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

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2004-2008 Lennart Poettering
   5
   6   PulseAudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as published
   8   by the Free Software Foundation; either version 2.1 of the License,
   9   or (at your option) any later version.
  10
  11   PulseAudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with PulseAudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <stdlib.h>
  27 #include <sys/stat.h>
  28 #include <stdio.h>
  29 #include <errno.h>
  30 #include <string.h>
  31 #include <fcntl.h>
  32 #include <unistd.h>
  33 #include <limits.h>
  34
  35 #include <pulse/rtclock.h>
  36 #include <pulse/timeval.h>
  37 #include <pulse/xmalloc.h>
  38 #include <pulse/i18n.h>
  39
  40 #include <pulsecore/macro.h>
  41 #include <pulsecore/sink.h>
  42 #include <pulsecore/module.h>
  43 #include <pulsecore/core-rtclock.h>
  44 #include <pulsecore/core-util.h>
  45 #include <pulsecore/core-error.h>
  46 #include <pulsecore/modargs.h>
  47 #include <pulsecore/log.h>
  48 #include <pulsecore/thread.h>
  49 #include <pulsecore/thread-mq.h>
  50 #include <pulsecore/rtpoll.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         "sink_name=<name of sink> "
  60         "sink_properties=<properties for the sink> "
  61         "format=<sample format> "
  62         "rate=<sample rate> "
  63         "channels=<number of channels> "
  64         "channel_map=<channel map>");
  65
  66 #define DEFAULT_SINK_NAME "null"
  67 #define BLOCK_USEC (PA_USEC_PER_SEC * 2)
  68
  69 struct userdata {
  70     pa_core *core;
  71     pa_module *module;
  72     pa_sink *sink;
  73
  74     pa_thread *thread;
  75     pa_thread_mq thread_mq;
  76     pa_rtpoll *rtpoll;
  77
  78     pa_usec_t block_usec;
  79     pa_usec_t timestamp;
  80 };
  81
  82 static const char* const valid_modargs[] = {
  83     "sink_name",
  84     "sink_properties",
  85     "format",
  86     "rate",
  87     "channels",
  88     "channel_map",
  89     "description", /* supported for compatibility reasons, made redundant by sink_properties= */
  90     NULL
  91 };
  92
  93 static int sink_process_msg(
  94         pa_msgobject *o,
  95         int code,
  96         void *data,
  97         int64_t offset,
  98         pa_memchunk *chunk) {
  99
 100     struct userdata *u = PA_SINK(o)->userdata;
 101
 102     switch (code) {
 103         case PA_SINK_MESSAGE_SET_STATE:
 104
 105             if (PA_PTR_TO_UINT(data) == PA_SINK_RUNNING)
 106                 u->timestamp = pa_rtclock_now();
 107
 108             break;
 109
 110         case PA_SINK_MESSAGE_GET_LATENCY: {
 111             pa_usec_t now;
 112
 113             now = pa_rtclock_now();
 114             *((pa_usec_t*) data) = u->timestamp > now ? u->timestamp - now : 0ULL;
 115
 116             return 0;
 117         }
 118     }
 119
 120     return pa_sink_process_msg(o, code, data, offset, chunk);
 121 }
 122
 123 static void sink_update_requested_latency_cb(pa_sink *s) {
 124     struct userdata *u;
 125     size_t nbytes;
 126
 127     pa_sink_assert_ref(s);
 128     pa_assert_se(u = s->userdata);
 129
 130     u->block_usec = pa_sink_get_requested_latency_within_thread(s);
 131
 132     if (u->block_usec == (pa_usec_t) -1)
 133         u->block_usec = s->thread_info.max_latency;
 134
 135     nbytes = pa_usec_to_bytes(u->block_usec, &s->sample_spec);
 136     pa_sink_set_max_rewind_within_thread(s, nbytes);
 137     pa_sink_set_max_request_within_thread(s, nbytes);
 138 }
 139
 140 static void process_rewind(struct userdata *u, pa_usec_t now) {
