Libav
vf_settb.c
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1 /*
2  * Copyright (c) 2010 Stefano Sabatini
3  *
4  * This file is part of Libav.
5  *
6  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
26 #include <inttypes.h>
27 #include <stdio.h>
28 
29 #include "libavutil/avstring.h"
30 #include "libavutil/eval.h"
31 #include "libavutil/internal.h"
32 #include "libavutil/mathematics.h"
33 #include "libavutil/opt.h"
34 #include "libavutil/rational.h"
35 #include "avfilter.h"
36 #include "internal.h"
37 #include "video.h"
38 
39 static const char *const var_names[] = {
40  "E",
41  "PHI",
42  "PI",
43  "AVTB", /* default timebase 1/AV_TIME_BASE */
44  "intb", /* input timebase */
45  NULL
46 };
47 
48 enum var_name {
55 };
56 
57 typedef struct {
58  const AVClass *class;
59  char *tb_expr;
60  double var_values[VAR_VARS_NB];
61 } SetTBContext;
62 
63 static int config_output_props(AVFilterLink *outlink)
64 {
65  AVFilterContext *ctx = outlink->src;
66  SetTBContext *settb = ctx->priv;
67  AVFilterLink *inlink = ctx->inputs[0];
68  AVRational time_base;
69  int ret;
70  double res;
71 
72  settb->var_values[VAR_E] = M_E;
73  settb->var_values[VAR_PHI] = M_PHI;
74  settb->var_values[VAR_PI] = M_PI;
76  settb->var_values[VAR_INTB] = av_q2d(inlink->time_base);
77 
78  outlink->w = inlink->w;
79  outlink->h = inlink->h;
80 
81  if ((ret = av_expr_parse_and_eval(&res, settb->tb_expr, var_names, settb->var_values,
82  NULL, NULL, NULL, NULL, NULL, 0, NULL)) < 0) {
83  av_log(ctx, AV_LOG_ERROR, "Invalid expression '%s' for timebase.\n", settb->tb_expr);
84  return ret;
85  }
86  time_base = av_d2q(res, INT_MAX);
87  if (time_base.num <= 0 || time_base.den <= 0) {
88  av_log(ctx, AV_LOG_ERROR,
89  "Invalid non-positive values for the timebase num:%d or den:%d.\n",
90  time_base.num, time_base.den);
91  return AVERROR(EINVAL);
92  }
93 
94  outlink->time_base = time_base;
95  av_log(outlink->src, AV_LOG_VERBOSE, "tb:%d/%d -> tb:%d/%d\n",
96  inlink ->time_base.num, inlink ->time_base.den,
97  outlink->time_base.num, outlink->time_base.den);
98 
99  return 0;
100 }
101 
102 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
103 {
104  AVFilterContext *ctx = inlink->dst;
105  AVFilterLink *outlink = ctx->outputs[0];
106 
107  if (av_cmp_q(inlink->time_base, outlink->time_base)) {
108  int64_t orig_pts = frame->pts;
109  frame->pts = av_rescale_q(frame->pts, inlink->time_base, outlink->time_base);
110  av_log(ctx, AV_LOG_DEBUG, "tb:%d/%d pts:%"PRId64" -> tb:%d/%d pts:%"PRId64"\n",
111  inlink ->time_base.num, inlink ->time_base.den, orig_pts,
112  outlink->time_base.num, outlink->time_base.den, frame->pts);
113  }
114 
115  return ff_filter_frame(outlink, frame);
116 }
117 
118 #define OFFSET(x) offsetof(SetTBContext, x)
119 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM
120 static const AVOption options[] = {
121  { "expr", "Expression determining the output timebase", OFFSET(tb_expr), AV_OPT_TYPE_STRING, { .str = "intb" }, .flags = FLAGS },
122  { NULL },
123 };
124 
125 static const AVClass settb_class = {
126  .class_name = "settb",
127  .item_name = av_default_item_name,
128  .option = options,
129  .version = LIBAVUTIL_VERSION_INT,
130 };
131 
133  {
134  .name = "default",
135  .type = AVMEDIA_TYPE_VIDEO,
136  .get_video_buffer = ff_null_get_video_buffer,
137  .filter_frame = filter_frame,
138  },
139  { NULL }
140 };
141 
143  {
144  .name = "default",
145  .type = AVMEDIA_TYPE_VIDEO,
146  .config_props = config_output_props,
147  },
148  { NULL }
149 };
150 
152  .name = "settb",
153  .description = NULL_IF_CONFIG_SMALL("Set timebase for the output link."),
154 
155  .priv_size = sizeof(SetTBContext),
156  .priv_class = &settb_class,
157 
158  .inputs = avfilter_vf_settb_inputs,
159 
160  .outputs = avfilter_vf_settb_outputs,
161 };
This structure describes decoded (raw) audio or video data.
