m

Signed-off-by: Mattias Andrée <maandree@member.fsf.org>

1 files changed, 0 insertions, 503 deletions

diff --git a/src/send.c b/src/send.c
deleted file mode 100644
index b841e1f..0000000
--- a/src/send.c
+++ /dev/null
@@ -1,503 +0,0 @@
-/**
- * Copyright © 2015  Mattias Andrée (maandree@member.fsf.org)
- * 
- * This program 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/>.
- */
-#include "common.h"
-
-#include <stdio.h>
-#include <stdint.h>
-#include <signal.h>
-#include <errno.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <string.h>
-#include <alloca.h>
-#include <getopt.h>
-#include <math.h> /* -lm */
-#include <alsa/asoundlib.h> /* dep: alsa-lib (pkg-config alsa) */
-
-
-
-#define UTYPE   uint32_t
-#define SMIN    INT32_MIN
-#define SMAX    INT32_MAX
-#define FORMAT  SND_PCM_FORMAT_U32
-
-#define SAMPLE_RATE  52000   /* Hz */
-#define DURATION     100     /* ms */ /* 100 ms → 10 Bd → 5 B/s */
-#define LATENCY      100000  /* µs */
-
-
-
-/**
- * Number of samples per tone.
- */
-#define N  (SAMPLE_RATE / 1000 * DURATION)
-
-
-
-/**
- * The process's name.
- */
-static const char* argv0;
-
-/**
- * Audio descriptor.
- */
-static snd_pcm_t* sound_handle = NULL;
-
-/**
- * Audio playback buffer for each nibble.
- */
-static UTYPE buffers[16][N];
-
-/**
- * The number of parity tones in the hamming code.
- */
-static int parity = 3;
-
-/**
- * Whether to add an additional parity tone (of all
- * data tones) in addition to those numerated by `parity`.
- */
-static int use_extra_parity = 0;
-
-/**
- * Whether to add redundancy frequencies in the tones.
- */
-static int use_redundant_freq = 0;
-
-/**
- * Frequencies multiple for the redundant frequencies.
- */
-static double redundant_freq_mul = 0;
-
-/**
- * Data buffer used for error correcting code support.
- */
-static int* data;
-
-/**
- * Code buffer used for error correcting code support.
- */
-static int* code;
-
-/**
- * The number elements that can be stored in `data`.
- */
-static int data_n;
-
-/**
- * The number elements that can be stored in `code`.
- */
-static int code_n;
-
-/**
- * File descriptor to write the audio to (with any metadata)
- * rather than sending it to the audio subsystem.
- * 
- * This is available for developers of the receiver.
- * It is not intend to be used for anything else.
- */
-static int output_fd = -1;
-
-
-
-/**
- * Use to accept signals, without doing anything
- * about them, just be interrupted.
- * 
- * @param  signo  The received signal.
- */
-static void signoop(int signo)
-{
-  (void) signo;
-}
-
-
-/**
- * Get the tones used to transmit a nibble.
- * 
- * @param  nibble  The nibble.
- * @param  low     Output parameter for the lower frequency.
- * @param  high    Output parameter for the higher frequency.
- */
-static void get_freq(int nibble, int* low, int* high)
-{
-  static const int LOW[]  = {  697,  770,  852,  941 };
-  static const int HIGH[] = { 1209, 1336, 1477, 1663 };
-  
-  *low  =  LOW[(nibble >> 0) & 0x03];
-  *high = HIGH[(nibble >> 2) & 0x03];
-}
-
-
-/**
- * Initialise to before for each nibble.
- */
-static void init_buffers(void)
-{
-#define GENERATE_TONE(tone)  sin(2 * M_PI * ((double)i / (SAMPLE_RATE / (tone))))
-  
-  size_t i;
-  UTYPE* buffer;
-  int j, low, high;
-  
-  for (j = 0; j < 16; j++)
-    {
-      buffer = buffers[j];
-      get_freq(j, &low, &high);
-      
-      if (use_redundant_freq)
-	for (i = 0; i < N; i++)
-	  buffer[i] = (GENERATE_TONE(low) +
-		       GENERATE_TONE(high) + 
-		       GENERATE_TONE(low * redundant_freq_mul) +
-		       GENERATE_TONE(high * redundant_freq_mul)) *
-	    (SMAX / 4) - SMIN;
-      else
-	for (i = 0; i < N; i++)
-	  buffer[i] = (GENERATE_TONE(low) + GENERATE_TONE(high)) *
-	    (SMAX / 2) - SMIN;
-    }
-}
-
-
-/**
- * Transmit a nibble.
- * 
- * @param   n  The nibble.
- * @return     0 on success, -1 on error.
