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audio.c
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1 /*
2  * Copyright (c) Stefano Sabatini | stefasab at gmail.com
3  * Copyright (c) S.N. Hemanth Meenakshisundaram | smeenaks at ucsd.edu
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 #include "libavutil/avassert.h"
24 #include "libavutil/common.h"
25 
26 #include "audio.h"
27 #include "avfilter.h"
28 #include "internal.h"
29 
30 #define BUFFER_ALIGN 0
31 
32 
34 {
35  return ff_get_audio_buffer(link->dst->outputs[0], nb_samples);
36 }
37 
39 {
40  AVFrame *frame = NULL;
41  int channels = link->channels;
42 
44 
45  if (!link->frame_pool) {
47  nb_samples, link->format, BUFFER_ALIGN);
48  if (!link->frame_pool)
49  return NULL;
50  } else {
51  int pool_channels = 0;
52  int pool_nb_samples = 0;
53  int pool_align = 0;
54  enum AVSampleFormat pool_format = AV_SAMPLE_FMT_NONE;
55 
57  &pool_channels, &pool_nb_samples,
58  &pool_format, &pool_align) < 0) {
59  return NULL;
60  }
61 
62  if (pool_channels != channels || pool_nb_samples < nb_samples ||
63  pool_format != link->format || pool_align != BUFFER_ALIGN) {
64 
67  nb_samples, link->format, BUFFER_ALIGN);
68  if (!link->frame_pool)
69  return NULL;
70  }
71  }
72 
73  frame = ff_frame_pool_get(link->frame_pool);
74  if (!frame)
75  return NULL;
76 
77  frame->nb_samples = nb_samples;
78  frame->channel_layout = link->channel_layout;
79  frame->sample_rate = link->sample_rate;
80 
81  av_samples_set_silence(frame->extended_data, 0, nb_samples, channels, link->format);
82 
83  return frame;
84 }
85 
86 AVFrame *ff_get_audio_buffer(AVFilterLink *link, int nb_samples)
87 {
88  AVFrame *ret = NULL;
89 
90  if (link->dstpad->get_audio_buffer)
91  ret = link->dstpad->get_audio_buffer(link, nb_samples);
92 
93  if (!ret)
94  ret = ff_default_get_audio_buffer(link, nb_samples);
95 
96  return ret;
97 }
#define NULL
Definition: coverity.c:32
FFFramePool * ff_frame_pool_audio_init(AVBufferRef *(*alloc)(int size), int channels, int nb_samples, enum AVSampleFormat format, int align)
Allocate and initialize an audio frame pool.
Definition: framepool.c:119
This structure describes decoded (raw) audio or video data.
Definition: frame.h:190
AVFrame * ff_frame_pool_get(FFFramePool *pool)
Allocate a new AVFrame, reussing old buffers from the pool when available.
Definition: framepool.c:195
Main libavfilter public API header.
int av_get_channel_layout_nb_channels(uint64_t channel_layout)
Return the number of channels in the channel layout.
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
void ff_frame_pool_uninit(FFFramePool **pool)
Deallocate the frame pool.
Definition: framepool.c:284
int ff_frame_pool_get_audio_config(FFFramePool *pool, int *channels, int *nb_samples, enum AVSampleFormat *format, int *align)
Get the audio frame pool configuration.
Definition: framepool.c:176
static AVFrame * frame
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
simple assert() macros that are a bit more flexible than ISO C assert().
Frame pool.
Definition: framepool.c:30
uint64_t channel_layout
Channel layout of the audio data.
Definition: frame.h:359
audio channel layout utility functions
AVFrame * ff_null_get_audio_buffer(AVFilterLink *link, int nb_samples)
get_audio_buffer() handler for filters which simply pass audio along
Definition: audio.c:33
AVFrame *(* get_audio_buffer)(AVFilterLink *link, int nb_samples)
Callback function to get an audio buffer.
Definition: internal.h:81
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
AVBufferRef * av_buffer_allocz(int size)
Same as av_buffer_alloc(), except the returned buffer will be initialized to zero.
Definition: buffer.c:82
int sample_rate
Sample rate of the audio data.
Definition: frame.h:354
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:333
common internal and external API header
AVFrame * ff_default_get_audio_buffer(AVFilterLink *link, int nb_samples)
default handler for get_audio_buffer() for audio inputs
Definition: audio.c:38
#define BUFFER_ALIGN
Definition: audio.c:30
internal API functions
uint8_t ** extended_data
pointers to the data planes/channels.
Definition: frame.h:237
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:247