code.delx.au - pulseaudio/blob - src/modules/module-null-sink.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   5
   6   Copyright 2004-2008 Lennart Poettering
   7
   8   PulseAudio is free software; you can redistribute it and/or modify
   9   it under the terms of the GNU Lesser General Public License as published
  10   by the Free Software Foundation; either version 2 of the License,
  11   or (at your option) any later version.
  12
  13   PulseAudio is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with PulseAudio; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  21   USA.
  22 ***/
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include <stdlib.h>
  29 #include <sys/stat.h>
  30 #include <stdio.h>
  31 #include <errno.h>
  32 #include <string.h>
  33 #include <fcntl.h>
  34 #include <unistd.h>
  35 #include <limits.h>
  36
  37 #include <pulse/timeval.h>
  38 #include <pulse/xmalloc.h>
  39
  40 #include <pulsecore/macro.h>
  41 #include <pulsecore/sink.h>
  42 #include <pulsecore/module.h>
  43 #include <pulsecore/core-util.h>
  44 #include <pulsecore/core-error.h>
  45 #include <pulsecore/modargs.h>
  46 #include <pulsecore/log.h>
  47 #include <pulsecore/thread.h>
  48 #include <pulsecore/thread-mq.h>
  49 #include <pulsecore/rtpoll.h>
  50 #include <pulsecore/rtclock.h>
  51
  52 #include "module-null-sink-symdef.h"
  53
  54 PA_MODULE_AUTHOR("Lennart Poettering");
  55 PA_MODULE_DESCRIPTION("Clocked NULL sink");
  56 PA_MODULE_VERSION(PACKAGE_VERSION);
  57 PA_MODULE_LOAD_ONCE(FALSE);
  58 PA_MODULE_USAGE(
  59         "format=<sample format> "
  60         "channels=<number of channels> "
  61         "rate=<sample rate> "
  62         "sink_name=<name of sink>"
  63         "channel_map=<channel map>"
  64         "description=<description for the sink>");
  65
  66 #define DEFAULT_SINK_NAME "null"
  67 #define MAX_LATENCY_USEC (PA_USEC_PER_SEC * 2)
  68
  69 struct userdata {
  70     pa_core *core;
  71     pa_module *module;
  72     pa_sink *sink;
  73
  74     pa_thread *thread;
  75     pa_thread_mq thread_mq;
  76     pa_rtpoll *rtpoll;
  77
  78     size_t block_size;
  79
  80     pa_usec_t block_usec;
  81     pa_usec_t timestamp;
  82 };
  83
  84 static const char* const valid_modargs[] = {
  85     "rate",
  86     "format",
  87     "channels",
  88     "sink_name",
  89     "channel_map",
  90     "description",
  91     NULL
  92 };
  93
  94 static int sink_process_msg(pa_msgobject *o, int code, void *data, int64_t offset, pa_memchunk *chunk) {
  95     struct userdata *u = PA_SINK(o)->userdata;
  96
  97     switch (code) {
  98         case PA_SINK_MESSAGE_SET_STATE:
  99
 100             if (PA_PTR_TO_UINT(data) == PA_SINK_RUNNING)
 101                 u->timestamp = pa_rtclock_usec();
 102
 103             break;
 104
 105         case PA_SINK_MESSAGE_GET_LATENCY: {
 106             pa_usec_t now;
 107
 108             now = pa_rtclock_usec();
 109             *((pa_usec_t*) data) = u->timestamp > now ? u->timestamp - now : 0;
 110
 111             return 0;
 112         }
 113     }
 114
 115     return pa_sink_process_msg(o, code, data, offset, chunk);
 116 }
 117
 118 static void sink_update_requested_latency_cb(pa_sink *s) {
 119     struct userdata *u;
 120
 121     pa_sink_assert_ref(s);
 122     u = s->userdata;
 123     pa_assert(u);
 124
 125     u->block_usec = pa_sink_get_requested_latency_within_thread(s);
 126 }
 127
 128 static void process_rewind(struct userdata *u, pa_usec_t now) {
 129     size_t rewind_nbytes, in_buffer;
 130     pa_usec_t delay;
 131
 132     pa_assert(u);
 133
 134     /* Figure out how much we shall rewind and reset the counter */
 135     rewind_nbytes = u->sink->thread_info.rewind_nbytes;
 136     u->sink->thread_info.rewind_nbytes = 0;
 137
 138     pa_assert(rewind_nbytes > 0);
 139     pa_log_debug("Requested to rewind %lu bytes.", (unsigned long) rewind_nbytes);
 140
 141     if (u->timestamp <= now)
 142         return;
 143
 144     delay = u->timestamp - now;
 145     in_buffer = pa_usec_to_bytes(delay, &u->sink->sample_spec);
 146
 147     if (in_buffer <= 0)
 148         return;
 149
 150     if (rewind_nbytes > in_buffer)
 151         rewind_nbytes = in_buffer;
 152
 153     pa_sink_process_rewind(u->sink, rewind_nbytes);
 154     u->timestamp -= pa_bytes_to_usec(rewind_nbytes, &u->sink->sample_spec);
 155
 156     pa_log_debug("Rewound %lu bytes.", (unsigned long) rewind_nbytes);
 157 }
 158
 159 static void process_render(struct userdata *u, pa_usec_t now) {
 160     size_t nbytes;
 161     size_t ate = 0;
 162
 163     /* This is the configured latency. Sink inputs connected to us
 164     might not have a single frame more than this value queued. Hence:
 165     at maximum read this many bytes from the sink inputs. */
 166
 167     nbytes = pa_usec_to_bytes(u->block_usec, &u->sink->sample_spec);
 168
 169     /* Fill the buffer up the the latency size */
