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     size_t block_size;
  77
  78     pa_usec_t block_usec;
  79     pa_usec_t timestamp;
  80 };
  81
  82 static const char* const valid_modargs[] = {
  83     "rate",
  84     "format",
  85     "channels",
  86     "sink_name",
  87     "channel_map",
  88     "description",
  89     NULL
  90 };
  91
  92 static int sink_process_msg(pa_msgobject *o, int code, void *data, int64_t offset, pa_memchunk *chunk) {
  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_usec();
 100
 101             break;
 102
 103         case PA_SINK_MESSAGE_GET_LATENCY: {
 104             pa_usec_t now;
 105
 106             now = pa_rtclock_usec();
 107             *((pa_usec_t*) data) = u->timestamp > now ? u->timestamp - now : 0;
 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
 119     pa_sink_assert_ref(s);
 120     u = s->userdata;
 121     pa_assert(u);
 122
 123     u->block_usec = pa_sink_get_requested_latency_within_thread(s);
 124 }
 125
 126 static void process_rewind(struct userdata *u, pa_usec_t now) {
 127     size_t rewind_nbytes, in_buffer;
 128     pa_usec_t delay;
 129
 130     pa_assert(u);
 131
 132     /* Figure out how much we shall rewind and reset the counter */
 133     rewind_nbytes = u->sink->thread_info.rewind_nbytes;
 134     u->sink->thread_info.rewind_nbytes = 0;
 135
 136     pa_assert(rewind_nbytes > 0);
 137     pa_log_debug("Requested to rewind %lu bytes.", (unsigned long) rewind_nbytes);
 138
 139     if (u->timestamp <= now)
 140         return;
 141
 142     delay = u->timestamp - now;
 143     in_buffer = pa_usec_to_bytes(delay, &u->sink->sample_spec);
 144
 145     if (in_buffer <= 0)
 146         return;
 147
 148     if (rewind_nbytes > in_buffer)
 149         rewind_nbytes = in_buffer;
 150
 151     pa_sink_process_rewind(u->sink, rewind_nbytes);
 152     u->timestamp -= pa_bytes_to_usec(rewind_nbytes, &u->sink->sample_spec);
 153
 154     pa_log_debug("Rewound %lu bytes.", (unsigned long) rewind_nbytes);
 155 }
 156
 157 static void process_render(struct userdata *u, pa_usec_t now) {
 158     size_t ate = 0;
 159
 160     pa_assert(u);
 161
 162     /* This is the configured latency. Sink inputs connected to us
 163     might not have a single frame more than the maxrequest value
 164     queed. Hence: at maximum read this many bytes from the sink
 165     inputs. */
 166
 167     /* Fill the buffer up the the latency size */
 168     while (u->timestamp < now + u->block_usec) {
 169         pa_memchunk chunk;
 170
 171         pa_sink_render(u->sink, u->sink->thread_info.max_request, &chunk);
 172         pa_memblock_unref(chunk.memblock);
 173
 174 /*         pa_log_debug("Ate %lu bytes.", (unsigned long) chunk.length); */
 175         u->timestamp += pa_bytes_to_usec(chunk.length, &u->sink->sample_spec);
 176
 177         ate += chunk.length;
 178
 179         if (ate >= u->sink->thread_info.max_request)
 180             break;
 181     }
 182
 183 /*     pa_log_debug("Ate in sum %lu bytes (of %lu)", (unsigned long) ate, (unsigned long) nbytes); */
 184 }
 185
 186 static void thread_func(void *userdata) {
 187     struct userdata *u = userdata;
 188
 189     pa_assert(u);
 190
 191     pa_log_debug("Thread starting up");
 192
 193     pa_thread_mq_install(&u->thread_mq);
 194     pa_rtpoll_install(u->rtpoll);
 195
 196     u->timestamp = pa_rtclock_usec();
 197
 198     for (;;) {
 199         int ret;
 200
 201         /* Render some data and drop it immediately */
 202         if (PA_SINK_IS_OPENED(u->sink->thread_info.state)) {
 203             pa_usec_t now;
 204
 205             now = pa_rtclock_usec();
 206
 207             if (u->sink->thread_info.rewind_nbytes > 0)
 208                 process_rewind(u, now);
 209
 210             if (u->timestamp <= now)
 211                 process_render(u, now);
