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

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of polypaudio.
   5
   6   polypaudio 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   polypaudio 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 polypaudio; 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 <stdio.h>
  27 #include <assert.h>
  28 #include <math.h>
  29
  30 #include <polypcore/sink-input.h>
  31 #include <polypcore/module.h>
  32 #include <polypcore/modargs.h>
  33 #include <polypcore/xmalloc.h>
  34 #include <polypcore/namereg.h>
  35 #include <polypcore/log.h>
  36
  37 #include "module-sine-symdef.h"
  38
  39 PA_MODULE_AUTHOR("Lennart Poettering")
  40 PA_MODULE_DESCRIPTION("Sine wave generator")
  41 PA_MODULE_USAGE("sink=<sink to connect to> frequency=<frequency in Hz>")
  42 PA_MODULE_VERSION(PACKAGE_VERSION)
  43
  44 struct userdata {
  45     pa_core *core;
  46     pa_module *module;
  47     pa_sink_input *sink_input;
  48     pa_memblock *memblock;
  49     size_t peek_index;
  50 };
  51
  52 static const char* const valid_modargs[] = {
  53     "sink",
  54     "frequency",
  55     NULL,
  56 };
  57
  58 static int sink_input_peek(pa_sink_input *i, pa_memchunk *chunk) {
  59     struct userdata *u;
  60     assert(i && chunk && i->userdata);
  61     u = i->userdata;
  62
  63     chunk->memblock = pa_memblock_ref(u->memblock);
  64     chunk->index = u->peek_index;
  65     chunk->length = u->memblock->length - u->peek_index;
  66     return 0;
  67 }
  68
  69 static void sink_input_drop(pa_sink_input *i, const pa_memchunk *chunk, size_t length) {
  70     struct userdata *u;
  71     assert(i && chunk && length && i->userdata);
  72     u = i->userdata;
  73
  74     assert(chunk->memblock == u->memblock && length <= u->memblock->length-u->peek_index);
  75
  76     u->peek_index += length;
  77
  78     if (u->peek_index >= u->memblock->length)
  79         u->peek_index = 0;
  80 }
  81
  82 static void sink_input_kill(pa_sink_input *i) {
  83     struct userdata *u;
  84     assert(i && i->userdata);
  85     u = i->userdata;
  86
  87     pa_sink_input_disconnect(u->sink_input);
  88     pa_sink_input_unref(u->sink_input);
  89     u->sink_input = NULL;
  90
  91     pa_module_unload_request(u->module);
  92 }
  93
  94 static void calc_sine(float *f, size_t l, float freq) {
  95     size_t i;
  96
  97     l /= sizeof(float);
  98
  99     for (i = 0; i < l; i++)
 100         f[i] = (float) sin((double) i/l*M_PI*2*freq)/2;
 101 }
 102
 103 int pa__init(pa_core *c, pa_module*m) {
 104     pa_modargs *ma = NULL;
 105     struct userdata *u;
 106     pa_sink *sink;
 107     const char *sink_name;
 108     pa_sample_spec ss;
 109     uint32_t frequency;
 110     char t[256];
 111
 112     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 113         pa_log(__FILE__": Failed to parse module arguments");
 114         goto fail;
 115     }
 116
 117     m->userdata = u = pa_xmalloc(sizeof(struct userdata));
 118     u->core = c;
 119     u->module = m;
 120     u->sink_input = NULL;
 121     u->memblock = NULL;
 122
 123     sink_name = pa_modargs_get_value(ma, "sink", NULL);
 124
 125     if (!(sink = pa_namereg_get(c, sink_name, PA_NAMEREG_SINK, 1))) {
 126         pa_log(__FILE__": No such sink.");
 127         goto fail;
 128     }
 129
 130     ss.format = PA_SAMPLE_FLOAT32;
 131     ss.rate = sink->sample_spec.rate;
 132     ss.channels = 1;
 133
 134     frequency = 440;
 135     if (pa_modargs_get_value_u32(ma, "frequency", &frequency) < 0 || frequency < 1 || frequency > ss.rate/2) {
 136         pa_log(__FILE__": Invalid frequency specification");
 137         goto fail;
 138     }
 139
 140     u->memblock = pa_memblock_new(pa_bytes_per_second(&ss), c->memblock_stat);
 141     calc_sine(u->memblock->data, u->memblock->length, frequency);
 142
 143     snprintf(t, sizeof(t), "Sine Generator at %u Hz", frequency);
 144     if (!(u->sink_input = pa_sink_input_new(sink, __FILE__, t, &ss, NULL, 0, -1)))
 145         goto fail;
 146
 147     u->sink_input->peek = sink_input_peek;
 148     u->sink_input->drop = sink_input_drop;
 149     u->sink_input->kill = sink_input_kill;
 150     u->sink_input->userdata = u;
 151     u->sink_input->owner = m;
 152
 153     u->peek_index = 0;
 154
 155     pa_modargs_free(ma);
 156     return 0;
 157
 158 fail:
 159     if (ma)
 160         pa_modargs_free(ma);
 161
 162     pa__done(c, m);
 163     return -1;
 164 }
 165
 166 void pa__done(pa_core *c, pa_module*m) {
 167     struct userdata *u = m->userdata;
 168     assert(c && m);
 169
 170     if (!u)
 171         return;
 172
 173     if (u->sink_input) {
 174         pa_sink_input_disconnect(u->sink_input);
 175         pa_sink_input_unref(u->sink_input);
 176     }
 177
 178     if (u->memblock)
 179         pa_memblock_unref(u->memblock);
 180     pa_xfree(u);
 181 }
 182