code.delx.au - pulseaudio/blob - src/modules/alsa-util.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 <sys/types.h>
  27 #include <asoundlib.h>
  28
  29 #include <polyp/sample.h>
  30 #include <polypcore/xmalloc.h>
  31 #include <polypcore/log.h>
  32
  33 #include "alsa-util.h"
  34
  35 /* Set the hardware parameters of the given ALSA device. Returns the
  36  * selected fragment settings in *period and *period_size */
  37 int pa_alsa_set_hw_params(snd_pcm_t *pcm_handle, const pa_sample_spec *ss, uint32_t *periods, snd_pcm_uframes_t *period_size) {
  38     int ret = -1;
  39     snd_pcm_uframes_t buffer_size;
  40     snd_pcm_hw_params_t *hwparams = NULL;
  41     unsigned int r = ss->rate;
  42
  43     static const snd_pcm_format_t format_trans[] = {
  44         [PA_SAMPLE_U8] = SND_PCM_FORMAT_U8,
  45         [PA_SAMPLE_ALAW] = SND_PCM_FORMAT_A_LAW,
  46         [PA_SAMPLE_ULAW] = SND_PCM_FORMAT_MU_LAW,
  47         [PA_SAMPLE_S16LE] = SND_PCM_FORMAT_S16_LE,
  48         [PA_SAMPLE_S16BE] = SND_PCM_FORMAT_S16_BE,
  49         [PA_SAMPLE_FLOAT32LE] = SND_PCM_FORMAT_FLOAT_LE,
  50         [PA_SAMPLE_FLOAT32BE] = SND_PCM_FORMAT_FLOAT_BE,
  51     };
  52     assert(pcm_handle && ss && periods && period_size);
  53
  54     if (snd_pcm_hw_params_malloc(&hwparams) < 0 ||
  55         snd_pcm_hw_params_any(pcm_handle, hwparams) < 0 ||
  56         snd_pcm_hw_params_set_access(pcm_handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED) < 0 ||
  57         snd_pcm_hw_params_set_format(pcm_handle, hwparams, format_trans[ss->format]) < 0 ||
  58         snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, &r, NULL) < 0 ||
  59         snd_pcm_hw_params_set_channels(pcm_handle, hwparams, ss->channels) < 0 ||
  60         (*periods > 0 && snd_pcm_hw_params_set_periods_near(pcm_handle, hwparams, periods, NULL) < 0) ||
  61         (*period_size > 0 && snd_pcm_hw_params_set_period_size_near(pcm_handle, hwparams, period_size, NULL) < 0) ||
  62         snd_pcm_hw_params(pcm_handle, hwparams) < 0)
  63         goto finish;
  64
  65     if (ss->rate != r)
  66         pa_log_info(__FILE__": device doesn't support %u Hz, changed to %u Hz.\n", ss->rate, r);
  67
  68     if (snd_pcm_prepare(pcm_handle) < 0)
  69         goto finish;
  70
  71     if (snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size) < 0 ||
  72         snd_pcm_hw_params_get_period_size(hwparams, period_size, NULL) < 0)
  73         goto finish;
  74
  75     assert(buffer_size > 0);
  76     assert(*period_size > 0);
  77     *periods = buffer_size / *period_size;
  78     assert(*periods > 0);
  79
  80     ret = 0;
  81
  82 finish:
  83     if (hwparams)
  84         snd_pcm_hw_params_free(hwparams);
  85
  86     return ret;
  87 }
  88
  89 /* Allocate an IO event for every ALSA poll descriptor for the
  90  * specified ALSA device. Return a pointer to such an array in
  91  * *io_events. Store the length of that array in *n_io_events. Use the
  92  * specified callback function and userdata. The array has to be freed
  93  * with pa_free_io_events(). */
  94 int pa_create_io_events(snd_pcm_t *pcm_handle, pa_mainloop_api* m, pa_io_event ***io_events, unsigned *n_io_events, void (*cb)(pa_mainloop_api*a, pa_io_event *e, int fd, pa_io_event_flags_t events, void *userdata), void *userdata) {
  95     unsigned i;
  96     struct pollfd *pfds, *ppfd;
  97     pa_io_event **ios;
  98     assert(pcm_handle && m && io_events && n_io_events && cb);
  99
 100     *n_io_events = snd_pcm_poll_descriptors_count(pcm_handle);
 101
 102     pfds = pa_xmalloc(sizeof(struct pollfd) * *n_io_events);
 103     if (snd_pcm_poll_descriptors(pcm_handle, pfds, *n_io_events) < 0) {
 104         pa_xfree(pfds);
 105         return -1;
 106     }
 107
 108     *io_events = pa_xmalloc(sizeof(void*) * *n_io_events);
 109
 110     for (i = 0, ios = *io_events, ppfd = pfds; i < *n_io_events; i++, ios++, ppfd++) {
 111         *ios = m->io_new(m, ppfd->fd,
 112                             ((ppfd->events & POLLIN) ? PA_IO_EVENT_INPUT : 0) |
 113                             ((ppfd->events & POLLOUT) ? PA_IO_EVENT_OUTPUT : 0), cb, userdata);
 114         assert(*ios);
 115     }
 116
 117     pa_xfree(pfds);
 118     return 0;
 119 }
 120
 121 /* Free the memory allocated by pa_create_io_events() */
 122 void pa_free_io_events(pa_mainloop_api* m, pa_io_event **io_events, unsigned n_io_events) {
 123     unsigned i;
 124     pa_io_event **ios;
 125     assert(m && io_events);
 126
 127     for (ios = io_events, i = 0; i < n_io_events; i++, ios++)
 128         m->io_free(*ios);
 129     pa_xfree(io_events);
 130 }