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