code.delx.au - pulseaudio/blob - src/modules/module-null-sink.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   5
   6   Copyright 2004-2006 Lennart Poettering
   7
   8   PulseAudio is free software; you can redistribute it and/or modify
   9   it under the terms of the GNU Lesser General Public License as published
  10   by the Free Software Foundation; either version 2 of the License,
  11   or (at your option) any later version.
  12
  13   PulseAudio is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with PulseAudio; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  21   USA.
  22 ***/
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include <stdlib.h>
  29 #include <sys/stat.h>
  30 #include <stdio.h>
  31 #include <errno.h>
  32 #include <string.h>
  33 #include <fcntl.h>
  34 #include <unistd.h>
  35 #include <limits.h>
  36
  37 #include <pulse/timeval.h>
  38 #include <pulse/xmalloc.h>
  39
  40 #include <pulsecore/macro.h>
  41 #include <pulsecore/sink.h>
  42 #include <pulsecore/module.h>
  43 #include <pulsecore/core-util.h>
  44 #include <pulsecore/core-error.h>
  45 #include <pulsecore/modargs.h>
  46 #include <pulsecore/log.h>
  47 #include <pulsecore/thread.h>
  48 #include <pulsecore/thread-mq.h>
  49 #include <pulsecore/rtpoll.h>
  50 #include <pulsecore/rtclock.h>
  51
  52 #include "module-null-sink-symdef.h"
  53
  54 PA_MODULE_AUTHOR("Lennart Poettering");
  55 PA_MODULE_DESCRIPTION("Clocked NULL sink");
  56 PA_MODULE_VERSION(PACKAGE_VERSION);
  57 PA_MODULE_LOAD_ONCE(FALSE);
  58 PA_MODULE_USAGE(
  59         "format=<sample format> "
  60         "channels=<number of channels> "
  61         "rate=<sample rate> "
  62         "sink_name=<name of sink>"
  63         "channel_map=<channel map>"
  64         "description=<description for the sink>");
  65
  66 #define DEFAULT_SINK_NAME "null"
  67
  68 struct userdata {
  69     pa_core *core;
  70     pa_module *module;
  71     pa_sink *sink;
  72
  73     pa_thread *thread;
  74     pa_thread_mq thread_mq;
  75     pa_rtpoll *rtpoll;
  76
  77     size_t block_size;
  78
  79     struct timeval timestamp;
  80 };
  81
  82 static const char* const valid_modargs[] = {
  83     "rate",
  84     "format",
  85     "channels",
  86     "sink_name",
  87     "channel_map",
  88     "description",
  89     NULL
  90 };
  91
  92 static int sink_process_msg(pa_msgobject *o, int code, void *data, int64_t offset, pa_memchunk *chunk) {
  93     struct userdata *u = PA_SINK(o)->userdata;
  94
  95     switch (code) {
  96         case PA_SINK_MESSAGE_SET_STATE:
  97
  98             if (PA_PTR_TO_UINT(data) == PA_SINK_RUNNING)
  99                 pa_rtclock_get(&u->timestamp);
 100
 101             break;
 102
 103         case PA_SINK_MESSAGE_GET_LATENCY: {
 104             struct timeval now;
 105
 106             pa_rtclock_get(&now);
 107
 108             if (pa_timeval_cmp(&u->timestamp, &now) > 0)
 109                 *((pa_usec_t*) data) = 0;
 110             else
 111                 *((pa_usec_t*) data) = pa_timeval_diff(&u->timestamp, &now);
 112             break;
 113         }
 114     }
 115
 116     return pa_sink_process_msg(o, code, data, offset, chunk);
 117 }
 118
 119 static void thread_func(void *userdata) {
 120     struct userdata *u = userdata;
 121
 122     pa_assert(u);
 123
 124     pa_log_debug("Thread starting up");
 125
 126     pa_thread_mq_install(&u->thread_mq);
 127     pa_rtpoll_install(u->rtpoll);
 128
 129     pa_rtclock_get(&u->timestamp);
 130
 131     for (;;) {
 132         int ret;
 133
 134         /* Render some data and drop it immediately */
 135         if (u->sink->thread_info.state == PA_SINK_RUNNING) {
