stream/ai_alsa1x.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <sys/time.h>
   4 #include <alloca.h>
   5
   6 #include "config.h"
   7
   8 #include <alsa/asoundlib.h>
   9 #include "audio_in.h"
  10 #include "mp_msg.h"
  11 #include "help_mp.h"
  12
  13 int ai_alsa_setup(audio_in_t *ai)
  14 {
  15     snd_pcm_hw_params_t *params;
  16     snd_pcm_sw_params_t *swparams;
  17     snd_pcm_uframes_t buffer_size, period_size;
  18     int err;
  19     int dir;
  20     unsigned int rate;
  21
  22     snd_pcm_hw_params_alloca(&params);
  23     snd_pcm_sw_params_alloca(&swparams);
  24
  25     err = snd_pcm_hw_params_any(ai->alsa.handle, params);
  26     if (err < 0) {
  27         mp_tmsg(MSGT_TV, MSGL_ERR, "Broken configuration for this PCM: no configurations available.\n");
  28         return -1;
  29     }
  30
  31     err = snd_pcm_hw_params_set_access(ai->alsa.handle, params,
  32                                        SND_PCM_ACCESS_RW_INTERLEAVED);
  33     if (err < 0) {
  34         mp_tmsg(MSGT_TV, MSGL_ERR, "Access type not available.\n");
  35         return -1;
  36     }
  37
  38     err = snd_pcm_hw_params_set_format(ai->alsa.handle, params, SND_PCM_FORMAT_S16_LE);
  39     if (err < 0) {
  40         mp_tmsg(MSGT_TV, MSGL_ERR, "Sample format not available.\n");
  41         return -1;
  42     }
  43
  44     err = snd_pcm_hw_params_set_channels(ai->alsa.handle, params, ai->req_channels);
  45     if (err < 0) {
  46         snd_pcm_hw_params_get_channels(params, &ai->channels);
  47         mp_tmsg(MSGT_TV, MSGL_ERR, "Channel count not available - reverting to default: %d\n",
  48                ai->channels);
  49     } else {
  50         ai->channels = ai->req_channels;
  51     }
  52
  53     dir = 0;
  54     rate = ai->req_samplerate;
  55     err = snd_pcm_hw_params_set_rate_near(ai->alsa.handle, params, &rate, &dir);
  56     if (err < 0) {
  57         mp_tmsg(MSGT_TV, MSGL_ERR, "Cannot set samplerate.\n");
  58     }
  59     ai->samplerate = rate;
  60
  61     dir = 0;
  62     ai->alsa.buffer_time = 1000000;
  63     err = snd_pcm_hw_params_set_buffer_time_near(ai->alsa.handle, params,
  64                                                  &ai->alsa.buffer_time, &dir);
  65     if (err < 0) {
  66         mp_tmsg(MSGT_TV, MSGL_ERR, "Cannot set buffer time.\n");
  67     }
  68
  69     dir = 0;
  70     ai->alsa.period_time = ai->alsa.buffer_time / 4;
  71     err = snd_pcm_hw_params_set_period_time_near(ai->alsa.handle, params,
  72                                                  &ai->alsa.period_time, &dir);
  73     if (err < 0) {
  74         mp_tmsg(MSGT_TV, MSGL_ERR, "Cannot set period time.\n");
  75     }
  76
  77     err = snd_pcm_hw_params(ai->alsa.handle, params);
  78     if (err < 0) {
  79         mp_tmsg(MSGT_TV, MSGL_ERR, "Unable to install hardware paramameters: %s", snd_strerror(err));
  80         snd_pcm_hw_params_dump(params, ai->alsa.log);
  81         return -1;
  82     }
  83
  84     dir = -1;
  85     snd_pcm_hw_params_get_period_size(params, &period_size, &dir);
  86     snd_pcm_hw_params_get_buffer_size(params, &buffer_size);
  87     ai->alsa.chunk_size = period_size;
  88     if (period_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
  93     snd_pcm_sw_params_current(ai->alsa.handle, swparams);
  94     err = snd_pcm_sw_params_set_sleep_min(ai->alsa.handle, swparams,0);
