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buffersink.c
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1 /*
2  * Copyright (c) 2011 Stefano Sabatini
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
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  * 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 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 FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * buffer sink
24  */
25 
26 #include "libavutil/audio_fifo.h"
27 #include "libavutil/avassert.h"
29 #include "libavutil/common.h"
30 #include "libavutil/mathematics.h"
31 
32 #include "audio.h"
33 #include "avfilter.h"
34 #include "buffersink.h"
35 #include "internal.h"
36 
37 typedef struct {
38  AVFilterBufferRef *cur_buf; ///< last buffer delivered on the sink
39  AVAudioFifo *audio_fifo; ///< FIFO for audio samples
40  int64_t next_pts; ///< interpolating audio pts
42 
43 static av_cold void uninit(AVFilterContext *ctx)
44 {
45  BufferSinkContext *sink = ctx->priv;
46 
47  if (sink->audio_fifo)
49 }
50 
52 {
53  BufferSinkContext *s = link->dst->priv;
54 
55 // av_assert0(!s->cur_buf);
56  s->cur_buf = buf;
57 
58  return 0;
59 }
60 
62 {
63  BufferSinkContext *s = ctx->priv;
64  AVFilterLink *link = ctx->inputs[0];
65  int ret;
66 
67  if (!buf)
68  return ff_poll_frame(ctx->inputs[0]);
69 
70  if ((ret = ff_request_frame(link)) < 0)
71  return ret;
72 
73  if (!s->cur_buf)
74  return AVERROR(EINVAL);
75 
76  *buf = s->cur_buf;
77  s->cur_buf = NULL;
78 
79  return 0;
80 }
81 
83  int nb_samples)
84 {
85  BufferSinkContext *s = ctx->priv;
86  AVFilterLink *link = ctx->inputs[0];
87  AVFilterBufferRef *buf;
88 
89  if (!(buf = ff_get_audio_buffer(link, AV_PERM_WRITE, nb_samples)))
90  return AVERROR(ENOMEM);
91  av_audio_fifo_read(s->audio_fifo, (void**)buf->extended_data, nb_samples);
92 
93  buf->pts = s->next_pts;
94  s->next_pts += av_rescale_q(nb_samples, (AVRational){1, link->sample_rate},
95  link->time_base);
96 
97  *pbuf = buf;
98  return 0;
99 
100 }
101 
103  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  AVFilterBufferRef *buf;
117 
118  if (av_audio_fifo_size(s->audio_fifo) >= nb_samples)
119  return read_from_fifo(ctx, pbuf, nb_samples);
120 
121  ret = av_buffersink_read(ctx, &buf);
122  if (ret == AVERROR_EOF && av_audio_fifo_size(s->audio_fifo))
123  return read_from_fifo(ctx, pbuf, av_audio_fifo_size(s->audio_fifo));
124  else if (ret < 0)
125  return ret;
126 
127  if (buf->pts != AV_NOPTS_VALUE) {
128  s->next_pts = buf->pts -
130  (AVRational){ 1, link->sample_rate },
131  link->time_base);
132  }
133 
134  ret = av_audio_fifo_write(s->audio_fifo, (void**)buf->extended_data,
135  buf->audio->nb_samples);
137  }
138 
139  return ret;
140 }
141 
143  {
144  .name = "default",
145  .type = AVMEDIA_TYPE_VIDEO,
146  .filter_frame = filter_frame,
147  .min_perms = AV_PERM_READ,
148  .needs_fifo = 1
149  },
150  { NULL }
151 };
152 
154 #if AV_HAVE_INCOMPATIBLE_FORK_ABI
155  .name = "buffersink",
156 #else
157  .name = "buffersink_old",
158 #endif
159  .description = NULL_IF_CONFIG_SMALL("Buffer video frames, and make them available to the end of the filter graph."),
160  .priv_size = sizeof(BufferSinkContext),
161  .uninit = uninit,
162 
163  .inputs = avfilter_vsink_buffer_inputs,
164  .outputs = NULL,
165 };
166 
168  {
169  .name = "default",
170  .type = AVMEDIA_TYPE_AUDIO,
171  .filter_frame = filter_frame,
172  .min_perms = AV_PERM_READ,
173  .needs_fifo = 1
174  },
175  { NULL }
176 };
177 
179 #if AV_HAVE_INCOMPATIBLE_FORK_ABI
180  .name = "abuffersink",
181 #else
182  .name = "abuffersink_old",
183 #endif
184  .description = NULL_IF_CONFIG_SMALL("Buffer audio frames, and make them available to the end of the filter graph."),
185  .priv_size = sizeof(BufferSinkContext),
186  .uninit = uninit,
187 
188  .inputs = avfilter_asink_abuffer_inputs,
189  .outputs = NULL,
190 };