 212
 213             pa_rtpoll_set_timer_absolute(u->rtpoll, u->timestamp);
 214         } else
 215             pa_rtpoll_set_timer_disabled(u->rtpoll);
 216
 217         /* Hmm, nothing to do. Let's sleep */
 218         if ((ret = pa_rtpoll_run(u->rtpoll, TRUE)) < 0)
 219             goto fail;
 220
 221         if (ret == 0)
 222             goto finish;
 223     }
 224
 225 fail:
 226     /* If this was no regular exit from the loop we have to continue
 227      * processing messages until we received PA_MESSAGE_SHUTDOWN */
 228     pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
 229     pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
 230
 231 finish:
 232     pa_log_debug("Thread shutting down");
 233 }
 234
 235 int pa__init(pa_module*m) {
 236     struct userdata *u = NULL;
 237     pa_sample_spec ss;
 238     pa_channel_map map;
 239     pa_modargs *ma = NULL;
 240     pa_sink_new_data data;
 241
 242     pa_assert(m);
 243
 244     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 245         pa_log("Failed to parse module arguments.");
 246         goto fail;
 247     }
 248
 249     ss = m->core->default_sample_spec;
 250     if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
 251         pa_log("Invalid sample format specification or channel map");
 252         goto fail;
 253     }
 254
 255     m->userdata = u = pa_xnew0(struct userdata, 1);
 256     u->core = m->core;
 257     u->module = m;
 258     u->rtpoll = pa_rtpoll_new();
 259     pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll);
 260
 261     pa_sink_new_data_init(&data);
 262     data.driver = __FILE__;
 263     data.module = m;
 264     pa_sink_new_data_set_name(&data, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
 265     pa_sink_new_data_set_sample_spec(&data, &ss);
 266     pa_sink_new_data_set_channel_map(&data, &map);
 267     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_DESCRIPTION, pa_modargs_get_value(ma, "description", "Null Output"));
 268     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_CLASS, "abstract");
 269
 270     u->sink = pa_sink_new(m->core, &data, PA_SINK_LATENCY);
 271     pa_sink_new_data_done(&data);
 272
 273     if (!u->sink) {
 274         pa_log("Failed to create sink object.");
 275         goto fail;
 276     }
 277
 278     u->sink->parent.process_msg = sink_process_msg;
 279     u->sink->update_requested_latency = sink_update_requested_latency_cb;
 280     u->sink->userdata = u;
 281
 282     pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
 283     pa_sink_set_rtpoll(u->sink, u->rtpoll);
 284
 285     pa_sink_set_latency_range(u->sink, (pa_usec_t) -1, MAX_LATENCY_USEC);
 286     u->block_usec = u->sink->thread_info.max_latency;
 287
 288     u->sink->thread_info.max_rewind =
 289         u->sink->thread_info.max_request =
 290         pa_usec_to_bytes(u->block_usec, &u->sink->sample_spec);
 291
 292     if (!(u->thread = pa_thread_new(thread_func, u))) {
 293         pa_log("Failed to create thread.");
 294         goto fail;
 295     }
 296
 297     pa_sink_put(u->sink);
 298
 299     pa_modargs_free(ma);
 300
 301     return 0;
 302
 303 fail:
 304     if (ma)
 305         pa_modargs_free(ma);
 306
 307     pa__done(m);
 308
 309     return -1;
 310 }
 311
 312 void pa__done(pa_module*m) {
 313     struct userdata *u;
 314
 315     pa_assert(m);
 316
 317     if (!(u = m->userdata))
 318         return;
 319
 320     if (u->sink)
 321         pa_sink_unlink(u->sink);
 322
 323     if (u->thread) {
 324         pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
 325         pa_thread_free(u->thread);
 326     }
 327
 328     pa_thread_mq_done(&u->thread_mq);
 329
 330     if (u->sink)
 331         pa_sink_unref(u->sink);
 332
 333     if (u->rtpoll)
 334         pa_rtpoll_free(u->rtpoll);
 335
 336     pa_xfree(u);
 337 }