code.delx.au - pulseaudio/blob - polyp/module-alsa-sink.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 <assert.h>
  27 #include <stdio.h>
  28 #include <sys/poll.h>
  29
  30 #include <asoundlib.h>
  31
  32 #include "module.h"
  33 #include "core.h"
  34 #include "memchunk.h"
  35 #include "sink.h"
  36 #include "modargs.h"
  37 #include "util.h"
  38 #include "sample-util.h"
  39 #include "alsa-util.h"
  40
  41 struct userdata {
  42     snd_pcm_t *pcm_handle;
  43     struct pa_sink *sink;
  44     void **io_sources;
  45     unsigned n_io_sources;
  46
  47     size_t frame_size, fragment_size;
  48     struct pa_memchunk memchunk, silence;
  49 };
  50
  51 static const char* const valid_modargs[] = {
  52     "device",
  53     "sink_name",
  54     "format",
  55     "channels",
  56     "rate",
  57     "fragments",
  58     "fragment_size",
  59     NULL
  60 };
  61
  62 #define DEFAULT_SINK_NAME "alsa_output"
  63 #define DEFAULT_DEVICE "plughw:0,0"
  64
  65 static void xrun_recovery(struct userdata *u) {
  66     assert(u);
  67
  68     fprintf(stderr, "*** ALSA-XRUN (playback) ***\n");
  69
  70     if (snd_pcm_prepare(u->pcm_handle) < 0)
  71         fprintf(stderr, "snd_pcm_prepare() failed\n");
  72 }
  73
  74 static void do_write(struct userdata *u) {
  75     assert(u);
  76
  77     for (;;) {
  78         struct pa_memchunk *memchunk = NULL;
  79         snd_pcm_sframes_t frames;
  80
  81         if (u->memchunk.memblock)
  82             memchunk = &u->memchunk;
  83         else {
  84             if (pa_sink_render(u->sink, u->fragment_size, &u->memchunk) < 0)
  85                 memchunk = &u->silence;
  86             else
  87                 memchunk = &u->memchunk;
  88         }
  89
  90         assert(memchunk->memblock && memchunk->memblock->data && memchunk->length && memchunk->memblock->length && (memchunk->length % u->frame_size) == 0);
  91
  92         if ((frames = snd_pcm_writei(u->pcm_handle, memchunk->memblock->data + memchunk->index, memchunk->length / u->frame_size)) < 0) {
  93             if (frames == -EAGAIN)
  94                 return;
  95
  96             if (frames == -EPIPE) {
  97                 xrun_recovery(u);
  98                 continue;
  99             }
 100
 101             fprintf(stderr, "snd_pcm_writei() failed\n");
 102             return;
 103         }
 104
 105         if (memchunk == &u->memchunk) {
 106             size_t l = frames * u->frame_size;
 107             memchunk->index += l;
 108             memchunk->length -= l;
 109
 110             if (memchunk->length == 0) {
 111                 pa_memblock_unref(memchunk->memblock);
 112                 memchunk->memblock = NULL;
 113                 memchunk->index = memchunk->length = 0;
 114             }
 115         }
 116
 117         break;
 118     }
 119 }
 120
 121 static void io_callback(struct pa_mainloop_api*a, void *id, int fd, enum pa_mainloop_api_io_events events, void *userdata) {
 122     struct userdata *u = userdata;
 123     assert(u && a && id);
 124
 125     if (snd_pcm_state(u->pcm_handle) == SND_PCM_STATE_XRUN)
 126         xrun_recovery(u);
 127
 128     do_write(u);
 129 }
 130
 131 static uint32_t sink_get_latency_cb(struct pa_sink *s) {
 132     struct userdata *u = s->userdata;
 133     snd_pcm_sframes_t frames;
 134     assert(s && u && u->sink);
 135
 136     if (snd_pcm_delay(u->pcm_handle, &frames) < 0) {
 137         fprintf(stderr, __FILE__": failed to get delay\n");
 138         s->get_latency = NULL;
 139         return 0;
 140     }
 141
 142     if (frames < 0)
 143         frames = 0;
 144
 145     return pa_samples_usec(frames * u->frame_size, &s->sample_spec);
 146 }
 147
 148 int pa_module_init(struct pa_core *c, struct pa_module*m) {
