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af_asetrate.c
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1 /*
2  * Copyright (c) 2013 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 "libavutil/opt.h"
22 #include "avfilter.h"
23 #include "internal.h"
24 
25 typedef struct {
26  const AVClass *class;
30 
31 #define CONTEXT ASetRateContext
32 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
33 
34 #define OPT_GENERIC(name, field, def, min, max, descr, type, deffield, ...) \
35  { name, descr, offsetof(CONTEXT, field), AV_OPT_TYPE_ ## type, \
36  { .deffield = def }, min, max, FLAGS, __VA_ARGS__ }
37 
38 #define OPT_INT(name, field, def, min, max, descr, ...) \
39  OPT_GENERIC(name, field, def, min, max, descr, INT, i64, __VA_ARGS__)
40 
41 static const AVOption asetrate_options[] = {
42  OPT_INT("sample_rate", sample_rate, 44100, 1, INT_MAX, "set the sample rate",),
43  OPT_INT("r", sample_rate, 44100, 1, INT_MAX, "set the sample rate",),
44  {NULL},
45 };
46 
47 AVFILTER_DEFINE_CLASS(asetrate);
48 
50 {
51  ASetRateContext *sr = ctx->priv;
52  int sample_rates[] = { sr->sample_rate, -1 };
53 
54  return ff_formats_ref(ff_make_format_list(sample_rates),
55  &ctx->outputs[0]->in_samplerates);
56 }
57 
58 static av_cold int config_props(AVFilterLink *outlink)
59 {
60  AVFilterContext *ctx = outlink->src;
61  ASetRateContext *sr = ctx->priv;
62  AVFilterLink *inlink = ctx->inputs[0];
63  AVRational intb = ctx->inputs[0]->time_base;
64  int inrate = inlink->sample_rate;
65 
66  if (intb.num == 1 && intb.den == inrate) {
67  outlink->time_base.num = 1;
68  outlink->time_base.den = outlink->sample_rate;
69  } else {
70  outlink->time_base = intb;
71  sr->rescale_pts = 1;
72  if (av_q2d(intb) > 1.0 / FFMAX(inrate, outlink->sample_rate))
73  av_log(ctx, AV_LOG_WARNING, "Time base is inaccurate\n");
74  }
75  return 0;
76 }
77 
78 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
79 {
80  AVFilterContext *ctx = inlink->dst;
81  ASetRateContext *sr = ctx->priv;
82  AVFilterLink *outlink = ctx->outputs[0];
83 
84  frame->sample_rate = outlink->sample_rate;
85  if (sr->rescale_pts)
86  frame->pts = av_rescale(frame->pts, inlink->sample_rate,
87  outlink->sample_rate);
88  return ff_filter_frame(outlink, frame);
89 }
90 
91 static const AVFilterPad asetrate_inputs[] = {
92  {
93  .name = "default",
94  .type = AVMEDIA_TYPE_AUDIO,
95  .filter_frame = filter_frame,
96  },
97  { NULL }
98 };
99 
100 static const AVFilterPad asetrate_outputs[] = {
101  {
102  .name = "default",
103  .type = AVMEDIA_TYPE_AUDIO,
104  .config_props = config_props,
105  },
106  { NULL }
107 };
108 
110  .name = "asetrate",
111  .description = NULL_IF_CONFIG_SMALL("Change the sample rate without "
112  "altering the data."),
113  .query_formats = query_formats,
114  .priv_size = sizeof(ASetRateContext),
115  .inputs = asetrate_inputs,
116  .outputs = asetrate_outputs,
117  .priv_class = &asetrate_class,
118 };
#define NULL
Definition: coverity.c:32
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: af_asetrate.c:78
static av_cold int config_props(AVFilterLink *outlink)
Definition: af_asetrate.c:58
This structure describes decoded (raw) audio or video data.
Definition: frame.h:180
AVOption.
Definition: opt.h:245
static const AVFilterPad asetrate_inputs[]
Definition: af_asetrate.c:91
AVFormatContext * ctx
Definition: movenc-test.c:48
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
Main libavfilter public API header.
int num
numerator
Definition: rational.h:44
static const AVOption asetrate_options[]
Definition: af_asetrate.c:41
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:283
const char * name
Pad name.
Definition: internal.h:59
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:313
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1180
#define av_cold
Definition: attributes.h:82
AVOptions.
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:264
static AVFrame * frame
static double av_q2d(AVRational a)
Convert rational to double.
Definition: rational.h:80
AVFilter ff_af_asetrate
Definition: af_asetrate.c:109
#define av_log(a,...)
A filter pad used for either input or output.
Definition: internal.h:53
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
void * priv
private data for use by the filter
Definition: avfilter.h:320
#define FFMAX(a, b)
Definition: common.h:94
static const int sample_rates[]
Definition: dcaenc.h:32
static const AVFilterPad asetrate_outputs[]
Definition: af_asetrate.c:100
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
Definition: mathematics.c:129
int ff_formats_ref(AVFilterFormats *f, AVFilterFormats **ref)
Add *ref as a new reference to formats.
Definition: formats.c:440
static av_cold int query_formats(AVFilterContext *ctx)
Definition: af_asetrate.c:49
static const AVFilterPad outputs[]
Definition: af_afftfilt.c:386
sample_rate
static const AVFilterPad inputs[]
Definition: af_afftfilt.c:376
AVFILTER_DEFINE_CLASS(asetrate)
Describe the class of an AVClass context structure.
Definition: log.h:67
int sample_rate
Sample rate of the audio data.
Definition: frame.h:340
Filter definition.
Definition: avfilter.h:142
rational number numerator/denominator
Definition: rational.h:43
const char * name
Filter name.
Definition: avfilter.h:146
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:317
int den
denominator
Definition: rational.h:45
#define OPT_INT(name, field, def, min, max, descr,...)
Definition: af_asetrate.c:38
An instance of a filter.
Definition: avfilter.h:305
internal API functions