FFmpeg
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 "config_components.h"
22 
23 #include "libavutil/opt.h"
24 #include "libavutil/time.h"
25 #include "audio.h"
26 #include "avfilter.h"
27 #include "filters.h"
28 #include "video.h"
29 #include <float.h>
30 
31 typedef struct RealtimeContext {
32  const AVClass *class;
35  double speed;
36  unsigned inited;
38 
40 {
41  AVFilterContext *ctx = inlink->dst;
42  RealtimeContext *s = ctx->priv;
43 
44  if (frame->pts != AV_NOPTS_VALUE) {
45  int64_t pts = av_rescale_q(frame->pts, inlink->time_base, AV_TIME_BASE_Q) / s->speed;
47  int64_t sleep = pts - now + s->delta;
48  if (!s->inited) {
49  s->inited = 1;
50  sleep = 0;
51  s->delta = now - pts;
52  }
53  if (FFABS(sleep) > s->limit / s->speed) {
55  "time discontinuity detected: %"PRIi64" us, resetting\n",
56  sleep);
57  sleep = 0;
58  s->delta = now - pts;
59  }
60  if (sleep > 0) {
61  av_log(ctx, AV_LOG_DEBUG, "sleeping %"PRIi64" us\n", sleep);
62  for (; sleep > 600000000; sleep -= 600000000)
63  av_usleep(600000000);
64  av_usleep(sleep);
65  }
66  }
67  return ff_filter_frame(inlink->dst->outputs[0], frame);
68 }
69 
70 #define OFFSET(x) offsetof(RealtimeContext, x)
71 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_RUNTIME_PARAM
72 static const AVOption options[] = {
73  { "limit", "sleep time limit", OFFSET(limit), AV_OPT_TYPE_DURATION, { .i64 = 2000000 }, 0, INT64_MAX, FLAGS },
74  { "speed", "speed factor", OFFSET(speed), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, DBL_MIN, DBL_MAX, FLAGS },
75  { NULL }
76 };
77 
78 AVFILTER_DEFINE_CLASS_EXT(realtime, "(a)realtime", options);
79 
80 #if CONFIG_REALTIME_FILTER
81 
82 static const AVFilterPad avfilter_vf_realtime_inputs[] = {
83  {
84  .name = "default",
85  .type = AVMEDIA_TYPE_VIDEO,
86  .filter_frame = filter_frame,
87  },
88 };
89 
90 const AVFilter ff_vf_realtime = {
91  .name = "realtime",
92  .description = NULL_IF_CONFIG_SMALL("Slow down filtering to match realtime."),
93  .priv_size = sizeof(RealtimeContext),
94  .priv_class = &realtime_class,
96  FILTER_INPUTS(avfilter_vf_realtime_inputs),
98  .process_command = ff_filter_process_command,
99 };
100 #endif /* CONFIG_REALTIME_FILTER */
101 
102 #if CONFIG_AREALTIME_FILTER
103 
104 static const AVFilterPad arealtime_inputs[] = {
105  {
106  .name = "default",
107  .type = AVMEDIA_TYPE_AUDIO,
108  .filter_frame = filter_frame,
109  },
110 };
111 
112 const AVFilter ff_af_arealtime = {
113  .name = "arealtime",
114  .description = NULL_IF_CONFIG_SMALL("Slow down filtering to match realtime."),
115  .priv_class = &realtime_class,
116  .priv_size = sizeof(RealtimeContext),
118  FILTER_INPUTS(arealtime_inputs),
120  .process_command = ff_filter_process_command,
121 };
122 #endif /* CONFIG_AREALTIME_FILTER */
av_gettime_relative
int64_t av_gettime_relative(void)
Get the current time in microseconds since some unspecified starting point.
Definition: time.c:56
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:215
RealtimeContext::speed
double speed
Definition: f_realtime.c:35
opt.h
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1025
RealtimeContext::limit
int64_t limit
Definition: f_realtime.c:34
AV_TIME_BASE_Q
#define AV_TIME_BASE_Q
Internal time base represented as fractional value.
Definition: avutil.h:264
int64_t
long long int64_t
Definition: coverity.c:34
inlink
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
Definition: filter_design.txt:212
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: filters.h:262
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:389
AVOption
AVOption.
Definition: opt.h:429
AV_OPT_TYPE_DURATION
@ AV_OPT_TYPE_DURATION
Underlying C type is int64_t.
Definition: opt.h:319
float.h
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:205
video.h
options
static const AVOption options[]
Definition: f_realtime.c:72
RealtimeContext::delta
int64_t delta
Definition: f_realtime.c:33
pts
static int64_t pts
Definition: transcode_aac.c:644
AVFilterPad
A filter pad used for either input or output.
Definition: filters.h:38
ff_video_default_filterpad
const AVFilterPad ff_video_default_filterpad[1]
An AVFilterPad array whose only entry has name "default" and is of type AVMEDIA_TYPE_VIDEO.
Definition: video.c:37
s
#define s(width, name)
Definition: cbs_vp9.c:198
AV_OPT_TYPE_DOUBLE
@ AV_OPT_TYPE_DOUBLE
Underlying C type is double.
Definition: opt.h:267
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
filters.h
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:230
ctx
AVFormatContext * ctx
Definition: movenc.c:49
av_rescale_q
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
RealtimeContext::inited
unsigned inited
Definition: f_realtime.c:36
av_usleep
int av_usleep(unsigned usec)
Sleep for a period of time.
Definition: time.c:84
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: filters.h:263
FFABS
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:74
RealtimeContext
Definition: f_realtime.c:31
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:75
NULL
#define NULL
Definition: coverity.c:32
ff_audio_default_filterpad
const AVFilterPad ff_audio_default_filterpad[1]
An AVFilterPad array whose only entry has name "default" and is of type AVMEDIA_TYPE_AUDIO.
Definition: audio.c:34
time.h
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:94
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: f_realtime.c:39
ff_filter_process_command
int ff_filter_process_command(AVFilterContext *ctx, const char *cmd, const char *arg, char *res, int res_len, int flags)
Generic processing of user supplied commands that are set in the same way as the filter options.
Definition: avfilter.c:896
FLAGS
#define FLAGS
Definition: f_realtime.c:71
AVFilterPad::name
const char * name
Pad name.
Definition: filters.h:44
OFFSET
#define OFFSET(x)
Definition: f_realtime.c:70
limit
static double limit(double x)
Definition: vf_pseudocolor.c:142
AVFilter
Filter definition.
Definition: avfilter.h:201
frame
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
Definition: filter_design.txt:264
avfilter.h
AVFILTER_FLAG_METADATA_ONLY
#define AVFILTER_FLAG_METADATA_ONLY
The filter is a "metadata" filter - it does not modify the frame data in any way.
Definition: avfilter.h:168
AVFilterContext
An instance of a filter.
Definition: avfilter.h:457
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
audio.h
ff_af_arealtime
const AVFilter ff_af_arealtime
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:482
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVFILTER_DEFINE_CLASS_EXT
AVFILTER_DEFINE_CLASS_EXT(realtime, "(a)realtime", options)
ff_vf_realtime
const AVFilter ff_vf_realtime