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/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         "sink_name=<name of sink> "
  58         "sink_properties=<properties for the sink> "
  59         "format=<sample format> "
  60         "rate=<sample rate> "
  61         "channels=<number of channels> "
  62         "channel_map=<channel map>");
  63
  64 #define DEFAULT_SINK_NAME "null"
  65 #define BLOCK_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     "sink_name",
  82     "sink_properties",
  83     "format",
  84     "rate",
  85     "channels",
  86     "channel_map",
  87     "description", /* supported for compatibility reasons, made redundant by sink_properties= */
  88     NULL
  89 };
  90
  91 static int sink_process_msg(
  92         pa_msgobject *o,
  93         int code,
  94         void *data,
  95         int64_t offset,
  96         pa_memchunk *chunk) {
  97
  98     struct userdata *u = PA_SINK(o)->userdata;
  99
 100     switch (code) {
 101         case PA_SINK_MESSAGE_SET_STATE:
 102
 103             if (PA_PTR_TO_UINT(data) == PA_SINK_RUNNING)
 104                 u->timestamp = pa_rtclock_usec();
 105
 106             break;
 107
 108         case PA_SINK_MESSAGE_GET_LATENCY: {
 109             pa_usec_t now;
 110
 111             now = pa_rtclock_usec();
 112             *((pa_usec_t*) data) = u->timestamp > now ? u->timestamp - now : 0ULL;
 113
 114             return 0;
 115         }
 116     }
 117
 118     return pa_sink_process_msg(o, code, data, offset, chunk);
 119 }
 120
 121 static void sink_update_requested_latency_cb(pa_sink *s) {
 122     struct userdata *u;
 123     size_t nbytes;
 124
 125     pa_sink_assert_ref(s);
 126     pa_assert_se(u = s->userdata);
 127
 128     u->block_usec = pa_sink_get_requested_latency_within_thread(s);
 129
 130     if (u->block_usec == (pa_usec_t) -1)
 131         u->block_usec = s->thread_info.max_latency;
 132
 133     nbytes = pa_usec_to_bytes(u->block_usec, &s->sample_spec);
 134     pa_sink_set_max_rewind_within_thread(s, nbytes);
 135     pa_sink_set_max_request_within_thread(s, nbytes);
 136 }
 137
 138 static void process_rewind(struct userdata *u, pa_usec_t now) {
 139     size_t rewind_nbytes, in_buffer;
 140     pa_usec_t delay;
 141
 142     pa_assert(u);
 143
 144     /* Figure out how much we shall rewind and reset the counter */
 145     rewind_nbytes = u->sink->thread_info.rewind_nbytes;
 146     u->sink->thread_info.rewind_nbytes = 0;
 147
 148     pa_assert(rewind_nbytes > 0);
 149     pa_log_debug("Requested to rewind %lu bytes.", (unsigned long) rewind_nbytes);
 150
 151     if (u->timestamp <= now)
 152         goto do_nothing;
 153
 154     delay = u->timestamp - now;
 155     in_buffer = pa_usec_to_bytes(delay, &u->sink->sample_spec);
 156
 157     if (in_buffer <= 0)
 158         goto do_nothing;
 159
 160     if (rewind_nbytes > in_buffer)
 161         rewind_nbytes = in_buffer;
 162
 163     pa_sink_process_rewind(u->sink, rewind_nbytes);
 164     u->timestamp -= pa_bytes_to_usec(rewind_nbytes, &u->sink->sample_spec);
 165
 166     pa_log_debug("Rewound %lu bytes.", (unsigned long) rewind_nbytes);
 167     return;
 168
 169 do_nothing:
 170
 171     pa_sink_process_rewind(u->sink, 0);
 172 }
 173
 174 static void process_render(struct userdata *u, pa_usec_t now) {
 175     size_t ate = 0;
 176
 177     pa_assert(u);
 178
 179     /* This is the configured latency. Sink inputs connected to us
 180     might not have a single frame more than the maxrequest value
 181     queed. Hence: at maximum read this many bytes from the sink
 182     inputs. */
 183
 184     /* Fill the buffer up the the latency size */
 185     while (u->timestamp < now + u->block_usec) {
 186         pa_memchunk chunk;
 187
 188         pa_sink_render(u->sink, u->sink->thread_info.max_request, &chunk);
 189         pa_memblock_unref(chunk.memblock);
 190
 191 /*         pa_log_debug("Ate %lu bytes.", (unsigned long) chunk.length); */
 192         u->timestamp += pa_bytes_to_usec(chunk.length, &u->sink->sample_spec);
 193
 194         ate += chunk.length;
 195
 196         if (ate >= u->sink->thread_info.max_request)
 197             break;
 198     }
 199
 200 /*     pa_log_debug("Ate in sum %lu bytes (of %lu)", (unsigned long) ate, (unsigned long) nbytes); */
 201 }
 202
 203 static void thread_func(void *userdata) {
 204     struct userdata *u = userdata;
 205
 206     pa_assert(u);
 207
 208     pa_log_debug("Thread starting up");
 209
 210     pa_thread_mq_install(&u->thread_mq);
 211
 212     u->timestamp = pa_rtclock_usec();
 213
 214     for (;;) {
 215         int ret;
 216
 217         /* Render some data and drop it immediately */
 218         if (PA_SINK_IS_OPENED(u->sink->thread_info.state)) {
