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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;
40 } PulseData;
41 
43 {
44  PulseData *s = h->priv_data;
45  AVStream *st = NULL;
46  int ret;
47  pa_sample_spec ss;
48  pa_buffer_attr attr = { -1, -1, -1, -1, -1 };
49  const char *stream_name = s->stream_name;
50 
51  if (h->nb_streams != 1 || h->streams[0]->codec->codec_type != AVMEDIA_TYPE_AUDIO) {
52  av_log(s, AV_LOG_ERROR, "Only a single audio stream is supported.\n");
53  return AVERROR(EINVAL);
54  }
55  st = h->streams[0];
56 
57  if (!stream_name) {
58  if (h->filename[0])
59  stream_name = h->filename;
60  else
61  stream_name = "Playback";
62  }
63 
64  if (s->buffer_duration) {
65  int64_t bytes = s->buffer_duration;
66  bytes *= st->codec->channels * st->codec->sample_rate *
68  bytes /= 1000;
69  attr.tlength = FFMAX(s->buffer_size, av_clip64(bytes, 0, UINT32_MAX - 1));
71  "Buffer duration: %ums recalculated into %"PRId64" bytes buffer.\n",
72  s->buffer_duration, bytes);
73  av_log(s, AV_LOG_DEBUG, "Real buffer length is %u bytes\n", attr.tlength);
74  } else if (s->buffer_size)
75  attr.tlength = s->buffer_size;
76 
77  ss.format = ff_codec_id_to_pulse_format(st->codec->codec_id);
78  ss.rate = st->codec->sample_rate;
79  ss.channels = st->codec->channels;
80 
81  s->pa = pa_simple_new(s->server, // Server
82  s->name, // Application name
83  PA_STREAM_PLAYBACK,
84  s->device, // Device
85  stream_name, // Description of a stream
86  &ss, // Sample format
87  NULL, // Use default channel map
88  &attr, // Buffering attributes
89  &ret); // Result
90 
91  if (!s->pa) {
92  av_log(s, AV_LOG_ERROR, "pa_simple_new failed: %s\n", pa_strerror(ret));
93  return AVERROR(EIO);
94  }
95 
96  avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
97 
98  return 0;
99 }
100 
102 {
103  PulseData *s = h->priv_data;
104  pa_simple_flush(s->pa, NULL);
105  pa_simple_free(s->pa);
106  s->pa = NULL;
107  return 0;
108 }
109 
111 {
112  PulseData *s = h->priv_data;
113  int error;
114 
115  if (!pkt) {
116  if (pa_simple_flush(s->pa, &error) < 0) {
117  av_log(s, AV_LOG_ERROR, "pa_simple_flush failed: %s\n", pa_strerror(error));
118  return AVERROR(EIO);
119  }
120  return 1;
121  }
122 
123  if (pkt->dts != AV_NOPTS_VALUE)
124  s->timestamp = pkt->dts;
125 
126  if (pkt->duration) {
127  s->timestamp += pkt->duration;
128  } else {
129  AVStream *st = h->streams[0];
130  AVCodecContext *codec_ctx = st->codec;
131  AVRational r = { 1, codec_ctx->sample_rate };
132  int64_t samples = pkt->size / (av_get_bytes_per_sample(codec_ctx->sample_fmt) * codec_ctx->channels);
133  s->timestamp += av_rescale_q(samples, r, st->time_base);
134  }
135 
136  if (pa_simple_write(s->pa, pkt->data, pkt->size, &error) < 0) {
137  av_log(s, AV_LOG_ERROR, "pa_simple_write failed: %s\n", pa_strerror(error));
138  return AVERROR(EIO);
139  }
140 
141  return 0;
142 }
143 
144 static void pulse_get_output_timestamp(AVFormatContext *h, int stream, int64_t *dts, int64_t *wall)
145 {
146  PulseData *s = h->priv_data;
147  pa_usec_t latency = pa_simple_get_latency(s->pa, NULL);
148  *wall = av_gettime();
149  *dts = s->timestamp - latency;
150 }
151 
152 #define OFFSET(a) offsetof(PulseData, a)
153 #define E AV_OPT_FLAG_ENCODING_PARAM
154 
155 static const AVOption options[] = {
156  { "server", "set PulseAudio server", OFFSET(server), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
157  { "name", "set application name", OFFSET(name), AV_OPT_TYPE_STRING, {.str = LIBAVFORMAT_IDENT}, 0, 0, E },
158  { "stream_name", "set stream description", OFFSET(stream_name), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
159  { "device", "set device name", OFFSET(device), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
160  { "buffer_size", "set buffer size in bytes", OFFSET(buffer_size), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E },
161  { "buffer_duration", "set buffer duration in millisecs", OFFSET(buffer_duration), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E },
162  { NULL }
163 };
164 
165 static const AVClass pulse_muxer_class = {
166  .class_name = "Pulse muxer",
167  .item_name = av_default_item_name,
168  .option = options,
169  .version = LIBAVUTIL_VERSION_INT,
170 };
171 
173  .name = "pulse",
174  .long_name = NULL_IF_CONFIG_SMALL("Pulse audio output"),
175  .priv_data_size = sizeof(PulseData),
177  .video_codec = AV_CODEC_ID_NONE,
178  .write_header = pulse_write_header,
179  .write_packet = pulse_write_packet,
180  .write_trailer = pulse_write_trailer,
181  .get_output_timestamp = pulse_get_output_timestamp,
182  .flags = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
183  .priv_class = &pulse_muxer_class,
184 };