 170     while (u->timestamp < now + u->block_usec) {
 171         pa_memchunk chunk;
 172
 173         pa_sink_render(u->sink, nbytes, &chunk);
 174         pa_memblock_unref(chunk.memblock);
 175
 176         pa_log_debug("Ate %lu bytes.", (unsigned long) chunk.length);
 177         u->timestamp += pa_bytes_to_usec(chunk.length, &u->sink->sample_spec);
 178
 179         ate += chunk.length;
 180
 181         if (ate >= nbytes)
 182             break;
 183     }
 184
 185     pa_log_debug("Ate in sum %lu bytes (of %lu)", (unsigned long) ate, (unsigned long) nbytes);
 186 }
 187
 188 static void thread_func(void *userdata) {
 189     struct userdata *u = userdata;
 190
 191     pa_assert(u);
 192
 193     pa_log_debug("Thread starting up");
 194
 195     pa_thread_mq_install(&u->thread_mq);
 196     pa_rtpoll_install(u->rtpoll);
 197
 198     u->timestamp = pa_rtclock_usec();
 199
 200     for (;;) {
 201         int ret;
 202
 203         /* Render some data and drop it immediately */
 204         if (u->sink->thread_info.state == PA_SINK_RUNNING) {
 205             pa_usec_t now;
 206
 207             now = pa_rtclock_usec();
 208
 209             if (u->sink->thread_info.rewind_nbytes > 0)
 210                 process_rewind(u, now);
 211
 212             if (u->timestamp <= now)
 213                 process_render(u, now);
 214
 215             pa_rtpoll_set_timer_absolute(u->rtpoll, u->timestamp);
 216         } else
 217             pa_rtpoll_set_timer_disabled(u->rtpoll);
 218
 219         /* Hmm, nothing to do. Let's sleep */
 220         if ((ret = pa_rtpoll_run(u->rtpoll, 1)) < 0)
 221             goto fail;
 222
 223         if (ret == 0)
 224             goto finish;
 225     }
 226
 227 fail:
 228     /* If this was no regular exit from the loop we have to continue
 229      * processing messages until we received PA_MESSAGE_SHUTDOWN */
 230     pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
 231     pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
 232
 233 finish:
 234     pa_log_debug("Thread shutting down");
 235 }
 236
 237 int pa__init(pa_module*m) {
 238     struct userdata *u = NULL;
 239     pa_sample_spec ss;
 240     pa_channel_map map;
 241     pa_modargs *ma = NULL;
 242     pa_sink_new_data data;
 243
 244     pa_assert(m);
 245
 246     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 247         pa_log("Failed to parse module arguments.");
 248         goto fail;
 249     }
 250
 251     ss = m->core->default_sample_spec;
 252     if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
 253         pa_log("Invalid sample format specification or channel map");
 254         goto fail;
 255     }
 256
 257     u = pa_xnew0(struct userdata, 1);
 258     u->core = m->core;
 259     u->module = m;
 260     m->userdata = u;
 261     u->rtpoll = pa_rtpoll_new();
 262     pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll);
 263
 264     pa_sink_new_data_init(&data);
 265     data.driver = __FILE__;
 266     data.module = m;
 267     pa_sink_new_data_set_name(&data, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
 268     pa_sink_new_data_set_sample_spec(&data, &ss);
 269     pa_sink_new_data_set_channel_map(&data, &map);
 270     pa_proplist_sets(data.proplist, PA_PROP_DEVICE_DESCRIPTION, pa_modargs_get_value(ma, "description", "Null Output"));
 271
 272     u->sink = pa_sink_new(m->core, &data, PA_SINK_LATENCY);
 273     pa_sink_new_data_done(&data);
 274
 275     if (!u->sink) {
 276         pa_log("Failed to create sink object.");
 277         goto fail;
 278     }
 279
 280     u->sink->parent.process_msg = sink_process_msg;
 281     u->sink->update_requested_latency = sink_update_requested_latency_cb;
 282     u->sink->userdata = u;
 283
 284     pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
 285     pa_sink_set_rtpoll(u->sink, u->rtpoll);
 286
 287     u->block_usec = u->sink->max_latency = MAX_LATENCY_USEC;
 288
 289     u->sink->thread_info.max_rewind = pa_usec_to_bytes(u->block_usec, &u->sink->sample_spec);
 290
 291     if (!(u->thread = pa_thread_new(thread_func, u))) {
 292         pa_log("Failed to create thread.");
 293         goto fail;
 294     }
 295
 296     pa_sink_put(u->sink);
 297
 298     pa_modargs_free(ma);
 299
 300     return 0;
 301
 302 fail:
 303     if (ma)
 304         pa_modargs_free(ma);
 305
 306     pa__done(m);
 307
 308     return -1;
 309 }
 310
 311 void pa__done(pa_module*m) {
 312     struct userdata *u;
 313
 314     pa_assert(m);
 315
 316     if (!(u = m->userdata))
 317         return;
 318
 319     if (u->sink)
 320         pa_sink_unlink(u->sink);
 321
 322     if (u->thread) {
 323         pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
 324         pa_thread_free(u->thread);
 325     }
 326
 327     pa_thread_mq_done(&u->thread_mq);
 328
 329     if (u->sink)
 330         pa_sink_unref(u->sink);
 331
 332     if (u->rtpoll)
 333         pa_rtpoll_free(u->rtpoll);
 334
 335     pa_xfree(u);
 336 }