
116  { NULL }
117 };
118 
119 static const AVFilterPad arealtime_outputs[] = {
120  {
121  .name = "default",
122  .type = AVMEDIA_TYPE_AUDIO,
123  },
124  { NULL }
125 };
126 
128  .name = "arealtime",
129  .description = NULL_IF_CONFIG_SMALL("Slow down filtering to match realtime."),
130  .priv_size = sizeof(RealtimeContext),
131  .priv_class = &arealtime_class,
132  .inputs = arealtime_inputs,
133  .outputs = arealtime_outputs,
134 };
135 #endif /* CONFIG_AREALTIME_FILTER */
#define NULL
Definition: coverity.c:32
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
AVOption.
Definition: opt.h:246
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
Main libavfilter public API header.
#define OFFSET(x)
Definition: f_realtime.c:66
int av_usleep(unsigned usec)
Sleep for a period of time.
Definition: time.c:84
const char * name
Pad name.
Definition: internal.h:60
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1080
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: f_realtime.c:35
AVOptions.
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:388
static AVFrame * frame
#define av_log(a,...)
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
#define FLAGS
Definition: f_realtime.c:67
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
void * priv
private data for use by the filter
Definition: avfilter.h:353
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
AVFilter ff_vf_realtime
AVFilter ff_af_arealtime
AVFormatContext * ctx
Definition: movenc.c:48
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
#define s(width, name)
Definition: cbs_vp9.c:257
static const AVFilterPad inputs[]
Definition: af_acontrast.c:193
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
#define AV_TIME_BASE_Q
Internal time base represented as fractional value.
Definition: avutil.h:260
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
int64_t limit
Definition: f_realtime.c:30
const char * name
Filter name.
Definition: avfilter.h:148
unsigned inited
Definition: f_realtime.c:32
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:350
static int64_t pts
int64_t av_gettime_relative(void)
Get the current time in microseconds since some unspecified starting point.
Definition: time.c:56
static const AVOption options[]
Definition: f_realtime.c:68
#define AVFILTER_DEFINE_CLASS(fname)
Definition: internal.h:334
An instance of a filter.
Definition: avfilter.h:338
int64_t delta
Definition: f_realtime.c:29
internal API functions
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248