Here's an Arduino code for capturing video with the ESP32-CAM module:

#include "esp_camera.h"

// Define camera pins
#define PWDN_GPIO_NUM     32
#define RESET_GPIO_NUM    -1
#define XCLK_GPIO_NUM      0
#define SIOD_GPIO_NUM     26
#define SIOC_GPIO_NUM     27

#define Y9_GPIO_NUM       35
#define Y8_GPIO_NUM       34
#define Y7_GPIO_NUM       39
#define Y6_GPIO_NUM       36
#define Y5_GPIO_NUM       21
#define Y4_GPIO_NUM       19
#define Y3_GPIO_NUM       18
#define Y2_GPIO_NUM        5
#define VSYNC_GPIO_NUM    25
#define HREF_GPIO_NUM     23
#define PCLK_GPIO_NUM     22

void setup() {
  Serial.begin(115200);
  // Initialize camera
  camera_config_t config;
  config.ledc_channel = LEDC_CHANNEL_0;
  config.ledc_timer = LEDC_TIMER_0;
  config.pin_d0 = Y2_GPIO_NUM;
  config.pin_d1 = Y3_GPIO_NUM;
  config.pin_d2 = Y4_GPIO_NUM;
  config.pin_d3 = Y5_GPIO_NUM;
  config.pin_d4 = Y6_GPIO_NUM;
  config.pin_d5 = Y7_GPIO_NUM;
  config.pin_d6 = Y8_GPIO_NUM;
  config.pin_d7 = Y9_GPIO_NUM;
  config.pin_xclk = XCLK_GPIO_NUM;
  config.pin_pclk = PCLK_GPIO_NUM;
  config.pin_vsync = VSYNC_GPIO_NUM;
  config.pin_href = HREF_GPIO_NUM;
  config.pin_sscb_sda = SIOD_GPIO_NUM;
  config.pin_sscb_scl = SIOC_GPIO_NUM;
  config.pin_pwdn = PWDN_GPIO_NUM;
  config.pin_reset = RESET_GPIO_NUM;
  config.xclk_freq_hz = 20000000;
  config.pixel_format = PIXFORMAT_JPEG;
  // Set the resolution
  config.frame_size = FRAMESIZE_SVGA;
  config.jpeg_quality = 12;
  config.fb_count = 1;
  // Initialize the camera
  esp_err_t err = esp_camera_init(&config);
  if (err != ESP_OK) {
    Serial.printf("Camera init failed with error 0x%x", err);
    return;
  }
  Serial.println("Camera initialized successfully");
}

void loop() {
  // Start video streaming
  Serial.println("Starting video streaming");
  camera_fb_t *fb = NULL;
  esp_err_t res = ESP_OK;
  while (true) {
    fb = esp_camera_fb_get();
    if (!fb) {
      Serial.println("Failed to capture frame");
      res = ESP_FAIL;
      break;
    }
    // Send the frame to serial port
    Serial.write(fb->buf, fb->len);
    // Release the memory
    esp_camera_fb_return(fb);
  }
  // Stop video streaming
  Serial.println("Stopping video streaming");
}

This code initializes the ESP32-CAM camera and starts video streaming using the esp_camera_fb_get() function. The frames are then sent to the serial port using the Serial.write() function. You can adjust the camera settings such as resolution and quality in the camera_config_t struct. Note that video streaming can be resource-intensive and may require additional optimization for better performance.