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 = pa_memblock_get_length(u->memblock) - 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);
  78     assert(length <= pa_memblock_get_length(u->memblock)-u->peek_index);
  79
  80     u->peek_index += length;
  81
  82     if (u->peek_index >= pa_memblock_get_length(u->memblock))
  83         u->peek_index = 0;
  84 }
  85
  86 static void sink_input_kill(pa_sink_input *i) {
  87     struct userdata *u;
  88     assert(i && i->userdata);
  89     u = i->userdata;
  90
  91     pa_sink_input_disconnect(u->sink_input);
  92     pa_sink_input_unref(u->sink_input);
  93     u->sink_input = NULL;
  94
  95     pa_module_unload_request(u->module);
  96 }
  97
  98 static void calc_sine(float *f, size_t l, float freq) {
  99     size_t i;
 100
 101     l /= sizeof(float);
 102
 103     for (i = 0; i < l; i++)
 104         f[i] = (float) sin((double) i/l*M_PI*2*freq)/2;
 105 }
 106
 107 int pa__init(pa_core *c, pa_module*m) {
 108     pa_modargs *ma = NULL;
 109     struct userdata *u;
 110     pa_sink *sink;
 111     const char *sink_name;
 112     pa_sample_spec ss;
 113     uint32_t frequency;
 114     char t[256];
 115     void *p;
 116     pa_sink_input_new_data data;
 117
 118     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 119         pa_log("Failed to parse module arguments");
 120         goto fail;
 121     }
 122
 123     m->userdata = u = pa_xmalloc(sizeof(struct userdata));
 124     u->core = c;
 125     u->module = m;
 126     u->sink_input = NULL;
 127     u->memblock = NULL;
 128
 129     sink_name = pa_modargs_get_value(ma, "sink", NULL);
 130
 131     if (!(sink = pa_namereg_get(c, sink_name, PA_NAMEREG_SINK, 1))) {
 132         pa_log("No such sink.");
 133         goto fail;
 134     }
 135
 136     ss.format = PA_SAMPLE_FLOAT32;
 137     ss.rate = sink->sample_spec.rate;
 138     ss.channels = 1;
 139
 140     frequency = 440;
 141     if (pa_modargs_get_value_u32(ma, "frequency", &frequency) < 0 || frequency < 1 || frequency > ss.rate/2) {
 142         pa_log("Invalid frequency specification");
 143         goto fail;
 144     }
 145
 146     u->memblock = pa_memblock_new(c->mempool, pa_bytes_per_second(&ss));
 147     p = pa_memblock_acquire(u->memblock);
 148     calc_sine(p, pa_memblock_get_length(u->memblock), frequency);
 149     pa_memblock_release(u->memblock);
 150
 151     snprintf(t, sizeof(t), "Sine Generator at %u Hz", frequency);
 152
 153     pa_sink_input_new_data_init(&data);
 154     data.sink = sink;
 155     data.driver = __FILE__;
 156     data.name = t;
 157     pa_sink_input_new_data_set_sample_spec(&data, &ss);
 158     data.module = m;
 159
 160     if (!(u->sink_input = pa_sink_input_new(c, &data, 0)))
 161         goto fail;
 162
 163     u->sink_input->peek = sink_input_peek;
 164     u->sink_input->drop = sink_input_drop;
 165     u->sink_input->kill = sink_input_kill;
 166     u->sink_input->userdata = u;
 167
 168     u->peek_index = 0;
 169
 170     pa_modargs_free(ma);
 171     return 0;
 172
 173 fail:
 174     if (ma)
 175         pa_modargs_free(ma);
 176
 177     pa__done(c, m);
 178     return -1;
 179 }
 180
 181 void pa__done(pa_core *c, pa_module*m) {
 182     struct userdata *u = m->userdata;
 183     assert(c && m);
 184
 185     if (!u)
 186         return;
 187
 188     if (u->sink_input) {
 189         pa_sink_input_disconnect(u->sink_input);
 190         pa_sink_input_unref(u->sink_input);
 191     }
 192
 193     if (u->memblock)
 194         pa_memblock_unref(u->memblock);
 195     pa_xfree(u);
 196 }
 197