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pulse_audio_enc.c
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1 /*
2  * Copyright (c) 2013 Lukasz Marek <lukasz.m.luki@gmail.com>
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 #include <pulse/simple.h>
22 #include <pulse/error.h>
23 #include "libavformat/avformat.h"
24 #include "libavformat/internal.h"
25 #include "libavutil/opt.h"
26 #include "libavutil/time.h"
27 #include "libavutil/log.h"
28 #include "pulse_audio_common.h"
29 
30 typedef struct PulseData {
31  AVClass *class;
32  const char *server;
33  const char *name;
34  const char *stream_name;
35  const char *device;
36  pa_simple *pa;
37  int64_t timestamp;
38 } PulseData;
39 
41 {
42  PulseData *s = h->priv_data;
43  AVStream *st = NULL;
44  int ret;
45  pa_sample_spec ss;
46  pa_buffer_attr attr = { -1, -1, -1, -1, -1 };
47  const char *stream_name = s->stream_name;
48 
49  if (h->nb_streams != 1 || h->streams[0]->codec->codec_type != AVMEDIA_TYPE_AUDIO) {
50  av_log(s, AV_LOG_ERROR, "Only a single audio stream is supported.\n");
51  return AVERROR(EINVAL);
52  }
53  st = h->streams[0];
54 
55  if (!stream_name) {
56  if (h->filename[0])
57  stream_name = h->filename;
58  else
59  stream_name = "Playback";
60  }
61 
62  ss.format = codec_id_to_pulse_format(st->codec->codec_id);
63  ss.rate = st->codec->sample_rate;
64  ss.channels = st->codec->channels;
65 
66  s->pa = pa_simple_new(s->server, // Server
67  s->name, // Application name
68  PA_STREAM_PLAYBACK,
69  s->device, // Device
70  stream_name, // Description of a stream
71  &ss, // Sample format
72  NULL, // Use default channel map
73  &attr, // Buffering attributes
74  &ret); // Result
75 
76  if (!s->pa) {
77  av_log(s, AV_LOG_ERROR, "pa_simple_new failed: %s\n", pa_strerror(ret));
78  return AVERROR(EIO);
79  }
80 
81  avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
82 
83  return 0;
84 }
85 
87 {
88  PulseData *s = h->priv_data;
89  pa_simple_flush(s->pa, NULL);
90  pa_simple_free(s->pa);
91  s->pa = NULL;
92  return 0;
93 }
94 
96 {
97  PulseData *s = h->priv_data;
98  int error;
99 
100  if (!pkt) {
101  if (pa_simple_flush(s->pa, &error) < 0) {
102  av_log(s, AV_LOG_ERROR, "pa_simple_flush failed: %s\n", pa_strerror(error));
103  return AVERROR(EIO);
104  }
105  return 0;
106  }
107 
108  if (pkt->dts != AV_NOPTS_VALUE)
109  s->timestamp = pkt->dts;
110 
111  if (pkt->duration) {
112  s->timestamp += pkt->duration;
113  } else {
114  AVStream *st = h->streams[0];
115  AVCodecContext *codec_ctx = st->codec;
116  AVRational r = { 1, codec_ctx->sample_rate };
117  int64_t samples = pkt->size / (av_get_bytes_per_sample(codec_ctx->sample_fmt) * codec_ctx->channels);
118  s->timestamp += av_rescale_q(samples, r, st->time_base);
119  }
120 
121  if (pa_simple_write(s->pa, pkt->data, pkt->size, &error) < 0) {
122  av_log(s, AV_LOG_ERROR, "pa_simple_write failed: %s\n", pa_strerror(error));
123  return AVERROR(EIO);
124  }
125 
126  return 0;
127 }
128 
129 static void pulse_get_output_timestamp(AVFormatContext *h, int stream, int64_t *dts, int64_t *wall)
130 {
131  PulseData *s = h->priv_data;
132  pa_usec_t latency = pa_simple_get_latency(s->pa, NULL);
133  *wall = av_gettime();
134  *dts = s->timestamp - latency;
135 }
136 
137 #define OFFSET(a) offsetof(PulseData, a)
138 #define E AV_OPT_FLAG_ENCODING_PARAM
139 
140 static const AVOption options[] = {
141  { "server", "set PulseAudio server", OFFSET(server), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
142  { "name", "set application name", OFFSET(name), AV_OPT_TYPE_STRING, {.str = LIBAVFORMAT_IDENT}, 0, 0, E },
143  { "stream_name", "set stream description", OFFSET(stream_name), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
144  { "device", "set device name", OFFSET(device), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
145  { NULL }
146 };
147 
148 static const AVClass pulse_muxer_class = {
149  .class_name = "Pulse muxer",
150  .item_name = av_default_item_name,
151  .option = options,
152  .version = LIBAVUTIL_VERSION_INT,
153 };
154 
156  .name = "pulse",
157  .long_name = NULL_IF_CONFIG_SMALL("Pulse audio output"),
158  .priv_data_size = sizeof(PulseData),
160  .video_codec = AV_CODEC_ID_NONE,
161  .write_header = pulse_write_header,
162  .write_packet = pulse_write_packet,
163  .write_trailer = pulse_write_trailer,
164  .get_output_timestamp = pulse_get_output_timestamp,
165  .flags = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
166  .priv_class = &pulse_muxer_class,
167 };