- */
-static int send_nibble(int n)
-{
-  UTYPE* buffer = buffers[n];
-  snd_pcm_sframes_t frames;
-  int r;
-  
-  if (output_fd >= 0)
-    {
-      char* buf = (char*)buffer;
-      size_t ptr = 0;
-      ssize_t wrote;
-      while (ptr < N)
-	{
-	  wrote = write(output_fd, buf + ptr, N - ptr);
-	  if (wrote < 0)
-	    return -1;
-	  ptr += (size_t)write;
-	}
-      return 0;
-    }
-  
-  r = frames = snd_pcm_writei(sound_handle, buffer, N);
-  if (frames < 0)
-    r = frames = snd_pcm_recover(sound_handle, r, 0 /* do not print error reason? */);
-  if (r < 0)
-    {
-      fprintf(stderr, "%s: snd_pcm_writei: %s\n", argv0, snd_strerror(r));
-      errno = 0;
-      return -1;
-    }
-  if ((r > 0) && ((size_t)r < N))
-    printf("%s: short write: expected %zu, wrote %zu\n", argv0, N, (size_t)frames);
-  
-  return 0;
-}
-
-
-/**
- * Transmit a byte.
- * 
- * @param   c  The byte.
- * @return     0 on success, -1 on error.
- */
-static int send_byte(int c)
-{
-#ifdef DEBUG
-  fprintf(stderr, "%s: sending byte: %i\n", argv0, c);
-#endif
-  if (send_nibble((c >> 0) & 0x0F))  return -1;
-  if (send_nibble((c >> 4) & 0x0F))  return -1;
-  return 0;
-}
-
-
-/**
- * Transmit a byte with error correcting code.
- * 
- * This function uses a buffer so that it can
- * create an error correcting code. The bytes
- * are not transmitted until this buffer has
- * been filled.
- * 
- * @param   c  The byte, the negative of that byte (intended
- *             only for `CHAR_END` and `CHAR_CANCEL`) to fill
- *             the remained of the buffer with the byte.
- *             Note that if a negative value is used, it is
- *             no necessary that anything will happen.
- * @return     0 on success, -1 on error.
- */
-static int send_byte_with_ecc(int c)
-{
-  static int ptr = 0;
-  int i, j, d, p;
-  
-  if (parity < 2)
-    {
-      if (c < 0)
-	return 0;
-      if (send_byte(c))
-	return -1;
-      if (parity)
-	if (send_byte(c))
-	  return -1;
-      if (use_extra_parity)
-	if (send_byte(c))
-	  return -1;
-      return 0;
-    }
-  
-  /* Fill buffer. */
-  if (c < 0)
-    {
-      if (ptr > 0)
-	while (ptr < data_n)
-	  data[ptr++] = -c;
-    }
-  else
-    data[ptr++] = c;
-  
-  /* Is it full? */
-  if (ptr < data_n)
-    return 0;
-  ptr = 0;
-  
-  /* Hamming code. */
-  memset(code, 0, code_n * sizeof(*code));
-  for (i = 1, j = 0; i <= (1 << parity) - 1; i++)
-    {
-      if ((i & -i) == i)
-	continue;
-      for (d = i, p = 0; d; d >>= 1, p++)
-	if (d & 1)
-	  code[(1 << p) - 1] ^= data[j];
-      code[i - 1] = data[j];
-      j++;
-    }
-  if (use_extra_parity)
-    for (i = 0; i < data_n; i++)
-      code[(1 << parity) - 1] ^= data[i];
-  
-  /* Transmit. */
-  for (i = 0; i < code_n; i++)
-    if (send_byte(code[i]))
-      return -1;
-  
-  return 0;
-}
-
-
-/**
- * Transmit a chunk of bytes.
- * 
- * @param   buf  The chunk to transmit.
- * @param   n    The number of bytes in the chunk.
- * @return       0 on success, -1 on failure.
- */
-static int send_chunk(char* buf, size_t n)
-{
-  size_t i;
-  int c;
-  
-  for (i = 0; i < n; i++)
-    {
-      c = buf[i];
-      if ((c == CHAR_ESCAPE) || (c == CHAR_CANCEL) || (c == CHAR_END))
-	if (send_byte_with_ecc(CHAR_ESCAPE))
-	  goto qfile;
-      if (send_byte_with_ecc(c))
-	goto qfile;
-    }
-  
-  return 0;
- qfile:
-  errno = 0;
- fail:
-  return -1;
-}
-
-
-/**
- * Read all input from stdin and transmit it as it is being read.
- * 
- * @return  0 on success, -1 on failure.
