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 <stdio.h>
  28 #include <errno.h>
  29 #include <unistd.h>
  30
  31 #include <pulse/rtclock.h>
  32 #include <pulse/timeval.h>
  33 #include <pulse/xmalloc.h>
  34
  35 #include <pulsecore/i18n.h>
  36 #include <pulsecore/macro.h>
  37 #include <pulsecore/sink.h>
  38 #include <pulsecore/module.h>
  39 #include <pulsecore/core-util.h>
  40 #include <pulsecore/modargs.h>
  41 #include <pulsecore/log.h>
  42 #include <pulsecore/thread.h>
  43 #include <pulsecore/thread-mq.h>
  44 #include <pulsecore/rtpoll.h>
  45
  46 #include "module-null-sink-symdef.h"
  47
  48 PA_MODULE_AUTHOR("Lennart Poettering");
  49 PA_MODULE_DESCRIPTION(_("Clocked NULL sink"));
  50 PA_MODULE_VERSION(PACKAGE_VERSION);
  51 PA_MODULE_LOAD_ONCE(false);
  52 PA_MODULE_USAGE(
  53         "sink_name=<name of sink> "
  54         "sink_properties=<properties for the sink> "
  55         "format=<sample format> "
  56         "rate=<sample rate> "
  57         "channels=<number of channels> "
  58         "channel_map=<channel map>");
  59
  60 #define DEFAULT_SINK_NAME "null"
  61 #define BLOCK_USEC (PA_USEC_PER_SEC * 2)
  62
  63 struct userdata {
  64     pa_core *core;
  65     pa_module *module;
  66     pa_sink *sink;
  67
  68     pa_thread *thread;
  69     pa_thread_mq thread_mq;
  70     pa_rtpoll *rtpoll;
  71
  72     pa_usec_t block_usec;
  73     pa_usec_t timestamp;
  74 };
  75
  76 static const char* const valid_modargs[] = {
  77     "sink_name",
  78     "sink_properties",
  79     "format",
  80     "rate",
  81     "channels",
  82     "channel_map",
  83     NULL
  84 };
  85
  86 static int sink_process_msg(
  87         pa_msgobject *o,
  88         int code,
  89         void *data,
  90         int64_t offset,
  91         pa_memchunk *chunk) {
  92
  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                 u->timestamp = pa_rtclock_now();
 100
 101             break;
 102
 103         case PA_SINK_MESSAGE_GET_LATENCY: {
 104             pa_usec_t now;
 105
 106             now = pa_rtclock_now();
 107             *((pa_usec_t*) data) = u->timestamp > now ? u->timestamp - now : 0ULL;
 108
 109             return 0;
 110         }
 111     }
 112
 113     return pa_sink_process_msg(o, code, data, offset, chunk);
 114 }
 115
 116 static void sink_update_requested_latency_cb(pa_sink *s) {
 117     struct userdata *u;
 118     size_t nbytes;
 119
 120     pa_sink_assert_ref(s);
 121     pa_assert_se(u = s->userdata);
 122
 123     u->block_usec = pa_sink_get_requested_latency_within_thread(s);
 124
 125     if (u->block_usec == (pa_usec_t) -1)
 126         u->block_usec = s->thread_info.max_latency;
 127
 128     nbytes = pa_usec_to_bytes(u->block_usec, &s->sample_spec);
 129     pa_sink_set_max_rewind_within_thread(s, nbytes);
 130     pa_sink_set_max_request_within_thread(s, nbytes);
 131 }
 132
 133 static void process_rewind(struct userdata *u, pa_usec_t now) {
 134     size_t rewind_nbytes, in_buffer;
 135     pa_usec_t delay;
 136
 137     pa_assert(u);
 138
 139     rewind_nbytes = u->sink->thread_info.rewind_nbytes;
 140
 141     if (!PA_SINK_IS_OPENED(u->sink->thread_info.state) || rewind_nbytes <= 0)
 142         goto do_nothing;
 143
 144     pa_log_debug("Requested to rewind %lu bytes.", (unsigned long) rewind_nbytes);
 145
 146     if (u->timestamp <= now)
 147         goto do_nothing;
 148
 149     delay = u->timestamp - now;
 150     in_buffer = pa_usec_to_bytes(delay, &u->sink->sample_spec);
 151
 152     if (in_buffer <= 0)
 153         goto do_nothing;
 154
 155     if (rewind_nbytes > in_buffer)
 156         rewind_nbytes = in_buffer;
 157
 158     pa_sink_process_rewind(u->sink, rewind_nbytes);
 159     u->timestamp -= pa_bytes_to_usec(rewind_nbytes, &u->sink->sample_spec);
 160
 161     pa_log_debug("Rewound %lu bytes.", (unsigned long) rewind_nbytes);
 162     return;
 163
 164 do_nothing:
 165
 166     pa_sink_process_rewind(u->sink, 0);
 167 }
 168
 169 static void process_render(struct userdata *u, pa_usec_t now) {
 170     size_t ate = 0;
 171
 172     pa_assert(u);
 173
 174     /* This is the configured latency. Sink inputs connected to us
 175     might not have a single frame more than the maxrequest value
 176     queued. Hence: at maximum read this many bytes from the sink
 177     inputs. */
 178
 179     /* Fill the buffer up the latency size */
 180     while (u->timestamp < now + u->block_usec) {
 181         pa_memchunk chunk;
 182
 183         pa_sink_render(u->sink, u->sink->thread_info.max_request, &chunk);
 184         pa_memblock_unref(chunk.memblock);
 185
 186 /*         pa_log_debug("Ate %lu bytes.", (unsigned long) chunk.length); */
 187         u->timestamp += pa_bytes_to_usec(chunk.length, &u->sink->sample_spec);
 188
 189         ate += chunk.length;
 190
 191         if (ate >= u->sink->thread_info.max_request)
 192             break;
 193     }
 194
 195 /*     pa_log_debug("Ate in sum %lu bytes (of %lu)", (unsigned long) ate, (unsigned long) nbytes); */
 196 }
 197
 198 static void thread_func(void *userdata) {