Definition: frame.h:107
AVOption.
Definition: opt.h:233
static const AVFilterPad outputs[]
Definition: af_ashowinfo.c:122
Main libavfilter public API header.
Definition: vf_settb.c:49
int num
numerator
Definition: rational.h:44
AVFrame * ff_null_get_video_buffer(AVFilterLink *link, int w, int h)
Definition: video.c:30
static int av_cmp_q(AVRational a, AVRational b)
Compare two rationals.
Definition: rational.h:55
char * tb_expr
Definition: vf_settb.c:59
const char * name
Pad name.
Definition: internal.h:42
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:38
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:571
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:728
AVOptions.
AVFilter ff_vf_settb
Definition: vf_settb.c:151
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:183
static double av_q2d(AVRational a)
Convert rational to double.
Definition: rational.h:69
static const AVFilterPad avfilter_vf_settb_inputs[]
Definition: vf_settb.c:132
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:139
A filter pad used for either input or output.
Definition: internal.h:36
static const AVClass settb_class
Definition: vf_settb.c:125
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:122
int av_expr_parse_and_eval(double *d, const char *s, const char *const *const_names, const double *const_values, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), void *opaque, int log_offset, void *log_ctx)
Parse and evaluate an expression.
Definition: eval.c:551
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:142
void * priv
private data for use by the filter
Definition: avfilter.h:584
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:144
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:148
common internal API header
AVRational av_d2q(double d, int max)
Convert a double precision floating point number to a rational.
Definition: rational.c:105
static int config_output_props(AVFilterLink *outlink)
Definition: vf_settb.c:63
#define M_E
Definition: ratecontrol.c:38
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: vf_settb.c:102
LIBAVUTIL_VERSION_INT
Definition: eval.c:55
NULL
Definition: eval.c:55
#define AV_TIME_BASE_Q
Internal time base represented as fractional value.
Definition: avutil.h:240
av_default_item_name
Definition: dnxhdenc.c:45
Describe the class of an AVClass context structure.
Definition: log.h:33
Filter definition.
Definition: avfilter.h:421
static const AVFilterPad inputs[]
Definition: af_ashowinfo.c:111
rational number numerator/denominator
Definition: rational.h:43
#define M_PHI
Definition: mathematics.h:34
const char * name
Filter name.
Definition: avfilter.h:425
#define FLAGS
Definition: vf_settb.c:119
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:578
static const char *const var_names[]
Definition: vf_settb.c:39
static const AVOption options[]
Definition: vf_settb.c:120
#define OFFSET(x)
Definition: vf_settb.c:118
rational numbers
int den
denominator
Definition: rational.h:45
An instance of a filter.
Definition: avfilter.h:563
double var_values[VAR_VARS_NB]
Definition: vf_settb.c:60
internal API functions
static const AVFilterPad avfilter_vf_settb_outputs[]
Definition: vf_settb.c:142
var_name
Definition: setpts.c:58
simple arithmetic expression evaluator