 219             pa_usec_t now;
 220
 221             now = pa_rtclock_usec();
 222
 223             if (u->sink->thread_info.rewind_requested) {
 224                 if (u->sink->thread_info.rewind_nbytes > 0)
 225                     process_rewind(u, now);
 226                 else
 227                     pa_sink_process_rewind(u->sink, 0);
 228             }
 229
 230             if (u->timestamp <= now)
 231                 process_render(u, now);
 232
 233             pa_rtpoll_set_timer_absolute(u->rtpoll, u->timestamp);
 234         } else
 235             pa_rtpoll_set_timer_disabled(u->rtpoll);
 236
 237         /* Hmm, nothing to do. Let's sleep */
 238         if ((ret = pa_rtpoll_run(u->rtpoll, TRUE)) < 0)
 239             goto fail;
 240
 241         if (ret == 0)
 242             goto finish;
 243     }
 244
 245 fail:
 246     /* If this was no regular exit from the loop we have to continue
 247      * processing messages until we received PA_MESSAGE_SHUTDOWN */
 248     pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
 249     pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
 250
 251 finish:
 252     pa_log_debug("Thread shutting down");
 253 }
 254
 255 int pa__init(pa_module*m) {
 256     struct userdata *u = NULL;
 257     pa_sample_spec ss;
 258     pa_channel_map map;
 259     pa_modargs *ma = NULL;
 260     pa_sink_new_data data;
 261     size_t nbytes;
 262
 263     pa_assert(m);
 264
 265     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 266         pa_log("Failed to parse module arguments.");
 267         goto fail;
 268     }
 269
 270     ss = m->core->default_sample_spec;
 271     map = m->core->default_channel_map;
 272     if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
 273         pa_log("Invalid sample format specification or channel map");
 274         goto fail;
 275     }
 276
 277     m->userdata = u = pa_xnew0(struct userdata, 1);
 278     u->core = m->core;
 279     u->module = m;
 280     u->rtpoll = pa_rtpoll_new();
 281     pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll);
 282
 283     pa_sink_new_data_init(&data);
 284     data.driver = __FILE__;
 285     data.module = m;
 286     pa_sink_new_data_set_name(&data, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
 287     pa_sink_new_data_set_sample_spec(&data, &ss);
 288     pa_sink_new_data_set_channel_map(&data, &map);
 289     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_DESCRIPTION, pa_modargs_get_value(ma, "description", "Null Output"));
 290     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_CLASS, "abstract");
 291
 292     if (pa_modargs_get_proplist(ma, "sink_properties", data.proplist, PA_UPDATE_REPLACE) < 0) {
 293         pa_log("Invalid properties");
 294         pa_sink_new_data_done(&data);
 295         goto fail;
 296     }
 297
 298     u->sink = pa_sink_new(m->core, &data, PA_SINK_LATENCY|PA_SINK_DYNAMIC_LATENCY);
 299     pa_sink_new_data_done(&data);
 300
 301     if (!u->sink) {
 302         pa_log("Failed to create sink object.");
 303         goto fail;
 304     }
 305
 306     u->sink->parent.process_msg = sink_process_msg;
 307     u->sink->update_requested_latency = sink_update_requested_latency_cb;
 308     u->sink->userdata = u;
 309
 310     pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
 311     pa_sink_set_rtpoll(u->sink, u->rtpoll);
 312
 313     u->block_usec = BLOCK_USEC;
 314     nbytes = pa_usec_to_bytes(u->block_usec, &u->sink->sample_spec);
 315     pa_sink_set_max_rewind(u->sink, nbytes);
 316     pa_sink_set_max_request(u->sink, nbytes);
 317
 318     if (!(u->thread = pa_thread_new(thread_func, u))) {
 319         pa_log("Failed to create thread.");
 320         goto fail;
 321     }
 322
 323     pa_sink_put(u->sink);
 324
 325     pa_modargs_free(ma);
 326
 327     return 0;
 328
 329 fail:
 330     if (ma)
 331         pa_modargs_free(ma);
 332
 333     pa__done(m);
 334
 335     return -1;
 336 }
 337
 338 int pa__get_n_used(pa_module *m) {
 339     struct userdata *u;
 340
 341     pa_assert(m);
 342     pa_assert_se(u = m->userdata);
 343
 344     return pa_sink_linked_by(u->sink);
 345 }
 346
 347 void pa__done(pa_module*m) {
 348     struct userdata *u;
 349
 350     pa_assert(m);
 351
 352     if (!(u = m->userdata))
 353         return;
 354
 355     if (u->sink)
 356         pa_sink_unlink(u->sink);
 357
 358     if (u->thread) {
 359         pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
 360         pa_thread_free(u->thread);
 361     }
 362
 363     pa_thread_mq_done(&u->thread_mq);
 364
 365     if (u->sink)
 366         pa_sink_unref(u->sink);
 367
 368     if (u->rtpoll)
 369         pa_rtpoll_free(u->rtpoll);
 370
 371     pa_xfree(u);
 372 }