 199     struct userdata *u = userdata;
 200
 201     pa_assert(u);
 202
 203     pa_log_debug("Thread starting up");
 204
 205     pa_thread_mq_install(&u->thread_mq);
 206
 207     u->timestamp = pa_rtclock_now();
 208
 209     for (;;) {
 210         pa_usec_t now = 0;
 211         int ret;
 212
 213         if (PA_SINK_IS_OPENED(u->sink->thread_info.state))
 214             now = pa_rtclock_now();
 215
 216         if (PA_UNLIKELY(u->sink->thread_info.rewind_requested))
 217             process_rewind(u, now);
 218
 219         /* Render some data and drop it immediately */
 220         if (PA_SINK_IS_OPENED(u->sink->thread_info.state)) {
 221             if (u->timestamp <= now)
 222                 process_render(u, now);
 223
 224             pa_rtpoll_set_timer_absolute(u->rtpoll, u->timestamp);
 225         } else
 226             pa_rtpoll_set_timer_disabled(u->rtpoll);
 227
 228         /* Hmm, nothing to do. Let's sleep */
 229         if ((ret = pa_rtpoll_run(u->rtpoll, true)) < 0)
 230             goto fail;
 231
 232         if (ret == 0)
 233             goto finish;
 234     }
 235
 236 fail:
 237     /* If this was no regular exit from the loop we have to continue
 238      * processing messages until we received PA_MESSAGE_SHUTDOWN */
 239     pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
 240     pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
 241
 242 finish:
 243     pa_log_debug("Thread shutting down");
 244 }
 245
 246 int pa__init(pa_module*m) {
 247     struct userdata *u = NULL;
 248     pa_sample_spec ss;
 249     pa_channel_map map;
 250     pa_modargs *ma = NULL;
 251     pa_sink_new_data data;
 252     size_t nbytes;
 253
 254     pa_assert(m);
 255
 256     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 257         pa_log("Failed to parse module arguments.");
 258         goto fail;
 259     }
 260
 261     ss = m->core->default_sample_spec;
 262     map = m->core->default_channel_map;
 263     if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
 264         pa_log("Invalid sample format specification or channel map");
 265         goto fail;
 266     }
 267
 268     m->userdata = u = pa_xnew0(struct userdata, 1);
 269     u->core = m->core;
 270     u->module = m;
 271     u->rtpoll = pa_rtpoll_new();
 272     pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll);
 273
 274     pa_sink_new_data_init(&data);
 275     data.driver = __FILE__;
 276     data.module = m;
 277     pa_sink_new_data_set_name(&data, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
 278     pa_sink_new_data_set_sample_spec(&data, &ss);
 279     pa_sink_new_data_set_channel_map(&data, &map);
 280     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_DESCRIPTION, _("Null Output"));
 281     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_CLASS, "abstract");
 282
 283     if (pa_modargs_get_proplist(ma, "sink_properties", data.proplist, PA_UPDATE_REPLACE) < 0) {
 284         pa_log("Invalid properties");
 285         pa_sink_new_data_done(&data);
 286         goto fail;
 287     }
 288
 289     u->sink = pa_sink_new(m->core, &data, PA_SINK_LATENCY|PA_SINK_DYNAMIC_LATENCY);
 290     pa_sink_new_data_done(&data);
 291
 292     if (!u->sink) {
 293         pa_log("Failed to create sink object.");
 294         goto fail;
 295     }
 296
 297     u->sink->parent.process_msg = sink_process_msg;
 298     u->sink->update_requested_latency = sink_update_requested_latency_cb;
 299     u->sink->userdata = u;
 300
 301     pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
 302     pa_sink_set_rtpoll(u->sink, u->rtpoll);
 303
 304     u->block_usec = BLOCK_USEC;
 305     nbytes = pa_usec_to_bytes(u->block_usec, &u->sink->sample_spec);
 306     pa_sink_set_max_rewind(u->sink, nbytes);
 307     pa_sink_set_max_request(u->sink, nbytes);
 308
 309     if (!(u->thread = pa_thread_new("null-sink", thread_func, u))) {
 310         pa_log("Failed to create thread.");
 311         goto fail;
 312     }
 313
 314     pa_sink_set_latency_range(u->sink, 0, BLOCK_USEC);
 315
 316     pa_sink_put(u->sink);
 317
 318     pa_modargs_free(ma);
 319
 320     return 0;
 321
 322 fail:
 323     if (ma)
 324         pa_modargs_free(ma);
 325
 326     pa__done(m);
 327
 328     return -1;
 329 }
 330
 331 int pa__get_n_used(pa_module *m) {
 332     struct userdata *u;
 333
 334     pa_assert(m);
 335     pa_assert_se(u = m->userdata);
 336
 337     return pa_sink_linked_by(u->sink);
 338 }
 339
 340 void pa__done(pa_module*m) {
 341     struct userdata *u;
 342
 343     pa_assert(m);
 344
 345     if (!(u = m->userdata))
 346         return;
 347
 348     if (u->sink)
 349         pa_sink_unlink(u->sink);
 350
 351     if (u->thread) {
 352         pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
 353         pa_thread_free(u->thread);
 354     }
 355
 356     pa_thread_mq_done(&u->thread_mq);
 357
 358     if (u->sink)
 359         pa_sink_unref(u->sink);
 360
 361     if (u->rtpoll)
 362         pa_rtpoll_free(u->rtpoll);
 363
 364     pa_xfree(u);
 365 }