added host_linux files

host_linux/Makefile

@@ -0,0 +1,22 @@
+TARGETS = doubledown oddbits evenbits
+BINDIR = /usr/local/bin
+all: $(TARGETS)
+
+doubledown: doubledown.c
+	gcc -Wall doubledown.c -lasound -o doubledown
+
+oddbits: oddbits.c
+	gcc -Wall oddbits.c -o oddbits
+
+evenbits: oddbits
+	ln -f oddbits evenbits
+
+install: all
+	install -m 0755 $(TARGETS) $(BINDIR)
+.PHONY: install
+
+clean:
+	-rm -f *.o
+	-rm -f $(TARGETS)
+	-rm -f *~
+

host_linux/README.md

@@ -0,0 +1,7 @@
+This software needs the Debian packages
+	libasound2-dev
+	libasound2-doc (usefull for development)
+
+$ make
+$ sudo make install
+$ make clean

host_linux/doubledown.c

@@ -0,0 +1,317 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h> // for getopt() & nice()
+//#include "sound.h"
+
+#define BUF_SIZE 1024 // alter the kilobytes logic if this changes
+//#define ID_STRING "Cypress_Digital_Audio_DVK" // Bill has one of these
+#define ID_STRING "REDOUBLER_Random_Number_Generator"
+#define FALSE 0
+#define TRUE 1
+
+#define DEFAULT_HW_DEVICE           "hw:0"
+#define DEFAULT_HW_ITEM             "capture"
+#define DEFAULT_SAMPLE_RATE         48000
+#define DEFAULT_SKIP_BYTES          (48000 * 4 * 1)
+#define PAGE_SIZE 4096
+
+
+/******************** start of sound.c, in-lined so just one .c file ****************/
+
+/*
+ * (c) 2008-2014 Nicholas J. Kain <njkain at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// Peter Allan <[email protected]> modified for use with REDOUBLER
+// Original found in snd-egd package on Github
+
+#include <alsa/asoundlib.h>
+#include <linux/soundcard.h>
+//#include "nk/log.h" not needed, APA
+//#include "defines.h" needed parts brought in above
+//#include "sound.h" needed parts brought in above
+
+static char *cdevice = DEFAULT_HW_DEVICE;
+static const char *cdev_id = DEFAULT_HW_ITEM;
+static unsigned int sample_rate = DEFAULT_SAMPLE_RATE;
+static snd_pcm_t *pcm_handle = NULL;
+static size_t pcm_bytes_per_frame;
+static int snd_format = -1;
+static unsigned int skip_bytes = DEFAULT_SKIP_BYTES;
+static int pcm_can_pause;
+
+void suicide(const char * fmt, ...) // APA guess
+{
+  va_list args;
+
+  va_start(args,fmt);
+  vfprintf(stderr,fmt, args);
+  fprintf(stderr,"\n");
+  exit(1);
+}
+
+int sound_read(void *buf, size_t size)
+{
+    snd_pcm_sframes_t fr;
+
+    fr = snd_pcm_readi(pcm_handle, buf, size / pcm_bytes_per_frame);
+    /* Make sure we aren't hitting a disconnect/suspend case */
+    if (fr < 0)
+        fr = snd_pcm_recover(pcm_handle, fr, 0);
+    /* Nope, something else is wrong. Bail. */
+    if (fr < 0 || (fr == -1 && errno != EINTR))
+        suicide("sound_read(): Read error: %m");
+    return fr*pcm_bytes_per_frame;
+}
+
+void sound_stop(void)
+{
+    if (pcm_can_pause)
+        snd_pcm_pause(pcm_handle, 1);
+}
+
+void sound_open(void)
+{
+    char buf[PAGE_SIZE];
+    int err, i;
+    snd_pcm_hw_params_t *ct_params;
+
+    if ((err = snd_pcm_open(&pcm_handle, cdevice, SND_PCM_STREAM_CAPTURE, 0)) < 0)
+        suicide("Error opening PCM device %s: %s", cdevice, snd_strerror(err));
+
+    snd_pcm_hw_params_alloca(&ct_params);
+
+    err = snd_pcm_hw_params_any(pcm_handle, ct_params);
+    if (err < 0)
+        suicide("Broken configuration for %s PCM: no configurations available: %s",
+                   cdev_id, snd_strerror(err));
+
+    /* Disable rate resampling */
+    err = snd_pcm_hw_params_set_rate_resample(pcm_handle, ct_params, 0);
+    if (err < 0)
+        suicide("Could not disable rate resampling: %s", snd_strerror(err));
+
+    /* Set access to SND_PCM_ACCESS_RW_INTERLEAVED -- NONINTERLEAVED would
+     * be preferable, but it's uncommon on sound cards.*/
+    err = snd_pcm_hw_params_set_access(pcm_handle, ct_params,
+                                       SND_PCM_ACCESS_RW_INTERLEAVED);
+    if (err < 0)
+        suicide("Could not set access to SND_PCM_ACCESS_RW_INTERLEAVED: %s",
+                   snd_strerror(err));
+
+    /* Choose rate nearest to our target rate */
+    err = snd_pcm_hw_params_set_rate_near(pcm_handle, ct_params, &sample_rate, 0);
+    if (err < 0)
+        suicide("Rate %iHz not available for %s: %s",
+                   sample_rate, cdev_id, snd_strerror(err));
+
+    /* Set sample format -- prefer endianness equal to that of the CPU */
+#ifdef HOST_ENDIAN_BE
+    snd_format = SND_PCM_FORMAT_S16_BE;
+#else
+    snd_format = SND_PCM_FORMAT_S16_LE;
+#endif
+    err = snd_pcm_hw_params_set_format(pcm_handle, ct_params, snd_format);
+    if (err < 0) {
+#ifdef HOST_ENDIAN_BE
+        snd_format = SND_PCM_FORMAT_S16_LE;
+#else
+        snd_format = SND_PCM_FORMAT_S16_BE;