 141     size_t rewind_nbytes, in_buffer;
 142     pa_usec_t delay;
 143
 144     pa_assert(u);
 145
 146     /* Figure out how much we shall rewind and reset the counter */
 147     rewind_nbytes = u->sink->thread_info.rewind_nbytes;
 148     u->sink->thread_info.rewind_nbytes = 0;
 149
 150     pa_assert(rewind_nbytes > 0);
 151     pa_log_debug("Requested to rewind %lu bytes.", (unsigned long) rewind_nbytes);
 152
 153     if (u->timestamp <= now)
 154         goto do_nothing;
 155
 156     delay = u->timestamp - now;
 157     in_buffer = pa_usec_to_bytes(delay, &u->sink->sample_spec);
 158
 159     if (in_buffer <= 0)
 160         goto do_nothing;
 161
 162     if (rewind_nbytes > in_buffer)
 163         rewind_nbytes = in_buffer;
 164
 165     pa_sink_process_rewind(u->sink, rewind_nbytes);
 166     u->timestamp -= pa_bytes_to_usec(rewind_nbytes, &u->sink->sample_spec);
 167
 168     pa_log_debug("Rewound %lu bytes.", (unsigned long) rewind_nbytes);
 169     return;
 170
 171 do_nothing:
 172
 173     pa_sink_process_rewind(u->sink, 0);
 174 }
 175
 176 static void process_render(struct userdata *u, pa_usec_t now) {
 177     size_t ate = 0;
 178
 179     pa_assert(u);
 180
 181     /* This is the configured latency. Sink inputs connected to us
 182     might not have a single frame more than the maxrequest value
 183     queed. Hence: at maximum read this many bytes from the sink
 184     inputs. */
 185
 186     /* Fill the buffer up the the latency size */
 187     while (u->timestamp < now + u->block_usec) {
 188         pa_memchunk chunk;
 189
 190         pa_sink_render(u->sink, u->sink->thread_info.max_request, &chunk);
 191         pa_memblock_unref(chunk.memblock);
 192
 193 /*         pa_log_debug("Ate %lu bytes.", (unsigned long) chunk.length); */
 194         u->timestamp += pa_bytes_to_usec(chunk.length, &u->sink->sample_spec);
 195
 196         ate += chunk.length;
 197
 198         if (ate >= u->sink->thread_info.max_request)
 199             break;
 200     }
 201
 202 /*     pa_log_debug("Ate in sum %lu bytes (of %lu)", (unsigned long) ate, (unsigned long) nbytes); */
 203 }
 204
 205 static void thread_func(void *userdata) {
 206     struct userdata *u = userdata;
 207
 208     pa_assert(u);
 209
 210     pa_log_debug("Thread starting up");
 211
 212     pa_thread_mq_install(&u->thread_mq);
 213
 214     u->timestamp = pa_rtclock_now();
 215
 216     for (;;) {
 217         int ret;
 218
 219         /* Render some data and drop it immediately */
 220         if (PA_SINK_IS_OPENED(u->sink->thread_info.state)) {
 221             pa_usec_t now;
 222
 223             now = pa_rtclock_now();
 224
 225             if (u->sink->thread_info.rewind_requested) {
 226                 if (u->sink->thread_info.rewind_nbytes > 0)
 227                     process_rewind(u, now);
 228                 else
 229                     pa_sink_process_rewind(u->sink, 0);
 230             }
 231
 232             if (u->timestamp <= now)
 233                 process_render(u, now);
 234
 235             pa_rtpoll_set_timer_absolute(u->rtpoll, u->timestamp);
 236         } else
 237             pa_rtpoll_set_timer_disabled(u->rtpoll);
 238
 239         /* Hmm, nothing to do. Let's sleep */
 240         if ((ret = pa_rtpoll_run(u->rtpoll, TRUE)) < 0)
 241             goto fail;
 242
 243         if (ret == 0)
 244             goto finish;
 245     }
 246
 247 fail:
 248     /* If this was no regular exit from the loop we have to continue
 249      * processing messages until we received PA_MESSAGE_SHUTDOWN */
 250     pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
 251     pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
