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settb.c
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1 /*
2  * Copyright (c) 2010 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  * Set timebase for the output link.
24  */
25 
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 "audio.h"
36 #include "avfilter.h"
37 #include "internal.h"
38 #include "video.h"
39 
40 static const char *const var_names[] = {
41  "AVTB", /* default timebase 1/AV_TIME_BASE */
42  "intb", /* input timebase */
43  "sr", /* sample rate */
44  NULL
45 };
46 
47 enum var_name {
52 };
53 
54 typedef struct SetTBContext {
55  const AVClass *class;
56  char *tb_expr;
58 } SetTBContext;
59 
60 #define OFFSET(x) offsetof(SetTBContext, x)
61 #define DEFINE_OPTIONS(filt_name, filt_type) \
62 static const AVOption filt_name##_options[] = { \
63  { "expr", "set expression determining the output timebase", OFFSET(tb_expr), AV_OPT_TYPE_STRING, {.str="intb"}, \
64  .flags=AV_OPT_FLAG_##filt_type##_PARAM|AV_OPT_FLAG_FILTERING_PARAM }, \
65  { "tb", "set expression determining the output timebase", OFFSET(tb_expr), AV_OPT_TYPE_STRING, {.str="intb"}, \
66  .flags=AV_OPT_FLAG_##filt_type##_PARAM|AV_OPT_FLAG_FILTERING_PARAM }, \
67  { NULL } \
68 }
69 
70 static int config_output_props(AVFilterLink *outlink)
71 {
72  AVFilterContext *ctx = outlink->src;
73  SetTBContext *settb = ctx->priv;
74  AVFilterLink *inlink = ctx->inputs[0];
75  AVRational time_base;
76  int ret;
77  double res;
78 
80  settb->var_values[VAR_INTB] = av_q2d(inlink->time_base);
81  settb->var_values[VAR_SR] = inlink->sample_rate;
82 
83  outlink->w = inlink->w;
84  outlink->h = inlink->h;
85 
86  if ((ret = av_expr_parse_and_eval(&res, settb->tb_expr, var_names, settb->var_values,
87  NULL, NULL, NULL, NULL, NULL, 0, NULL)) < 0) {
88  av_log(ctx, AV_LOG_ERROR, "Invalid expression '%s' for timebase.\n", settb->tb_expr);
89  return ret;
90  }
91  time_base = av_d2q(res, INT_MAX);
92  if (time_base.num <= 0 || time_base.den <= 0) {
93  av_log(ctx, AV_LOG_ERROR,
94  "Invalid non-positive values for the timebase num:%d or den:%d.\n",
95  time_base.num, time_base.den);
96  return AVERROR(EINVAL);
97  }
98 
99  outlink->time_base = time_base;
100  av_log(outlink->src, AV_LOG_VERBOSE, "tb:%d/%d -> tb:%d/%d\n",
101  inlink ->time_base.num, inlink ->time_base.den,
102  outlink->time_base.num, outlink->time_base.den);
103 
104  return 0;
105 }
106 
107 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
108 {
109  AVFilterContext *ctx = inlink->dst;
110  AVFilterLink *outlink = ctx->outputs[0];
111 
112  if (av_cmp_q(inlink->time_base, outlink->time_base)) {
113  int64_t orig_pts = frame->pts;
114  frame->pts = av_rescale_q(frame->pts, inlink->time_base, outlink->time_base);
115  av_log(ctx, AV_LOG_DEBUG, "tb:%d/%d pts:%"PRId64" -> tb:%d/%d pts:%"PRId64"\n",
116  inlink ->time_base.num, inlink ->time_base.den, orig_pts,
117  outlink->time_base.num, outlink->time_base.den, frame->pts);
118  }
119 
120  return ff_filter_frame(outlink, frame);
121 }
122 
123 #if CONFIG_SETTB_FILTER
124 
125 DEFINE_OPTIONS(settb, VIDEO);
126 AVFILTER_DEFINE_CLASS(settb);
127 
128 static const AVFilterPad avfilter_vf_settb_inputs[] = {
129  {
130  .name = "default",
131  .type = AVMEDIA_TYPE_VIDEO,
132  .filter_frame = filter_frame,
133  },
134  { NULL }
135 };
136 
137 static const AVFilterPad avfilter_vf_settb_outputs[] = {
138  {
139  .name = "default",
140  .type = AVMEDIA_TYPE_VIDEO,
141  .config_props = config_output_props,
142  },
143  { NULL }
144 };
145 
