stream/ai_alsa1x.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     snd_pcm_uframes_t buffer_size, period_size;
  35     int err;
  36     int dir;
  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
  48     err = snd_pcm_hw_params_set_access(ai->alsa.handle, params,
  49                                        SND_PCM_ACCESS_RW_INTERLEAVED);
  50     if (err < 0) {
  51         mp_tmsg(MSGT_TV, MSGL_ERR, "Access type not available.\n");
  52         return -1;
  53     }
  54
  55     err = snd_pcm_hw_params_set_format(ai->alsa.handle, params, SND_PCM_FORMAT_S16_LE);
  56     if (err < 0) {
  57         mp_tmsg(MSGT_TV, MSGL_ERR, "Sample format not available.\n");
  58         return -1;
  59     }
  60
  61     err = snd_pcm_hw_params_set_channels(ai->alsa.handle, params, ai->req_channels);
  62     if (err < 0) {
  63         snd_pcm_hw_params_get_channels(params, &ai->channels);
  64         mp_tmsg(MSGT_TV, MSGL_ERR, "Channel count not available - reverting to default: %d\n",
  65                ai->channels);
  66     } else {
  67         ai->channels = ai->req_channels;
  68     }
  69
  70     dir = 0;
  71     rate = ai->req_samplerate;
  72     err = snd_pcm_hw_params_set_rate_near(ai->alsa.handle, params, &rate, &dir);
  73     if (err < 0) {
  74         mp_tmsg(MSGT_TV, MSGL_ERR, "Cannot set samplerate.\n");
  75     }
  76     ai->samplerate = rate;
  77
  78     dir = 0;
  79     ai->alsa.buffer_time = 1000000;
  80     err = snd_pcm_hw_params_set_buffer_time_near(ai->alsa.handle, params,
  81                                                  &ai->alsa.buffer_time, &dir);
  82     if (err < 0) {
  83         mp_tmsg(MSGT_TV, MSGL_ERR, "Cannot set buffer time.\n");
  84     }
  85
  86     dir = 0;
  87     ai->alsa.period_time = ai->alsa.buffer_time / 4;
  88     err = snd_pcm_hw_params_set_period_time_near(ai->alsa.handle, params,
  89                                                  &ai->alsa.period_time, &dir);
  90     if (err < 0) {
  91         mp_tmsg(MSGT_TV, MSGL_ERR, "Cannot set period time.\n");
  92     }
  93
  94     err = snd_pcm_hw_params(ai->alsa.handle, params);
  95     if (err < 0) {
  96         mp_tmsg(MSGT_TV, MSGL_ERR, "Unable to install hardware parameters: %s", snd_strerror(err));
  97         snd_pcm_hw_params_dump(params, ai->alsa.log);
  98         return -1;
  99     }
 100
 101     dir = -1;
 102     snd_pcm_hw_params_get_period_size(params, &period_size, &dir);
 103     snd_pcm_hw_params_get_buffer_size(params, &buffer_size);
 104     ai->alsa.chunk_size = period_size;
 105     if (period_size == buffer_size) {
 106         mp_tmsg(MSGT_TV, MSGL_ERR, "Can't use period equal to buffer size (%u == %lu)\n", ai->alsa.chunk_size, (long)buffer_size);
 107         return -1;
 108     }
 109
 110     snd_pcm_sw_params_current(ai->alsa.handle, swparams);
 111     err = snd_pcm_sw_params_set_avail_min(ai->alsa.handle, swparams, ai->alsa.chunk_size);
 112
 113     err = snd_pcm_sw_params_set_start_threshold(ai->alsa.handle, swparams, 0);
 114     err = snd_pcm_sw_params_set_stop_threshold(ai->alsa.handle, swparams, buffer_size);
 115
 116     if (snd_pcm_sw_params(ai->alsa.handle, swparams) < 0) {
 117         mp_tmsg(MSGT_TV, MSGL_ERR, "Unable to install software parameters:\n");
 118         snd_pcm_sw_params_dump(swparams, ai->alsa.log);
 119         return -1;
 120     }
 121
 122     if (mp_msg_test(MSGT_TV, MSGL_V)) {
 123         snd_pcm_dump(ai->alsa.handle, ai->alsa.log);
 124     }
 125
 126     ai->alsa.bits_per_sample = snd_pcm_format_physical_width(SND_PCM_FORMAT_S16_LE);
 127     ai->alsa.bits_per_frame = ai->alsa.bits_per_sample * ai->channels;
 128     ai->blocksize = ai->alsa.chunk_size * ai->alsa.bits_per_frame / 8;
 129     ai->samplesize = ai->alsa.bits_per_sample;
 130     ai->bytes_per_sample = ai->alsa.bits_per_sample/8;
 131
 132     return 0;
 133 }
 134
 135 int ai_alsa_init(audio_in_t *ai)
 136 {
 137     int err;
 138
 139     err = snd_pcm_open(&ai->alsa.handle, ai->alsa.device, SND_PCM_STREAM_CAPTURE, 0);
 140     if (err < 0) {
 141         mp_tmsg(MSGT_TV, MSGL_ERR, "Error opening audio: %s\n", snd_strerror(err));
 142         return -1;
 143     }
 144
 145     err = snd_output_stdio_attach(&ai->alsa.log, stderr, 0);
 146
 147     if (err < 0) {
 148         return -1;
 149     }
 150
 151     err = ai_alsa_setup(ai);
 152
 153     return err;
 154 }
 155
 156 #ifndef timersub
 157 #define timersub(a, b, result) \
 158 do { \
 159         (result)->tv_sec = (a)->tv_sec - (b)->tv_sec; \
 160         (result)->tv_usec = (a)->tv_usec - (b)->tv_usec; \
 161         if ((result)->tv_usec < 0) { \
 162                 --(result)->tv_sec; \
 163                 (result)->tv_usec += 1000000; \
 164         } \
 165 } while (0)
 166 #endif
 167
 168 int ai_alsa_xrun(audio_in_t *ai)
 169 {
 170     snd_pcm_status_t *status;
 171     int res;
 172
 173     snd_pcm_status_alloca(&status);
 174     if ((res = snd_pcm_status(ai->alsa.handle, status))<0) {
 175         mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA status error: %s", snd_strerror(res));
 176         return -1;
 177     }
 178     if (snd_pcm_status_get_state(status) == SND_PCM_STATE_XRUN) {
 179         struct timeval now, diff, tstamp;
 180         gettimeofday(&now, 0);
 181         snd_pcm_status_get_trigger_tstamp(status, &tstamp);
 182         timersub(&now, &tstamp, &diff);
 183         mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA xrun!!! (at least %.3f ms long)\n",
 184                diff.tv_sec * 1000 + diff.tv_usec / 1000.0);
 185         if (mp_msg_test(MSGT_TV, MSGL_V)) {
 186             mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA Status:\n");
 187             snd_pcm_status_dump(status, ai->alsa.log);
 188         }
 189         if ((res = snd_pcm_prepare(ai->alsa.handle))<0) {
 190             mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA xrun: prepare error: %s", snd_strerror(res));
 191             return -1;
 192         }
 193         return 0;               /* ok, data should be accepted again */
 194     }
 195     mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA read/write error");
 196     return -1;
 197 }