 252
 253 finish:
 254     pa_log_debug("Thread shutting down");
 255 }
 256
 257 int pa__init(pa_module*m) {
 258     struct userdata *u = NULL;
 259     pa_sample_spec ss;
 260     pa_channel_map map;
 261     pa_modargs *ma = NULL;
 262     pa_sink_new_data data;
 263     size_t nbytes;
 264
 265     pa_assert(m);
 266
 267     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 268         pa_log("Failed to parse module arguments.");
 269         goto fail;
 270     }
 271
 272     ss = m->core->default_sample_spec;
 273     map = m->core->default_channel_map;
 274     if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
 275         pa_log("Invalid sample format specification or channel map");
 276         goto fail;
 277     }
 278
 279     m->userdata = u = pa_xnew0(struct userdata, 1);
 280     u->core = m->core;
 281     u->module = m;
 282     u->rtpoll = pa_rtpoll_new();
 283     pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll);
 284
 285     pa_sink_new_data_init(&data);
 286     data.driver = __FILE__;
 287     data.module = m;
 288     pa_sink_new_data_set_name(&data, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
 289     pa_sink_new_data_set_sample_spec(&data, &ss);
 290     pa_sink_new_data_set_channel_map(&data, &map);
 291     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_DESCRIPTION, pa_modargs_get_value(ma, "description", _("Null Output")));
 292     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_CLASS, "abstract");
 293
 294     if (pa_modargs_get_proplist(ma, "sink_properties", data.proplist, PA_UPDATE_REPLACE) < 0) {
 295         pa_log("Invalid properties");
 296         pa_sink_new_data_done(&data);
 297         goto fail;
 298     }
 299
 300     u->sink = pa_sink_new(m->core, &data, PA_SINK_LATENCY|PA_SINK_DYNAMIC_LATENCY);
 301     pa_sink_new_data_done(&data);
 302
 303     if (!u->sink) {
 304         pa_log("Failed to create sink object.");
 305         goto fail;
 306     }
 307
 308     u->sink->parent.process_msg = sink_process_msg;
 309     u->sink->update_requested_latency = sink_update_requested_latency_cb;
 310     u->sink->userdata = u;
 311
 312     pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
 313     pa_sink_set_rtpoll(u->sink, u->rtpoll);
 314
 315     u->block_usec = BLOCK_USEC;
 316     nbytes = pa_usec_to_bytes(u->block_usec, &u->sink->sample_spec);
 317     pa_sink_set_max_rewind(u->sink, nbytes);
 318     pa_sink_set_max_request(u->sink, nbytes);
 319
 320     if (!(u->thread = pa_thread_new(thread_func, u))) {
 321         pa_log("Failed to create thread.");
 322         goto fail;
 323     }
 324
 325     pa_sink_put(u->sink);
 326
 327     pa_modargs_free(ma);
 328
 329     return 0;
 330
 331 fail:
 332     if (ma)
 333         pa_modargs_free(ma);
 334
 335     pa__done(m);
 336
 337     return -1;
 338 }
 339
 340 int pa__get_n_used(pa_module *m) {
 341     struct userdata *u;
 342
 343     pa_assert(m);
 344     pa_assert_se(u = m->userdata);
 345
 346     return pa_sink_linked_by(u->sink);
 347 }
 348
 349 void pa__done(pa_module*m) {
 350     struct userdata *u;
 351
 352     pa_assert(m);
 353
 354     if (!(u = m->userdata))
 355         return;
 356
 357     if (u->sink)
 358         pa_sink_unlink(u->sink);
 359
 360     if (u->thread) {
 361         pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
 362         pa_thread_free(u->thread);
 363     }
 364
 365     pa_thread_mq_done(&u->thread_mq);
 366
 367     if (u->sink)
 368         pa_sink_unref(u->sink);
 369
 370     if (u->rtpoll)
 371         pa_rtpoll_free(u->rtpoll);
 372
 373     pa_xfree(u);
 374 }