- */
-static int send_file(void)
-{
-  char buf[1024];
-  ssize_t n;
-  
-  for (;;)
-    {
-      n = read(STDIN_FILENO, buf, sizeof(buf));
-      if (n < 0)   goto fail;
-      if (n == 0)  break;
-      if (send_chunk(buf, (size_t)n))
-	goto fail;
-    }
-  
-  return 0;
- fail:
-  return -1;
-}
-
-
-/**
- * Read all input from stdin, and then transmit it.
- * 
- * @return  0 on success, -1 on failure.
- */
-static int send_term(void)
-{
-  char* buf = NULL;
-  size_t size = 0;
-  size_t ptr = 0;
-  ssize_t n;
-  void* new;
-  int saved_errno;
-  
-  for (;;)
-    {
-      if (ptr == size)
-	{
-	  size = size ? (size << 1) : 128;
-	  new = realloc(buf, size);
-	  if (new == NULL)
-	    goto fail;
-	  buf = new;
-	}
-      n = read(STDIN_FILENO, buf + ptr, size - ptr);
-      if (n < 0)   goto fail;
-      if (n == 0)  break;
-      ptr += (size_t)n;
-    }
-  if (send_chunk(buf, ptr))
-    goto fail;
-  
-  return 0;
- fail:
-  saved_errno = errno;
-  free(buf);
-  errno = saved_errno;
-  return -1;
-}
-
-
-/**
- * Transmit a file over audio.
- * 
- * @param   argc  The number of elements in `argv`.
- * @param   argv  Command line arguments.
- * @return        0 on success, 1 on failure.
- */
-int main(int argc, char* argv[])
-{
-  struct sigaction act;
-  int r, rc = 1;
-  
-  /* Parse command line. */
-  argv0 = argc ? argv[0] : "";
-  for (;;)
-    {
-      r = getopt (argc, argv, "f:pr:o:");
-      if (r == -1)
-	break;
-      else if (r == 'f')  use_redundant_freq = 1, redundant_freq_mul = atof(optarg);
-      else if (r == 'p')  use_extra_parity = 1;
-      else if (r == 'r')  parity = atoi(optarg);
-      else if (r == 'o')  output_fd = atoi(optarg);
-      else if (r != '?')
-	abort();
-    }
-  
-  /* Set up signal handling. */
-  siginterrupt(SIGTERM, 1);
-  siginterrupt(SIGQUIT, 1);
-  siginterrupt(SIGINT, 1);
-  siginterrupt(SIGHUP, 1);
-  sigemptyset(&(act.sa_mask));
-  act.sa_handler = signoop;
-  act.sa_flags   = 0;
-  sigaction(SIGTERM, &act, NULL);
-  sigaction(SIGQUIT, &act, NULL);
-  sigaction(SIGHUP, &act, NULL);
-  sigprocmask(SIG_SETMASK, &(act.sa_mask), NULL);
-  
-  /* Generate the tones to play. */
-  init_buffers();
-  /* Generate buffers for error correcting code. */
-  data_n = (1 << parity) - parity - 1;
-  code_n = (1 << parity) - 1 + use_extra_parity;
-  data = alloca(data_n * sizeof(*data));
-  code = alloca(code_n * sizeof(*code));
-  
-  /* Set up audio. */
-  if (output_fd >= 0)
-    goto no_audio;
-  r = snd_pcm_open(&sound_handle, "default", SND_PCM_STREAM_PLAYBACK, 0);
-  if (r < 0)
-    return fprintf(stderr, "%s: snd_pcm_open: %s\n", *argv, snd_strerror(r)), 1;
-  if (sound_handle == NULL)
-    perror("snd_pcm_open");
-  /* Configure audio. */
-  r = snd_pcm_set_params(sound_handle, FORMAT, SND_PCM_ACCESS_RW_INTERLEAVED, 1 /* channels */,
-			 SAMPLE_RATE, 1 /* allow resampling? */, LATENCY);
-  if (r < 0)
-    return fprintf(stderr, "%s: snd_pcm_set_params: %s\n", *argv, snd_strerror(r)), 1;
- no_audio:
-  
-  /* Send message. */
-  if (isatty(STDIN_FILENO))
-    {
-      if (send_term())
-	goto fail;
-    }
-  else
-    if (send_file())
-      goto fail;
-  
-  /* Mark end of transmission. */
-  if (send_byte_with_ecc(CHAR_END))   goto cleanup;
-  if (send_byte_with_ecc(-CHAR_END))  goto cleanup;
-  
-  /* Done! */
-  rc = 0;
-  goto cleanup;
- fail:
-  if (errno)
-    perror(argv0);
- cleanup:
-  if (output_fd >= 0)
-    snd_pcm_close(sound_handle);
-  /* Mark aborted transmission. */
-  if (rc)
-    {
-      send_byte_with_ecc(CHAR_CANCEL);
-      send_byte_with_ecc(-CHAR_CANCEL);
-    }
-  return rc;
-}
-