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

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   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 <stdio.h>
  27 #include <assert.h>
  28 #include <math.h>
  29
  30 #include <pulse/xmalloc.h>
  31
  32 #include <pulsecore/sink-input.h>
  33 #include <pulsecore/module.h>
  34 #include <pulsecore/modargs.h>
  35 #include <pulsecore/namereg.h>
  36 #include <pulsecore/log.h>
  37
  38 #include "module-sine-symdef.h"
  39
  40 PA_MODULE_AUTHOR("Lennart Poettering")
  41 PA_MODULE_DESCRIPTION("Sine wave generator")
  42 PA_MODULE_USAGE("sink=<sink to connect to> frequency=<frequency in Hz>")
  43 PA_MODULE_VERSION(PACKAGE_VERSION)
  44
  45 struct userdata {
  46     pa_core *core;
  47     pa_module *module;
  48     pa_sink_input *sink_input;
  49     pa_memblock *memblock;
  50     size_t peek_index;
  51 };
  52
  53 static const char* const valid_modargs[] = {
  54     "sink",
  55     "frequency",
  56     NULL,
  57 };
  58
  59 static int sink_input_peek(pa_sink_input *i, pa_memchunk *chunk) {
  60     struct userdata *u;
  61     assert(i && chunk && i->userdata);
  62     u = i->userdata;
  63
  64     chunk->memblock = pa_memblock_ref(u->memblock);
  65     chunk->index = u->peek_index;
  66     chunk->length = u->memblock->length - u->peek_index;
  67     return 0;
  68 }
  69
  70 static void sink_input_drop(pa_sink_input *i, const pa_memchunk *chunk, size_t length) {
  71     struct userdata *u;
  72     assert(i && chunk && length && i->userdata);
  73     u = i->userdata;
  74
  75     assert(chunk->memblock == u->memblock && length <= u->memblock->length-u->peek_index);
  76
  77     u->peek_index += length;
  78
  79     if (u->peek_index >= u->memblock->length)
  80         u->peek_index = 0;
  81 }
  82
  83 static void sink_input_kill(pa_sink_input *i) {
  84     struct userdata *u;
  85     assert(i && i->userdata);
  86     u = i->userdata;
  87
  88     pa_sink_input_disconnect(u->sink_input);
  89     pa_sink_input_unref(u->sink_input);
  90     u->sink_input = NULL;
  91
  92     pa_module_unload_request(u->module);
  93 }
  94
  95 static void calc_sine(float *f, size_t l, float freq) {
  96     size_t i;
  97
  98     l /= sizeof(float);
  99
 100     for (i = 0; i < l; i++)
 101         f[i] = (float) sin((double) i/l*M_PI*2*freq)/2;
 102 }
 103
 104 int pa__init(pa_core *c, pa_module*m) {
 105     pa_modargs *ma = NULL;
 106     struct userdata *u;
 107     pa_sink *sink;
 108     const char *sink_name;
 109     pa_sample_spec ss;
 110     uint32_t frequency;
 111     char t[256];
 112
 113     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 114         pa_log(__FILE__": Failed to parse module arguments");
 115         goto fail;
 116     }
 117
 118     m->userdata = u = pa_xmalloc(sizeof(struct userdata));
 119     u->core = c;
 120     u->module = m;
 121     u->sink_input = NULL;
 122     u->memblock = NULL;
 123
 124     sink_name = pa_modargs_get_value(ma, "sink", NULL);
 125
 126     if (!(sink = pa_namereg_get(c, sink_name, PA_NAMEREG_SINK, 1))) {
 127         pa_log(__FILE__": No such sink.");
 128         goto fail;
 129     }
 130
 131     ss.format = PA_SAMPLE_FLOAT32;
 132     ss.rate = sink->sample_spec.rate;
 133     ss.channels = 1;
 134
 135     frequency = 440;
 136     if (pa_modargs_get_value_u32(ma, "frequency", &frequency) < 0 || frequency < 1 || frequency > ss.rate/2) {
 137         pa_log(__FILE__": Invalid frequency specification");
 138         goto fail;
 139     }
 140
 141     u->memblock = pa_memblock_new(pa_bytes_per_second(&ss), c->memblock_stat);
 142     calc_sine(u->memblock->data, u->memblock->length, frequency);
 143
 144     snprintf(t, sizeof(t), "Sine Generator at %u Hz", frequency);
 145     if (!(u->sink_input = pa_sink_input_new(sink, __FILE__, t, &ss, NULL, NULL, 0, -1)))
 146         goto fail;
 147
 148     u->sink_input->peek = sink_input_peek;
 149     u->sink_input->drop = sink_input_drop;
 150     u->sink_input->kill = sink_input_kill;
 151     u->sink_input->userdata = u;
 152     u->sink_input->owner = m;
 153
 154     u->peek_index = 0;
 155
 156     pa_modargs_free(ma);
 157     return 0;
 158
 159 fail:
 160     if (ma)
 161         pa_modargs_free(ma);
 162
 163     pa__done(c, m);
 164     return -1;
 165 }
 166
 167 void pa__done(pa_core *c, pa_module*m) {
 168     struct userdata *u = m->userdata;
 169     assert(c && m);
 170
 171     if (!u)
 172         return;
 173
 174     if (u->sink_input) {
 175         pa_sink_input_disconnect(u->sink_input);
 176         pa_sink_input_unref(u->sink_input);
 177     }
 178
 179     if (u->memblock)
 180         pa_memblock_unref(u->memblock);
 181     pa_xfree(u);
 182 }
 183