stream/ai_alsa.c

   1 /*
   2  * This file is part of MPlayer.
   3  *
   4  * MPlayer is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * MPlayer is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <sys/time.h>
  22 #include <alloca.h>
  23
  24 #include "config.h"
  25
  26 #include <alsa/asoundlib.h>
  27 #include "audio_in.h"
  28 #include "mp_msg.h"
  29
  30 int ai_alsa_setup(audio_in_t *ai)
  31 {
  32     snd_pcm_hw_params_t *params;
  33     snd_pcm_sw_params_t *swparams;
  34     int buffer_size;
  35     int err;
  36     unsigned int rate;
  37
  38     snd_pcm_hw_params_alloca(&params);
  39     snd_pcm_sw_params_alloca(&swparams);
  40
  41     err = snd_pcm_hw_params_any(ai->alsa.handle, params);
  42     if (err < 0) {
  43         mp_tmsg(MSGT_TV, MSGL_ERR, "Broken configuration for this PCM: no configurations available.\n");
  44         return -1;
  45     }
  46     err = snd_pcm_hw_params_set_access(ai->alsa.handle, params,
  47                                        SND_PCM_ACCESS_RW_INTERLEAVED);
  48     if (err < 0) {
  49         mp_tmsg(MSGT_TV, MSGL_ERR, "Access type not available.\n");
  50         return -1;
  51     }
  52     err = snd_pcm_hw_params_set_format(ai->alsa.handle, params, SND_PCM_FORMAT_S16_LE);
  53     if (err < 0) {
  54         mp_tmsg(MSGT_TV, MSGL_ERR, "Sample format not available.\n");
  55         return -1;
  56     }
  57     err = snd_pcm_hw_params_set_channels(ai->alsa.handle, params, ai->req_channels);
  58     if (err < 0) {
  59         ai->channels = snd_pcm_hw_params_get_channels(params);
  60         mp_tmsg(MSGT_TV, MSGL_ERR, "Channel count not available - reverting to default: %d\n",
  61                ai->channels);
  62     } else {
  63         ai->channels = ai->req_channels;
  64     }
  65
  66     err = snd_pcm_hw_params_set_rate_near(ai->alsa.handle, params, ai->req_samplerate, 0);
  67     assert(err >= 0);
  68     rate = err;
  69     ai->samplerate = rate;
  70
  71     ai->alsa.buffer_time = 1000000;
  72     ai->alsa.buffer_time = snd_pcm_hw_params_set_buffer_time_near(ai->alsa.handle, params,
  73                                                                ai->alsa.buffer_time, 0);
  74     assert(ai->alsa.buffer_time >= 0);
  75     ai->alsa.period_time = ai->alsa.buffer_time / 4;
  76     ai->alsa.period_time = snd_pcm_hw_params_set_period_time_near(ai->alsa.handle, params,
  77                                                                ai->alsa.period_time, 0);
  78     assert(ai->alsa.period_time >= 0);
  79     err = snd_pcm_hw_params(ai->alsa.handle, params);
  80     if (err < 0) {
  81         mp_tmsg(MSGT_TV, MSGL_ERR, "Unable to install hardware paramameters: %s");
  82         snd_pcm_hw_params_dump(params, ai->alsa.log);
  83         return -1;
  84     }
  85     ai->alsa.chunk_size = snd_pcm_hw_params_get_period_size(params, 0);
  86     buffer_size = snd_pcm_hw_params_get_buffer_size(params);
  87     if (ai->alsa.chunk_size == buffer_size) {
  88         mp_tmsg(MSGT_TV, MSGL_ERR, "Can't use period equal to buffer size (%u == %lu)\n", ai->alsa.chunk_size, (long)buffer_size);
  89         return -1;
  90     }
  91     snd_pcm_sw_params_current(ai->alsa.handle, swparams);
  92     err = snd_pcm_sw_params_set_sleep_min(ai->alsa.handle, swparams,0);
  93     assert(err >= 0);
  94     err = snd_pcm_sw_params_set_avail_min(ai->alsa.handle, swparams, ai->alsa.chunk_size);
