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 "filters.h"
38 #include "internal.h"
39 #include "video.h"
40 
41 static const char *const var_names[] = {
42  "AVTB", /* default timebase 1/AV_TIME_BASE */
43  "intb", /* input timebase */
44  "sr", /* sample rate */
45  NULL
46 };
47 
48 enum var_name {
53 };
54 
55 typedef struct SetTBContext {
56  const AVClass *class;
57  char *tb_expr;
59 } SetTBContext;
60 
61 #define OFFSET(x) offsetof(SetTBContext, x)
62 #define DEFINE_OPTIONS(filt_name, filt_type) \
63 static const AVOption filt_name##_options[] = { \
64  { "expr", "set expression determining the output timebase", OFFSET(tb_expr), AV_OPT_TYPE_STRING, {.str="intb"}, \
65  .flags=AV_OPT_FLAG_##filt_type##_PARAM|AV_OPT_FLAG_FILTERING_PARAM }, \
66  { "tb", "set expression determining the output timebase", OFFSET(tb_expr), AV_OPT_TYPE_STRING, {.str="intb"}, \
67  .flags=AV_OPT_FLAG_##filt_type##_PARAM|AV_OPT_FLAG_FILTERING_PARAM }, \
68  { NULL } \
69 }
70 
71 static int config_output_props(AVFilterLink *outlink)
72 {
73  AVFilterContext *ctx = outlink->src;
74  SetTBContext *settb = ctx->priv;
75  AVFilterLink *inlink = ctx->inputs[0];
76  AVRational time_base;
77  int ret;
78  double res;
79 
81  settb->var_values[VAR_INTB] = av_q2d(inlink->time_base);
82  settb->var_values[VAR_SR] = inlink->sample_rate;
83 
84  outlink->w = inlink->w;
85  outlink->h = inlink->h;
86 
87  if ((ret = av_expr_parse_and_eval(&res, settb->tb_expr, var_names, settb->var_values,
88  NULL, NULL, NULL, NULL, NULL, 0, NULL)) < 0) {
89  av_log(ctx, AV_LOG_ERROR, "Invalid expression '%s' for timebase.\n", settb->tb_expr);
90  return ret;
91  }
92  time_base = av_d2q(res, INT_MAX);
93  if (time_base.num <= 0 || time_base.den <= 0) {
95  "Invalid non-positive values for the timebase num:%d or den:%d.\n",
96  time_base.num, time_base.den);
97  return AVERROR(EINVAL);
98  }
99 
100  outlink->time_base = time_base;
101  av_log(outlink->src, AV_LOG_VERBOSE, "tb:%d/%d -> tb:%d/%d\n",
102  inlink ->time_base.num, inlink ->time_base.den,
103  outlink->time_base.num, outlink->time_base.den);
104 
105  return 0;
106 }
107 
108 static int64_t rescale_pts(AVFilterLink *inlink, AVFilterLink *outlink, int64_t orig_pts)
109 {
110  AVFilterContext *ctx = inlink->dst;
111  int64_t new_pts = orig_pts;
112 
113  if (av_cmp_q(inlink->time_base, outlink->time_base)) {
114  new_pts = av_rescale_q(orig_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, new_pts);
118  }
119 
120  return new_pts;
121 }
122 
124 {
125  AVFilterContext *ctx = inlink->dst;
126  AVFilterLink *outlink = ctx->outputs[0];
127 
128  frame->pts = rescale_pts(inlink, outlink, frame->pts);
129 
130  return ff_filter_frame(outlink, frame);
131 }
132 
134 {
135  AVFilterLink *inlink = ctx->inputs[0];
136  AVFilterLink *outlink = ctx->outputs[0];
137  AVFrame *in;
138  int status;
139  int64_t pts;
140  int ret;
141 
143 
145  if (ret < 0)
146  return ret;
147  if (ret > 0)
148  return filter_frame(inlink, in);
149 
151  ff_outlink_set_status(outlink, status, rescale_pts(inlink, outlink, pts));
152  return 0;
153  }
154 
156 
157  return FFERROR_NOT_READY;
158 }
159 
160 #if CONFIG_SETTB_FILTER
161 
162 DEFINE_OPTIONS(settb, VIDEO);
163 AVFILTER_DEFINE_CLASS(settb);
164 
165 static const AVFilterPad avfilter_vf_settb_inputs[] = {
166  {
167  .name = "default",
168  .type = AVMEDIA_TYPE_VIDEO,
169  },
170 };
171 
172 static const AVFilterPad avfilter_vf_settb_outputs[] = {
173  {
174  .name = "default",
175  .type = AVMEDIA_TYPE_VIDEO,
176  .config_props = config_output_props,
177  },
178 };
179 
180 const AVFilter ff_vf_settb = {
181  .name = "settb",
182  .description = NULL_IF_CONFIG_SMALL("Set timebase for the video output link."),
183  .priv_size = sizeof(SetTBContext),
184  .priv_class = &settb_class,
185  FILTER_INPUTS(avfilter_vf_settb_inputs),
186  FILTER_OUTPUTS(avfilter_vf_settb_outputs),
187  .activate = activate,
188 };
189 #endif /* CONFIG_SETTB_FILTER */
190 
191 #if CONFIG_ASETTB_FILTER
192 
193 DEFINE_OPTIONS(asettb, AUDIO);
194 AVFILTER_DEFINE_CLASS(asettb);
195 
196 static const AVFilterPad avfilter_af_asettb_inputs[] = {
197  {
198  .name = "default",
199  .type = AVMEDIA_TYPE_AUDIO,
200  },
201 };
202 
203 static const AVFilterPad avfilter_af_asettb_outputs[] = {
204  {
205  .name = "default",
206  .type = AVMEDIA_TYPE_AUDIO,
207  .config_props = config_output_props,
208  },
209 };
210 
211 const AVFilter ff_af_asettb = {
212  .name = "asettb",
213  .description = NULL_IF_CONFIG_SMALL("Set timebase for the audio output link."),
