Add local network camera monitor (#138)

This feature is located at `http://[camera-ip]/monitor` and gives quick access to up to 5  cameras running the web server example.
Features:
- Finds up to 5 cameras in the local network through mDNS
- Grabs periodicaly and image from each camera (period can be set or turned off)
- Cycles the cameras at given period (off when camera is selected manually)
- Shows basic info for each camera (model, sensor, resolution)
- Allows for easy access to each camer's control panel
- Allows change of resolution and XCLK
- Can save current snapshot

examples/single_chip/camera_web_server/main/CMakeLists.txt

@@ -13,6 +13,7 @@ set(COMPONENT_REQUIRES
 set(COMPONENT_EMBED_FILES
         "www/index_ov2640.html.gz"
         "www/index_ov3660.html.gz"
-        "www/index_ov5640.html.gz")
+        "www/index_ov5640.html.gz"
+        "www/monitor.html.gz")
 
 register_component()

examples/single_chip/camera_web_server/main/Kconfig.projbuild

@@ -1,6 +1,12 @@
 menu "Camera Web Server"
 
 menu "WiFi Settings"
+config ESP_HOST_NAME
+    string "Camera Host Name"
+    default ""
+    help
+    Hostname that the camera will advertise over mDNS.
+
 config ESP_WIFI_SSID
     string "WiFi STA SSID"
     default ""

examples/single_chip/camera_web_server/main/app_httpd.c

@@ -21,6 +21,7 @@
 //#include "camera_index.h"
 #include "sdkconfig.h"
 #include "app_mdns.h"
+#include "app_camera.h"
 
 #if defined(ARDUINO_ARCH_ESP32) && defined(CONFIG_ARDUHAL_ESP_LOG)
 #include "esp32-hal-log.h"
@@ -840,6 +841,9 @@ static esp_err_t status_handler(httpd_req_t *req)
         p+=print_reg(p, s, 0x132, 0xFF);
     }
 
+    p += sprintf(p, "\"board\":\"%s\",", CAM_BOARD);
+    p += sprintf(p, "\"xclk\":%u,", s->xclk_freq_hz / 1000000);
+    p += sprintf(p, "\"pixformat\":%u,", s->pixformat);
     p += sprintf(p, "\"framesize\":%u,", s->status.framesize);
     p += sprintf(p, "\"quality\":%u,", s->status.quality);
     p += sprintf(p, "\"brightness\":%d,", s->status.brightness);
@@ -1086,10 +1090,20 @@ static esp_err_t index_handler(httpd_req_t *req)
     }
 }
 
+static esp_err_t monitor_handler(httpd_req_t *req)
+{
+    extern const unsigned char monitor_html_gz_start[] asm("_binary_monitor_html_gz_start");
+    extern const unsigned char monitor_html_gz_end[] asm("_binary_monitor_html_gz_end");
+    size_t monitor_html_gz_len = monitor_html_gz_end - monitor_html_gz_start;
+    httpd_resp_set_type(req, "text/html");
+    httpd_resp_set_hdr(req, "Content-Encoding", "gzip");
+    return httpd_resp_send(req, (const char *)monitor_html_gz_start, monitor_html_gz_len);
+}
+
 void app_httpd_main()
 {
     httpd_config_t config = HTTPD_DEFAULT_CONFIG();
-    config.max_uri_handlers = 10;
+    config.max_uri_handlers = 12;
 
     httpd_uri_t index_uri = {
         .uri = "/",
@@ -1157,6 +1171,12 @@ void app_httpd_main()
         .handler = mdns_handler,
         .user_ctx = NULL};
 
+    httpd_uri_t monitor_uri = {
+        .uri = "/monitor",
+        .method = HTTP_GET,
+        .handler = monitor_handler,
+        .user_ctx = NULL};
+
     ra_filter_init(&ra_filter, 20);
 
 #if CONFIG_ESP_FACE_DETECT_ENABLED
@@ -1201,6 +1221,7 @@ void app_httpd_main()
         httpd_register_uri_handler(camera_httpd, &win_uri);
 
         httpd_register_uri_handler(camera_httpd, &mdns_uri);
+        httpd_register_uri_handler(camera_httpd, &monitor_uri);
     }
 
     config.server_port += 1;

examples/single_chip/camera_web_server/main/app_mdns.c

@@ -177,11 +177,6 @@ void app_mdns_main()
 	}
 	xSemaphoreGive(query_lock);
 
-    if (esp_read_mac(mac, ESP_MAC_WIFI_STA) != ESP_OK) {
-        ESP_LOGE(TAG, "esp_read_mac() Failed");
-        return;
-    }
-
     sensor_t * s = esp_camera_sensor_get();
     switch(s->id.PID){
         case OV2640_PID: model = "OV2640"; break;
@@ -190,7 +185,17 @@ void app_mdns_main()
         case OV7725_PID: model = "OV7725"; break;
         default: model = "UNKNOWN"; break;
     }
+    
+    if (strlen(CONFIG_ESP_HOST_NAME) > 0) {
+        snprintf(iname, 64, "%s", CONFIG_ESP_HOST_NAME);
+    } else {
+        if (esp_read_mac(mac, ESP_MAC_WIFI_STA) != ESP_OK) {
+            ESP_LOGE(TAG, "esp_read_mac() Failed");
+            return;
+        }
         snprintf(iname, 64, "%s-%s-%02X%02X%02X", CAM_BOARD, model, mac[3], mac[4], mac[5]);
+    }
+
     snprintf(framesize, 4, "%d", s->status.framesize);
     snprintf(pixformat, 4, "%d", s->pixformat);
 

examples/single_chip/camera_web_server/main/component.mk

@@ -9,3 +9,4 @@
 COMPONENT_EMBED_FILES := www/index_ov2640.html.gz
 COMPONENT_EMBED_FILES += www/index_ov3660.html.gz
 COMPONENT_EMBED_FILES += www/index_ov5640.html.gz
+COMPONENT_EMBED_FILES += www/monitor.html.gz