+#endif
+        err = snd_pcm_hw_params_set_format(pcm_handle, ct_params, snd_format);
+    }
+    if (err < 0)
+        suicide("Sample format (SND_PCM_FORMAT_S16_BE and _LE) not available for %s: %s",
+                   cdev_id, snd_strerror(err));
+
+    /* Set stereo for faster sampling. */
+    err = snd_pcm_hw_params_set_channels(pcm_handle, ct_params, 2);
+    if (err < 0)
+        suicide("Channels count (%i) not available for %s: %s",
+                   2, cdev_id, snd_strerror(err));
+
+    /* Apply settings to sound device */
+    err = snd_pcm_hw_params(pcm_handle, ct_params);
+    if (err < 0)
+        suicide("Could not apply settings to sound device!");
+
+    pcm_bytes_per_frame = snd_pcm_frames_to_bytes(pcm_handle, 1);
+    //fprintf(stderr,"bytes-per-frame: %d\n", pcm_bytes_per_frame);
+    pcm_can_pause = snd_pcm_hw_params_can_pause(ct_params);
+
+    /* Discard the initial data; it may be a click or something else odd. */
+    for (i = skip_bytes; i > 0; i -= (sizeof buf))
+        sound_read(buf, sizeof buf);
+    //fprintf(stderr,"skipped %d bytes of pcm input\n", skip_bytes);
+
+    if (pcm_can_pause) {
+        sound_stop();
+        //fprintf(stderr,"alsa device supports pcm pause\n");
+    }
+}
+
+int sound_bytes_per_frame(void)
+{
+    return pcm_bytes_per_frame;
+}
+
+void sound_start(void)
+{
+    if (pcm_can_pause)
+        snd_pcm_pause(pcm_handle, 0);
+}
+
+void sound_close(void)
+{
+    snd_pcm_close(pcm_handle);
+    pcm_handle = NULL;
+}
+
+int sound_is_le(void)
+{
+    if (snd_format == SND_PCM_FORMAT_S16_BE)
+        return 0;
+    return 1;
+}
+
+int sound_is_be(void)
+{
+    if (snd_format == SND_PCM_FORMAT_S16_LE)
+        return 0;
+    return 1;
+}
+
+void sound_set_device(char *str)
+{
+    cdevice = strdup(str);
+}
+
+void sound_set_port(char *str)
+{
+    cdev_id = strdup(str);
+}
+
+void sound_set_sample_rate(int rate)
+{
+    if (rate > 0)
+        sample_rate = rate;
+    else
+        sample_rate = DEFAULT_SAMPLE_RATE;
+}
+
+void sound_set_skip_bytes(int sb)
+{
+    if (sb > -1)
+        skip_bytes = sb;
+    else
+        skip_bytes = DEFAULT_SKIP_BYTES;
+}
+/********************************* end of original sound.c *******************************************/
+
+int default_card(const int list)
+{
+  char buf[BUF_SIZE];
+  char serial[80];
+  int  card_num;
+  int first=-1;
+  FILE *fp;
+
+  sprintf(buf,"ls -l /dev/snd/by-id | grep %s | sed -e 's/^.*%s_//' -e 's|-00 -> ../controlC|\t|'",ID_STRING,ID_STRING);
+  fp=popen(buf,"r");
+  if(fp==NULL){
+    fprintf(stderr,"Could not open command: %s\n",buf);
+    exit(9);
+  }
+  if(list) fprintf(stderr,"%-20s\t%-10s\t%-20s\n","Available REDOUBLERs:","Card #","Serial Number");
+  while(fgets(buf,BUF_SIZE,fp)){
+    sscanf(buf,"%s\t%d",serial,&card_num);
+    if(list) fprintf(stderr,"%-20s\t%-10d\t%-20s\n","",card_num,serial);
+    if(first==-1) first=card_num;
+  }
+  pclose(fp);
+  return(first);
+}
+
+int main(int argc, char *argv[])
+{
+  unsigned char buf[BUF_SIZE];
+  char device[80];
+  int c, card_num,kilobytes=0,kb_out=0,n_opt=0;
+  int actual_bytes;
+  FILE *fo;
+
+  card_num=default_card(FALSE);
+
+  while((c=getopt(argc,argv,"lc:k:n"))!=-1){
+    switch(c){
+      case 'l':
+        default_card(TRUE);
+        exit(0);
+      case 'c':
+        card_num=atoi(optarg);
+        break;
+      case 'k':
+        kilobytes=atoi(optarg)+1; // extra to account for the skipped bytes
+        break;
+      case 'n':
+        n_opt=1;
+        break;
+      default:
+        fprintf(stderr,"Usage: %s [-l] [-c card_num] [-k kilobytes]\n",argv[0]);
+        exit(3);
+    }
+  }
+
+  if(card_num<0) {
+    fprintf(stderr,"%s: Valid REDOUBLER card_num neither found nor specified.\n",argv[0]);
+    exit(9);
+  }
+  sprintf(device,"hw:%d",card_num);
+  sound_set_device(device);
+  sound_set_skip_bytes(960);
+  sound_open();
+  atexit(sound_close);
+
+  fo=popen("cat | cat","w"); // quick-and-dirty double buffering, done before nice()
+  if(n_opt) if(nice(-10)==-1) fprintf(stderr,"%s: Only root can increase priority.\n",argv[0]);
+  if(fo == NULL){
+    fprintf(stderr,"%s: Could not open ouput buffering process.\n",argv[0]);
+    exit(11);
+  }
+  sound_start();
+  while((kilobytes <= 0) || (kb_out < kilobytes)){
+    actual_bytes=sound_read(buf,BUF_SIZE);
+    if(actual_bytes==BUF_SIZE){
+      fwrite(buf,1,BUF_SIZE,fo);
+      kb_out++;
+    }
+    else fprintf(stderr,"%s: Read glitch, actual_bytes = %d\n",argv[0],actual_bytes);
+  }
+  sound_stop();
+  pclose(fo);
+
+  exit(0); // shoud trigger atexit()
+}

