code.delx.au - pulseaudio/blob - src/modules/module-alsa-source.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 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   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 Lesser 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 <assert.h>
  27 #include <stdio.h>
  28
  29 #ifdef HAVE_SYS_POLL_H
  30 #include <sys/poll.h>
  31 #else
  32 #include "poll.h"
  33 #endif
  34
  35 #include <asoundlib.h>
  36
  37 #include <polypcore/core.h>
  38 #include <polypcore/module.h>
  39 #include <polypcore/memchunk.h>
  40 #include <polypcore/sink.h>
  41 #include <polypcore/modargs.h>
  42 #include <polypcore/util.h>
  43 #include <polypcore/sample-util.h>
  44 #include <polypcore/xmalloc.h>
  45 #include <polypcore/log.h>
  46
  47 #include "module-alsa-source-symdef.h"
  48 #include "alsa-util.h"
  49
  50 PA_MODULE_AUTHOR("Lennart Poettering")
  51 PA_MODULE_DESCRIPTION("ALSA Source")
  52 PA_MODULE_VERSION(PACKAGE_VERSION)
  53 PA_MODULE_USAGE("source_name=<name for the source> device=<ALSA device> format=<sample format> channels=<number of channels> rate=<sample rate> fragments=<number of fragments> fragment_size=<fragment size>")
  54
  55 struct userdata {
  56     snd_pcm_t *pcm_handle;
  57     pa_source *source;
  58     pa_io_event **io_events;
  59     unsigned n_io_events;
  60
  61     size_t frame_size, fragment_size;
  62     pa_memchunk memchunk;
  63     pa_module *module;
  64 };
  65
  66 static const char* const valid_modargs[] = {
  67     "device",
  68     "source_name",
  69     "channels",
  70     "rate",
  71     "format",
  72     "fragments",
  73     "fragment_size",
  74     NULL
  75 };
  76
  77 #define DEFAULT_SOURCE_NAME "alsa_input"
  78 #define DEFAULT_DEVICE "hw:0,0"
  79
  80 static void update_usage(struct userdata *u) {
  81    pa_module_set_used(u->module,
  82                       (u->source ? pa_idxset_size(u->source->outputs) : 0));
  83 }
  84
  85 static void xrun_recovery(struct userdata *u) {
  86     assert(u);
  87
  88     pa_log(__FILE__": *** ALSA-XRUN (capture) ***\n");
  89
  90     if (snd_pcm_prepare(u->pcm_handle) < 0)
  91         pa_log(__FILE__": snd_pcm_prepare() failed\n");
  92 }
  93
  94 static void do_read(struct userdata *u) {
  95     assert(u);
  96
  97     update_usage(u);
  98
  99     for (;;) {
 100         pa_memchunk post_memchunk;
 101         snd_pcm_sframes_t frames;
 102         size_t l;
 103
 104         if (!u->memchunk.memblock) {
 105             u->memchunk.memblock = pa_memblock_new(u->memchunk.length = u->fragment_size, u->source->core->memblock_stat);
 106             u->memchunk.index = 0;
 107         }
 108
 109         assert(u->memchunk.memblock && u->memchunk.memblock->data && u->memchunk.length && u->memchunk.memblock->length && (u->memchunk.length % u->frame_size) == 0);
 110
 111         if ((frames = snd_pcm_readi(u->pcm_handle, (uint8_t*) u->memchunk.memblock->data + u->memchunk.index, u->memchunk.length / u->frame_size)) < 0) {
 112             if (frames == -EAGAIN)
 113                 return;
 114
 115             if (frames == -EPIPE) {
 116                 xrun_recovery(u);
 117                 continue;
 118             }
 119
 120             pa_log(__FILE__": snd_pcm_readi() failed: %s\n", strerror(-frames));
 121             return;
 122         }
 123
 124         l = frames * u->frame_size;
 125
 126         post_memchunk = u->memchunk;
 127         post_memchunk.length = l;
 128
 129         pa_source_post(u->source, &post_memchunk);
 130
 131         u->memchunk.index += l;
 132         u->memchunk.length -= l;
 133
 134         if (u->memchunk.length == 0) {
 135             pa_memblock_unref(u->memchunk.memblock);
 136             u->memchunk.memblock = NULL;
 137             u->memchunk.index = u->memchunk.length = 0;
 138         }
 139
 140         break;
 141     }
 142 }
 143
 144 static void io_callback(pa_mainloop_api*a, pa_io_event *e, PA_GCC_UNUSED int fd, PA_GCC_UNUSED pa_io_event_flags_t f, void *userdata) {
 145     struct userdata *u = userdata;
 146     assert(u && a && e);
 147
