DriveWorks Recording Library

The DriveWorks recording library provides functionality to easily record multiple sensors. The library is configurable with a JSON file. The JSON file syntax is described as below.

Currently, there are 6 types of sensors supported (camera, CAN, GPS, IMU, Lidar, Radar) and the JSON file is written this way.

{
    "version": "0.8",

This is the version number. If this version number mismatches the in code version number, the recorder will throw an exception.

"path": ".",

This is where the recording library stores its captured data. Each time a new capture session is invoked, a new folder is created at this path with the time and location (if available) in the folder name.

"log-level": "verbose",

This is log level used within DriveWorks. Valid values are verbose, debug, warn, or error.

"file-buffer-size": 2097152,

This is the size of the buffer for file writing.

"camera": {
    "separate-thread": true,
    "write-file-pattern": "video_*",
    "sensors": [
      {
            "protocol": "camera.gmsl",
            "params": "camera-type=ar0231-rccb,csi-port=ef,camera-count=4,fifo-size=12",
            "channel-names": [
                                "first",
                                "second",
                                "third",
                                "fourth"
                             ]
      }
    ]
},

Each sensor group is set up the same way. Multiple sensors are added by creating a new object in the sensors array section of each group. For example to connect four cameras to each of the "ab" and "cd" interfaces the code above can be replaced with:

"camera": {
    "separate-thread": true,
    "write-file-pattern": "video_*",
    "sensors": [
      {
            "protocol": "camera.gmsl",
            "params": "camera-type=ar0231-rccb,csi-port=ab,camera-count=4,fifo-size=12",
            "channel-names": [
                                "ab_first",
                                "ab_second",
                                "ab_third",
                                "ab_fourth"
                             ]
      },
      {
            "protocol": "camera.gmsl",
            "params": "camera-type=ar0231-rccb,csi-port=cd,camera-count=4,fifo-size=12",
            "channel-names": [
                                "cd_first",
                                "cd_second",
                                "cd_third",
                                "cd_fourth"
                             ]
      }
    ]
},

write-file-patternmust contain an asterisk, which is replaced by the channel number or channel-name of the sensor being recorded. The write-file-pattern needs no extension for any of the sensors, as this is automatically inferred based on the sensor params. Each sensor group can share a capture thread with the other sensor groups by using separate-thread=false. If separate-thread=true, a new thread spawns for this sensor group to capture and record data separately from the other sensor groups. If separate-thread is not present, it defaults to false.

The protocol for camera can be camera.gmsl only.

The params must follow the params given to a Driveworks sensor at initialization. In order to record in other formats besides h264, add output-format=[raw,lraw,h264,raw+h264,lraw+h264] with one of the listed output formats to the params. In order to record camera frames at a lower rate than the default, use frame-skip-count in the params.

For example, a value of frame-skip-count=1 records at 15 FPS if the camera hardware runs at 30 FPS. Setting record-frame-count=2 with frame-skip-count=1 records two (2) frames and skips 1, and then repeats.

For sensors that control multiple sources (such as camera), channel-names array can be specified. This replaces the * in the write-file-pattern when the file is saved to disk. If no channel-names array is specified, the * in write-file-pattern is replaced with the channel number. Specific GMSL cameras can be selected by using the camera-mask=1111 where a 0 represents off and a 1 represents on. This is an alternative to the camera-count option in the params.

In order to record asyncronously, add async-record=1 to the params. The default is async-record=0, which writes to disk on the same thread where the camera is read.

For certain kinds of camera, e.g., ar0231-rccb, the camera framerate can be controlled by the required-framerate option. Valid values for now are 20, 30, and 36.

Note

It is not possible to intermix cameras of different type on the same CSI port.

"can" : {
    "separate-thread": false,
    "write-file-pattern": "can_*",
    "sensors" : [
        {
            "protocol": "can.socket",
            "params": "device=can0",
            "channel-name": "0"
        }
    ]
},

The CAN protocol supports both can.socket and can.aurix. In general, it follows the same rules as camera. To add multiple CAN sensors, add another object literal in the sensors array. channel-name specifies the replacement for the * in write-file-pattern and is optional. If none is specified, it defaults to a numeric system.

For gps.uart:

"gps" : {
    "separate-thread": false,
    "write-file-pattern": "gps_*",
    "sensors" : [
        {
          "protocol": "gps.uart",
          "params": "device=/dev/ttyACM0,baud=115200",
          "channel-name": "0"
        }
    ]
},

For gps.xsens:

"gps" : {
    "separate-thread": false,
    "write-file-pattern": "gps_*",
    "sensors" : [
        {
          "protocol": "gps.xsens",
          "params": "device=0,frequency=100",
          "channel-name": "0"
        }
    ]
},

GPS protocol supports gps.uart and gps.xsens. In general, it follows the same rules as camera. To add multiple GPS sensors, add another object literal in the sensors array. channel-name specifies the replacement for the * in write-file-pattern and is optional. If none is specified, it defaults to a numeric system.

For imu.uart

"imu" : {
    "separate-thread": false,
    "write-file-pattern": "imu_*",
    "sensors" : [
        {
            "protocol": "imu.uart",
            "params": "device=/dev/ttyUSB0,baud=115200",
            "channel-name": "0"
        }
    ]
},

For imu.xsens:

"imu" : {
    "separate-thread": false,
    "write-file-pattern": "imu_*",
    "sensors" : [
        {
          "protocol": "imu.xsens",
          "params": "device=0,frequency=100",
          "channel-name": "0"
        }
    ]
},

IMU protocol supports imu.uart and imu.xsens. In general, it follows the same rules as camera. To add multiple IMU sensors, add another object literal in the sensors array. channel-name specifies the replacement for the * in write-file-pattern and is optional. If none is specified, it defaults to a numeric system.

"lidar" : {
    "separate-thread": false,
    "write-file-pattern": "lidar_*",
    "sensors" : [
        {
            "protocol": "lidar.socket",
            "params": "ip=192.168.1.201,port=2368,device=VELO_VLP16,scan-frequency=10",
            "channel-name": "0"
        }
    ]
},

Lidar protocol supports lidar.socket. In general, it follows the same rules as camera. To add multiple Lidar sensors, add another object literal in the sensors array. channel-name specifies the replacement for the * in write-file-pattern and is optional. If none is specified, it defaults to a numeric system.

"radar" : {
    "separate-thread": false,
    "write-file-pattern": "radar_*",
    "sensors" : [
        {
            "protocol": "radar.socket",
            "params": "ip=192.168.1.201,port=2368,device=DELPHI_ESR2_5",
            "channel-name": "0"
        }
    ]
},

Radar protocol supports radar.socket. In general, it follows the same rules as camera. To add multiple Radar sensors, add another object literal in the sensors array. channel-name specifies the replacement for the * in write-file-pattern and is optional. If none is specified, it defaults to a numeric system.

}