MV Camera Application Development Guide on Rochchip
Application Layer Usage and Development Guide for MV/RAW Series Camera Modules on the Rockchip Platform
1 Overview
This document applies to scenarios where the camera hardware is correctly connected, the driver is properly installed, and the MV/RAW series camera has been successfully recognized.
The main objectives of this guide are to:
- Query the device information of the connected MV/RAW series camera
- Configure and prepare the camera operating modes
- Introduce several methods for previewing and capturing images
- Explain camera parameter configuration
- Provide guidance for customer-specific development
On the Rockchip platform, regardless of the method used to access the camera, it is necessary to complete device detection and media-ctl configuration before performing any further operations. Therefore, the following sections first cover device detection and media-ctl setup.
2 Device Detection and Environment Configuration
Here, we provide two scripts that can automatically retrieve key information about the connected camera.
2.1 probe_camera_info-rk.sh
This script is used to probe connected and successfully registered camera devices, retrieving underlying information such as the corresponding media device node, video device node, sub-device node, I²C bus, and device name.
After execution, an auto_camera_index.json file will be generated in the current directory, containing the retrieved information.
Example usage:
$ ./probe_camera_info-rk.sh
cat auto_camera_index.json
[
{
"media_node": "/dev/media0",
"video_node": "/dev/video0",
"video_subnode": "/dev/v4l-subdev2",
"media_entity_name": "m00_b_mvcam 7-003b",
"i2c_bus": "7"
}
]
Each {} block represents a single camera. If the board supports multiple camera modules, multiple {} blocks will be present in the file.
Explanation of Camera Information：
| Field | Name | Purpose | Usage |
|---|---|---|---|
| media_node | Media device node | Used to access the device within the media-controller framework | Used when configuring resolution and format via the media-ctl command
|
| video_node | Video capture device node | Standard V4L2 video device | Used with v4l2-ctl or customer applications to capture images
|
| video_subnode | V4L2 sub-device node | Used for configuring certain camera parameters | Accessed via v4l2-ctl commands
|
| media_entity_name | Media entity name | Describes the device, e.g., "m00_b_mvcam 7-003b"
|
Used when setting resolution and format with media-ctl
|
| i2c_bus | I²C bus | Indicates the I²C bus to which the device is connected | Used as the underlying communication channel for camera parameter configuration, e.g., by the mv_mipi_i2c.sh script
|