  95     err = snd_pcm_sw_params_set_avail_min(ai->alsa.handle, swparams, ai->alsa.chunk_size);
  96
  97     err = snd_pcm_sw_params_set_start_threshold(ai->alsa.handle, swparams, 0);
  98     err = snd_pcm_sw_params_set_stop_threshold(ai->alsa.handle, swparams, buffer_size);
  99
 100     if (snd_pcm_sw_params(ai->alsa.handle, swparams) < 0) {
 101         mp_tmsg(MSGT_TV, MSGL_ERR, "Unable to install software parameters:\n");
 102         snd_pcm_sw_params_dump(swparams, ai->alsa.log);
 103         return -1;
 104     }
 105
 106     if (mp_msg_test(MSGT_TV, MSGL_V)) {
 107         snd_pcm_dump(ai->alsa.handle, ai->alsa.log);
 108     }
 109
 110     ai->alsa.bits_per_sample = snd_pcm_format_physical_width(SND_PCM_FORMAT_S16_LE);
 111     ai->alsa.bits_per_frame = ai->alsa.bits_per_sample * ai->channels;
 112     ai->blocksize = ai->alsa.chunk_size * ai->alsa.bits_per_frame / 8;
 113     ai->samplesize = ai->alsa.bits_per_sample;
 114     ai->bytes_per_sample = ai->alsa.bits_per_sample/8;
 115
 116     return 0;
 117 }
 118
 119 int ai_alsa_init(audio_in_t *ai)
 120 {
 121     int err;
 122
 123     err = snd_pcm_open(&ai->alsa.handle, ai->alsa.device, SND_PCM_STREAM_CAPTURE, 0);
 124     if (err < 0) {
 125         mp_tmsg(MSGT_TV, MSGL_ERR, "Error opening audio: %s\n", snd_strerror(err));
 126         return -1;
 127     }
 128
 129     err = snd_output_stdio_attach(&ai->alsa.log, stderr, 0);
 130
 131     if (err < 0) {
 132         return -1;
 133     }
 134
 135     err = ai_alsa_setup(ai);
 136
 137     return err;
 138 }
 139
 140 #ifndef timersub
 141 #define timersub(a, b, result) \
 142 do { \
 143         (result)->tv_sec = (a)->tv_sec - (b)->tv_sec; \
 144         (result)->tv_usec = (a)->tv_usec - (b)->tv_usec; \
 145         if ((result)->tv_usec < 0) { \
 146                 --(result)->tv_sec; \
 147                 (result)->tv_usec += 1000000; \
 148         } \
 149 } while (0)
 150 #endif
 151
 152 int ai_alsa_xrun(audio_in_t *ai)
 153 {
 154     snd_pcm_status_t *status;
 155     int res;
 156
 157     snd_pcm_status_alloca(&status);
 158     if ((res = snd_pcm_status(ai->alsa.handle, status))<0) {
 159         mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA status error: %s", snd_strerror(res));
 160         return -1;
 161     }
 162     if (snd_pcm_status_get_state(status) == SND_PCM_STATE_XRUN) {
 163         struct timeval now, diff, tstamp;
 164         gettimeofday(&now, 0);
 165         snd_pcm_status_get_trigger_tstamp(status, &tstamp);
 166         timersub(&now, &tstamp, &diff);
 167         mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA xrun!!! (at least %.3f ms long)\n",
 168                diff.tv_sec * 1000 + diff.tv_usec / 1000.0);
 169         if (mp_msg_test(MSGT_TV, MSGL_V)) {
 170             mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA Status:\n");
 171             snd_pcm_status_dump(status, ai->alsa.log);
 172         }
 173         if ((res = snd_pcm_prepare(ai->alsa.handle))<0) {
 174             mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA xrun: prepare error: %s", snd_strerror(res));
 175             return -1;
 176         }
 177         return 0;               /* ok, data should be accepted again */
 178     }
 179     mp_tmsg(MSGT_TV, MSGL_ERR, "ALSA read/write error");
 180     return -1;
 181 }