  95     assert(err >= 0);
  96
  97     err = snd_pcm_sw_params_set_start_threshold(ai->alsa.handle, swparams, 0);
  98     assert(err >= 0);
  99     err = snd_pcm_sw_params_set_stop_threshold(ai->alsa.handle, swparams, buffer_size);
 100     assert(err >= 0);
 101
 102     assert(err >= 0);
 103     if (snd_pcm_sw_params(ai->alsa.handle, swparams) < 0) {
 104         mp_tmsg(MSGT_TV, MSGL_ERR, "Unable to install software parameters:\n");
 105         snd_pcm_sw_params_dump(swparams, ai->alsa.log);
 106         return -1;
 107     }
 108
 109     if (mp_msg_test(MSGT_TV, MSGL_V)) {
 110         snd_pcm_dump(ai->alsa.handle, ai->alsa.log);
 111     }
 112
 113     ai->alsa.bits_per_sample = snd_pcm_format_physical_width(SND_PCM_FORMAT_S16_LE);
 114     ai->alsa.bits_per_frame = ai->alsa.bits_per_sample * ai->channels;
 115     ai->blocksize = ai->alsa.chunk_size * ai->alsa.bits_per_frame / 8;
 116     ai->samplesize = ai->alsa.bits_per_sample;
 117     ai->bytes_per_sample = ai->alsa.bits_per_sample/8;
 118
 119     return 0;
 120 }
 121
 122 int ai_alsa_init(audio_in_t *ai)
 123 {
 124     int err;
 125
 126     err = snd_pcm_open(&ai->alsa.handle, ai->alsa.device, SND_PCM_STREAM_CAPTURE, 0);
 127     if (err < 0) {
 128         mp_tmsg(MSGT_TV, MSGL_ERR, "Error opening audio: %s\n", snd_strerror(err));
 129         return -1;
 130     }
 131
 132     err = snd_output_stdio_attach(&ai->alsa.log, stderr, 0);
 133
 134     if (err < 0) {
 135         return -1;
 136     }
 137
 138     err = ai_alsa_setup(ai);
 139
 140     return err;
 141 }
 142
 143 #ifndef timersub
 144 #define timersub(a, b, result) \
 145 do { \
 146         (result)->tv_sec = (a)->tv_sec - (b)->tv_sec; \
 147         (result)->tv_usec = (a)->tv_usec - (b)->tv_usec; \
 148         if ((result)->tv_usec < 0) { \
 149                 --(result)->tv_sec; \
 150                 (result)->tv_usec += 1000000; \
 151         } \
 152 } while (0)
 153 #endif
 154
 155 int ai_alsa_xrun(audio_in_t *ai)
 156 {
 157     snd_pcm_status_t *status;
 158     int res;
 159
 160     snd_pcm_status_alloca(&status);
 161     if ((res = snd_pcm_status(ai->alsa.handle, status))<0) {
 162         mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA status error: %s", snd_strerror(res));
 163         return -1;
 164     }
 165     if (snd_pcm_status_get_state(status) == SND_PCM_STATE_XRUN) {
 166         struct timeval now, diff, tstamp;
 167         gettimeofday(&now, 0);
 168         snd_pcm_status_get_trigger_tstamp(status, &tstamp);
 169         timersub(&now, &tstamp, &diff);
 170         mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA xrun!!! (at least %.3f ms long)\n",
 171                diff.tv_sec * 1000 + diff.tv_usec / 1000.0);
 172         if (mp_msg_test(MSGT_TV, MSGL_V)) {
 173             mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA Status:\n");
 174             snd_pcm_status_dump(status, ai->alsa.log);
 175         }
 176         if ((res = snd_pcm_prepare(ai->alsa.handle))<0) {
 177             mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA xrun: prepare error: %s", snd_strerror(res));
 178             return -1;
 179         }
 180         return 0;               /* ok, data should be accepted again */
 181     }
 182     mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA read/write error");
 183     return -1;
 184 }