Demo Configuration file¶
The demo config file uses YAML format to define input sources, models, outputs
and finally the flows which defines how everything is connected. Config files
for out-of-box demos are kept in
edge_ai_apps/configs folder. The
folder contains config files for all the use cases and also multi-input and
multi-inference case. The folder also has a template YAML file
app_config_template.yaml which has detailed explanation of all the
parameters supported in the config file.
Config file is divided in 4 sections:
The input section defines a list of supported inputs like camera, filesrc etc. Their properties like shown below.
inputs: input0: #Camera Input source: /dev/video2 #Device file entry of the camera format: jpeg #Input data format suported by camera width: 1280 #Width and Height of the input height: 720 framerate: 30 #Framerate of the source input1: #Video Input source: ../data/videos/video_0000_h264.mp4 #Video file format: h264 #File encoding format width: 1280 height: 720 framerate: 25 input2: #Image Input source: ../data/images/%04d.jpg #Sequence of Image files, printf style formatting is used width: 1280 height: 720 index: 0 #Starting Index (optional) framerate: 1
All supported inputs are listed in template config file. Below are the details of most commonly used inputs.
Camera sources (v4l2)¶
v4l2src GStreamer element is used to capture frames from camera sources which are exposed as v4l2 devices. In Linux, there are many devices which are implemented as v4l2 devices. Not all of them will be camera devices. You need to make sure the correct device is configured for running the demo successfully.
init_script.sh is ran when you login, which detects all cameras conected and
prints the detail like below:
root@j7-evm:/opt/edge_ai_apps# ./init_script.sh USB Camera detected device = /dev/video18 format = jpeg CSI Camera 0 detected device = /dev/video2 name = imx219 8-0010 format = [fmt:SRGGB8_1X8/1920x1080] subdev_id = 2 isp_required = yes Note: format need to be specified as 'raw' in source config if ISP is needed by the sensor and also subdev_id should be configured. If ISP is not needed format can be specified as 'auto'
script can also be run manually later to get the camera details.
From the above log we can determine that 1 USB cameras is connected (/dev/video18), and 1 CSI camera is connected (/dev/video2) which is imx219 raw sensor and nees ISP.
Using this method, you can configure correct device for camera capture in the input section of config file.
input0: source: /dev/video18 #USB Camera format: jpeg #if connected USB camera supports jpeg width: 1280 height: 720 framerate: 30 input1: source: /dev/video2 #CSI Camera format: auto #let the gstreamer negotiate the format width: 1280 height: 720 framerate: 30 input2: source: /dev/video2 #IMX219 raw sensor that nees ISP format: raw #ISP will be added in the pipeline width: 1920 height: 1080 framerate: 30 subdev-id: 2 #needed by ISP to control sensor params via ioctls
Make sure to configure correct
format for camera input.
jpeg for USB
camera that supports MJPEG (Ex. C270 logitech USB camera).
auto for CSI
camera to allow gstreamer to negotiate the format.
raw for sensor that needs
H.264 and H.265 encoded videos can be provided as input sources to the demos.
Sample video files are provided under
input1: source: ../data/videos/video_0000_h264.mp4 format: h264 width: 1280 height: 720 framerate: 25 input2: source: ../data/videos/video_0000_h265.mp4 format: h265 width: 1280 height: 720 framerate: 25
Make sure to configure correct
format for video input as shown above.
By default the format is set to
auto which will then use the GStreamer
JPEG compressed images can be provided as inputs to the demos. A sample set of
images are provided under
/opt/edge_ai_apps/data/images. The names of the
files are numbered sequentially and incrementally and the demo plays the files
at the fps specified by the user.
input2: source: ../data/images/%04d.jpg width: 1280 height: 720 index: 0 framerate: 1
H.264 encoded video streams either coming from a RTSP compliant IP camera or via RTSP server running on a remote PC can be provided as inputs to the demo.
input0: source: rtsp://172.24.145.220:8554/test # rtsp stream url, replace this with correct url width: 1280 height: 720 framerate: 30
Usually video streams from any IP camera will be encrypted and cannot be played back directly without a decryption key. We tested RTSP source by setting up an RTSP server on a Ubuntu 18.04 PC by refering to this writeup, Setting up RTSP server on PC
The model section defines a list of models that are used in the demo. Path to the model directory is a required argument for each model and rest are optional properties specific to given use cases like shown below.
