Adds esp_camera_return_all() (#519)

Author: Wouter de Bie

driver/cam_hal.c

@@ -506,3 +506,9 @@ void cam_give(camera_fb_t *dma_buffer)
         }
     }
 }
+
+void cam_give_all(void) {
+    for (int x = 0; x < cam_obj->frame_cnt; x++) {
+        cam_obj->frames[x].en = 1;
+    }
+}

driver/esp_camera.c

@@ -476,3 +476,11 @@ esp_err_t esp_camera_load_from_nvs(const char *key)
         return ret;
     }
 }
+
+void esp_camera_return_all(void) {
+    if (s_state == NULL) {
+        return;
+    }
+    cam_give_all();
+}
+

driver/include/esp_camera.h

@@ -231,6 +231,12 @@ esp_err_t esp_camera_save_to_nvs(const char *key);
  */
 esp_err_t esp_camera_load_from_nvs(const char *key);
 
+/**
+ * @brief Return all frame buffers to be reused again.
+ */
+void esp_camera_return_all(void);
+
+
 #ifdef __cplusplus
 }
 #endif

driver/private_include/cam_hal.h

@@ -55,6 +55,8 @@ camera_fb_t *cam_take(TickType_t timeout);
 
 void cam_give(camera_fb_t *dma_buffer);
 
+void cam_give_all(void);
+
 #ifdef __cplusplus
 }
 #endif