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     pa_sink_input_new_data data;
 113
 114     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 115         pa_log(__FILE__": Failed to parse module arguments");
 116         goto fail;
 117     }
 118
 119     m->userdata = u = pa_xmalloc(sizeof(struct userdata));
 120     u->core = c;
 121     u->module = m;
 122     u->sink_input = NULL;
 123     u->memblock = NULL;
 124
 125     sink_name = pa_modargs_get_value(ma, "sink", NULL);
 126
 127     if (!(sink = pa_namereg_get(c, sink_name, PA_NAMEREG_SINK, 1))) {
 128         pa_log(__FILE__": No such sink.");
 129         goto fail;
 130     }
 131
 132     ss.format = PA_SAMPLE_FLOAT32;
 133     ss.rate = sink->sample_spec.rate;
 134     ss.channels = 1;
 135
 136     frequency = 440;
 137     if (pa_modargs_get_value_u32(ma, "frequency", &frequency) < 0 || frequency < 1 || frequency > ss.rate/2) {
 138         pa_log(__FILE__": Invalid frequency specification");
 139         goto fail;
 140     }
 141
 142     u->memblock = pa_memblock_new(pa_bytes_per_second(&ss), c->memblock_stat);
 143     calc_sine(u->memblock->data, u->memblock->length, frequency);
 144
 145     snprintf(t, sizeof(t), "Sine Generator at %u Hz", frequency);
 146
 147     pa_sink_input_new_data_init(&data);
 148     data.sink = sink;
 149     data.driver = __FILE__;
 150     data.name = t;
 151     pa_sink_input_new_data_set_sample_spec(&data, &ss);
 152     data.module = m;
 153
 154     if (!(u->sink_input = pa_sink_input_new(c, &data, 0)))
 155         goto fail;
 156
 157     u->sink_input->peek = sink_input_peek;
 158     u->sink_input->drop = sink_input_drop;
 159     u->sink_input->kill = sink_input_kill;
 160     u->sink_input->userdata = u;
 161
 162     u->peek_index = 0;
 163
 164     pa_modargs_free(ma);
 165     return 0;
 166
 167 fail:
 168     if (ma)
 169         pa_modargs_free(ma);
 170
 171     pa__done(c, m);
 172     return -1;
 173 }
 174
 175 void pa__done(pa_core *c, pa_module*m) {
 176     struct userdata *u = m->userdata;
 177     assert(c && m);
 178
 179     if (!u)
 180         return;
 181
 182     if (u->sink_input) {
 183         pa_sink_input_disconnect(u->sink_input);
 184         pa_sink_input_unref(u->sink_input);
 185     }
 186
 187     if (u->memblock)
 188         pa_memblock_unref(u->memblock);
 189     pa_xfree(u);
 190 }
 191