Rename interpretor to interpreter.
[Faustine.git] / interpreter / preprocessor / faust-0.9.47mr3 / architecture / audio / alsa-dsp.h
diff --git a/interpreter/preprocessor/faust-0.9.47mr3/architecture/audio/alsa-dsp.h b/interpreter/preprocessor/faust-0.9.47mr3/architecture/audio/alsa-dsp.h
new file mode 100644 (file)
index 0000000..e3a4f28
--- /dev/null
@@ -0,0 +1,693 @@
+/************************************************************************
+
+       IMPORTANT NOTE : this file contains two clearly delimited sections :
+       the ARCHITECTURE section (in two parts) and the USER section. Each section
+       is governed by its own copyright and license. Please check individually
+       each section for license and copyright information.
+*************************************************************************/
+
+/*******************BEGIN ARCHITECTURE SECTION (part 1/2)****************/
+
+/************************************************************************
+    FAUST Architecture File
+       Copyright (C) 2003-2011 GRAME, Centre National de Creation Musicale
+    ---------------------------------------------------------------------
+    This Architecture section is free software; you can redistribute it
+    and/or modify it under the terms of the GNU General Public License
+       as published by the Free Software Foundation; either version 3 of
+       the License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+       along with this program; If not, see <http://www.gnu.org/licenses/>.
+
+       EXCEPTION : As a special exception, you may create a larger work
+       that contains this FAUST architecture section and distribute
+       that work under terms of your choice, so long as this FAUST
+       architecture section is not modified.
+
+
+ ************************************************************************
+ ************************************************************************/
+
+#ifndef __alsa_dsp__
+#define __alsa_dsp__
+
+#include <stdio.h>
+#include <pthread.h>
+#include <sys/types.h>
+#include <pwd.h>
+
+#include <alsa/asoundlib.h>
+#include "audio.h"
+#include "dsp.h"
+
+/**
+DEFAULT ALSA PARAMETERS CONTROLLED BY ENVIRONMENT VARIABLES
+
+Some default parameters of Faust's ALSA applications are controlled by the following environment variables :
+
+    FAUST2ALSA_DEVICE   = "hw:0"
+    FAUST2ALSA_FREQUENCY= 44100
+    FAUST2ALSA_BUFFER   = 1024
+    FAUST2ALSA_PERIODS  = 2
+
+*/
+
+using namespace std;
+
+// handle 32/64 bits int size issues
+
+#ifdef __x86_64__
+
+#define uint32 unsigned int
+#define uint64 unsigned long int
+
+#define int32  int
+#define int64  long int
+
+#else
+
+#define uint32 unsigned int
+#define uint64 unsigned long long int
+
+#define int32  int
+#define int64  long long int
+#endif
+
+// check 32/64 bits issues are correctly handled
+
+#define check_error(err) if (err) { printf("%s:%d, alsa error %d : %s\n", __FILE__, __LINE__, err, snd_strerror(err)); exit(1); }
+#define check_error_msg(err,msg) if (err) { fprintf(stderr, "%s:%d, %s : %s(%d)\n", __FILE__, __LINE__, msg, snd_strerror(err), err); exit(1); }
+#define display_error_msg(err,msg) if (err) { fprintf(stderr, "%s:%d, %s : %s(%d)\n", __FILE__, __LINE__, msg, snd_strerror(err), err); }
+
+#define max(x,y) (((x)>(y)) ? (x) : (y))
+#define min(x,y) (((x)<(y)) ? (x) : (y))
+
+/**
+ * Used to set the priority and scheduling of the audi#include <sys/types.h>
+       #include <pwd.h>
+o thread
+ */
+static bool setRealtimePriority ()
+{
+    struct passwd *         pw;
+    int                     err;
+    uid_t                   uid;
+    struct sched_param      param;
+
+    uid = getuid ();
+    pw = getpwnam ("root");
+    setuid (pw->pw_uid);
+    param.sched_priority = 50; /* 0 to 99  */
+    err = sched_setscheduler(0, SCHED_RR, &param);
+    setuid (uid);
+    return (err != -1);
+}
+
+/******************************************************************************
+*******************************************************************************
+
+                                                               AUDIO INTERFACE
+
+*******************************************************************************
+*******************************************************************************/
+
+enum { kRead = 1, kWrite = 2, kReadWrite = 3 };
+
+/**
+ * A convenient class to pass parameters to AudioInterface
+ */
+class AudioParam
+{
+  public:
+
+       const char*             fCardName;
