SLAM APP

UI Design

App Startup page

Navigation menu bar

Function is introduced

Camera stream settings

Whether to record camera stream

If you choose , When you press the record button, the camera stream will open according to the settings , The camera stream preview window will display the camera picture in real time , The resulting data folder will contain... Named after the timestamp of a single frame image png File and a list of all image timestamps ; If you don't choose , Camera stream will not open , The resulting data folder will not contain picture and image timestamp data .

The camera id selection

app At startup, it will automatically check the camera on the device that meets the following requirements , And put their id Add to the drop-down menu for selection . These requirements are ：

1. On Android camera api In the definition , The camera is physical camera, instead of logical camera;
2. This camera is a rear camera ;
3. The camera is on AE when , Support 60hz Frame rate ;
4. The camera supports yuv_420_888 Image format ;
5. The camera also supports 640x480,1080x720,1920x1080 The resolution of the ;

If you do not find a camera that meets the above requirements , By default, a... Will be added to the drop-down menu id “0”, This is the camera number that most Android devices can turn on .

Camera stream resolution selection

From include 640x480,1080x720,1920x1080 Select a desired image resolution from the drop-down menu of . The size of the camera stream preview window will change according to the selected resolution .

Recording 60hz Camera stream

If you choose , The camera will work on AE In mode , And try to achieve 60hz Frame rate . But according to the light and darkness of the current shooting scene , The actual frame rate of the camera stream will be 30~60hz Range float . If you don't choose , The camera stream frame rate will be kept at 30hz, Working in AE Pattern .

Image timestamp file format

From include csv, txt Select the desired file format from the drop-down menu of .

imu Data flow settings

Whether to record imu data

If you choose ,acc and gyr The sensor data stream will open , The resulting data folder will contain at least one acc Data and a gyr A text file of data . Be careful , The inertial sensor chip on the mobile phone ,acc and gyr For two independent sensor Share a data bus output , Not directly aligned imu data .

Whether to generate timestamp aligned imu data

If you choose , The resulting data folder will contain an additional alignment imu A text file of data .

imu Frame rate selection

app Startup time , It will automatically query the inertial sensor frame rate supported by the current device and add the query results to the drop-down menu for selection , It is generally called imu Frame rate , In fact, some Android devices acc and gyr The frame rate can be different . The possible frame rate values provided in the drop-down menu are 200,400,800, The frame rate of the actual data stream may not always be , It depends on the inertial sensor chip and HAL The realization of the layer .

imu Data file format

From include csv, txt Select the desired file format from the drop-down menu of .

The alignment of the imu In the data file ,acc and gyr The order of priority

If you select generate timestamp aligned imu data , In this drop-down menu acc in front and gyr in front Corresponding to imu In the data file acc Before and after gyr before .

Data folder name

Data folder name You can enter a text box

If you don't type , The default value is "default".

postfix with time

If you choose , Will be entered in data folder name Add the following format as '-D'yyyy-MM-dd'-T'HH-mm-ss Year, day, hour, minute and second suffixes of .

Data stream frame rate and packet size

Camera stream frame rate

It should be noted that , there current cam fps For real data stream frame rate , Instead of previewing the frame rate . such as , When choosing 1920x1080 Resolution time , For the same 60hz The preview of does not appear 640x480 Resolution down 60hz The preview of is smooth , That's because , When the image is too large , Preview window background memory swap It may not be that fast , This causes the preview frame rate to be lower than the real data stream frame rate . however , The resulting data folder , Images are still saved in real data streams .

Packet size

When selecting a larger image resolution or 60hz Frame rate ,current data size The displayed packet size will lag behind the actual folder size at the current time . This is because , In order not to block the data flow , The file is stored in asynchronous working mode . in other words , The current data cache may contain content that has not been written to the storage device , and current data size It shows the space occupied by the written device storage .

Recording switch

About pressing the end recording button will not reset immediately

When selecting a larger image resolution or 60hz Frame rate , When you press the button to end recording , The recording switch will block app Reset after a period of time . This is to indicate that there is something in the data cache that has not been written to the storage device , Wait for the data cache to be emptied , The recording switch will reset , And you can restart the next recording .

About reusing the same folder name

If the data folder name of this time uses the same value as that of the previous recording , Press the record switch app The last recording result will be completely cleared first , Then start the recording .

Recording data storage path

App The storage root directory used in the device is /sdcard/slam_app/, The data folder from each recording is saved in /sdcard/slam_app/RecordedData/" Name of this recording folder "/ Under the directory of . This directory will also contain a file named record_config Of json file , The content is the configuration used for this recording , Such as ：

{
  "folder_name": "",
  "post_with_time": false,
  "time_postfix": "-D2022-03-01-T18-26-30",
  "record_camera": true,
  "save_image": true,
  "camera_id": "0",
  "camera_resolution": 0,
  "enable60hz": true,
  "image_ts_file_type": "csv",
  "record_imu": true,
  "sync_acc_gyr": true,
  "imu_freq": 0,
  "imu_file_type": "csv",
  "acc_gyr_order": 0,
  "pack_rosbag": false
}

App Permanent download link

Download QR code
follow-up App When there is an update , It will automatically download updates and prompt for installation when connected to the network .

Written in the back

SLAM APP Some more interesting functions are planned later , I will take the time to implement and push updates one by one , Coming soon ~
If you think the tool I made has helped you , You can reward me with the QR code provided below , Unlimited amount , Thank you very much. ~