| Supported Targets | ESP32-P4 |
| ----------------- | -------- |
# Simple Video Server Example
## 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:
| URL | Method | Description |
| ------- | ------ | ------------------------------------------------------------ |
| /pic | GET | Used for clients to get a jpeg image, Refreshing the webpage can retrieve a new image, which can be saved by right clicking on the save button on the webpage. |
| /record | GET | Used for clients to get binary data describing the original image. |
| /stream | GET | Used for clients to get continuous MJPEG stream. The server continuously pushes JPEG images from the background to the client. So when you save images on the webpage, the saved images may not be in real-time. |
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
### Hardware Required
* A ESP32-P4 development board with MIPI-CSI interface (e.g., ESP32-P4-Function-EV-Board)
* A camera sensor that has been adapted, see the [esp_cam_sensor](https://github.com/espressif/esp-video-components/tree/master/esp_cam_sensor)
* A USB Type-C cable for power supply and programming
### Configure the project
Open the project configuration menu (`idf.py menuconfig`).
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).
* 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.
In the `Example Connection Configuration` menu:
* 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.
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`:
```c
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:
```c
#define CAM_DEV_PATH ESP_VIDEO_MIPI_CSI_DEVICE_NAME
```
Refer [video-device](https://github.com/espressif/esp-video-components/tree/master/esp_video) can be used to query the names of various devices. If the DVP interface is selected to connect to the camera, this code is:
```c
#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:
```c
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));
```
### 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](https://docs.espressif.com/projects/esp-idf/en/latest/esp32p4/get-started/index.html) 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:
```
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.
To create a project from this example, run:
idf.py create-project-from-example "espressif/esp_video^0.7.0:simple_video_server"