FFmpeg
af_asetnsamples.c
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1 /*
2  * Copyright (c) 2012 Andrey Utkin
3  * Copyright (c) 2012 Stefano Sabatini
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * Filter that changes number of samples on single output operation
25  */
26 
27 #include "libavutil/avassert.h"
29 #include "libavutil/opt.h"
30 #include "avfilter.h"
31 #include "audio.h"
32 #include "filters.h"
33 #include "internal.h"
34 #include "formats.h"
35 
36 typedef struct ASNSContext {
37  const AVClass *class;
38  int nb_out_samples; ///< how many samples to output
39  int pad;
40 } ASNSContext;
41 
42 #define OFFSET(x) offsetof(ASNSContext, x)
43 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
44 
45 static const AVOption asetnsamples_options[] = {
46  { "nb_out_samples", "set the number of per-frame output samples", OFFSET(nb_out_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },
47  { "n", "set the number of per-frame output samples", OFFSET(nb_out_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },
48  { "pad", "pad last frame with zeros", OFFSET(pad), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },
49  { "p", "pad last frame with zeros", OFFSET(pad), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },
50  { NULL }
51 };
52 
53 AVFILTER_DEFINE_CLASS(asetnsamples);
54 
56 {
57  AVFilterLink *inlink = ctx->inputs[0];
58  AVFilterLink *outlink = ctx->outputs[0];
59  ASNSContext *s = ctx->priv;
60  AVFrame *frame = NULL, *pad_frame;
61  int ret;
62 
63  FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
64 
65  ret = ff_inlink_consume_samples(inlink, s->nb_out_samples, s->nb_out_samples, &frame);
66  if (ret < 0)
67  return ret;
68 
69  if (ret > 0) {
70  if (!s->pad || frame->nb_samples == s->nb_out_samples) {
71  ret = ff_filter_frame(outlink, frame);
72  if (ff_inlink_queued_samples(inlink) >= s->nb_out_samples)
73  ff_filter_set_ready(ctx, 100);
74  return ret;
75  }
76 
77  pad_frame = ff_get_audio_buffer(outlink, s->nb_out_samples);
78  if (!pad_frame) {
79  av_frame_free(&frame);
80  return AVERROR(ENOMEM);
81  }
82 
83  ret = av_frame_copy_props(pad_frame, frame);
84  if (ret < 0) {
85  av_frame_free(&pad_frame);
86  av_frame_free(&frame);
87  return ret;
88  }
89 
90  av_samples_copy(pad_frame->extended_data, frame->extended_data,
91  0, 0, frame->nb_samples, frame->channels, frame->format);
92  av_samples_set_silence(pad_frame->extended_data, frame->nb_samples,
93  s->nb_out_samples - frame->nb_samples, frame->channels,
94  frame->format);
95  av_frame_free(&frame);
96  return ff_filter_frame(outlink, pad_frame);
97  }
98 
99  FF_FILTER_FORWARD_STATUS(inlink, outlink);
100  FF_FILTER_FORWARD_WANTED(outlink, inlink);
101 
102  return FFERROR_NOT_READY;
103 }
104 
106  {
107  .name = "default",
108  .type = AVMEDIA_TYPE_AUDIO,
109  },
110  { NULL }
111 };
112 
114  {
115  .name = "default",
116  .type = AVMEDIA_TYPE_AUDIO,
117  },
118  { NULL }
119 };
120 
122  .name = "asetnsamples",
123  .description = NULL_IF_CONFIG_SMALL("Set the number of samples for each output audio frames."),
124  .priv_size = sizeof(ASNSContext),
125  .priv_class = &asetnsamples_class,
126  .inputs = asetnsamples_inputs,
127  .outputs = asetnsamples_outputs,
128  .activate = activate,
129 };
#define NULL
Definition: coverity.c:32
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
AVOption.
Definition: opt.h:246
static const AVOption asetnsamples_options[]
AVFilter ff_af_asetnsamples
Main libavfilter public API header.
FF_FILTER_FORWARD_STATUS(inlink, outlink)
return FFERROR_NOT_READY
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:1093
AVOptions.
static const AVFilterPad asetnsamples_outputs[]
#define FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink)
Forward the status on an output link to an input link.
Definition: filters.h:199
static const AVFilterPad asetnsamples_inputs[]
A filter pad used for either input or output.
Definition: internal.h:54
int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples, int nb_channels, enum AVSampleFormat sample_fmt)
Fill an audio buffer with silence.
Definition: samplefmt.c:237
AVFrame * ff_get_audio_buffer(AVFilterLink *link, int nb_samples)
Request an audio samples buffer with a specific set of permissions.
Definition: audio.c:86
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
#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 OFFSET(x)
simple assert() macros that are a bit more flexible than ISO C assert().
static int activate(AVFilterContext *ctx)
#define FLAGS
int channels
number of audio channels, only used for audio.
Definition: frame.h:601
audio channel layout utility functions
int ff_inlink_queued_samples(AVFilterLink *link)
Definition: avfilter.c:1474
AVFormatContext * ctx
Definition: movenc.c:48
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
#define s(width, name)
Definition: cbs_vp9.c:257
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames...
Definition: frame.h:368
int ff_inlink_consume_samples(AVFilterLink *link, unsigned min, unsigned max, AVFrame **rframe)
Take samples from the link&#39;s FIFO and update the link&#39;s stats.
Definition: avfilter.c:1513
int av_samples_copy(uint8_t **dst, uint8_t *const *src, int dst_offset, int src_offset, int nb_samples, int nb_channels, enum AVSampleFormat sample_fmt)
Copy samples from src to dst.
Definition: samplefmt.c:213
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
int nb_out_samples
how many samples to output
const char * name
Filter name.
Definition: avfilter.h:148
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:350
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
AVFILTER_DEFINE_CLASS(asetnsamples)
void ff_filter_set_ready(AVFilterContext *filter, unsigned priority)
Mark a filter ready and schedule it for activation.
Definition: avfilter.c:193
FF_FILTER_FORWARD_WANTED(outlink, inlink)
An instance of a filter.
Definition: avfilter.h:338
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
uint8_t ** extended_data
pointers to the data planes/channels.
Definition: frame.h:342
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:361
int av_frame_copy_props(AVFrame *dst, const AVFrame *src)
Copy only "metadata" fields from src to dst.
Definition: frame.c:654