214  .priv_size = sizeof(SetTBContext),
215  FILTER_INPUTS(avfilter_af_asettb_inputs),
216  FILTER_OUTPUTS(avfilter_af_asettb_outputs),
217  .priv_class = &asettb_class,
218  .activate = activate,
219 };
220 #endif /* CONFIG_ASETTB_FILTER */
VAR_INTB
@ VAR_INTB
Definition: settb.c:50
status
they must not be accessed directly The fifo field contains the frames that are queued in the input for processing by the filter The status_in and status_out fields contains the queued status(EOF or error) of the link
AVERROR
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
opt.h
DEFINE_OPTIONS
#define DEFINE_OPTIONS(filt_name, filt_type)
Definition: settb.c:62
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1019
SetTBContext::tb_expr
char * tb_expr
Definition: settb.c:57
FFERROR_NOT_READY
return FFERROR_NOT_READY
Definition: filter_design.txt:204
rational.h
AV_TIME_BASE_Q
#define AV_TIME_BASE_Q
Internal time base represented as fractional value.
Definition: avutil.h:260
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
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
AV_LOG_VERBOSE
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:196
mathematics.h
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:153
video.h
var_names
static const char *const var_names[]
Definition: settb.c:41
FF_FILTER_FORWARD_STATUS_BACK
#define FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink)
Forward the status on an output link to an input link.
Definition: filters.h:199
ff_inlink_consume_frame
int ff_inlink_consume_frame(AVFilterLink *link, AVFrame **rframe)
Take a frame from the link's FIFO and update the link's stats.
Definition: avfilter.c:1418
config_output_props
static int config_output_props(AVFilterLink *outlink)
Definition: settb.c:71
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: settb.c:123
pts
static int64_t pts
Definition: transcode_aac.c:653
AVRational::num
int num
Numerator.
Definition: rational.h:59
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:50
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
ff_outlink_set_status
static void ff_outlink_set_status(AVFilterLink *link, int status, int64_t pts)
Set the status field of a link from the source filter.
Definition: filters.h:189
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
av_q2d
static double av_q2d(AVRational a)
Convert an AVRational to a double.
Definition: rational.h:104
filters.h
var_name
var_name
Definition: noise_bsf.c:47
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:201
ctx
AVFormatContext * ctx
Definition: movenc.c:48
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:141
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:152
activate
static int activate(AVFilterContext *ctx)
Definition: settb.c:133
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
ff_inlink_acknowledge_status
int ff_inlink_acknowledge_status(AVFilterLink *link, int *rstatus, int64_t *rpts)
Test and acknowledge the change of status on the link.
Definition: avfilter.c:1372
eval.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:117
av_expr_parse_and_eval
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:776
VAR_SR
@ VAR_SR
Definition: settb.c:51
VAR_AVTB
@ VAR_AVTB
Definition: settb.c:49
SetTBContext::var_values
double var_values[VAR_VARS_NB]
Definition: settb.c:58
FF_FILTER_FORWARD_WANTED
FF_FILTER_FORWARD_WANTED(outlink, inlink)
internal.h
AVFILTER_DEFINE_CLASS
#define AVFILTER_DEFINE_CLASS(fname)
Definition: internal.h:289
rescale_pts
static int64_t rescale_pts(AVFilterLink *inlink, AVFilterLink *outlink, int64_t orig_pts)
Definition: settb.c:108
internal.h
av_d2q
AVRational av_d2q(double d, int max)
Convert a double precision floating point number to a rational.
Definition: rational.c:106
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:56
av_cmp_q
static int av_cmp_q(AVRational a, AVRational b)
Compare two rationals.
Definition: rational.h:89
AVFilter
Filter definition.
Definition: avfilter.h:149
ret
ret
Definition: filter_design.txt:187
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
VAR_VARS_NB
@ VAR_VARS_NB
Definition: settb.c:52
AVRational::den
int den
Denominator.
Definition: rational.h:60
avfilter.h
ff_af_asettb
const AVFilter ff_af_asettb
AVFilterContext
An instance of a filter.
Definition: avfilter.h:346
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
audio.h
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:153
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
avstring.h
ff_vf_settb
const AVFilter ff_vf_settb
SetTBContext
Definition: settb.c:55