Added the fluxdump command, for exporting a fluxmap into something like

Audacity where it can be visualised.

Makefile

@@ -13,6 +13,7 @@ SRCS = \
 	cmd_write.c \
 	cmd_decode.c \
 	cmd_testpattern.c \
+	cmd_fluxdump.c \
 
 OBJS = $(patsubst %.c, .objs/%.o, $(SRCS))
 

cmd_fluxdump.c

@@ -0,0 +1,112 @@
+#include "globals.h"
+#include "sql.h"
+#include <unistd.h>
+
+static const char* input_filename = NULL;
+static const char* output_filename = NULL;
+static int track = 0;
+static int side = 0;
+static int resolution_ns = NS_PER_TICK;
+static sqlite3* db;
+
+static void syntax_error(void)
+{
+    fprintf(stderr,
+        "syntax: fluxclient fluxdump <options>:\n"
+        "  -i <filename>       input filename (.flux)\n"
+        "  -o <filename>       output filename (.raw)\n"
+        "  -t <track>          track to dump\n"
+        "  -0                  dump side 0\n"
+        "  -1                  dump side 1\n"
+        "  -r <resolution>     time per sample in ns (default: one tick)\n"
+    );
+    exit(1);
+}
+
+static char* const* parse_options(char* const* argv)
+{
+	for (;;)
+	{
+		switch (getopt(countargs(argv), argv, "+i:o:t:01r:L"))
+		{
+			case -1:
+				return argv + optind - 1;
+
+            case 'i':
+                input_filename = optarg;
+                break;
+
+			case 'o':
+                output_filename = optarg;
+                break;
+
+            case 't':
+                track = atoi(optarg);
+                break;
+
+            case '0':
+                side = 0;
+                break;
+
+            case '1':
+                side = 1;
+                break;
+
+            case 'r':
+                resolution_ns = atoi(optarg);
+                break;
+
+			default:
+				syntax_error();
+		}
+	}
+}
+
+static void close_file(void)
+{
+    sqlite3_close(db);
+}
+
+static void open_file(void)
+{
+    db = sql_open(input_filename, SQLITE_OPEN_READONLY);
+    atexit(close_file);
+}
+
+void cmd_fluxdump(char* const* argv)
+{
+    argv = parse_options(argv);
+    if (countargs(argv) != 1)
+        syntax_error();
+    if (!input_filename)
+        error("you must supply a filename to read from");
+    if (!output_filename)
+        error("you must supply a filename to write to");
+    if (resolution_ns < NS_PER_TICK)
+        error("resolution too fine (minimum: %dns)", NS_PER_TICK);
+
+    open_file();
+    struct fluxmap* fluxmap = sql_read_flux(db, track, side);
+    if (!fluxmap)
+        error("no data for that track in the file");
+    
+    printf("Length: %d ms\n", fluxmap->length_us / 1000);
+    int length_r = fluxmap->length_us * 1000 / resolution_ns;
+    printf("Output size: %d bytes\n", length_r);
+
+    uint8_t* buffer = calloc(1, length_r);
+    int cursor_ns = 0;
+    for (int i=0; i<fluxmap->bytes; i++)
+    {
+        uint8_t t = fluxmap->intervals[i];
+        cursor_ns += t * NS_PER_TICK / resolution_ns;
+        if (cursor_ns < length_r)
+            buffer[cursor_ns] = 0x7f;
+    }
+
+    FILE* fp = fopen(output_filename, "wb");
+    fwrite(buffer, length_r, 1, fp);
+    fclose(fp);
+    free(buffer);
+}
+

globals.h

@@ -63,5 +63,6 @@ extern void cmd_read(char* const* argv);
 extern void cmd_write(char* const* argv);
 extern void cmd_decode(char* const* argv);
 extern void cmd_testpattern(char* const* argv);
+extern void cmd_fluxdump(char* const* argv);
 
 #endif

main.c

@@ -78,6 +78,8 @@ int main(int argc, char* const* argv)
         cmd_decode(argv);
     else if (strcmp(argv[0], "testpattern") == 0)
         cmd_testpattern(argv);
+    else if (strcmp(argv[0], "fluxdump") == 0)
+        cmd_fluxdump(argv);
     else
         syntax_error();
 

protocol.h

@@ -28,6 +28,7 @@ enum
     FRAME_SIZE = 64,
     TICK_FREQUENCY = 12000000,
     TICKS_PER_US = TICK_FREQUENCY / 1000000,
+    NS_PER_TICK = 1000000000 / TICK_FREQUENCY,
 };
 
 enum