+       unsigned int    fFrequency;
+       unsigned int    fBuffering;
+       unsigned int    fPeriods;
+
+       unsigned int    fSoftInputs;
+       unsigned int    fSoftOutputs;
+
+  public :
+       AudioParam() :
+               fCardName("hw:0"),
+               fFrequency(44100),
+               fBuffering(512),
+               fPeriods(2),
+               fSoftInputs(2),
+               fSoftOutputs(2)
+       {}
+
+       AudioParam&     cardName(const char* n) { fCardName = n;                return *this; }
+       AudioParam&     frequency(int f)                { fFrequency = f;               return *this; }
+       AudioParam&     buffering(int fpb)              { fBuffering = fpb;     return *this; }
+       AudioParam&     periods(int p)                  { fPeriods = p;                 return *this; }
+       AudioParam&     inputs(int n)                   { fSoftInputs = n;              return *this; }
+       AudioParam&     outputs(int n)                  { fSoftOutputs = n;     return *this; }
+};
+
+/**
+ * An ALSA audio interface
+ */
+class AudioInterface : public AudioParam
+{
+ public :
+       snd_pcm_t*                              fOutputDevice ;
+       snd_pcm_t*                              fInputDevice ;
+       snd_pcm_hw_params_t*    fInputParams;
+       snd_pcm_hw_params_t*    fOutputParams;
+
+       snd_pcm_format_t                fSampleFormat;
+       snd_pcm_access_t                fSampleAccess;
+
+       unsigned int                    fCardInputs;
+       unsigned int                    fCardOutputs;
+
+       unsigned int                    fChanInputs;
+       unsigned int                    fChanOutputs;
+
+       // interleaved mode audiocard buffers
+       void*           fInputCardBuffer;
+       void*           fOutputCardBuffer;
+
+       // non interleaved mode audiocard buffers
+       void*           fInputCardChannels[256];
+       void*           fOutputCardChannels[256];
+
+       // non interleaved mod, floating point software buffers
+       float*          fInputSoftChannels[256];
+       float*          fOutputSoftChannels[256];
+
+ public :
+
+       const char*     cardName()                              { return fCardName;     }
+       int                     frequency()                             { return fFrequency;    }
+       int                     buffering()                             { return fBuffering;    }
+       int                     periods()                               { return fPeriods;      }
+
+       float**         inputSoftChannels()             { return fInputSoftChannels;    }
+       float**         outputSoftChannels()    { return fOutputSoftChannels;   }
+
+
+       AudioInterface(const AudioParam& ap = AudioParam()) : AudioParam(ap)
+       {
+
+               fInputDevice                    = 0;
+               fOutputDevice                   = 0;
+               fInputParams                    = 0;
+               fOutputParams                   = 0;
+       }
+
+       /**
+        * Open the audio interface
+        */
+       void open()
+       {
+               int err;
+
+               // allocation d'un stream d'entree et d'un stream de sortie
+               err = snd_pcm_open( &fInputDevice,  fCardName, SND_PCM_STREAM_CAPTURE, 0 );     check_error(err)
+               err = snd_pcm_open( &fOutputDevice, fCardName, SND_PCM_STREAM_PLAYBACK, 0 );    check_error(err)
+
+               // recherche des parametres d'entree
+               err = snd_pcm_hw_params_malloc  ( &fInputParams );      check_error(err);
+               setAudioParams(fInputDevice, fInputParams);
+
+               // recherche des parametres de sortie
+               err = snd_pcm_hw_params_malloc  ( &fOutputParams );             check_error(err)
+               setAudioParams(fOutputDevice, fOutputParams);
+
+               // set the number of physical input and output channels close to what we need
+               fCardInputs     = fSoftInputs;
+               fCardOutputs    = fSoftOutputs;
+
+               snd_pcm_hw_params_set_channels_near(fInputDevice, fInputParams, &fCardInputs);
+               snd_pcm_hw_params_set_channels_near(fOutputDevice, fOutputParams, &fCardOutputs);
+
+               printf("inputs : %u, outputs : %u\n", fCardInputs, fCardOutputs);
+
+               // enregistrement des parametres d'entree-sortie
+
+               err = snd_pcm_hw_params (fInputDevice,  fInputParams );         check_error (err);