 149     struct pa_modargs *ma = NULL;
 150     int ret = -1;
 151     struct userdata *u = NULL;
 152     const char *dev;
 153     struct pa_sample_spec ss;
 154     unsigned periods, fragsize;
 155     snd_pcm_uframes_t buffer_size;
 156     size_t frame_size;
 157
 158     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 159         fprintf(stderr, __FILE__": failed to parse module arguments\n");
 160         goto fail;
 161     }
 162
 163     ss = c->default_sample_spec;
 164     if (pa_modargs_get_sample_spec(ma, &ss) < 0) {
 165         fprintf(stderr, __FILE__": failed to parse sample specification\n");
 166         goto fail;
 167     }
 168     frame_size = pa_sample_size(&ss);
 169
 170     periods = 12;
 171     fragsize = 1024;
 172     if (pa_modargs_get_value_u32(ma, "fragments", &periods) < 0 || pa_modargs_get_value_u32(ma, "fragment_size", &fragsize) < 0) {
 173         fprintf(stderr, __FILE__": failed to parse buffer metrics\n");
 174         goto fail;
 175     }
 176     buffer_size = fragsize/frame_size*periods;
 177
 178     u = malloc(sizeof(struct userdata));
 179     assert(u);
 180     memset(u, 0, sizeof(struct userdata));
 181     m->userdata = u;
 182
 183     if (snd_pcm_open(&u->pcm_handle, dev = pa_modargs_get_value(ma, "device", DEFAULT_DEVICE), SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK) < 0) {
 184         fprintf(stderr, __FILE__": Error opening PCM device %s\n", dev);
 185         goto fail;
 186     }
 187
 188     if (pa_alsa_set_hw_params(u->pcm_handle, &ss, &periods, &buffer_size) < 0) {
 189         fprintf(stderr, __FILE__": Failed to set hardware parameters\n");
 190         goto fail;
 191     }
 192
 193     u->sink = pa_sink_new(c, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME), 0, &ss);
 194     assert(u->sink);
 195
 196     u->sink->get_latency = sink_get_latency_cb;
 197     u->sink->userdata = u;
 198     pa_sink_set_owner(u->sink, m);
 199     u->sink->description = pa_sprintf_malloc("Advanced Linux Sound Architecture PCM on '%s'", dev);
 200
 201     if (pa_create_io_sources(u->pcm_handle, c->mainloop, &u->io_sources, &u->n_io_sources, io_callback, u) < 0) {
 202         fprintf(stderr, __FILE__": failed to obtain file descriptors\n");
 203         goto fail;
 204     }
 205
 206     u->frame_size = frame_size;
 207     u->fragment_size = buffer_size*u->frame_size/periods;
 208
 209     fprintf(stderr, __FILE__": using %u fragments of size %u bytes.\n", periods, u->fragment_size);
 210
 211     u->silence.memblock = pa_memblock_new(u->silence.length = u->fragment_size);
 212     assert(u->silence.memblock);
 213     pa_silence_memblock(u->silence.memblock, &ss);
 214     u->silence.index = 0;
 215
 216     u->memchunk.memblock = NULL;
 217     u->memchunk.index = u->memchunk.length = 0;
 218
 219     ret = 0;
 220
 221 finish:
 222      if (ma)
 223          pa_modargs_free(ma);
 224
 225     return ret;
 226
 227 fail:
 228
 229     if (u)
 230         pa_module_done(c, m);
 231
 232     goto finish;
 233 }
 234
 235 void pa_module_done(struct pa_core *c, struct pa_module*m) {
 236     struct userdata *u;
 237     assert(c && m);
 238
 239     if ((u = m->userdata)) {
 240         if (u->sink)
 241             pa_sink_free(u->sink);
 242
 243         if (u->io_sources)
 244             pa_free_io_sources(c->mainloop, u->io_sources, u->n_io_sources);
 245
 246         if (u->pcm_handle) {
 247             snd_pcm_drop(u->pcm_handle);
 248             snd_pcm_close(u->pcm_handle);
 249         }
 250
 251         if (u->memchunk.memblock)
 252             pa_memblock_unref(u->memchunk.memblock);
 253         if (u->silence.memblock)
 254             pa_memblock_unref(u->silence.memblock);
 255
 256         free(u);
 257     }
 258 }
 259