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 #include "help_mp.h"
  30
  31 int ai_alsa_setup(audio_in_t *ai)
  32 {
  33     snd_pcm_hw_params_t *params;
  34     snd_pcm_sw_params_t *swparams;
  35     int buffer_size;
  36     int err;
  37     unsigned int rate;
  38
  39     snd_pcm_hw_params_alloca(&params);
  40     snd_pcm_sw_params_alloca(&swparams);
  41
  42     err = snd_pcm_hw_params_any(ai->alsa.handle, params);
  43     if (err < 0) {
  44         mp_tmsg(MSGT_TV, MSGL_ERR, "Broken configuration for this PCM: no configurations available.\n");
  45         return -1;
  46     }
  47     err = snd_pcm_hw_params_set_access(ai->alsa.handle, params,
  48                                        SND_PCM_ACCESS_RW_INTERLEAVED);
  49     if (err < 0) {
  50         mp_tmsg(MSGT_TV, MSGL_ERR, "Access type not available.\n");
  51         return -1;
  52     }
  53     err = snd_pcm_hw_params_set_format(ai->alsa.handle, params, SND_PCM_FORMAT_S16_LE);
  54     if (err < 0) {
  55         mp_tmsg(MSGT_TV, MSGL_ERR, "Sample format not available.\n");
  56         return -1;
  57     }
  58     err = snd_pcm_hw_params_set_channels(ai->alsa.handle, params, ai->req_channels);
  59     if (err < 0) {
  60         ai->channels = snd_pcm_hw_params_get_channels(params);
  61         mp_tmsg(MSGT_TV, MSGL_ERR, "Channel count not available - reverting to default: %d\n",
  62                ai->channels);
  63     } else {
  64         ai->channels = ai->req_channels;
  65     }
  66
  67     err = snd_pcm_hw_params_set_rate_near(ai->alsa.handle, params, ai->req_samplerate, 0);
  68     assert(err >= 0);
  69     rate = err;
  70     ai->samplerate = rate;
  71
  72     ai->alsa.buffer_time = 1000000;
  73     ai->alsa.buffer_time = snd_pcm_hw_params_set_buffer_time_near(ai->alsa.handle, params,
  74                                                                ai->alsa.buffer_time, 0);
  75     assert(ai->alsa.buffer_time >= 0);
  76     ai->alsa.period_time = ai->alsa.buffer_time / 4;
  77     ai->alsa.period_time = snd_pcm_hw_params_set_period_time_near(ai->alsa.handle, params,
  78                                                                ai->alsa.period_time, 0);
  79     assert(ai->alsa.period_time >= 0);
  80     err = snd_pcm_hw_params(ai->alsa.handle, params);
  81     if (err < 0) {
  82         mp_tmsg(MSGT_TV, MSGL_ERR, "Unable to install hardware paramameters: %s");
  83         snd_pcm_hw_params_dump(params, ai->alsa.log);
  84         return -1;
  85     }
  86     ai->alsa.chunk_size = snd_pcm_hw_params_get_period_size(params, 0);
  87     buffer_size = snd_pcm_hw_params_get_buffer_size(params);
  88     if (ai->alsa.chunk_size == buffer_size) {
  89         mp_tmsg(MSGT_TV, MSGL_ERR, "Can't use period equal to buffer size (%u == %lu)\n", ai->alsa.chunk_size, (long)buffer_size);
  90         return -1;
  91     }
  92     snd_pcm_sw_params_current(ai->alsa.handle, swparams);
  93     err = snd_pcm_sw_params_set_sleep_min(ai->alsa.handle, swparams,0);
  94     assert(err >= 0);
  95     err = snd_pcm_sw_params_set_avail_min(ai->alsa.handle, swparams, ai->alsa.chunk_size);
  96     assert(err >= 0);
  97
  98     err = snd_pcm_sw_params_set_start_threshold(ai->alsa.handle, swparams, 0);
  99     assert(err >= 0);
 100     err = snd_pcm_sw_params_set_stop_threshold(ai->alsa.handle, swparams, buffer_size);
 101     assert(err >= 0);
 102
 103     assert(err >= 0);
 104     if (snd_pcm_sw_params(ai->alsa.handle, swparams) < 0) {
 105         mp_tmsg(MSGT_TV, MSGL_ERR, "Unable to install software parameters:\n");
 106         snd_pcm_sw_params_dump(swparams, ai->alsa.log);
 107         return -1;
 108     }
 109
 110     if (mp_msg_test(MSGT_TV, MSGL_V)) {
 111         snd_pcm_dump(ai->alsa.handle, ai->alsa.log);
 112     }
 113
 114     ai->alsa.bits_per_sample = snd_pcm_format_physical_width(SND_PCM_FORMAT_S16_LE);
 115     ai->alsa.bits_per_frame = ai->alsa.bits_per_sample * ai->channels;
 116     ai->blocksize = ai->alsa.chunk_size * ai->alsa.bits_per_frame / 8;
 117     ai->samplesize = ai->alsa.bits_per_sample;
 118     ai->bytes_per_sample = ai->alsa.bits_per_sample/8;
 119
 120     return 0;
 121 }
 122
 123 int ai_alsa_init(audio_in_t *ai)
 124 {
 125     int err;
 126
 127     err = snd_pcm_open(&ai->alsa.handle, ai->alsa.device, SND_PCM_STREAM_CAPTURE, 0);
 128     if (err < 0) {
 129         mp_tmsg(MSGT_TV, MSGL_ERR, "Error opening audio: %s\n", snd_strerror(err));
 130         return -1;
 131     }
 132
 133     err = snd_output_stdio_attach(&ai->alsa.log, stderr, 0);
 134
 135     if (err < 0) {
 136         return -1;
 137     }
 138
 139     err = ai_alsa_setup(ai);
 140
 141     return err;
 142 }
 143
 144 #ifndef timersub
 145 #define timersub(a, b, result) \
 146 do { \
 147         (result)->tv_sec = (a)->tv_sec - (b)->tv_sec; \
 148         (result)->tv_usec = (a)->tv_usec - (b)->tv_usec; \
 149         if ((result)->tv_usec < 0) { \
 150                 --(result)->tv_sec; \
 151                 (result)->tv_usec += 1000000; \
 152         } \
 153 } while (0)
 154 #endif
 155
 156 int ai_alsa_xrun(audio_in_t *ai)
 157 {
 158     snd_pcm_status_t *status;
 159     int res;
 160
 161     snd_pcm_status_alloca(&status);
 162     if ((res = snd_pcm_status(ai->alsa.handle, status))<0) {
 163         mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA status error: %s", snd_strerror(res));
 164         return -1;
 165     }
 166     if (snd_pcm_status_get_state(status) == SND_PCM_STATE_XRUN) {
 167         struct timeval now, diff, tstamp;
 168         gettimeofday(&now, 0);
 169         snd_pcm_status_get_trigger_tstamp(status, &tstamp);
 170         timersub(&now, &tstamp, &diff);
 171         mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA xrun!!! (at least %.3f ms long)\n",
 172                diff.tv_sec * 1000 + diff.tv_usec / 1000.0);
 173         if (mp_msg_test(MSGT_TV, MSGL_V)) {
 174             mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA Status:\n");
 175             snd_pcm_status_dump(status, ai->alsa.log);
 176         }
 177         if ((res = snd_pcm_prepare(ai->alsa.handle))<0) {
 178             mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA xrun: prepare error: %s", snd_strerror(res));
 179             return -1;
 180         }
 181         return 0;               /* ok, data should be accepted again */
 182     }
 183     mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA read/write error");
 184     return -1;
 185 }