1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/drivers/audio_alsa.c	Sat Apr 19 00:36:36 2008 +0000
     1.3 @@ -0,0 +1,203 @@
     1.4 +/**
     1.5 + * $Id: audio_esd.c 602 2008-01-15 20:50:23Z nkeynes $
     1.6 + * 
     1.7 + * The asla  audio driver
     1.8 + *
     1.9 + * Copyright (c) 2008 Jonathan Muller
    1.10 + *
    1.11 + * This program is free software; you can redistribute it and/or modify
    1.12 + * it under the terms of the GNU General Public License as published by
    1.13 + * the Free Software Foundation; either version 2 of the License, or
    1.14 + * (at your option) any later version.
    1.15 + *
    1.16 + * This program is distributed in the hope that it will be useful,
    1.17 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.18 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    1.19 + * GNU General Public License for more details.
    1.20 + */
    1.21 +#include <stdio.h>
    1.22 +#include <unistd.h>
    1.23 +
    1.24 +/* Use the newer ALSA API */
    1.25 +#define ALSA_PCM_NEW_HW_PARAMS_API
    1.26 +
    1.27 +#include <alsa/asoundlib.h>
    1.28 +#include "config.h"
    1.29 +#include "aica/audio.h"
    1.30 +#include "dream.h"
    1.31 +
    1.32 +
    1.33 +static snd_pcm_t *_soundDevice = NULL;
    1.34 +static int frames;
    1.35 +static int frame_bytes;
    1.36 +
    1.37 +
    1.38 +struct lxdream_config_entry alsa_config[] = {
    1.39 +    {"device", CONFIG_TYPE_FILE, "default"},
    1.40 +    {NULL, CONFIG_TYPE_NONE}
    1.41 +};
    1.42 +
    1.43 +
    1.44 +gboolean audio_alsa_init(  )
    1.45 +{
    1.46 +    int err;
    1.47 +
    1.48 +    return TRUE;
    1.49 +}
    1.50 +
    1.51 +
    1.52 +gboolean audio_alsa_set_format( uint32_t rate, uint32_t format )
    1.53 +{
    1.54 +    int i;
    1.55 +    int err;
    1.56 +    snd_pcm_hw_params_t *hw_params;
    1.57 +    snd_pcm_sw_params_t *sw_params;
    1.58 +    snd_pcm_uframes_t frames;
    1.59 +    unsigned int resample = 1;
    1.60 +    unsigned int actualRate = rate;
    1.61 +    snd_pcm_uframes_t bufferSize;
    1.62 +    int dir;
    1.63 +
    1.64 +
    1.65 +    // Open the device we were told to open.
    1.66 +    err = snd_pcm_open( &_soundDevice, alsa_config[0].value,
    1.67 +                        SND_PCM_STREAM_PLAYBACK, 0 );
    1.68 +
    1.69 +    // Check for error on open.
    1.70 +    if ( err < 0 ) {
    1.71 +        ERROR( "Init: cannot open audio device %s (%s)\n",
    1.72 +               alsa_config[0].value, snd_strerror( err ) );
    1.73 +        return FALSE;
    1.74 +    } else {
    1.75 +        DEBUG( "Audio device opened successfully." );
    1.76 +    }
    1.77 +
    1.78 +    frame_bytes = ( 2 * ( snd_pcm_format_width( SND_PCM_FORMAT_S16_LE ) / 8 ) );
    1.79 +
    1.80 +
    1.81 +    //snd_pcm_hw_params_alloca (&hw_params);
    1.82 +    // Allocate the hardware parameter structure.
    1.83 +    if ( ( err = snd_pcm_hw_params_malloc( &hw_params ) ) < 0 ) {
    1.84 +        ERROR( "Init: cannot allocate hardware parameter structure (%s)\n",
    1.85 +               snd_strerror( err ) );
    1.86 +        return FALSE;
    1.87 +    }
    1.88 +
    1.89 +    if ( ( err = snd_pcm_hw_params_any( _soundDevice, hw_params ) ) < 0 ) {
    1.90 +        ERROR( "Init: cannot allocate hardware parameter structure (%s)\n",
    1.91 +               snd_strerror( err ) );
    1.92 +        return FALSE;
    1.93 +    }
    1.94 +    // Set access to RW interleaved.
    1.95 +    if ( ( err = snd_pcm_hw_params_set_access( _soundDevice, hw_params,
    1.96 +                                               SND_PCM_ACCESS_RW_INTERLEAVED ) )
    1.97 +         < 0 ) {
    1.98 +        ERROR( " Init: cannot set access type (%s)\n", snd_strerror( err ) );
    1.99 +        return FALSE;
   1.100 +    }
   1.101 +
   1.102 +    if ( ( err = snd_pcm_hw_params_set_format( _soundDevice, hw_params,
   1.103 +                                               SND_PCM_FORMAT_S16_LE ) ) <
   1.104 +         0 ) {
   1.105 +        ERROR( "Init: cannot set sample format (%s)\n", snd_strerror( err ) );
   1.106 +        return FALSE;
   1.107 +    }
   1.108 +
   1.109 +    err = snd_pcm_hw_params_set_rate_near( _soundDevice, hw_params, &rate, 0 );
   1.110 +    if ( err < 0 ) {
   1.111 +        ERROR( "Init: Resampling setup failed for playback: %s\n",
   1.112 +               snd_strerror( err ) );
   1.113 +        return err;
   1.114 +    }
   1.115 +    // Set channels to stereo (2).