models: model0: model_path: ../models/segmentation/ONR-SS-871-deeplabv3lite-mobv2-cocoseg21-512x512 #Model Directory alpha: 0.4 #alpha for blending segmentation mask (optional) model1: model_path: ../models/detection/TFL-OD-202-ssdLite-mobDet-DSP-coco-320x320 viz_threshold: 0.3 #Visualization threshold for adding bounding boxes (optional) model2: model_path: ../models/classification/TVM-CL-338-mobileNetV2-qat topN: 5 #Number of top N classes (optional)
Below are some of the use case specific properties:
alpha: This determines the weight of the mask for blending the semantic segmentation output with the input image
alpha * mask + (1 - alpha) * image
viz_threshold: Score threshold to draw the bounding boxes for detected objects in object detection. This can be used to control the number of boxes in the output, increase if there are too many and decrease if there are very few
topN: Number of most probable classes to overlay on image classification output
The content of the model directory and its structure is discussed in detail in Import Custom Models
The output section defines a list of supported outputs.
outputs: output0: #Display Output sink: kmssink width: 1920 #Width and Height of the output height: 1080 connector: 39 #Connector ID for kmssink (optional) output1: #Video Output sink: ../data/output/videos/output_video.mkv #Output video file width: 1920 height: 1080 output2: #Image Output sink: ../data/output/images/output_image_%04d.jpg #Image file name, printf style formatting is used width: 1920 height: 1080
All supported outputs are listed in template config file. Below are the details of most commonly used outputs
Display Sink (kmssink)¶
When you have only one display connected to the SK, kmssink will try to use it for displaying the output buffers. In case you have connected multiple display monitors (e.g. Display Port and HDMI), you can select a specific display for kmssink by passing a specific connector ID number. Following command finds out the connected displays available to use.
Note: Run this command outside docker container. The first number in each line is the connector-id which we will use in next step.
root@j7-evm:/opt/edge_ai_apps# modetest -M tidss -c | grep connected 39 38 connected DP-1 530x300 12 38 48 0 disconnected HDMI-A-1 0x0 0 47
From above output, we can see that connector ID 39 is connected. Configure the connector ID in the output section of the config file.
The post-processed outputs can be encoded in H.264 format and stored on disk. Please specify the location of the video file in the configuration file.
output1: sink: ../data/output/videos/output_video.mkv width: 1920 height: 1080
The post-processed outputs can be stored as JPEG compressed images. Please specify the location of the image files in the configuration file. The images will be named sequentially and incrementally as shown.
output2: sink: ../data/output/images/output_image_%04d.jpg width: 1920 height: 1080
The flows section defines how inputs, models and outputs are connected. Multiple flows can be defined to achieve multi input, multi inference like below.
flows: flow0: #First Flow input: input0 #Input for the Flow models: [model1, model2] #List of models to be used outputs: [output0, output0] #Outputs to be used for each model inference output mosaic: #Positions to place the inference outputs in the output frame mosaic0: width: 800 height: 450 pos_x: 160 pos_y: 90 mosaic1: width: 800 height: 450 pos_x: 960 pos_y: 90 flow1: #Second Flow input: input1 models: [model0, model3] outputs: [output0, output0] mosaic: mosaic0: width: 800 height: 450 pos_x: 160 pos_y: 540 mosaic1: width: 800 height: 450 pos_x: 960 pos_y: 540
Each flow should have exactly 1 input, n models to infer the given input and n outputs to render the output of each inference. Along with input, models and outputs it is required to define n mosaics which are the position of the inference output in the final output plane. This is needed because multiple inference outputs can be rendered to same output (Ex: Display).
Command line arguments¶
Limited set of command line arguments can be provided, run with ‘-h’ or ‘–help’ option to list the supported parameters.
usage: Run : ./app_edgeai.py -h for help positional arguments: config Path to demo config file ex: ./app_edgeai.py ../configs/app_config.yaml optional arguments: -h, --help show this help message and exit -n, --no-curses Disable curses report default: Disabled -v, --verbose Verbose option to print profile info on stdout default: Disabled