martin modes, and some bugfixes to get them working

main.c

@@ -1,14 +1,41 @@
 #include "sstv.h"
+#include "martin.h"
 #include <stdio.h>
+#include <string.h>
+
+static void usage(const char *prog) {
+    printf("Usage: %s <mode> input_image output.wav\n", prog);
+    printf("Modes:\n");
+    printf("  robot36   - Robot 36 (default)\n");
+    printf("  martin1   - Martin M1\n");
+    printf("  martin2   - Martin M2\n");
+}
 
 int main(int argc, char **argv) {
-    if (argc < 3) {
-        printf("Usage: %s input_image output.wav\n", argv[0]);
+    if (argc < 4) {
+        usage(argv[0]);
         return 1;
     }
 
-    if (!sstv_encode_robot36(argv[1], argv[2])) {
-        printf("Encoding failed\n");
+    const char *mode_str   = argv[1];
+    const char *input_img  = argv[2];
+    const char *output_wav = argv[3];
+    int ok = 0;
+
+    if (strcmp(mode_str, "robot36") == 0) {
+        ok = sstv_encode_robot36(input_img, output_wav);
+    } else if (strcmp(mode_str, "martin1") == 0) {
+        ok = sstv_encode_martin(input_img, output_wav, &MARTIN_M1);
+    } else if (strcmp(mode_str, "martin2") == 0) {
+        ok = sstv_encode_martin(input_img, output_wav, &MARTIN_M2);
+    } else {
+        fprintf(stderr, "Unknown mode: %s\n", mode_str);
+        usage(argv[0]);
+        return 1;
+    }
+
+    if (!ok) {
+        fprintf(stderr, "Encoding failed.\n");
         return 1;
     }