+               err = snd_pcm_hw_params (fOutputDevice, fOutputParams );        check_error (err);
+
+               //assert(snd_pcm_hw_params_get_period_size(fInputParams,NULL) == snd_pcm_hw_params_get_period_size(fOutputParams,NULL));
+
+               // allocation of alsa buffers
+               if (fSampleAccess == SND_PCM_ACCESS_RW_INTERLEAVED) {
+                       fInputCardBuffer = calloc(interleavedBufferSize(fInputParams), 1);
+                       fOutputCardBuffer = calloc(interleavedBufferSize(fOutputParams), 1);
+
+               } else {
+                       for (unsigned int i = 0; i < fCardInputs; i++) {
+                               fInputCardChannels[i] = calloc(noninterleavedBufferSize(fInputParams), 1);
+                       }
+                       for (unsigned int i = 0; i < fCardOutputs; i++) {
+                               fOutputCardChannels[i] = calloc(noninterleavedBufferSize(fOutputParams), 1);
+                       }
+
+               }
+
+               // allocation of floating point buffers needed by the dsp code
+
+               fChanInputs = max(fSoftInputs, fCardInputs);            assert (fChanInputs < 256);
+               fChanOutputs = max(fSoftOutputs, fCardOutputs);         assert (fChanOutputs < 256);
+
+               for (unsigned int i = 0; i < fChanInputs; i++) {
+                       fInputSoftChannels[i] = (float*) calloc (fBuffering, sizeof(float));
+                       for (unsigned int j = 0; j < fBuffering; j++) {
+                               fInputSoftChannels[i][j] = 0.0;
+                       }
+               }
+
+               for (unsigned int i = 0; i < fChanOutputs; i++) {
+                       fOutputSoftChannels[i] = (float*) calloc (fBuffering, sizeof(float));
+                       for (unsigned int j = 0; j < fBuffering; j++) {
+                               fOutputSoftChannels[i][j] = 0.0;
+                       }
+               }
+       }
+
+       void setAudioParams(snd_pcm_t* stream, snd_pcm_hw_params_t* params)
+       {
+               int     err;
+
+               // set params record with initial values
+               err = snd_pcm_hw_params_any     ( stream, params );
+               check_error_msg(err, "unable to init parameters")
+
+               // set alsa access mode (and fSampleAccess field) either to non interleaved or interleaved
+
+               err = snd_pcm_hw_params_set_access (stream, params, SND_PCM_ACCESS_RW_NONINTERLEAVED );
+               if (err) {
+                       err = snd_pcm_hw_params_set_access (stream, params, SND_PCM_ACCESS_RW_INTERLEAVED );
+                       check_error_msg(err, "unable to set access mode neither to non-interleaved or to interleaved");
+               }
+               snd_pcm_hw_params_get_access(params, &fSampleAccess);
+
+
+               // search for 32-bits or 16-bits format
+               err = snd_pcm_hw_params_set_format (stream, params, SND_PCM_FORMAT_S32);
+               if (err) {
+                       err = snd_pcm_hw_params_set_format (stream, params, SND_PCM_FORMAT_S16);
+                       check_error_msg(err, "unable to set format to either 32-bits or 16-bits");
+               }
+               snd_pcm_hw_params_get_format(params, &fSampleFormat);
+               // set sample frequency
+               snd_pcm_hw_params_set_rate_near (stream, params, &fFrequency, 0);
+
+               // set period and period size (buffering)
+               err = snd_pcm_hw_params_set_period_size (stream, params, fBuffering, 0);
+               check_error_msg(err, "period size not available");
+
+               err = snd_pcm_hw_params_set_periods (stream, params, fPeriods, 0);
+               check_error_msg(err, "number of periods not available");
+       }
+
+       ssize_t interleavedBufferSize (snd_pcm_hw_params_t* params)
+       {
+               _snd_pcm_format         format;         snd_pcm_hw_params_get_format(params, &format);
+               snd_pcm_uframes_t       psize;          snd_pcm_hw_params_get_period_size(params, &psize, NULL);
+               unsigned int            channels;       snd_pcm_hw_params_get_channels(params, &channels);
+               ssize_t bsize = snd_pcm_format_size (format, psize * channels);
+               return bsize;
+       }
+
+       ssize_t noninterleavedBufferSize (snd_pcm_hw_params_t* params)
+       {
+               _snd_pcm_format         format;         snd_pcm_hw_params_get_format(params, &format);
