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

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   5
   6   Copyright 2004-2006 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 <stdio.h>
  29 #include <assert.h>
  30 #include <math.h>
  31
  32 #include <pulse/xmalloc.h>
  33
  34 #include <pulsecore/sink-input.h>
  35 #include <pulsecore/module.h>
  36 #include <pulsecore/modargs.h>
  37 #include <pulsecore/namereg.h>
  38 #include <pulsecore/log.h>
  39
  40 #include "module-sine-symdef.h"
  41
  42 PA_MODULE_AUTHOR("Lennart Poettering")
  43 PA_MODULE_DESCRIPTION("Sine wave generator")
  44 PA_MODULE_USAGE("sink=<sink to connect to> frequency=<frequency in Hz>")
  45 PA_MODULE_VERSION(PACKAGE_VERSION)
  46
  47 struct userdata {
  48     pa_core *core;
  49     pa_module *module;
  50     pa_sink_input *sink_input;
  51     pa_memblock *memblock;
  52     size_t peek_index;
  53 };
  54
  55 static const char* const valid_modargs[] = {
  56     "sink",
  57     "frequency",
  58     NULL,
  59 };
  60
  61 static int sink_input_peek(pa_sink_input *i, pa_memchunk *chunk) {
  62     struct userdata *u;
  63     assert(i && chunk && i->userdata);
  64     u = i->userdata;
  65
  66     chunk->memblock = pa_memblock_ref(u->memblock);
  67     chunk->index = u->peek_index;
  68     chunk->length = u->memblock->length - u->peek_index;
  69     return 0;
  70 }
  71
  72 static void sink_input_drop(pa_sink_input *i, const pa_memchunk *chunk, size_t length) {
  73     struct userdata *u;
  74     assert(i && chunk && length && i->userdata);
  75     u = i->userdata;
  76
  77     assert(chunk->memblock == u->memblock && length <= u->memblock->length-u->peek_index);
  78
  79     u->peek_index += length;
  80
  81     if (u->peek_index >= u->memblock->length)
  82         u->peek_index = 0;
  83 }
  84
  85 static void sink_input_kill(pa_sink_input *i) {
  86     struct userdata *u;
  87     assert(i && i->userdata);
  88     u = i->userdata;
  89
  90     pa_sink_input_disconnect(u->sink_input);
  91     pa_sink_input_unref(u->sink_input);
  92     u->sink_input = NULL;
  93
  94     pa_module_unload_request(u->module);
  95 }
  96
  97 static void calc_sine(float *f, size_t l, float freq) {
  98     size_t i;
  99
 100     l /= sizeof(float);
 101
 102     for (i = 0; i < l; i++)
 103         f[i] = (float) sin((double) i/l*M_PI*2*freq)/2;
 104 }
 105
 106 int pa__init(pa_core *c, pa_module*m) {
 107     pa_modargs *ma = NULL;
 108     struct userdata *u;
 109     pa_sink *sink;
 110     const char *sink_name;
 111     pa_sample_spec ss;
 112     uint32_t frequency;
 113     char t[256];
 114     pa_sink_input_new_data data;
 115
 116     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 117         pa_log("Failed to parse module arguments");
 118         goto fail;
 119     }
 120
 121     m->userdata = u = pa_xmalloc(sizeof(struct userdata));
 122     u->core = c;
 123     u->module = m;
 124     u->sink_input = NULL;
 125     u->memblock = NULL;
 126
 127     sink_name = pa_modargs_get_value(ma, "sink", NULL);
 128
 129     if (!(sink = pa_namereg_get(c, sink_name, PA_NAMEREG_SINK, 1))) {
 130         pa_log("No such sink.");
 131         goto fail;
 132     }
 133
 134     ss.format = PA_SAMPLE_FLOAT32;
 135     ss.rate = sink->sample_spec.rate;
 136     ss.channels = 1;
 137
 138     frequency = 440;
 139     if (pa_modargs_get_value_u32(ma, "frequency", &frequency) < 0 || frequency < 1 || frequency > ss.rate/2) {
 140         pa_log("Invalid frequency specification");
 141         goto fail;
 142     }
 143
 144     u->memblock = pa_memblock_new(c->mempool, pa_bytes_per_second(&ss));
 145     calc_sine(u->memblock->data, u->memblock->length, frequency);
 146
 147     snprintf(t, sizeof(t), "Sine Generator at %u Hz", frequency);
 148
 149     pa_sink_input_new_data_init(&data);
 150     data.sink = sink;
 151     data.driver = __FILE__;
 152     data.name = t;
 153     pa_sink_input_new_data_set_sample_spec(&data, &ss);
 154     data.module = m;
 155
 156     if (!(u->sink_input = pa_sink_input_new(c, &data, 0)))
 157         goto fail;
 158
 159     u->sink_input->peek = sink_input_peek;
 160     u->sink_input->drop = sink_input_drop;
 161     u->sink_input->kill = sink_input_kill;
 162     u->sink_input->userdata = u;
 163
 164     u->peek_index = 0;
 165
 166     pa_modargs_free(ma);
 167     return 0;
 168
 169 fail:
 170     if (ma)
 171         pa_modargs_free(ma);
 172
 173     pa__done(c, m);
 174     return -1;
 175 }
 176
 177 void pa__done(pa_core *c, pa_module*m) {
 178     struct userdata *u = m->userdata;
 179     assert(c && m);
 180
 181     if (!u)
 182         return;
 183
 184     if (u->sink_input) {
 185         pa_sink_input_disconnect(u->sink_input);
 186         pa_sink_input_unref(u->sink_input);
 187     }
 188
 189     if (u->memblock)
 190         pa_memblock_unref(u->memblock);
 191     pa_xfree(u);
 192 }
 193