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 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/timeval.h>
  36 #include <pulse/xmalloc.h>
  37
  38 #include <pulsecore/macro.h>
  39 #include <pulsecore/sink.h>
  40 #include <pulsecore/module.h>
  41 #include <pulsecore/core-util.h>
  42 #include <pulsecore/core-error.h>
  43 #include <pulsecore/modargs.h>
  44 #include <pulsecore/log.h>
  45 #include <pulsecore/thread.h>
  46 #include <pulsecore/thread-mq.h>
  47 #include <pulsecore/rtpoll.h>
  48 #include <pulsecore/rtclock.h>
  49
  50 #include "module-null-sink-symdef.h"
  51
  52 PA_MODULE_AUTHOR("Lennart Poettering");
  53 PA_MODULE_DESCRIPTION("Clocked NULL sink");
  54 PA_MODULE_VERSION(PACKAGE_VERSION);
  55 PA_MODULE_LOAD_ONCE(FALSE);
  56 PA_MODULE_USAGE(
  57         "format=<sample format> "
  58         "channels=<number of channels> "
  59         "rate=<sample rate> "
  60         "sink_name=<name of sink> "
  61         "channel_map=<channel map> "
  62         "description=<description for the sink>");
  63
  64 #define DEFAULT_SINK_NAME "null"
  65 #define MAX_LATENCY_USEC (PA_USEC_PER_SEC * 2)
  66
  67 struct userdata {
  68     pa_core *core;
  69     pa_module *module;
  70     pa_sink *sink;
  71
  72     pa_thread *thread;
  73     pa_thread_mq thread_mq;
  74     pa_rtpoll *rtpoll;
  75
  76     pa_usec_t block_usec;
  77     pa_usec_t timestamp;
  78 };
  79
  80 static const char* const valid_modargs[] = {
  81     "rate",
  82     "format",
  83     "channels",
  84     "sink_name",
  85     "channel_map",
  86     "description",
  87     NULL
  88 };
  89
  90 static int sink_process_msg(
  91         pa_msgobject *o,
  92         int code,
  93         void *data,
  94         int64_t offset,
  95         pa_memchunk *chunk) {
  96
  97     struct userdata *u = PA_SINK(o)->userdata;
  98
  99     switch (code) {
 100         case PA_SINK_MESSAGE_SET_STATE:
 101
 102             if (PA_PTR_TO_UINT(data) == PA_SINK_RUNNING)
 103                 u->timestamp = pa_rtclock_usec();
 104
 105             break;
 106
 107         case PA_SINK_MESSAGE_GET_LATENCY: {
 108             pa_usec_t now;
 109
 110             now = pa_rtclock_usec();
 111             *((pa_usec_t*) data) = u->timestamp > now ? u->timestamp - now : 0ULL;
 112
 113             return 0;
 114         }
 115     }
 116
 117     return pa_sink_process_msg(o, code, data, offset, chunk);
 118 }
 119
 120 static void sink_update_requested_latency_cb(pa_sink *s) {
 121     struct userdata *u;
 122
 123     pa_sink_assert_ref(s);
 124     pa_assert_se(u = s->userdata);
 125
 126     u->block_usec = pa_sink_get_requested_latency_within_thread(s);
 127
 128     if (u->block_usec == (pa_usec_t) -1)
 129         u->block_usec = s->thread_info.max_latency;
 130 }
 131
 132 static void process_rewind(struct userdata *u, pa_usec_t now) {
 133     size_t rewind_nbytes, in_buffer;
 134     pa_usec_t delay;
 135
 136     pa_assert(u);
 137
 138     /* Figure out how much we shall rewind and reset the counter */
 139     rewind_nbytes = u->sink->thread_info.rewind_nbytes;
 140     u->sink->thread_info.rewind_nbytes = 0;
 141
 142     pa_assert(rewind_nbytes > 0);
 143     pa_log_debug("Requested to rewind %lu bytes.", (unsigned long) rewind_nbytes);
 144
 145     if (u->timestamp <= now)
 146         goto do_nothing;
 147
 148     delay = u->timestamp - now;
 149     in_buffer = pa_usec_to_bytes(delay, &u->sink->sample_spec);
 150
 151     if (in_buffer <= 0)
 152         goto do_nothing;
 153
 154     if (rewind_nbytes > in_buffer)
 155         rewind_nbytes = in_buffer;
 156
 157     pa_sink_process_rewind(u->sink, rewind_nbytes);
 158     u->timestamp -= pa_bytes_to_usec(rewind_nbytes, &u->sink->sample_spec);
 159
 160     pa_log_debug("Rewound %lu bytes.", (unsigned long) rewind_nbytes);
 161     return;
 162
 163 do_nothing:
 164
 165     pa_sink_process_rewind(u->sink, 0);
 166 }
 167
 168 static void process_render(struct userdata *u, pa_usec_t now) {
 169     size_t ate = 0;
 170
 171     pa_assert(u);
 172
 173     /* This is the configured latency. Sink inputs connected to us
 174     might not have a single frame more than the maxrequest value
 175     queed. Hence: at maximum read this many bytes from the sink
 176     inputs. */
 177
 178     /* Fill the buffer up the the latency size */
 179     while (u->timestamp < now + u->block_usec) {
 180         pa_memchunk chunk;
 181
 182         pa_sink_render(u->sink, u->sink->thread_info.max_request, &chunk);
 183         pa_memblock_unref(chunk.memblock);
 184
 185 /*         pa_log_debug("Ate %lu bytes.", (unsigned long) chunk.length); */
 186         u->timestamp += pa_bytes_to_usec(chunk.length, &u->sink->sample_spec);
 187
 188         ate += chunk.length;
 189
 190         if (ate >= u->sink->thread_info.max_request)
 191             break;
 192     }
 193
 194 /*     pa_log_debug("Ate in sum %lu bytes (of %lu)", (unsigned long) ate, (unsigned long) nbytes); */
 195 }
 196