+               snd_pcm_uframes_t       psize;          snd_pcm_hw_params_get_period_size(params, &psize, NULL);
+               ssize_t bsize = snd_pcm_format_size (format, psize);
+               return bsize;
+       }
+
+       void close()
+       {}
+
+       /**
+        * Read audio samples from the audio card. Convert samples to floats and take
+        * care of interleaved buffers
+        */
+       void read()
+       {
+        if (fSampleAccess == SND_PCM_ACCESS_RW_INTERLEAVED) {
+
+                       int count = snd_pcm_readi(fInputDevice, fInputCardBuffer, fBuffering);
+                       if (count<0) {
+                               display_error_msg(count, "reading samples");
+                                int err = snd_pcm_prepare(fInputDevice);
+                                check_error_msg(err, "preparing input stream");
+                       }
+
+                       if (fSampleFormat == SND_PCM_FORMAT_S16) {
+
+                               short*  buffer16b = (short*) fInputCardBuffer;
+                               for (unsigned int s = 0; s < fBuffering; s++) {
+                                       for (unsigned int c = 0; c < fCardInputs; c++) {
+                                               fInputSoftChannels[c][s] = float(buffer16b[c + s*fCardInputs])*(1.0/float(SHRT_MAX));
+                                       }
+                               }
+
+                       } else if (fSampleFormat == SND_PCM_FORMAT_S32) {
+
+                               int32*  buffer32b = (int32*) fInputCardBuffer;
+                               for (unsigned int s = 0; s < fBuffering; s++) {
+                                       for (unsigned int c = 0; c < fCardInputs; c++) {
+                                               fInputSoftChannels[c][s] = float(buffer32b[c + s*fCardInputs])*(1.0/float(INT_MAX));
+                                       }
+                               }
+                       } else {
+
+                               printf("unrecognized input sample format : %u\n", fSampleFormat);
+                               exit(1);
+                       }
+
+               } else if (fSampleAccess == SND_PCM_ACCESS_RW_NONINTERLEAVED) {
+
+                       int count = snd_pcm_readn(fInputDevice, fInputCardChannels, fBuffering);
+                       if (count<0) {
+                               display_error_msg(count, "reading samples");
+                                int err = snd_pcm_prepare(fInputDevice);
+                                check_error_msg(err, "preparing input stream");
+                       }
+
+                       if (fSampleFormat == SND_PCM_FORMAT_S16) {
+
+                               for (unsigned int c = 0; c < fCardInputs; c++) {
+                                       short*  chan16b = (short*) fInputCardChannels[c];
+                                       for (unsigned int s = 0; s < fBuffering; s++) {
+                                               fInputSoftChannels[c][s] = float(chan16b[s])*(1.0/float(SHRT_MAX));
+                                       }
+                               }
+
+                       } else if (fSampleFormat == SND_PCM_FORMAT_S32) {
+
+                               for (unsigned int c = 0; c < fCardInputs; c++) {
+                                       int32*  chan32b = (int32*) fInputCardChannels[c];
+                                       for (unsigned int s = 0; s < fBuffering; s++) {
+                                               fInputSoftChannels[c][s] = float(chan32b[s])*(1.0/float(INT_MAX));
+                                       }
+                               }
+                       } else {
+
+                               printf("unrecognized input sample format : %u\n", fSampleFormat);
+                               exit(1);
+                       }
+
+               } else {
+                       check_error_msg(-10000, "unknow access mode");
+               }
+    }
+
+       /**
+        * write the output soft channels to the audio card. Convert sample
+        * format and interleaves buffers when needed
+        */
+       void write()
+       {
+               recovery :
+
+               if (fSampleAccess == SND_PCM_ACCESS_RW_INTERLEAVED) {
+
+                       if (fSampleFormat == SND_PCM_FORMAT_S16) {
+
+                               short* buffer16b = (short*) fOutputCardBuffer;