   1.116 +    err = snd_pcm_hw_params_set_channels( _soundDevice, hw_params, 2 );
   1.117 +    if ( err < 0 ) {
   1.118 +        ERROR( "Init: cannot set channel count (%s)\n", snd_strerror( err ) );
   1.119 +        return FALSE;
   1.120 +    }
   1.121 +
   1.122 +    // frames = 4410;
   1.123 +    // snd_pcm_hw_params_set_period_size_near( _soundDevice, hw_params, &frames,
   1.124 +    //                                     &dir );
   1.125 +
   1.126 +    // Apply the hardware parameters that we've set.
   1.127 +    err = snd_pcm_hw_params( _soundDevice, hw_params );
   1.128 +    if ( err < 0 ) {
   1.129 +        DEBUG( "Init: cannot set parameters (%s)\n", snd_strerror( err ) );
   1.130 +        return FALSE;
   1.131 +    } else {
   1.132 +        DEBUG( "Audio device parameters have been set successfully." );
   1.133 +    }
   1.134 +
   1.135 +    snd_pcm_hw_params_get_period_size( hw_params, &frames, &dir );
   1.136 +    DEBUG( "period size = %d\n", frames );
   1.137 +
   1.138 +    // Get the buffer size.
   1.139 +    snd_pcm_hw_params_get_buffer_size( hw_params, &bufferSize );
   1.140 +    DEBUG("Buffer Size = %d\n", bufferSize);
   1.141 +
   1.142 +    // If we were going to do more with our sound device we would want to store
   1.143 +    // the buffer size so we know how much data we will need to fill it with.
   1.144 +
   1.145 +    //cout << "Init: Buffer size = " << bufferSize << " frames." << endl;
   1.146 +
   1.147 +    // Display the bit size of samples.
   1.148 +    //cout << "Init: Significant bits for linear samples = " << snd_pcm_hw_params_get_sbits(hw_params) << endl;
   1.149 +
   1.150 +    // Free the hardware parameters now that we're done with them.
   1.151 +    snd_pcm_hw_params_free( hw_params );
   1.152 +
   1.153 +    // Set the start threshold to reduce inter-buffer gaps
   1.154 +    snd_pcm_sw_params_alloca( &sw_params );
   1.155 +    snd_pcm_sw_params_current( _soundDevice, sw_params );
   1.156 +    snd_pcm_sw_params_set_start_threshold( _soundDevice, sw_params, bufferSize/2 );
   1.157 +    err = snd_pcm_sw_params( _soundDevice, sw_params );
   1.158 +    if( err < 0 ) {
   1.159 +	ERROR("Unable to set sw params for alsa driver: %s\n", snd_strerror(err));
   1.160 +	return FALSE;
   1.161 +    } 
   1.162 +
   1.163 +    err = snd_pcm_prepare( _soundDevice );
   1.164 +    if ( err < 0 ) {
   1.165 +        ERROR( "Init: cannot prepare audio interface for use (%s)\n",
   1.166 +               snd_strerror( err ) );
   1.167 +        return FALSE;
   1.168 +    }
   1.169 +    return TRUE;
   1.170 +}
   1.171 +
   1.172 +gboolean audio_alsa_process_buffer( audio_buffer_t buffer )
   1.173 +{
   1.174 +    int err;
   1.175 +    int length;
   1.176 +
   1.177 +
   1.178 +    length = buffer->length / frame_bytes;
   1.179 +
   1.180 +    err = snd_pcm_writei( _soundDevice, buffer->data, length );
   1.181 +    if( err == -EPIPE ) {
   1.182 +	snd_pcm_prepare( _soundDevice );
   1.183 +    } else if( err == -ESTRPIPE ) {
   1.184 +	snd_pcm_resume( _soundDevice );
   1.185 +    }
   1.186 +
   1.187 +    return TRUE;
   1.188 +}
   1.189 +
   1.190 +
   1.191 +gboolean audio_alsa_close(  )
   1.192 +{
   1.193 +    int err;
   1.194 +
   1.195 +    return TRUE;
   1.196 +}
   1.197 +
   1.198 +
   1.199 +
   1.200 +struct audio_driver audio_alsa_driver = { 
   1.201 +    "alsa",
   1.202 +    audio_alsa_init,
   1.203 +    audio_alsa_set_format,
   1.204 +    audio_alsa_process_buffer,
   1.205 +    audio_alsa_close
   1.206 +};