Extract argument parsing to specific functions

To avoid a big switch/case, implement the argument parsing logic in
separate static functions.

app/src/main.c

@@ -100,19 +100,7 @@ static void print_version(void) {
     fprintf(stderr, " - libavutil %d.%d.%d\n", LIBAVUTIL_VERSION_MAJOR, LIBAVUTIL_VERSION_MINOR, LIBAVUTIL_VERSION_MICRO);
 }
 
-static SDL_bool parse_args(struct args *args, int argc, char *argv[]) {
+static SDL_bool parse_bit_rate(char *optarg, Uint32 *bit_rate) {
-    static const struct option long_options[] = {
-        {"bit-rate", required_argument, NULL, 'b'},
-        {"help",     no_argument,       NULL, 'h'},
-        {"max-size", required_argument, NULL, 'm'},
-        {"port",     required_argument, NULL, 'p'},
-        {"version",  no_argument,       NULL, 'v'},
-        {NULL,       0,                 NULL, 0  },
-    };
-    int c;
-    while ((c = getopt_long(argc, argv, "b:hm:p:v", long_options, NULL)) != -1) {
-        switch (c) {
-            case 'b': {
     char *endptr;
     if (*optarg == '\0') {
         LOGE("Bit-rate parameter is empty");
@@ -138,14 +126,12 @@ static SDL_bool parse_args(struct args *args, int argc, char *argv[]) {
         LOGE("Bitrate must be positive and less than 2^32: %s", optarg);
         return SDL_FALSE;
     }
-                args->bit_rate = (Uint32) value * mul;
+
-                break;
+    *bit_rate = (Uint32) value * mul;
-            }
+    return SDL_TRUE;
-            case 'h': {
+}
-                args->help = SDL_TRUE;
+
-                break;
+static SDL_bool parse_max_size(char *optarg, Uint16 *max_size) {
-            }
-            case 'm': {
     char *endptr;
     if (*optarg == '\0') {
         LOGE("Max size parameter is empty");
@@ -160,10 +146,12 @@ static SDL_bool parse_args(struct args *args, int argc, char *argv[]) {
         LOGE("Max size must be between 0 and 65535: %ld", value);
         return SDL_FALSE;
     }
-                args->max_size = (Uint16) value;
+
-                break;
+    *max_size = (Uint16) value;
-            }
+    return SDL_TRUE;
-            case 'p': {
+}
+
+static SDL_bool parse_port(char *optarg, Uint16 *port) {
     char *endptr;
     if (*optarg == '\0') {
         LOGE("Invalid port parameter is empty");
@@ -178,7 +166,43 @@ static SDL_bool parse_args(struct args *args, int argc, char *argv[]) {
         LOGE("Port out of range: %ld", value);
         return SDL_FALSE;
     }
-                args->port = (Uint16) value;
+
+    *port = (Uint16) value;
+    return SDL_TRUE;
+}
+
+static SDL_bool parse_args(struct args *args, int argc, char *argv[]) {
+    static const struct option long_options[] = {
+        {"bit-rate", required_argument, NULL, 'b'},
+        {"help",     no_argument,       NULL, 'h'},
+        {"max-size", required_argument, NULL, 'm'},
+        {"port",     required_argument, NULL, 'p'},
+        {"version",  no_argument,       NULL, 'v'},
+        {NULL,       0,                 NULL, 0  },
+    };
+    int c;
+    while ((c = getopt_long(argc, argv, "b:hm:p:v", long_options, NULL)) != -1) {
+        switch (c) {
+            case 'b': {
+                if (!parse_bit_rate(optarg, &args->bit_rate)) {
+                    return SDL_FALSE;
+                }
+                break;
+            }
+            case 'h': {
+                args->help = SDL_TRUE;
+                break;
+            }
+            case 'm': {
+                if (!parse_max_size(optarg, &args->max_size)) {
+                    return SDL_FALSE;
+                }
+                break;
+            }
+            case 'p': {
+                if (!parse_port(optarg, &args->port)) {
+                    return SDL_FALSE;
+                }
                 break;
             }
             case 'v': {