 197 static void thread_func(void *userdata) {
 198     struct userdata *u = userdata;
 199
 200     pa_assert(u);
 201
 202     pa_log_debug("Thread starting up");
 203
 204     pa_thread_mq_install(&u->thread_mq);
 205     pa_rtpoll_install(u->rtpoll);
 206
 207     u->timestamp = pa_rtclock_usec();
 208
 209     for (;;) {
 210         int ret;
 211
 212         /* Render some data and drop it immediately */
 213         if (PA_SINK_IS_OPENED(u->sink->thread_info.state)) {
 214             pa_usec_t now;
 215
 216             now = pa_rtclock_usec();
 217
 218             if (u->sink->thread_info.rewind_requested) {
 219                 if (u->sink->thread_info.rewind_nbytes > 0)
 220                     process_rewind(u, now);
 221                 else
 222                     pa_sink_process_rewind(u->sink, 0);
 223             }
 224
 225             if (u->timestamp <= now)
 226                 process_render(u, now);
 227
 228             pa_rtpoll_set_timer_absolute(u->rtpoll, u->timestamp);
 229         } else
 230             pa_rtpoll_set_timer_disabled(u->rtpoll);
 231
 232         /* Hmm, nothing to do. Let's sleep */
 233         if ((ret = pa_rtpoll_run(u->rtpoll, TRUE)) < 0)
 234             goto fail;
 235
 236         if (ret == 0)
 237             goto finish;
 238     }
 239
 240 fail:
 241     /* If this was no regular exit from the loop we have to continue
 242      * processing messages until we received PA_MESSAGE_SHUTDOWN */
 243     pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
 244     pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
 245
 246 finish:
 247     pa_log_debug("Thread shutting down");
 248 }
 249
 250 int pa__init(pa_module*m) {
 251     struct userdata *u = NULL;
 252     pa_sample_spec ss;
 253     pa_channel_map map;
 254     pa_modargs *ma = NULL;
 255     pa_sink_new_data data;
 256
 257     pa_assert(m);
 258
 259     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 260         pa_log("Failed to parse module arguments.");
 261         goto fail;
 262     }
 263
 264     ss = m->core->default_sample_spec;
 265     map = m->core->default_channel_map;
 266     if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
 267         pa_log("Invalid sample format specification or channel map");
 268         goto fail;
 269     }
 270
 271     m->userdata = u = pa_xnew0(struct userdata, 1);
 272     u->core = m->core;
 273     u->module = m;
 274     u->rtpoll = pa_rtpoll_new();
 275     pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll);
 276
 277     pa_sink_new_data_init(&data);
 278     data.driver = __FILE__;
 279     data.module = m;
 280     pa_sink_new_data_set_name(&data, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
 281     pa_sink_new_data_set_sample_spec(&data, &ss);
 282     pa_sink_new_data_set_channel_map(&data, &map);
 283     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_DESCRIPTION, pa_modargs_get_value(ma, "description", "Null Output"));
 284     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_CLASS, "abstract");
 285
 286     u->sink = pa_sink_new(m->core, &data, PA_SINK_LATENCY);
 287     pa_sink_new_data_done(&data);
 288
 289     if (!u->sink) {
 290         pa_log("Failed to create sink object.");
 291         goto fail;
 292     }
 293
 294     u->sink->parent.process_msg = sink_process_msg;
 295     u->sink->update_requested_latency = sink_update_requested_latency_cb;
 296     u->sink->userdata = u;
 297
 298     pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
 299     pa_sink_set_rtpoll(u->sink, u->rtpoll);
 300
 301     pa_sink_set_latency_range(u->sink, (pa_usec_t) -1, MAX_LATENCY_USEC);
 302     u->block_usec = u->sink->thread_info.max_latency;
 303
 304     u->sink->thread_info.max_rewind =
 305         u->sink->thread_info.max_request =
 306         pa_usec_to_bytes(u->block_usec, &u->sink->sample_spec);
 307
 308     if (!(u->thread = pa_thread_new(thread_func, u))) {
 309         pa_log("Failed to create thread.");
 310         goto fail;
 311     }
 312
 313     pa_sink_put(u->sink);
 314
 315     pa_modargs_free(ma);
 316
 317     return 0;
 318
 319 fail:
 320     if (ma)
 321         pa_modargs_free(ma);
 322
 323     pa__done(m);
 324
 325     return -1;
 326 }
 327
 328 int pa__get_n_used(pa_module *m) {
 329     struct userdata *u;
 330
 331     pa_assert(m);
 332     pa_assert_se(u = m->userdata);
 333
 334     return pa_sink_linked_by(u->sink);
 335 }
 336
 337 void pa__done(pa_module*m) {
 338     struct userdata *u;
 339
 340     pa_assert(m);
 341
 342     if (!(u = m->userdata))
 343         return;
 344
 345     if (u->sink)
 346         pa_sink_unlink(u->sink);
 347
 348     if (u->thread) {
 349         pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
 350         pa_thread_free(u->thread);
 351     }
 352
 353     pa_thread_mq_done(&u->thread_mq);
 354
 355     if (u->sink)
 356         pa_sink_unref(u->sink);
 357
 358     if (u->rtpoll)
 359         pa_rtpoll_free(u->rtpoll);
 360
 361     pa_xfree(u);
 362 }