host_linux/oddbits.c

@@ -0,0 +1,29 @@
+// oddbits.c - takes bitstream on stdin and sends just the odd (or even) bits to stdout
+// Peter Allan <[email protected]> 2015, public domain
+// After compile 'ln oddbits evenbits'
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <libgen.h> // for non-GNU basename()
+
+int main(int argc, char **argv)
+{
+  int odd, i, j, c1, c2;
+  uint8_t lut[65536];
+
+  if(!strcmp(basename(argv[0]),"oddbits")) odd=1;
+  else if(!strcmp(basename(argv[0]),"evenbits")) odd=0;
+  else{
+    fprintf(stderr,"%s: Should be named oddbits or evenbits.\n",basename(argv[0]));
+    return 1;
+  }
+
+  // note convention: byte is bits b7,b6,b5,b4,b3,b2,b1,b0 and oddbits are b7,b5,b3,b1
+  for(i=0;i<65536;i++) for(lut[i]=0,j=0;j<8;j++) if((i>>(j*2+odd))&1) lut[i] |= 1<<j;
+
+  // assumes something about endian-ness, you might care
+  while((c1=getchar())>=0 && (c2=getchar())>=0) putchar(lut[c1|(c2<<8)]);
+  if(c1>=0) putchar(lut[c1]); // last byte, zero-padded
+
+  return 0;
+}