Simple Video Server Example

(See the README.md file in the upper level examples directory for more information about examples.)

Overview

The example starts a HTTP server on a local network. You can use a browser to access this local server. This example designs several APIs to fetch resources as follows:

By default, the example will start an MDNS domain name system. Therefore, the server can be accessed by domain name. For example, accessing the URL for obtaining images by entering URL http://esp-web.local/pic in the browser. Also, accessing URLs through the use of IP addresses is also allowed.

Note that this is a single-threaded simple server. When /stream is opened, other URLs will not be available. Therefore, please close the /stream webpage before using other URLs.

How to use example

Configure the project

Open the project configuration menu (idf.py menuconfig).

Pin Assignment:

In the Example Configuration menu:

• Choose the I2C Port and I2C pins connected to the sensor.
• Choose the reset pin and powerdown pin connected to the sensor(Set to -1 if not used).

Connection Configuration:

In the Example Connection Configuration menu:

• If you select the Wi-Fi interface, you also have to set:

  • Wi-Fi SSID and Wi-Fi password that your esp32 will connect to.
  • Wi-Fi SoftAP's SSID and password if you want esp32 work as an Access Point.

• If you select the Ethernet interface, you also have to set:

  • PHY model in Ethernet PHY option, e.g. IP101.
  • PHY address in PHY Address option, which should be determined by your board schematic.
  • EMAC Clock mode, GPIO used by SMI.

Configuration of the camera sensor

In the Espressif Camera Sensors Configurations menu:

• Select the camera sensor you want to connect to.
• Select the default format for this sensor.

The default format of the camera sensor determines the data format that can be used in the program. Therefore, when the camera sensor is selected to work in YUV422 format in the configuration menu, the format that should be configured in the app_main.c is V4L2_PIX_FMT_YUV422P:

app_video_init(video_cam_fd0, V4L2_PIX_FMT_YUV422P);

If the default format selected in the configuration menu is RAW8, the ISP can automatically generate interpolated data formats(e.g., RGB888, RGB565, YUV422, YUV420, etc). You can configure the output format to RAW8 or YUV422, etc.

Note that the MIPI-CSI interface is selected to connect the camera sensor by default, so there are:

#define CAM_DEV_PATH                 ESP_VIDEO_MIPI_CSI_DEVICE_NAME

Refer video-device can be used to query the names of various devices. If the DVP interface is selected to connect to the camera, this code is:

#define CAM_DEV_PATH                 ESP_VIDEO_DVP_DEVICE_NAME

In addition, this example allows you to build two web servers to display images from two cameras respectively. For related codes, please refer to:

int video_cam_fd = app_video_open(ESP_VIDEO_MIPI_CSI_DEVICE_NAME, EXAMPLE_VIDEO_FMT_RGB565);
if (video_cam_fd < 0) {
    ESP_LOGE(TAG, "video cam open failed");
    return;
}

ESP_ERROR_CHECK(start_cam_web_server(index, video_cam_fd));

index++;

video_cam_fd = app_video_open(ESP_VIDEO_DVP_DEVICE_NAME, EXAMPLE_VIDEO_FMT_RGB565);
if (video_cam_fd < 0) {
    ESP_LOGE(TAG, "video cam open failed");
    return;
}

ESP_ERROR_CHECK(start_cam_web_server(index, video_cam_fd));

For devices that do not support native WiFi, esp_wifi_remote is used to provide an additional wifi interface by default. In the Wi-Fi Remote menu:

• Choose the slave target connect to the MCU.

Build and Flash

Build the project and flash it to the board, then run monitor tool to view serial output:

idf.py -p PORT flash monitor

(To exit the serial monitor, type Ctrl-].)

See the ESP-IDF Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

Running this example, you will see the following log output on the serial monitor:

...
I (1606) main_task: Started on CPU0
I (1616) esp_psram: Reserving pool of 32K of internal memory for DMA/internal allocations
I (1616) main_task: Calling app_main()
I (1676) esp_eth.netif.netif_glue: 60:55:f9:f8:80:8a
I (1676) esp_eth.netif.netif_glue: ethernet attached to netif
I (3276) app_eth: Ethernet Started
I (3276) gpio: GPIO[22]| InputEn: 1| OutputEn: 1| OpenDrain: 1| Pullup: 1| Pulldown: 0| Intr:0 
I (3276) app_eth: Ethernet Link Up
I (3276) app_eth: Ethernet HW Addr 60:55:f9:f8:80:8a
I (3286) gpio: GPIO[23]| InputEn: 1| OutputEn: 1| OpenDrain: 1| Pullup: 1| Pulldown: 0| Intr:0 
I (3296) sc2336: Detected Camera sensor PID=0xcb3a with index 0
I (3366) app_video: version: 0.1.0
I (3366) app_video: driver:  MIPI-CSI
I (3366) app_video: card:    MIPI-CSI
I (3376) app_video: bus:     esp32p4:MIPI-CSI
I (3376) app_video: width=1280 height=720
I (3386) app_video: Capture RGB 5-6-5 format
I (3396) app_web: Starting stream HTTP server on port: '80'
I (3396) main_task: Returned from app_main()
I (4276) esp_netif_handlers: eth ip: 192.168.47.100, mask: 255.255.255.0, gw: 192.168.47.1
I (4276) app_eth: Ethernet Got IP Address
I (4276) app_eth: ~~~~~~~~~~~
I (4276) app_eth: ETHIP:192.168.47.100
I (4286) app_eth: ETHMASK:255.255.255.0
I (4286) app_eth: ETHGW:192.168.47.1
I (4286) app_eth: ~~~~~~~~~~~
I (7216) app_web: jpeg size = 50749
I (7966) app_web: jpeg size = 50749
I (8996) app_web: jpeg size = 50560
...

Enter http://esp-web.local/pic or 192.168.47.100/pic in the browser to access the image. Similar methods can also be used to access other URLs.

Troubleshooting

1. Error occurred:

   Plaintext

   E (1595) i2c.master: I2C transaction unexpected nack detected
   E (1595) i2c.master: s_i2c_synchronous_transaction(870): I2C transaction failed
   

   • Check that the camera sensor is connected to the board and that the pins are correctly configured in the menuconfig.

2. Error occurred:

   Plaintext

   E (1857) dvp_video: format is not supported
   E (1857) esp_video: video->ops->set_format=102
   

• Check if the parameters of command VIDIOC_S_FMT in the code match the format selected in the menuconfig.