+                               for (unsigned int f = 0; f < fBuffering; f++) {
+                                       for (unsigned int c = 0; c < fCardOutputs; c++) {
+                                               float x = fOutputSoftChannels[c][f];
+                                               buffer16b[c + f*fCardOutputs] = short( max(min(x,1.0),-1.0) * float(SHRT_MAX) ) ;
+                                       }
+                               }
+
+                       } else if (fSampleFormat == SND_PCM_FORMAT_S32)  {
+
+                               int32* buffer32b = (int32*) fOutputCardBuffer;
+                               for (unsigned int f = 0; f < fBuffering; f++) {
+                                       for (unsigned int c = 0; c < fCardOutputs; c++) {
+                                               float x = fOutputSoftChannels[c][f];
+                                               buffer32b[c + f*fCardOutputs] = int( max(min(x,1.0),-1.0) * float(INT_MAX) ) ;
+                                       }
+                               }
+                       } else {
+
+                               printf("unrecognized output sample format : %u\n", fSampleFormat);
+                               exit(1);
+                       }
+
+                       int count = snd_pcm_writei(fOutputDevice, fOutputCardBuffer, fBuffering);
+                       if (count<0) {
+                               display_error_msg(count, "w3");
+                               int err = snd_pcm_prepare(fOutputDevice);
+                               check_error_msg(err, "preparing output stream");
+                               goto recovery;
+                       }
+
+
+               } else if (fSampleAccess == SND_PCM_ACCESS_RW_NONINTERLEAVED) {
+
+                       if (fSampleFormat == SND_PCM_FORMAT_S16) {
+
+                               for (unsigned int c = 0; c < fCardOutputs; c++) {
+                                       short* chan16b = (short*) fOutputCardChannels[c];
+                                       for (unsigned int f = 0; f < fBuffering; f++) {
+                                               float x = fOutputSoftChannels[c][f];
+                                               chan16b[f] = short( max(min(x,1.0),-1.0) * float(SHRT_MAX) ) ;
+                                       }
+                               }
+
+                       } else if (fSampleFormat == SND_PCM_FORMAT_S32) {
+
+                               for (unsigned int c = 0; c < fCardOutputs; c++) {
+                                       int32* chan32b = (int32*) fOutputCardChannels[c];
+                                       for (unsigned int f = 0; f < fBuffering; f++) {
+                                               float x = fOutputSoftChannels[c][f];
+                                               chan32b[f] = int( max(min(x,1.0),-1.0) * float(INT_MAX) ) ;
+                                       }
+                               }
+
+                       } else {
+
+                               printf("unrecognized output sample format : %u\n", fSampleFormat);
+                               exit(1);
+                       }
+
+                       int count = snd_pcm_writen(fOutputDevice, fOutputCardChannels, fBuffering);
+                       if (count<0) {
+                               display_error_msg(count, "w3");
+                               int err = snd_pcm_prepare(fOutputDevice);
+                               check_error_msg(err, "preparing output stream");
+                               goto recovery;
+                       }
+
+               } else {
+                       check_error_msg(-10000, "unknow access mode");
+               }
+       }
+
+       /**
+        *  print short information on the audio device
+        */
+       void shortinfo()
+       {
+               int                                             err;
+               snd_ctl_card_info_t*    card_info;
+       snd_ctl_t*                              ctl_handle;
+               err = snd_ctl_open (&ctl_handle, fCardName, 0);         check_error(err);
+               snd_ctl_card_info_alloca (&card_info);
+               err = snd_ctl_card_info(ctl_handle, card_info);         check_error(err);
+               printf("%s|%d|%d|%d|%d|%s\n",
+                               snd_ctl_card_info_get_driver(card_info),
+                               fCardInputs, fCardOutputs,
