5. Configuring applications¶
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
edgeai-gst-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, video files etc. Their properties like shown below.
inputs: input0: #Camera Input source: /dev/video2 #Device file entry of the camera format: jpeg #Input data format supported 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.
5.1.1. 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 as part of systemd, which detects all cameras connected
and prints the detail like below in the UART console:
/opt/edgeai-gst-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 IMX390 Camera 0 detected device = /dev/video18 name = imx390 10-001a format = [fmt:SRGGB12_1X12/1936x1100 field: none] subdev_id = /dev/v4l-subdev7 isp_required = yes ldc_required = yes
script can also be run manually later to get the camera details.
From the above log we can determine that 1 USB camera is connected (/dev/video18), and 1 CSI camera is connected (/dev/video2) which is IMX219 raw sensor and needs ISP. IMX390 camera needs both ISP and LDC.
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 needs ISP format: rggb #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 input3: source: /dev/video2 #IMX390 raw sensor that needs ISP width: 1936 height: 1100 format: rggb12 #ISP will be added in the pipeline subdev-id: 2 #needed by ISP to control sensor params via ioctls framerate: 30 sen-id: imx390 ldc: True #LDC will be added in the pipeline
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.
rggb for sensor
that needs ISP.
5.1.2. Video sources¶
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
5.1.3. Image sources¶
JPEG compressed images can be provided as inputs to the demos. A sample set of
images are provided under
/opt/edgeai-gst-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
5.1.4. RTSP sources¶
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 referring 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 output3: sink: remote #Publish output to udp port as jpeg encoded frames width: 1280 height: 720 port: 8081 #udp port (optional default:8081) host: 0.0.0.0 #udp host (optional default:0.0.0.0)
All supported outputs are listed in template config file. Below are the details of most commonly used outputs
5.3.1. 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 to check which display is connected. The first number in each line is the connector-id to be used in the next step.
/opt/edgeai-gst-apps# modetest -M tidss -c | grep connected 39 38 connected DP-1 530x300 12 38 48 0 disconnected HDMI-A-1 0x0 0 47
Configure the required connector ID in the output section of the config file.
5.3.2. Video sinks¶
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
5.3.3. Image sinks¶
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
5.3.4. Remote sinks¶
The JPEG compressed post-processed frames can be send as udp packets to a port Please specify the sink as remote in the configuration file. The udp port and host to send packets to can be defined. If not, default port is 8081 and host is 0.0.0.0.
output3: sink: remote width: 1280 height: 720 port: 8081 host: 0.0.0.0 #IP of Remote PC.
The display can be viewed by running a simple GStreamer pipeline on the remote PC.
gst-launch-1.0 udpsrc port=8081 ! application/x-rtp,encoding=H264 ! rtph264depay ! h264parse ! avdec_h264 ! autovideosink
The flows section defines how inputs, models and outputs are connected. Multiple flows can be defined to achieve multi input, multi inference as shown
The format of specifying flows is changes as of 08.05.00 release to enable multiple outputs in the same sub-flow The older config files may not be compatible from this release onwards and should be changed to below format
flows: # flowname : [input,mode1,output,[mosaic_pos_x,mosaic_pos_y,width,height]] flow0: [input0,model1,output0,[160,90,800,450]] flow1: [input0,model2,output0,[960,90,800,450]] flow2: [input1,model0,output0,[160,540,800,450]] flow3: [input1,model3,output0,[960,540,800,450]]
Each flow defined here has exactly 1 input and 1 model. If multiple flows have same input, they are clubbed together internally in the application for optimization. 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).
5.4.1. 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
5.5. GStreamer plugins¶
The edgeai-gst-apps essentially constructs GStreamer pipelines for dataflow.
This pipeline is constructed optimally and dynamically based on a pool of
specific plugins available on the platform. The defined pool of plugins for
different platform can be found in
This file contains the plugin used for certain task and the property of plugin (if applicable).
5.5.1. Default GStreamer plugins map for TDA4VM¶
<soc-type>: dlcolorconvert: element: tiovxdlcolorconvert property: out-pool-size: 4 colorconvert: element: videoconvert scaler: element: tiovxmultiscaler dlpreproc: element: tiovxdlpreproc property: out-pool-size: 4 mosaic: element: tiovxmosaic isp: element: tiovxisp ldc: element: tiovxldc h264dec: element: v4l2h264dec h265dec: element: v4l2h265dec h264enc: element: v4l2h264enc h265enc: element: v4l2h265enc inferer: target: dsp core-id: