Libav
buffersink.c
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1 /*
2  * Copyright (c) 2011 Stefano Sabatini
3  *
4  * This file is part of Libav.
5  *
6  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
26 #include "libavutil/audio_fifo.h"
27 #include "libavutil/avassert.h"
29 #include "libavutil/common.h"
30 #include "libavutil/internal.h"
31 #include "libavutil/mathematics.h"
32 
33 #include "audio.h"
34 #include "avfilter.h"
35 #include "buffersink.h"
36 #include "internal.h"
37 
38 typedef struct BufferSinkContext {
41  int64_t next_pts;
43 
45 {
46  BufferSinkContext *sink = ctx->priv;
47 
48  if (sink->audio_fifo)
50 }
51 
52 static int filter_frame(AVFilterLink *link, AVFrame *frame)
53 {
54  BufferSinkContext *s = link->dst->priv;
55 
56  av_assert0(!s->cur_frame);
57  s->cur_frame = frame;
58 
59  return 0;
60 }
61 
63  AVFrame *frame)
64 {
65  BufferSinkContext *s = ctx->priv;
66  AVFilterLink *link = ctx->inputs[0];
67  int ret;
68 
69  if ((ret = ff_request_frame(link)) < 0)
70  return ret;
71 
72  if (!s->cur_frame)
73  return AVERROR(EINVAL);
74 
75  av_frame_move_ref(frame, s->cur_frame);
77 
78  return 0;
79 }
80 
82  int nb_samples)
83 {
84  BufferSinkContext *s = ctx->priv;
85  AVFilterLink *link = ctx->inputs[0];
86  AVFrame *tmp;
87 
88  if (!(tmp = ff_get_audio_buffer(link, nb_samples)))
89  return AVERROR(ENOMEM);
90  av_audio_fifo_read(s->audio_fifo, (void**)tmp->extended_data, nb_samples);
91 
92  tmp->pts = s->next_pts;
93  s->next_pts += av_rescale_q(nb_samples, (AVRational){1, link->sample_rate},
94  link->time_base);
95 
96  av_frame_move_ref(frame, tmp);
97  av_frame_free(&tmp);
98 
99  return 0;
100 }
101 
103  AVFrame *frame, int nb_samples)
104 {
105  BufferSinkContext *s = ctx->priv;
106  AVFilterLink *link = ctx->inputs[0];
107  int ret = 0;
108 
109  if (!s->audio_fifo) {
111  if (!(s->audio_fifo = av_audio_fifo_alloc(link->format, nb_channels, nb_samples)))
112  return AVERROR(ENOMEM);
113  }
114 
115  while (ret >= 0) {
116  if (av_audio_fifo_size(s->audio_fifo) >= nb_samples)
117  return read_from_fifo(ctx, frame, nb_samples);
118 
119  ret = ff_request_frame(link);
120  if (ret == AVERROR_EOF && av_audio_fifo_size(s->audio_fifo))
121  return read_from_fifo(ctx, frame, av_audio_fifo_size(s->audio_fifo));
122  else if (ret < 0)
123  return ret;
124 
125  if (s->cur_frame->pts != AV_NOPTS_VALUE) {
126  s->next_pts = s->cur_frame->pts -
128  (AVRational){ 1, link->sample_rate },
129  link->time_base);
130  }
131 
133  s->cur_frame->nb_samples);
135  }
136 
137  return ret;
138 }
139 
141  {
142  .name = "default",
143  .type = AVMEDIA_TYPE_VIDEO,
144  .filter_frame = filter_frame,
145  .needs_fifo = 1
146  },
147  { NULL }
148 };
149 
151  .name = "buffersink",
152  .description = NULL_IF_CONFIG_SMALL("Buffer video frames, and make them available to the end of the filter graph."),
153  .priv_size = sizeof(BufferSinkContext),
154  .uninit = uninit,
155 
156  .inputs = avfilter_vsink_buffer_inputs,
157  .outputs = NULL,
158 };
159 
161  {
162  .name = "default",
163  .type = AVMEDIA_TYPE_AUDIO,
164  .filter_frame = filter_frame,
165  .needs_fifo = 1
166  },
167  { NULL }
168 };
169 
171  .name = "abuffersink",
172  .description = NULL_IF_CONFIG_SMALL("Buffer audio frames, and make them available to the end of the filter graph."),
173  .priv_size = sizeof(BufferSinkContext),
174  .uninit = uninit,
175 
176  .inputs = avfilter_asink_abuffer_inputs,
177  .outputs = NULL,
178 };
AVAudioFifo * av_audio_fifo_alloc(enum AVSampleFormat sample_fmt, int channels, int nb_samples)
Allocate an AVAudioFifo.
