1 files changed, 66 insertions, 72 deletions

diff --git a/util/spkmodem_recv/spkmodem-recv.c b/util/spkmodem_recv/spkmodem-recv.c
index 30e13d8a..7de911ec 100644
--- a/util/spkmodem_recv/spkmodem-recv.c
+++ b/util/spkmodem_recv/spkmodem-recv.c
@@ -19,117 +19,111 @@
 #define FREQ_DATA_MAX 60
 #define THRESHOLD 500
 
-#define DEBUG 0
-#define FLUSH_TIMEOUT 1
+#define ERR() (errno = errno ? errno : ECANCELED)
+#define reset_char() ascii = 0, ascii_bit = 7
 
-signed short frame[2 * SAMPLES_PER_FRAME];
-signed short pulse[2 * SAMPLES_PER_FRAME];
-int f1, f2, lp, ascii_bit = 7;
+signed short frame[2 * SAMPLES_PER_FRAME], pulse[2 * SAMPLES_PER_FRAME];
+int ringpos, debug, freq_data, freq_separator, sample_count, ascii_bit = 7;
 char ascii = 0;
 
 void handle_audio(void);
-void print_char(void);
 void fetch_sample(void);
+void read_frame(void);
+int set_ascii_bit(void);
+void print_char(void);
+void print_stats(void);
 
 int
 main(int argc, char *argv[])
 {
 	int c;
-
-#ifdef HAVE_PLEDGE
+#ifdef __OpenBSD__
 	if (pledge("stdio", NULL) == -1)
-		err(errno, "pledge");
+		err(ERR(), "pledge");
 #endif
-
-	while ((c = getopt(argc, argv, "u")) != -1) {
-		switch (c) {
-		case 'u':
-			setvbuf(stdout, NULL, _IONBF, 0);
-			break;
-		default:
+	while ((c = getopt(argc, argv, "d")) != -1) {
+		if (c != 'd')
 			err(errno = EINVAL, NULL);
-		}
+		debug = 1;
 	}
-
+	setvbuf(stdout, NULL, _IONBF, 0);
 	while (!feof(stdin))
 		handle_audio();
-
+	if (errno && debug)
+		err(errno, "Unhandled error, errno %d", errno);
 	return errno;
 }
 
 void
 handle_audio(void)
 {
-	static int llp = 0;
-
-	if (lp > (3 * SAMPLES_PER_FRAME)) {
-		ascii_bit = 7;
-		ascii = 0;
-		lp = 0;
-		llp++;
-	}
-	if (llp == FLUSH_TIMEOUT)
-		if (fflush(stdout) == EOF)
-			err(errno, NULL);
-
-	if ((f2 <= FREQ_SEP_MIN) || (f2 >= FREQ_SEP_MAX)
-			|| (f1 <= FREQ_DATA_MIN) || (f1 >= FREQ_DATA_MAX)) {
+	if (sample_count > (3 * SAMPLES_PER_FRAME))
+		sample_count = reset_char();
+	if ((freq_separator <= FREQ_SEP_MIN) || (freq_separator >= FREQ_SEP_MAX)
+	    || (freq_data <= FREQ_DATA_MIN) || (freq_data >= FREQ_DATA_MAX)) {
 		fetch_sample();
 		return;
 	}
 
-	print_char();
-
-	lp = 0;
-	llp = 0;
-	for (int i = 0; i < SAMPLES_PER_FRAME; i++)
+	if (set_ascii_bit() < 0)
+		print_char();
+	sample_count = 0;
+	for (int sample = 0; sample < SAMPLES_PER_FRAME; sample++)
 		fetch_sample();
 }
 
 void
 fetch_sample(void)
 {
-	static int ringpos = 0;
-
-	f1 -= pulse[ringpos];
-	f1 += pulse[(ringpos + SAMPLES_PER_FRAME) % (2 * SAMPLES_PER_FRAME)];
-	f2 -= pulse[(ringpos + SAMPLES_PER_FRAME) % (2 * SAMPLES_PER_FRAME)];
-	if (fread(frame + ringpos, 1, sizeof(frame[0]), stdin)
-			!= sizeof(frame[0]))
-		err(errno = ECANCELED, "Could not read frame.");
+	freq_data -= pulse[ringpos];
+	freq_data += pulse[(ringpos + SAMPLES_PER_FRAME)
+	    % (2 * SAMPLES_PER_FRAME)];
+	freq_separator -= pulse[(ringpos + SAMPLES_PER_FRAME)
+	    % (2 * SAMPLES_PER_FRAME)];
+
+	read_frame();
+	if ((pulse[ringpos] = (abs(frame[ringpos]) > THRESHOLD) ? 1 : 0))
+		++freq_separator;
+	++ringpos;
+	ringpos %= 2 * SAMPLES_PER_FRAME;
+	++sample_count;
+}
 
-	if (abs(frame[ringpos]) > THRESHOLD) { /* rising/falling edge(pulse) */
-		pulse[ringpos] = 1;
-		f2++;
-	} else {
-		pulse[ringpos] = 0;
-	}
+void
+read_frame(void)
+{
+	if ((fread(frame + ringpos, 1, sizeof(frame[0]), stdin)
+	    != sizeof(frame[0])) || (ferror(stdin) != 0))
+		err(ERR(), "Could not read from frame.");
+}
 
-	ringpos++;
-	ringpos %= 2 * SAMPLES_PER_FRAME;
-	lp++;
+int
+set_ascii_bit(void)
+{
+	if (debug)
+		print_stats();
+	if (freq_data < FREQ_DATA_THRESHOLD)
+		ascii |= (1 << ascii_bit);
+	--ascii_bit;
+	return ascii_bit;
 }
 
 void
 print_char(void)
 {
-#if DEBUG
-	long stdin_pos = 0;
-	if ((stdin_pos = ftell(stdin)) == -1)
-		err(errno, NULL);
-	printf ("%d %d %d @%ld\n", f1, f2, FREQ_DATA_THRESHOLD,
-			stdin_pos - sizeof(frame));
-#endif
-	if (f1 < FREQ_DATA_THRESHOLD)
-		ascii |= (1 << ascii_bit);
-	ascii_bit--;
-	if (ascii_bit < 0) {
-#if DEBUG
+	if (debug)
 		printf("<%c, %x>", ascii, ascii);
-#else
+	else
 		printf("%c", ascii);
-#endif
-		ascii_bit = 7;
-		ascii = 0;
-	}
+	reset_char();
+}
+
+void
+print_stats(void)
+{
+	long stdin_pos = 0;
+	if ((stdin_pos = ftell(stdin)) == -1)
+		err(ERR(), NULL);
+	printf ("%d %d %d @%ld\n", freq_data, freq_separator,
+	    FREQ_DATA_THRESHOLD, stdin_pos - sizeof(frame));
 }