146 AVFilter ff_vf_settb = {
147  .name = "settb",
148  .description = NULL_IF_CONFIG_SMALL("Set timebase for the video output link."),
149  .priv_size = sizeof(SetTBContext),
150  .priv_class = &settb_class,
151  .inputs = avfilter_vf_settb_inputs,
152  .outputs = avfilter_vf_settb_outputs,
153 };
154 #endif /* CONFIG_SETTB_FILTER */
155 
156 #if CONFIG_ASETTB_FILTER
157 
158 DEFINE_OPTIONS(asettb, AUDIO);
159 AVFILTER_DEFINE_CLASS(asettb);
160 
161 static const AVFilterPad avfilter_af_asettb_inputs[] = {
162  {
163  .name = "default",
164  .type = AVMEDIA_TYPE_AUDIO,
165  .filter_frame = filter_frame,
166  },
167  { NULL }
168 };
169 
170 static const AVFilterPad avfilter_af_asettb_outputs[] = {
171  {
172  .name = "default",
173  .type = AVMEDIA_TYPE_AUDIO,
174  .config_props = config_output_props,
175  },
176  { NULL }
177 };
178 
179 AVFilter ff_af_asettb = {
180  .name = "asettb",
181  .description = NULL_IF_CONFIG_SMALL("Set timebase for the audio output link."),
182  .priv_size = sizeof(SetTBContext),
183  .inputs = avfilter_af_asettb_inputs,
184  .outputs = avfilter_af_asettb_outputs,
185  .priv_class = &asettb_class,
186 };
187 #endif /* CONFIG_ASETTB_FILTER */
#define NULL
Definition: coverity.c:32
This structure describes decoded (raw) audio or video data.
Definition: frame.h:187
Main libavfilter public API header.
static const char *const var_names[]
Definition: settb.c:40
int num
Numerator.
Definition: rational.h:59
#define DEFINE_OPTIONS(filt_name, filt_type)
Definition: settb.c:61
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: settb.c:107
Definition: settb.c:48
char * tb_expr
Definition: settb.c:56
const char * name
Pad name.
Definition: internal.h:60
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:331
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1125
AVOptions.
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:271
static AVFrame * frame
static double av_q2d(AVRational a)
Convert an AVRational to a double.
Definition: rational.h:104
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:192
static int config_output_props(AVFilterLink *outlink)
Definition: settb.c:70
#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
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:726
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#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:179
void * priv
private data for use by the filter
Definition: avfilter.h:338
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
var_name
Definition: aeval.c:46
common internal API header
AVFormatContext * ctx
Definition: movenc.c:48
Definition: settb.c:50
static const AVFilterPad outputs[]
Definition: af_afftfilt.c:386
static const AVFilterPad inputs[]
Definition: af_afftfilt.c:376
#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
Rational number (pair of numerator and denominator).
Definition: rational.h:58
const char * name
Filter name.
Definition: avfilter.h:148
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:335
AVRational av_d2q(double d, int max)
Convert a double precision floating point number to a rational.
Definition: rational.c:106
static int av_cmp_q(AVRational a, AVRational b)
Compare two rationals.
Definition: rational.h:89
Utilties for rational number calculation.
int den
Denominator.
Definition: rational.h:60
Definition: settb.c:49
#define AVFILTER_DEFINE_CLASS(fname)
Definition: internal.h:342
An instance of a filter.
Definition: avfilter.h:323
double var_values[VAR_VARS_NB]
Definition: settb.c:57
internal API functions
simple arithmetic expression evaluator