Application Development
From Boundary Devices Wiki
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This section will detail some details about some of the application development frameworks we’ve came across in the past.
Linux
This section will described the different options for our supported Linux distribution (Yocto, Buildroot, Ubuntu/Debian).
Qt
Maybe the most famous UI framework nowadays, offering many multimedia/connectivity features.
Some demos / blog posts have been published about Qt:
A common question about Qt is its licensing which can be unclear.
Therefore the QtCompany has created a webpage that should answer all your questions:
Crank
Another very attractive option is Crank which offers a unique UI experience.
Many of our demos leverage this framework:
GStreamer
GStreamer is the de-facto Linux Multimedia framework:
It can be used along with any of the above UI framework to process/control multimedia content.
It is therefore the preferred framework for Video decoding/encoding/streaming.
For those not really familiar with Gstreamer and its tools, here is a non-exhaustive list of tools that can help you get started.
gst-inspect
Provides information about a particular plugin
- Very useful to find and debug capabilities
- Useful to see which GObject properties or which signals an element supports
It can list all the plugins present on the target:
$ gst-inspect-1.0 lame: lamemp3enc: L.A.M.E. mp3 encoder videoscale: videoscale: Video scaler volume: volume: Volume videotestsrc: videotestsrc: Video test source ...
Or it can give specifics about one plugin:
$ gst-inspect-1.0 imxvpudec Factory Details: Rank primary + 1 (257) Long-name Freescale VPU video decoder ...
gst-launch
Used to create and test pipelines (prototyping).
$ gst-launch-1.0 filesrc location=/root/tears_of_steel_1080p.webm ! matroskademux ! imxvpudec ! imxipuvideosink
This tool will also allow you to easily troubleshoot issues by adding some log using the GST_DEBUG shell variable. It will then change the log level whose value range between 0 and 5 (5 will show all messages).
$ GST_DEBUG=5 gst-launch-1.0 playbin uri=file:///root/tears_of_steel_1080p.webm
You can specify which plugin you want to add traces to:
$ GST_DEBUG=imxvpudec:5 gst-launch-1.0 playbin uri=file:///root/tears_of_steel_1080p.webm
Examples
Camera (MIPI) Streaming to display using 3D GPU:
$ gst-launch-1.0 imxv4l2videosrc device=/dev/video1 ! imxeglvivsink
Camera (Parallel) Streaming to display using IPU:
$ gst-launch-1.0 imxv4l2videosrc device=/dev/video0 ! imxipuvideosink use-vsync=true
Camera Streaming to display using PXP (i.MX7 / i.MX6SX):
$ gst-launch-1.0 imxv4l2videosrc device=/dev/video1 ! imxpxpvideosink use-vsync=true
Movie playing:
$ gst-launch-1.0 playbin uri=file:///root/tears_of_steel_1080p.webm
Movie playing + Camera Streaming at once:
$ gst-launch-1.0 playbin uri=file:///root/tears_of_steel_1080p.webm video-sink="imxipuvideosink window-width=640 window-height=480" imxv4l2videosrc device=/dev/video0 ! imxeglvivsink window-x-coord=600 window-y-coord=400
h.264 stream over UDP with RTP and camera as source (courtesy of shondll):
$ gst-launch-1.0 imxv4l2videosrc device=/dev/video1 fps-n=30 capture-mode=4 ! imxvpuenc_h264 bitrate=1000 ! h264parse ! rtph264pay ! udpsink host=192.168.11.11 port=5001
For more examples, please read this blog post and especially the comment section since some people shared their own pipeline commands.
Yocto Eclipse IDE dev
If you want to develop and debug an application using the Eclipse IDE on Yocto, here are a couple of documents to read:
- Setting up the Eclipse IDE for Yocto Application Development
- Yocto Application Development Using Eclipse IDE
Android
Android is famous for its easy to use IDE/SDK combination that offers flexible and well documented API.
Although our platforms supporting Android act just like any other Android phone, this topic has been covered in a previous articble.
Android API/Documentation:
QNX
QNX also provides an easy to use IDE/SDK combination:
QNX API/Documentation: