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 #include <pulse/i18n.h>
  35
  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     "description", /* supported for compatibility reasons, made redundant by sink_properties= */
  84     NULL
  85 };
  86
  87 static int sink_process_msg(
  88         pa_msgobject *o,
  89         int code,
  90         void *data,
  91         int64_t offset,
  92         pa_memchunk *chunk) {
  93
  94     struct userdata *u = PA_SINK(o)->userdata;
  95
  96     switch (code) {
  97         case PA_SINK_MESSAGE_SET_STATE:
  98
  99             if (PA_PTR_TO_UINT(data) == PA_SINK_RUNNING)
 100                 u->timestamp = pa_rtclock_now();
 101
 102             break;
 103
 104         case PA_SINK_MESSAGE_GET_LATENCY: {
 105             pa_usec_t now;
 106
 107             now = pa_rtclock_now();
 108             *((pa_usec_t*) data) = u->timestamp > now ? u->timestamp - now : 0ULL;
 109
 110             return 0;
 111         }
 112     }
 113
 114     return pa_sink_process_msg(o, code, data, offset, chunk);
 115 }
 116
 117 static void sink_update_requested_latency_cb(pa_sink *s) {
 118     struct userdata *u;
 119     size_t nbytes;
 120
 121     pa_sink_assert_ref(s);
 122     pa_assert_se(u = s->userdata);
 123
 124     u->block_usec = pa_sink_get_requested_latency_within_thread(s);
 125
 126     if (u->block_usec == (pa_usec_t) -1)
 127         u->block_usec = s->thread_info.max_latency;
 128
 129     nbytes = pa_usec_to_bytes(u->block_usec, &s->sample_spec);
 130     pa_sink_set_max_rewind_within_thread(s, nbytes);
 131     pa_sink_set_max_request_within_thread(s, nbytes);
 132 }
 133
 134 static void process_rewind(struct userdata *u, pa_usec_t now) {
 135     size_t rewind_nbytes, in_buffer;
 136     pa_usec_t delay;
 137
 138     pa_assert(u);
 139
 140     /* Figure out how much we shall rewind and reset the counter */
 141     rewind_nbytes = u->sink->thread_info.rewind_nbytes;
 142     u->sink->thread_info.rewind_nbytes = 0;
 143
 144     pa_assert(rewind_nbytes > 0);
 145     pa_log_debug("Requested to rewind %lu bytes.", (unsigned long) rewind_nbytes);
 146
 147     if (u->timestamp <= now)
 148         goto do_nothing;
 149
 150     delay = u->timestamp - now;
 151     in_buffer = pa_usec_to_bytes(delay, &u->sink->sample_spec);
 152
 153     if (in_buffer <= 0)
 154         goto do_nothing;
 155
 156     if (rewind_nbytes > in_buffer)
 157         rewind_nbytes = in_buffer;
 158
 159     pa_sink_process_rewind(u->sink, rewind_nbytes);
 160     u->timestamp -= pa_bytes_to_usec(rewind_nbytes, &u->sink->sample_spec);
 161
 162     pa_log_debug("Rewound %lu bytes.", (unsigned long) rewind_nbytes);
 163     return;
 164
 165 do_nothing:
 166
 167     pa_sink_process_rewind(u->sink, 0);
 168 }
 169
 170 static void process_render(struct userdata *u, pa_usec_t now) {
 171     size_t ate = 0;
 172
 173     pa_assert(u);
 174
 175     /* This is the configured latency. Sink inputs connected to us
 176     might not have a single frame more than the maxrequest value
 177     queed. Hence: at maximum read this many bytes from the sink
 178     inputs. */
 179
 180     /* Fill the buffer up the the latency size */
 181     while (u->timestamp < now + u->block_usec) {
 182         pa_memchunk chunk;
 183
 184         pa_sink_render(u->sink, u->sink->thread_info.max_request, &chunk);
 185         pa_memblock_unref(chunk.memblock);
 186
 187 /*         pa_log_debug("Ate %lu bytes.", (unsigned long) chunk.length); */
 188         u->timestamp += pa_bytes_to_usec(chunk.length, &u->sink->sample_spec);
 189
 190         ate += chunk.length;
 191
 192         if (ate >= u->sink->thread_info.max_request)
 193             break;
 194     }
 195
 196 /*     pa_log_debug("Ate in sum %lu bytes (of %lu)", (unsigned long) ate, (unsigned long) nbytes); */
 197 }
 198
 199 static void thread_func(void *userdata) {
 200     struct userdata *u = userdata;
 201
 202     pa_assert(u);
 203
 204     pa_log_debug("Thread starting up");
 205
 206     pa_thread_mq_install(&u->thread_mq);
 207
 208     u->timestamp = pa_rtclock_now();
 209
 210     for (;;) {
 211         int ret;
 212
 213         /* Render some data and drop it immediately */
 214         if (PA_SINK_IS_OPENED(u->sink->thread_info.state)) {
 215             pa_usec_t now;
 216
 217             now = pa_rtclock_now();
 218
 219             if (u->sink->thread_info.rewind_requested) {
 220                 if (u->sink->thread_info.rewind_nbytes > 0)
 221                     process_rewind(u, now);
 222                 else
 223                     pa_sink_process_rewind(u->sink, 0);
 224             }
 225
 226             if (u->timestamp <= now)
 227                 process_render(u, now);
 228
 229             pa_rtpoll_set_timer_absolute(u->rtpoll, u->timestamp);
 230         } else
 231             pa_rtpoll_set_timer_disabled(u->rtpoll);
 232
 233         /* Hmm, nothing to do. Let's sleep */
 234         if ((ret = pa_rtpoll_run(u->rtpoll, TRUE)) < 0)
 235             goto fail;
 236
 237         if (ret == 0)
 238             goto finish;
 239     }
 240
 241 fail:
 242     /* If this was no regular exit from the loop we have to continue
 243      * processing messages until we received PA_MESSAGE_SHUTDOWN */
 244     pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
 245     pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
 246
 247 finish:
 248     pa_log_debug("Thread shutting down");
 249 }
 250
 251 int pa__init(pa_module*m) {
 252     struct userdata *u = NULL;
 253     pa_sample_spec ss;
 254     pa_channel_map map;
 255     pa_modargs *ma = NULL;
 256     pa_sink_new_data data;
 257     size_t nbytes;
 258
 259     pa_assert(m);
 260
 261     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 262         pa_log("Failed to parse module arguments.");
 263         goto fail;
 264     }
 265
 266     ss = m->core->default_sample_spec;
 267     map = m->core->default_channel_map;
 268     if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
 269         pa_log("Invalid sample format specification or channel map");
 270         goto fail;
 271     }
 272
 273     m->userdata = u = pa_xnew0(struct userdata, 1);
 274     u->core = m->core;
 275     u->module = m;
 276     u->rtpoll = pa_rtpoll_new();
 277     pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll);
 278
 279     pa_sink_new_data_init(&data);
 280     data.driver = __FILE__;
 281     data.module = m;
 282     pa_sink_new_data_set_name(&data, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
 283     pa_sink_new_data_set_sample_spec(&data, &ss);
 284     pa_sink_new_data_set_channel_map(&data, &map);
 285     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_DESCRIPTION, pa_modargs_get_value(ma, "description", _("Null Output")));
 286     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_CLASS, "abstract");
 287
 288     if (pa_modargs_get_proplist(ma, "sink_properties", data.proplist, PA_UPDATE_REPLACE) < 0) {
 289         pa_log("Invalid properties");
 290         pa_sink_new_data_done(&data);
 291         goto fail;
 292     }
 293
 294     u->sink = pa_sink_new(m->core, &data, PA_SINK_LATENCY|PA_SINK_DYNAMIC_LATENCY);
 295     pa_sink_new_data_done(&data);
 296
 297     if (!u->sink) {
 298         pa_log("Failed to create sink object.");
 299         goto fail;
 300     }
 301
 302     u->sink->parent.process_msg = sink_process_msg;
 303     u->sink->update_requested_latency = sink_update_requested_latency_cb;
 304     u->sink->userdata = u;
 305
 306     pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
 307     pa_sink_set_rtpoll(u->sink, u->rtpoll);
 308
 309     u->block_usec = BLOCK_USEC;
 310     nbytes = pa_usec_to_bytes(u->block_usec, &u->sink->sample_spec);
 311     pa_sink_set_max_rewind(u->sink, nbytes);
 312     pa_sink_set_max_request(u->sink, nbytes);
 313
 314     if (!(u->thread = pa_thread_new("null-sink", thread_func, u))) {
 315         pa_log("Failed to create thread.");
 316         goto fail;
 317     }
 318
 319     pa_sink_put(u->sink);
 320
 321     pa_modargs_free(ma);
 322
 323     return 0;
 324
 325 fail:
 326     if (ma)
 327         pa_modargs_free(ma);
 328
 329     pa__done(m);
 330
 331     return -1;
 332 }
 333
 334 int pa__get_n_used(pa_module *m) {
 335     struct userdata *u;
 336
 337     pa_assert(m);
 338     pa_assert_se(u = m->userdata);
 339
 340     return pa_sink_linked_by(u->sink);
 341 }
 342
 343 void pa__done(pa_module*m) {
 344     struct userdata *u;
 345
 346     pa_assert(m);
 347
 348     if (!(u = m->userdata))
 349         return;
 350
 351     if (u->sink)
 352         pa_sink_unlink(u->sink);
 353
 354     if (u->thread) {
 355         pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
 356         pa_thread_free(u->thread);
 357     }
 358
 359     pa_thread_mq_done(&u->thread_mq);
 360
 361     if (u->sink)
 362         pa_sink_unref(u->sink);
 363
 364     if (u->rtpoll)
 365         pa_rtpoll_free(u->rtpoll);
 366
 367     pa_xfree(u);
 368 }