plugins/dfsound/alsa.c

   1 /***************************************************************************
   2                             alsa.c  -  description
   3                              -------------------
   4     begin                : Sat Mar 01 2003
   5     copyright            : (C) 2002 by Pete Bernert
   6     email                : BlackDove@addcom.de
   7  ***************************************************************************/
   8 /***************************************************************************
   9  *                                                                         *
  10  *   This program is free software; you can redistribute it and/or modify  *
  11  *   it under the terms of the GNU General Public License as published by  *
  12  *   the Free Software Foundation; either version 2 of the License, or     *
  13  *   (at your option) any later version. See also the license.txt file for *
  14  *   additional informations.                                              *
  15  *                                                                         *
  16  ***************************************************************************/
  17
  18 #include "stdafx.h"
  19
  20 #define _IN_OSS
  21
  22 #include "externals.h"
  23
  24 #define ALSA_PCM_NEW_HW_PARAMS_API
  25 #define ALSA_PCM_NEW_SW_PARAMS_API
  26 #include <alsa/asoundlib.h>
  27
  28 static snd_pcm_t *handle = NULL;
  29 static snd_pcm_uframes_t buffer_size;
  30
  31 // SETUP SOUND
  32 void SetupSound(void)
  33 {
  34  snd_pcm_hw_params_t *hwparams;
  35  snd_pcm_status_t *status;
  36  unsigned int pspeed;
  37  int pchannels;
  38  int format;
  39  unsigned int buffer_time = 100000;
  40  unsigned int period_time = buffer_time / 4;
  41  int err;
  42
  43  pchannels=2;
  44
  45  pspeed = 44100;
  46  format = SND_PCM_FORMAT_S16;
  47
  48  if ((err = snd_pcm_open(&handle, "default",
  49                       SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK)) < 0)
  50   {
  51    printf("Audio open error: %s\n", snd_strerror(err));
  52    return;
  53   }
  54
  55  if((err = snd_pcm_nonblock(handle, 0))<0)
  56   {
  57    printf("Can't set blocking moded: %s\n", snd_strerror(err));
  58    return;
  59   }
  60
  61  snd_pcm_hw_params_alloca(&hwparams);
  62
  63  if((err=snd_pcm_hw_params_any(handle, hwparams))<0)
  64   {
  65    printf("Broken configuration for this PCM: %s\n", snd_strerror(err));
  66    return;
  67   }
  68
  69  if((err=snd_pcm_hw_params_set_access(handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED))<0)
  70   {
  71    printf("Access type not available: %s\n", snd_strerror(err));
  72    return;
  73   }
  74
  75  if((err=snd_pcm_hw_params_set_format(handle, hwparams, format))<0)
  76   {
  77    printf("Sample format not available: %s\n", snd_strerror(err));
  78    return;
  79   }
  80
  81  if((err=snd_pcm_hw_params_set_channels(handle, hwparams, pchannels))<0)
  82   {
  83    printf("Channels count not available: %s\n", snd_strerror(err));
  84    return;
  85   }
  86
  87  if((err=snd_pcm_hw_params_set_rate_near(handle, hwparams, &pspeed, 0))<0)
  88   {
  89    printf("Rate not available: %s\n", snd_strerror(err));
  90    return;
  91   }
  92
  93  if((err=snd_pcm_hw_params_set_buffer_time_near(handle, hwparams, &buffer_time, 0))<0)
  94   {
  95    printf("Buffer time error: %s\n", snd_strerror(err));
  96    return;
  97   }
  98
  99  if((err=snd_pcm_hw_params_set_period_time_near(handle, hwparams, &period_time, 0))<0)
 100   {
 101    printf("Period time error: %s\n", snd_strerror(err));
 102    return;
 103   }
 104
 105  if((err=snd_pcm_hw_params(handle, hwparams))<0)
 106   {
 107    printf("Unable to install hw params: %s\n", snd_strerror(err));
 108    return;
 109   }
 110
 111  snd_pcm_status_alloca(&status);
 112  if((err=snd_pcm_status(handle, status))<0)
 113   {
 114    printf("Unable to get status: %s\n", snd_strerror(err));
 115    return;
 116   }
 117
 118  buffer_size = snd_pcm_status_get_avail(status);
 119 }
 120
 121 // REMOVE SOUND
 122 void RemoveSound(void)
 123 {
 124  if(handle != NULL)
 125   {
 126    snd_pcm_drop(handle);
 127    snd_pcm_close(handle);
 128    handle = NULL;
 129   }
 130 }
 131
 132 // GET BYTES BUFFERED
 133 unsigned long SoundGetBytesBuffered(void)
 134 {
 135  unsigned long l;
 136
 137  if (handle == NULL)                                 // failed to open?
 138   return SOUNDSIZE;
 139  l = snd_pcm_avail(handle);
 140  if (l < 0) return 0;
 141  if (l < buffer_size / 2)                            // can we write in at least the half of fragments?
 142       l = SOUNDSIZE;                                 // -> no? wait
 143  else l = 0;                                         // -> else go on
 144
 145  return l;
 146 }
 147
 148 // FEED SOUND DATA
 149 void SoundFeedStreamData(unsigned char* pSound,long lBytes)
 150 {
 151  if (handle == NULL) return;
 152
 153  if (snd_pcm_state(handle) == SND_PCM_STATE_XRUN)
 154   snd_pcm_prepare(handle);
 155  snd_pcm_writei(handle,pSound, lBytes / 4);
 156 }