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sndio_dec.c
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1 /*
2  * sndio play and grab interface
3  * Copyright (c) 2010 Jacob Meuser
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 <stdint.h>
23 #include <sndio.h>
24 
25 #include "libavformat/avformat.h"
26 #include "libavformat/internal.h"
27 #include "libavutil/opt.h"
28 #include "libavutil/time.h"
29 
30 #include "sndio_common.h"
31 
33 {
34  SndioData *s = s1->priv_data;
35  AVStream *st;
36  int ret;
37 
38  st = avformat_new_stream(s1, NULL);
39  if (!st)
40  return AVERROR(ENOMEM);
41 
42  ret = ff_sndio_open(s1, 0, s1->filename);
43  if (ret < 0)
44  return ret;
45 
46  /* take real parameters */
48  st->codec->codec_id = s->codec_id;
49  st->codec->sample_rate = s->sample_rate;
50  st->codec->channels = s->channels;
51 
52  avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
53 
54  return 0;
55 }
56 
58 {
59  SndioData *s = s1->priv_data;
60  int64_t bdelay, cur_time;
61  int ret;
62 
63  if ((ret = av_new_packet(pkt, s->buffer_size)) < 0)
64  return ret;
65 
66  ret = sio_read(s->hdl, pkt->data, pkt->size);
67  if (ret == 0 || sio_eof(s->hdl)) {
68  av_free_packet(pkt);
69  return AVERROR_EOF;
70  }
71 
72  pkt->size = ret;
73  s->softpos += ret;
74 
75  /* compute pts of the start of the packet */
76  cur_time = av_gettime();
77 
78  bdelay = ret + s->hwpos - s->softpos;
79 
80  /* convert to pts */
81  pkt->pts = cur_time - ((bdelay * 1000000) /
82  (s->bps * s->channels * s->sample_rate));
83 
84  return 0;
85 }
86 
88 {
89  SndioData *s = s1->priv_data;
90 
91  ff_sndio_close(s);
92 
93  return 0;
94 }
95 
96 static const AVOption options[] = {
97  { "sample_rate", "", offsetof(SndioData, sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
98  { "channels", "", offsetof(SndioData, channels), AV_OPT_TYPE_INT, {.i64 = 2}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
99  { NULL },
100 };
101 
102 static const AVClass sndio_demuxer_class = {
103  .class_name = "sndio indev",
104  .item_name = av_default_item_name,
105  .option = options,
106  .version = LIBAVUTIL_VERSION_INT,
107 };
108 
110  .name = "sndio",
111  .long_name = NULL_IF_CONFIG_SMALL("sndio audio capture"),
112  .priv_data_size = sizeof(SndioData),
116  .flags = AVFMT_NOFILE,
117  .priv_class = &sndio_demuxer_class,
118 };