Definition: audio_fifo.c:60
int av_audio_fifo_read(AVAudioFifo *af, void **data, int nb_samples)
Read data from an AVAudioFifo.
Definition: audio_fifo.c:139
This structure describes decoded (raw) audio or video data.
Definition: frame.h:140
static const AVFilterPad outputs[]
Definition: af_ashowinfo.c:259
static av_cold void uninit(AVFilterContext *ctx)
Definition: buffersink.c:44
Main libavfilter public API header.
static int read_from_fifo(AVFilterContext *ctx, AVFrame *frame, int nb_samples)
Definition: buffersink.c:81
void av_audio_fifo_free(AVAudioFifo *af)
Free an AVAudioFifo.
Definition: audio_fifo.c:45
void av_frame_move_ref(AVFrame *dst, AVFrame *src)
Move everything contained in src to dst and reset src.
Definition: frame.c:319
memory buffer sink API
const char * name
Pad name.
Definition: internal.h:41
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:270
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
AVAudioFifo * audio_fifo
FIFO for audio samples.
Definition: buffersink.c:40
#define av_cold
Definition: attributes.h:66
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:211
#define AVERROR_EOF
End of file.
Definition: error.h:51
A filter pad used for either input or output.
Definition: internal.h:35
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:99
AVFrame * ff_get_audio_buffer(AVFilterLink *link, int nb_samples)
Request an audio samples buffer with a specific set of permissions.
Definition: audio.c:57
#define AVERROR(e)
Definition: error.h:43
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:80
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:148
void * priv
private data for use by the filter
Definition: avfilter.h:277
int av_get_channel_layout_nb_channels(uint64_t channel_layout)
Return the number of channels in the channel layout.
simple assert() macros that are a bit more flexible than ISO C assert().
static const AVFilterPad avfilter_asink_abuffer_inputs[]
Definition: buffersink.c:160
AVFilter ff_vsink_buffer
Definition: buffersink.c:150
Context for an Audio FIFO Buffer.
Definition: audio_fifo.c:34
common internal API header
int av_audio_fifo_size(AVAudioFifo *af)
Get the current number of samples in the AVAudioFifo available for reading.
Definition: audio_fifo.c:186
audio channel layout utility functions
int attribute_align_arg av_buffersink_get_samples(AVFilterContext *ctx, AVFrame *frame, int nb_samples)
Same as av_buffersink_get_frame(), but with the ability to specify the number of samples read...
Definition: buffersink.c:102
AVFormatContext * ctx
Definition: movenc.c:48
AVFilter ff_asink_abuffer
Definition: buffersink.c:170
#define attribute_align_arg
Definition: internal.h:55
NULL
Definition: eval.c:55
AVFrame * cur_frame
last frame delivered on the sink
Definition: buffersink.c:39
Filter definition.
Definition: avfilter.h:120
static const AVFilterPad inputs[]
Definition: af_ashowinfo.c:248
rational number numerator/denominator
Definition: rational.h:43
const char * name
Filter name.
Definition: avfilter.h:124
int av_audio_fifo_write(AVAudioFifo *af, void **data, int nb_samples)
Write data to an AVAudioFifo.
Definition: audio_fifo.c:113
int64_t next_pts
interpolating audio pts
Definition: buffersink.c:41
common internal and external API header
Audio FIFO Buffer.
static int filter_frame(AVFilterLink *link, AVFrame *frame)
Definition: buffersink.c:52
static uint8_t tmp[8]
Definition: des.c:38
An instance of a filter.
Definition: avfilter.h:262
static const AVFilterPad avfilter_vsink_buffer_inputs[]
Definition: buffersink.c:140
int ff_request_frame(AVFilterLink *link)
Request an input frame from the filter at the other end of the link.
Definition: avfilter.c:264
int nb_channels
internal API functions
uint8_t ** extended_data
pointers to the data planes/channels.
Definition: frame.h:174
int attribute_align_arg av_buffersink_get_frame(AVFilterContext *ctx, AVFrame *frame)
Get a frame with filtered data from sink and put it in frame.
Definition: buffersink.c:62
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:184
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:235