FFmpeg
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 ASetRateContext {
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 
55  &ctx->outputs[0]->incfg.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 
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 };
98 
99 static const AVFilterPad asetrate_outputs[] = {
100  {
101  .name = "default",
102  .type = AVMEDIA_TYPE_AUDIO,
103  .config_props = config_props,
104  },
105 };
106 
108  .name = "asetrate",
109  .description = NULL_IF_CONFIG_SMALL("Change the sample rate without "
110  "altering the data."),
111  .priv_size = sizeof(ASetRateContext),
115  .priv_class = &asetrate_class,
116 };
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
asetrate_options
static const AVOption asetrate_options[]
Definition: af_asetrate.c:41
opt.h
ff_make_format_list
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:381
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: af_asetrate.c:78
config_props
static av_cold int config_props(AVFilterLink *outlink)
Definition: af_asetrate.c:58
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1018
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
asetrate_outputs
static const AVFilterPad asetrate_outputs[]
Definition: af_asetrate.c:99
AVOption
AVOption.
Definition: opt.h:247
FILTER_QUERY_FUNC
#define FILTER_QUERY_FUNC(func)
Definition: internal.h:168
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:153
sample_rate
sample_rate
Definition: ffmpeg_filter.c:156
query_formats
static av_cold int query_formats(AVFilterContext *ctx)
Definition: af_asetrate.c:49
ASetRateContext::rescale_pts
int rescale_pts
Definition: af_asetrate.c:28
ASetRateContext
Definition: af_asetrate.c:25
AVRational::num
int num
Numerator.
Definition: rational.h:59
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:50
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(asetrate)
asetrate_inputs
static const AVFilterPad asetrate_inputs[]
Definition: af_asetrate.c:91
av_cold
#define av_cold
Definition: attributes.h:90
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
ff_formats_ref
int ff_formats_ref(AVFilterFormats *f, AVFilterFormats **ref)
Add *ref as a new reference to formats.
Definition: formats.c:555
av_q2d
static double av_q2d(AVRational a)
Convert an AVRational to a double.
Definition: rational.h:104
ctx
AVFormatContext * ctx
Definition: movenc.c:48
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:191
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
ff_af_asetrate
const AVFilter ff_af_asetrate
Definition: af_asetrate.c:107
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
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
sample_rates
sample_rates
Definition: ffmpeg_filter.c:156
internal.h
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:56
av_rescale
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:128
AVFilter
Filter definition.
Definition: avfilter.h:149
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
AVRational::den
int den
Denominator.
Definition: rational.h:60
avfilter.h
AVFilterContext
An instance of a filter.
Definition: avfilter.h:386
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:192
ASetRateContext::sample_rate
int sample_rate
Definition: af_asetrate.c:27
OPT_INT
#define OPT_INT(name, field, def, min, max, descr,...)
Definition: af_asetrate.c:38
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28