+                               fFrequency, fBuffering,
+                               snd_pcm_format_name((_snd_pcm_format)fSampleFormat));
+       }
+
+       /**
+        *  print more detailled information on the audio device
+        */
+       void longinfo()
+       {
+               int                                             err;
+               snd_ctl_card_info_t*    card_info;
+       snd_ctl_t*                              ctl_handle;
+
+               printf("Audio Interface Description :\n");
+               printf("Sampling Frequency : %d, Sample Format : %s, buffering : %d\n",
+                               fFrequency, snd_pcm_format_name((_snd_pcm_format)fSampleFormat), fBuffering);
+               printf("Software inputs : %2d, Software outputs : %2d\n", fSoftInputs, fSoftOutputs);
+               printf("Hardware inputs : %2d, Hardware outputs : %2d\n", fCardInputs, fCardOutputs);
+               printf("Channel inputs  : %2d, Channel outputs  : %2d\n", fChanInputs, fChanOutputs);
+
+               // affichage des infos de la carte
+               err = snd_ctl_open (&ctl_handle, fCardName, 0);         check_error(err);
+               snd_ctl_card_info_alloca (&card_info);
+               err = snd_ctl_card_info(ctl_handle, card_info);         check_error(err);
+               printCardInfo(card_info);
+
+               // affichage des infos liees aux streams d'entree-sortie
+               if (fSoftInputs > 0)    printHWParams(fInputParams);
+               if (fSoftOutputs > 0)   printHWParams(fOutputParams);
+       }
+
+       void printCardInfo(snd_ctl_card_info_t* ci)
+       {
+               printf("Card info (address : %p)\n", ci);
+               printf("\tID         = %s\n", snd_ctl_card_info_get_id(ci));
+               printf("\tDriver     = %s\n", snd_ctl_card_info_get_driver(ci));
+               printf("\tName       = %s\n", snd_ctl_card_info_get_name(ci));
+               printf("\tLongName   = %s\n", snd_ctl_card_info_get_longname(ci));
+               printf("\tMixerName  = %s\n", snd_ctl_card_info_get_mixername(ci));
+               printf("\tComponents = %s\n", snd_ctl_card_info_get_components(ci));
+               printf("--------------\n");
+       }
+
+       void printHWParams( snd_pcm_hw_params_t* params )
+       {
+               printf("HW Params info (address : %p)\n", params);
+#if 0
+               printf("\tChannels    = %d\n", snd_pcm_hw_params_get_channels(params));
+               printf("\tFormat      = %s\n", snd_pcm_format_name((_snd_pcm_format)snd_pcm_hw_params_get_format(params)));
+               printf("\tAccess      = %s\n", snd_pcm_access_name((_snd_pcm_access)snd_pcm_hw_params_get_access(params)));
+               printf("\tRate        = %d\n", snd_pcm_hw_params_get_rate(params, NULL));
+               printf("\tPeriods     = %d\n", snd_pcm_hw_params_get_periods(params, NULL));
+               printf("\tPeriod size = %d\n", (int)snd_pcm_hw_params_get_period_size(params, NULL));
+               printf("\tPeriod time = %d\n", snd_pcm_hw_params_get_period_time(params, NULL));
+               printf("\tBuffer size = %d\n", (int)snd_pcm_hw_params_get_buffer_size(params));
+               printf("\tBuffer time = %d\n", snd_pcm_hw_params_get_buffer_time(params, NULL));
+#endif
+               printf("--------------\n");
+       }
+
+};
+
+// lopt : Scan Command Line long int Arguments
+long lopt(int argc, char *argv[], const char* longname, const char* shortname, long def)
+{
+       for (int i=2; i<argc; i++)
+               if ( strcmp(argv[i-1], shortname) == 0 || strcmp(argv[i-1], longname) == 0 )
+                       return atoi(argv[i]);
+       return def;
+}
+
+// sopt : Scan Command Line string Arguments
+const char* sopt(int argc, char *argv[], const char* longname, const char* shortname, const char* def)
+{
+       for (int i=2; i<argc; i++)
+               if ( strcmp(argv[i-1], shortname) == 0 || strcmp(argv[i-1], longname) == 0 )
+                       return argv[i];
+       return def;
+}
+
+// fopt : Scan Command Line flag option (without argument), return true if the flag
+bool fopt(int argc, char *argv[], const char* longname, const char* shortname)
+{
+       for (int i=1; i<argc; i++)
+               if ( strcmp(argv[i], shortname) == 0 || strcmp(argv[i], longname) == 0 )
+                       return true;
+       return false;
+}
+
+/**
+ * Return the value of an environment variable or defval if undefined.
