stream/ai_alsa.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     int buffer_size;
  18     int err;
  19     unsigned int rate;
  20
  21     snd_pcm_hw_params_alloca(&params);
  22     snd_pcm_sw_params_alloca(&swparams);
  23
  24     err = snd_pcm_hw_params_any(ai->alsa.handle, params);
  25     if (err < 0) {
  26         mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_PcmBrokenConfig);
  27         return -1;
  28     }
  29     err = snd_pcm_hw_params_set_access(ai->alsa.handle, params,
  30                                        SND_PCM_ACCESS_RW_INTERLEAVED);
  31     if (err < 0) {
  32         mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_UnavailableAccessType);
  33         return -1;
  34     }
  35     err = snd_pcm_hw_params_set_format(ai->alsa.handle, params, SND_PCM_FORMAT_S16_LE);
  36     if (err < 0) {
  37         mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_UnavailableSampleFmt);
  38         return -1;
  39     }
  40     err = snd_pcm_hw_params_set_channels(ai->alsa.handle, params, ai->req_channels);
  41     if (err < 0) {
  42         ai->channels = snd_pcm_hw_params_get_channels(params);
  43         mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_UnavailableChanCount,
  44                ai->channels);
  45     } else {
  46         ai->channels = ai->req_channels;
  47     }
  48
  49     err = snd_pcm_hw_params_set_rate_near(ai->alsa.handle, params, ai->req_samplerate, 0);
  50     assert(err >= 0);
  51     rate = err;
  52     ai->samplerate = rate;
  53
  54     ai->alsa.buffer_time = 1000000;
  55     ai->alsa.buffer_time = snd_pcm_hw_params_set_buffer_time_near(ai->alsa.handle, params,
  56                                                                ai->alsa.buffer_time, 0);
  57     assert(ai->alsa.buffer_time >= 0);
  58     ai->alsa.period_time = ai->alsa.buffer_time / 4;
  59     ai->alsa.period_time = snd_pcm_hw_params_set_period_time_near(ai->alsa.handle, params,
  60                                                                ai->alsa.period_time, 0);
  61     assert(ai->alsa.period_time >= 0);
  62     err = snd_pcm_hw_params(ai->alsa.handle, params);
  63     if (err < 0) {
  64         mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_CannotInstallHWParams);
  65         snd_pcm_hw_params_dump(params, ai->alsa.log);
  66         return -1;
  67     }
  68     ai->alsa.chunk_size = snd_pcm_hw_params_get_period_size(params, 0);
  69     buffer_size = snd_pcm_hw_params_get_buffer_size(params);
  70     if (ai->alsa.chunk_size == buffer_size) {
  71         mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_PeriodEqualsBufferSize, ai->alsa.chunk_size, (long)buffer_size);
  72         return -1;
  73     }
  74     snd_pcm_sw_params_current(ai->alsa.handle, swparams);
  75     err = snd_pcm_sw_params_set_sleep_min(ai->alsa.handle, swparams,0);
  76     assert(err >= 0);
  77     err = snd_pcm_sw_params_set_avail_min(ai->alsa.handle, swparams, ai->alsa.chunk_size);
  78     assert(err >= 0);
  79
  80     err = snd_pcm_sw_params_set_start_threshold(ai->alsa.handle, swparams, 0);
  81     assert(err >= 0);
  82     err = snd_pcm_sw_params_set_stop_threshold(ai->alsa.handle, swparams, buffer_size);
  83     assert(err >= 0);
  84
  85     assert(err >= 0);
  86     if (snd_pcm_sw_params(ai->alsa.handle, swparams) < 0) {
  87         mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_CannotInstallSWParams);
  88         snd_pcm_sw_params_dump(swparams, ai->alsa.log);
  89         return -1;
  90     }
  91
  92     if (mp_msg_test(MSGT_TV, MSGL_V)) {
  93         snd_pcm_dump(ai->alsa.handle, ai->alsa.log);
  94     }
  95
  96     ai->alsa.bits_per_sample = snd_pcm_format_physical_width(SND_PCM_FORMAT_S16_LE);
  97     ai->alsa.bits_per_frame = ai->alsa.bits_per_sample * ai->channels;
  98     ai->blocksize = ai->alsa.chunk_size * ai->alsa.bits_per_frame / 8;
  99     ai->samplesize = ai->alsa.bits_per_sample;
 100     ai->bytes_per_sample = ai->alsa.bits_per_sample/8;
 101
 102     return 0;
 103 }
 104
 105 int ai_alsa_init(audio_in_t *ai)
 106 {
 107     int err;
 108
 109     err = snd_pcm_open(&ai->alsa.handle, ai->alsa.device, SND_PCM_STREAM_CAPTURE, 0);
 110     if (err < 0) {
 111         mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_ErrorOpeningAudio, snd_strerror(err));
 112         return -1;
 113     }
 114
 115     err = snd_output_stdio_attach(&ai->alsa.log, stderr, 0);
 116
 117     if (err < 0) {
 118         return -1;
 119     }
 120
 121     err = ai_alsa_setup(ai);
 122
 123     return err;
 124 }
 125
 126 #ifndef timersub
 127 #define timersub(a, b, result) \
 128 do { \
 129         (result)->tv_sec = (a)->tv_sec - (b)->tv_sec; \
 130         (result)->tv_usec = (a)->tv_usec - (b)->tv_usec; \
 131         if ((result)->tv_usec < 0) { \
 132                 --(result)->tv_sec; \
 133                 (result)->tv_usec += 1000000; \
 134         } \
 135 } while (0)
 136 #endif
 137
 138 int ai_alsa_xrun(audio_in_t *ai)
 139 {
 140     snd_pcm_status_t *status;
 141     int res;
 142
 143     snd_pcm_status_alloca(&status);
 144     if ((res = snd_pcm_status(ai->alsa.handle, status))<0) {
 145         mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_AlsaStatusError, snd_strerror(res));
 146         return -1;
 147     }
 148     if (snd_pcm_status_get_state(status) == SND_PCM_STATE_XRUN) {
 149         struct timeval now, diff, tstamp;
 150         gettimeofday(&now, 0);
 151         snd_pcm_status_get_trigger_tstamp(status, &tstamp);
 152         timersub(&now, &tstamp, &diff);
 153         mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_AlsaXRUN,
 154                diff.tv_sec * 1000 + diff.tv_usec / 1000.0);
 155         if (mp_msg_test(MSGT_TV, MSGL_V)) {
 156             mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_AlsaStatus);
 157             snd_pcm_status_dump(status, ai->alsa.log);
 158         }
 159         if ((res = snd_pcm_prepare(ai->alsa.handle))<0) {
 160             mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_AlsaXRUNPrepareError, snd_strerror(res));
 161             return -1;
 162         }
 163         return 0;               /* ok, data should be accepted again */
 164     }
 165     mp_msg(MSGT_TV, MSGL_ERR, MSGTR_MPDEMUX_AIALSA_AlsaReadWriteError);
 166     return -1;
 167 }