 148     if (snd_pcm_state(u->pcm_handle) == SND_PCM_STATE_XRUN)
 149         xrun_recovery(u);
 150
 151     do_read(u);
 152 }
 153
 154 static pa_usec_t source_get_latency_cb(pa_source *s) {
 155     struct userdata *u = s->userdata;
 156     snd_pcm_sframes_t frames;
 157     assert(s && u && u->source);
 158
 159     if (snd_pcm_delay(u->pcm_handle, &frames) < 0) {
 160         pa_log(__FILE__": failed to get delay\n");
 161         s->get_latency = NULL;
 162         return 0;
 163     }
 164
 165     return pa_bytes_to_usec(frames * u->frame_size, &s->sample_spec);
 166 }
 167
 168 int pa__init(pa_core *c, pa_module*m) {
 169     pa_modargs *ma = NULL;
 170     int ret = -1;
 171     struct userdata *u = NULL;
 172     const char *dev;
 173     pa_sample_spec ss;
 174     unsigned periods, fragsize;
 175     snd_pcm_uframes_t period_size;
 176     size_t frame_size;
 177     int err;
 178
 179     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 180         pa_log(__FILE__": failed to parse module arguments\n");
 181         goto fail;
 182     }
 183
 184     ss = c->default_sample_spec;
 185     if (pa_modargs_get_sample_spec(ma, &ss) < 0) {
 186         pa_log(__FILE__": failed to parse sample specification\n");
 187         goto fail;
 188     }
 189     frame_size = pa_frame_size(&ss);
 190
 191     periods = 12;
 192     fragsize = 1024;
 193     if (pa_modargs_get_value_u32(ma, "fragments", &periods) < 0 || pa_modargs_get_value_u32(ma, "fragment_size", &fragsize) < 0) {
 194         pa_log(__FILE__": failed to parse buffer metrics\n");
 195         goto fail;
 196     }
 197     period_size = fragsize;
 198
 199     u = pa_xmalloc0(sizeof(struct userdata));
 200     m->userdata = u;
 201     u->module = m;
 202
 203     snd_config_update_free_global();
 204     if ((err = snd_pcm_open(&u->pcm_handle, dev = pa_modargs_get_value(ma, "device", DEFAULT_DEVICE), SND_PCM_STREAM_CAPTURE, SND_PCM_NONBLOCK)) < 0) {
 205         pa_log(__FILE__": Error opening PCM device %s: %s\n", dev, snd_strerror(err));
 206         goto fail;
 207     }
 208
 209     if ((err = pa_alsa_set_hw_params(u->pcm_handle, &ss, &periods, &period_size)) < 0) {
 210         pa_log(__FILE__": Failed to set hardware parameters: %s\n", snd_strerror(err));
 211         goto fail;
 212     }
 213
 214     u->source = pa_source_new(c, __FILE__, pa_modargs_get_value(ma, "source_name", DEFAULT_SOURCE_NAME), 0, &ss, NULL);
 215     assert(u->source);
 216
 217     u->source->userdata = u;
 218     u->source->get_latency = source_get_latency_cb;
 219     pa_source_set_owner(u->source, m);
 220     u->source->description = pa_sprintf_malloc("Advanced Linux Sound Architecture PCM on '%s'", dev);
 221
 222     if (pa_create_io_events(u->pcm_handle, c->mainloop, &u->io_events, &u->n_io_events, io_callback, u) < 0) {
 223         pa_log(__FILE__": failed to obtain file descriptors\n");
 224         goto fail;
 225     }
 226
 227     u->frame_size = frame_size;
 228     u->fragment_size = period_size;
 229
 230     pa_log(__FILE__": using %u fragments of size %u bytes.\n", periods, u->fragment_size);
 231
 232     u->memchunk.memblock = NULL;
 233     u->memchunk.index = u->memchunk.length = 0;
 234
 235     snd_pcm_start(u->pcm_handle);
 236
 237     ret = 0;
 238
 239 finish:
 240      if (ma)
 241          pa_modargs_free(ma);
 242
 243     return ret;
 244
 245 fail:
 246
 247     if (u)
 248         pa__done(c, m);
 249
 250     goto finish;
 251 }
 252
 253 void pa__done(pa_core *c, pa_module*m) {
 254     struct userdata *u;
 255     assert(c && m);
 256
 257     if (!(u = m->userdata))
 258         return;
 259
 260     if (u->source) {
 261         pa_source_disconnect(u->source);
 262         pa_source_unref(u->source);
 263     }
 264
 265     if (u->io_events)
 266         pa_free_io_events(c->mainloop, u->io_events, u->n_io_events);
 267
 268     if (u->pcm_handle) {
 269         snd_pcm_drop(u->pcm_handle);
 270         snd_pcm_close(u->pcm_handle);
 271     }
 272
 273     if (u->memchunk.memblock)
 274         pa_memblock_unref(u->memchunk.memblock);
 275
 276     pa_xfree(u);
 277 }
 278