vidcaps with multiple inputs: use vidcap_params_get_count

common code

Author: MartinPulec

src/video_capture/aggregate.c

@@ -112,17 +112,10 @@ vidcap_aggregate_init(const struct vidcap_params *params, void **state)
         }
 
 
-        s->devices_cnt = 0;
-        const struct vidcap_params *tmp = params;
-        while((tmp = vidcap_params_get_next(tmp))) {
-                if (vidcap_params_get_driver(tmp) != NULL)
-                        s->devices_cnt++;
-                else
-                        break;
-        }
+        s->devices_cnt = (int) vidcap_params_get_count(params);
 
         s->devices = calloc(s->devices_cnt, sizeof(struct vidcap *));
-        tmp = params;
+        const struct vidcap_params *tmp = params;
         for (int i = 0; i < s->devices_cnt; ++i) {
                 tmp = vidcap_params_get_next(tmp);
                 struct vidcap_params *copy = vidcap_params_copy(tmp);

src/video_capture/gpustitch.cpp

@@ -533,14 +533,8 @@ vidcap_gpustitch_init(const vidcap_params *params, void **state)
 
         parse_fmt(s, vidcap_params_get_fmt(params));
 
-        s->devices_cnt = 0;
+        s->devices_cnt = vidcap_params_get_count(params);
         auto tmp = params;
-        while((tmp = vidcap_params_get_next(tmp))) {
-                if (vidcap_params_get_driver(tmp) != nullptr)
-                        s->devices_cnt++;
-                else
-                        break;
-        }
 
         if(s->tiled_capture && s->devices_cnt != 1){
                 log_msg(LOG_LEVEL_ERROR, "Number of capture devices must be exactly 1 when using tiled capture!\n");

src/video_capture/switcher.c

@@ -202,14 +202,7 @@ vidcap_switcher_init(const struct vidcap_params *params, void **state)
         module_init_default(&s->mod);
         s->mod.cls = MODULE_CLASS_DATA;
         module_register(&s->mod, vidcap_params_get_parent(params));
-        s->devices_cnt = 0;
-        const struct vidcap_params *tmp = params;
-        while((tmp = vidcap_params_get_next(tmp))) {
-                if (vidcap_params_get_driver(tmp) == NULL) {
-                        break;
-                }
-                s->devices_cnt++;
-        }
+        s->devices_cnt = vidcap_params_get_count(params);
 
         if (s->selected_device >= s->devices_cnt) {
                 MSG(ERROR, "Error: device #%d not available!\n",
@@ -219,7 +212,7 @@ vidcap_switcher_init(const struct vidcap_params *params, void **state)
 
         s->devices = calloc(s->devices_cnt, sizeof(struct vidcap *));
         s->device_names = calloc(s->devices_cnt, sizeof s->device_names[0]);
-        tmp = params;
+        const struct vidcap_params *tmp = params;
         for (unsigned int i = 0; i < s->devices_cnt; ++i) {
                 tmp = vidcap_params_get_next(tmp);
 

src/video_capture/swmix.c

@@ -1050,14 +1050,7 @@ static bool parse(struct vidcap_swmix_state *s, struct video_desc *desc, char *f
                 return false;
         }
 
-        s->devices_cnt = 0;
-        const struct vidcap_params *tmp = params;
-        while((tmp = vidcap_params_get_next(tmp))) {
-                if (vidcap_params_get_driver(tmp) != NULL)
-                        s->devices_cnt++;
-                else
-                        break;
-        }
+        s->devices_cnt = vidcap_params_get_count(params);
 
         if (s->grid_x != 0 && s->devices_cnt > s->grid_x * s->grid_y) {
                 log_msg(LOG_LEVEL_ERROR, "[swmix] Invalid layout! More devices given than layout size.\n");
@@ -1073,7 +1066,7 @@ static bool parse(struct vidcap_swmix_state *s, struct video_desc *desc, char *f
                 pthread_mutex_init(&(s->slaves[i].lock), NULL);
         }
 
-        tmp = params;
+        const struct vidcap_params *tmp = params;
         for (int i = 0; i < s->devices_cnt; ++i) {
                 tmp = vidcap_params_get_next(tmp);
                 s->slaves[i].device_params = vidcap_params_copy(tmp);

src/video_capture_params.cpp

@@ -338,3 +338,16 @@ vidcap_params_free(struct vidcap_params *params)
                 params = next;
         }
 }
+
+unsigned
+vidcap_params_get_count(const struct vidcap_params *params)
+{
+        unsigned count = 0;
+        while ((params = vidcap_params_get_next(params)) != nullptr) {
+                if (vidcap_params_get_driver(params) == nullptr) {
+                        return count;
+                }
+                count += 1;
+        }
+        return count;
+}

src/video_capture_params.h

@@ -84,6 +84,7 @@ void                  vidcap_params_set_flags(struct vidcap_params *params, unsi
 void                  vidcap_params_add_flags(struct vidcap_params *params, unsigned int flags);
 void                  vidcap_params_replace_fmt(struct vidcap_params *params,
                                                 const char           *new_fmt);
+unsigned              vidcap_params_get_count(const struct vidcap_params *params);
 /// @}
 
 #ifdef __cplusplus