 136             struct timeval now;
 137
 138             pa_rtclock_get(&now);
 139
 140             if (pa_timeval_cmp(&u->timestamp, &now) <= 0) {
 141                 pa_sink_skip(u->sink, u->block_size);
 142                 pa_timeval_add(&u->timestamp, pa_bytes_to_usec(u->block_size, &u->sink->sample_spec));
 143             }
 144
 145             pa_rtpoll_set_timer_absolute(u->rtpoll, &u->timestamp);
 146         } else
 147             pa_rtpoll_set_timer_disabled(u->rtpoll);
 148
 149         /* Hmm, nothing to do. Let's sleep */
 150         if ((ret = pa_rtpoll_run(u->rtpoll, 1)) < 0)
 151             goto fail;
 152
 153         if (ret == 0)
 154             goto finish;
 155     }
 156
 157 fail:
 158     /* If this was no regular exit from the loop we have to continue
 159      * processing messages until we received PA_MESSAGE_SHUTDOWN */
 160     pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
 161     pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
 162
 163 finish:
 164     pa_log_debug("Thread shutting down");
 165 }
 166
 167 int pa__init(pa_module*m) {
 168     struct userdata *u = NULL;
 169     pa_sample_spec ss;
 170     pa_channel_map map;
 171     pa_modargs *ma = NULL;
 172
 173     pa_assert(m);
 174
 175     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 176         pa_log("Failed to parse module arguments.");
 177         goto fail;
 178     }
 179
 180     ss = m->core->default_sample_spec;
 181     if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
 182         pa_log("Invalid sample format specification or channel map");
 183         goto fail;
 184     }
 185
 186     u = pa_xnew0(struct userdata, 1);
 187     u->core = m->core;
 188     u->module = m;
 189     m->userdata = u;
 190     pa_thread_mq_init(&u->thread_mq, m->core->mainloop);
 191     u->rtpoll = pa_rtpoll_new();
 192     pa_rtpoll_item_new_asyncmsgq(u->rtpoll, PA_RTPOLL_EARLY, u->thread_mq.inq);
 193
 194     if (!(u->sink = pa_sink_new(m->core, __FILE__, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME), 0, &ss, &map))) {
 195         pa_log("Failed to create sink.");
 196         goto fail;
 197     }
 198
 199     u->sink->parent.process_msg = sink_process_msg;
 200     u->sink->userdata = u;
 201     u->sink->flags = PA_SINK_LATENCY;
 202
 203     pa_sink_set_module(u->sink, m);
 204     pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
 205     pa_sink_set_rtpoll(u->sink, u->rtpoll);
 206     pa_sink_set_description(u->sink, pa_modargs_get_value(ma, "description", "NULL sink"));
 207
 208     u->block_size = pa_bytes_per_second(&ss) / 20; /* 50 ms */
 209     if (u->block_size <= 0)
 210         u->block_size = pa_frame_size(&ss);
 211
 212     if (!(u->thread = pa_thread_new(thread_func, u))) {
 213         pa_log("Failed to create thread.");
 214         goto fail;
 215     }
 216
 217     pa_sink_put(u->sink);
 218
 219     pa_modargs_free(ma);
 220
 221     return 0;
 222
 223 fail:
 224     if (ma)
 225         pa_modargs_free(ma);
 226
 227     pa__done(m);
 228
 229     return -1;
 230 }
 231
 232 void pa__done(pa_module*m) {
 233     struct userdata *u;
 234
 235     pa_assert(m);
 236
 237     if (!(u = m->userdata))
 238         return;
 239
 240     if (u->sink)
 241         pa_sink_unlink(u->sink);
 242
 243     if (u->thread) {
 244         pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
 245         pa_thread_free(u->thread);
 246     }
 247
 248     pa_thread_mq_done(&u->thread_mq);
 249
 250     if (u->sink)
 251         pa_sink_unref(u->sink);
 252
 253     if (u->rtpoll)
 254         pa_rtpoll_free(u->rtpoll);
 255
 256     pa_xfree(u);
 257 }