+ */
+static int getDefaultEnv(const char* name, int defval)
+{
+    const char* str = getenv(name);
+    if (str) {
+        return atoi(str);
+    } else {
+        return defval;
+    }
+}
+
+/**
+ * Return the value of an environment variable or defval if undefined.
+ */
+static const char* getDefaultEnv(const char* name, const char* defval)
+{
+    const char* str = getenv(name);
+    if (str) {
+        return str;
+    } else {
+        return defval;
+    }
+}
+
+/******************************************************************************
+*******************************************************************************
+
+                                                          ALSA audio interface
+
+*******************************************************************************
+*******************************************************************************/
+void* __run(void* ptr);
+
+class alsaaudio : public audio {
+       AudioInterface* fAudio;
+       dsp*                    fDSP;
+       pthread_t       fAudioThread;
+       bool            fRunning;
+
+ public:
+                        alsaaudio(int argc, char *argv[], dsp* DSP) : fAudio(0), fDSP(DSP), fRunning(false) {
+                                       fAudio = new AudioInterface (
+                                               AudioParam().cardName( sopt(argc, argv, "--device", "-d",     getDefaultEnv("FAUST2ALSA_DEVICE", "hw:0")  ) )
+                                               .frequency( lopt(argc, argv, "--frequency", "-f", getDefaultEnv("FAUST2ALSA_FREQUENCY",44100) ) )
+                                               .buffering( lopt(argc, argv, "--buffer", "-b",    getDefaultEnv("FAUST2ALSA_BUFFER",1024)     ) )
+                                               .periods( lopt(argc, argv, "--periods", "-p",     getDefaultEnv("FAUST2ALSA_PERIODS",2)       ) )
+                                               .inputs(DSP->getNumInputs())
+                                               .outputs(DSP->getNumOutputs()));
+                               }
+       virtual ~alsaaudio() { stop(); delete fAudio; }
+
+       virtual bool init(const char */*name*/, dsp* DSP) {
+               AVOIDDENORMALS;
+               fAudio->open();
+           DSP->init(fAudio->frequency());
+               return true;
+       }
+
+       virtual bool start() {
+               fRunning = true;
+               if (pthread_create( &fAudioThread, 0, __run, this))
+                       fRunning = false;
+               return fRunning;
+       }
+
+       virtual void stop() {
+               if (fRunning) {
+                       fRunning = false;
+                       pthread_join (fAudioThread, 0);
+               }
+       }
+
+       virtual void run() {
+               bool rt = setRealtimePriority();
+               printf(rt ? "RT : ":"NRT: "); fAudio->shortinfo();
+               fAudio->write();
+               fAudio->write();
+               while(fRunning) {
+                       fAudio->read();
+                       fDSP->compute(fAudio->buffering(), fAudio->inputSoftChannels(), fAudio->outputSoftChannels());
+                       fAudio->write();
+               }
+       }
+};
+
+void* __run (void* ptr)
+{
+       alsaaudio * alsa = (alsaaudio*)ptr;
+       alsa->run();
+       return 0;
+}
+
+#endif
+
+/********************END ARCHITECTURE SECTION (part 2/2)****************/
+