FFmpeg
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 
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 
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 
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:295
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:346
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1080
AVOptions.
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:388
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:744
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#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
var_name
Definition: aeval.c:46
common internal API header
AVFilter ff_vf_settb
AVFormatContext * ctx
Definition: movenc.c:48
Definition: settb.c:50
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
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
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 inputs
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:350
AVRational av_d2q(double d, int max)
Convert a double precision floating point number to a rational.
Definition: rational.c:106
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
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:334
An instance of a filter.
Definition: avfilter.h:338
double var_values[VAR_VARS_NB]
Definition: settb.c:57
internal API functions
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
AVFilter ff_af_asettb
simple arithmetic expression evaluator