From 6873c47633e0b6870c3421a42a3357c818ed6cd5 Mon Sep 17 00:00:00 2001
From: Josef Miegl <josef@miegl.cz>
Date: Mon, 14 Jun 2021 22:53:26 +0200
Subject: [PATCH] add ask2ft

---
 .gitignore |  1 +
 Makefile   |  3 +++
 ask2ft.c   | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 72 insertions(+)
 create mode 100644 ask2ft.c

diff --git a/.gitignore b/.gitignore
index 6abce07..86dfdd8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 garaz.sh
 pitxft
+ask2ft
 *.o
diff --git a/Makefile b/Makefile
index 8080c52..63a7f12 100644
--- a/Makefile
+++ b/Makefile
@@ -35,5 +35,8 @@ mailbox.o: mailbox.c mailbox.h
 pitxft.o: pitxft.c mailbox.h
 	$(CC) $(CFLAGS) pitxft.c
 
+ask2ft: ask2ft.c
+	$(CC) -O2 -o ask2ft ask2ft.c
+
 clean:
 	rm -f *.o
diff --git a/ask2ft.c b/ask2ft.c
new file mode 100644
index 0000000..180abe7
--- /dev/null
+++ b/ask2ft.c
@@ -0,0 +1,68 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <ctype.h>
+
+#pragma pack(1)
+
+struct __attribute__((__packed__)) ft {
+	double frequency;
+	uint32_t duration;
+	uint32_t padding;
+};
+
+int main(int argc, char **argv) {
+	// arguments: freq samplerate samples/bit 
+	
+	if(argc < 4) {
+		fprintf(stderr, "Error: set arguments: freq samplerate samples/bit\n");
+		exit(1);
+	}
+
+	int frequency = atoi(argv[1]);
+	int samplerate = atoi(argv[2]);
+	int samples = atoi(argv[3]);
+
+	fprintf(stderr, "Frequency: %d, Samplerate: %d, Samples/bit: %d\n", frequency, samplerate, samples);
+
+	freopen(NULL, "wb", stdout); // ft is a binary format
+
+	size_t ilen = 64;
+	char* input = calloc(ilen, sizeof(char));
+	for(size_t ch = 0; (input[ch] = getc(stdin)) != EOF && input[ch] != '\n'; ch++) {
+		if(ch == ilen -1) {
+			ilen *= 2;
+			input = realloc(input, sizeof(char)*ilen);
+		}
+	}
+
+	const char binary[16][5] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};
+	const char digits[] = "0123456789abcdef";
+	char* bininput = calloc(strlen(input)*4+1, sizeof(char));
+
+	size_t bi = 0;
+	while(input[bi]) {
+		char *v = strchr(digits, tolower(input[bi++]));
+		if(v) strcat(bininput, binary[v - digits]);
+	}
+
+	size_t i = 0;
+	char prevchar = 0;
+	size_t prevcharcount = 0;
+	while(bininput[i]) {
+		if((prevchar != bininput[i]) && (i > 0)) {
+			struct ft* ftchunk = calloc(1, sizeof(struct ft));
+			if(prevchar == '1') ftchunk->frequency = (double)frequency;
+			ftchunk->duration = (uint64_t)prevcharcount*samples*1000000000/samplerate;
+			fwrite(ftchunk, sizeof(struct ft), 1, stdout);
+			fprintf(stderr, "Writing chunk: %f %u\n", ftchunk->frequency, ftchunk->duration);
+			free(ftchunk);
+			prevcharcount = 0;
+		}
+		prevchar = bininput[i++];
+		prevcharcount++;
+	}
+
+	return 0;
+}