Internal

This section describes the internal project structure.

Folder Structure

This is a simplified folder structure of the tiscamera project:

tiscamera
├── cmake
│   └── modules
├── data - static data that is neither compiled or generated
│   ├── images - logos, icons, camera images, etc.
│   ├── systemd - systemd units
│   ├── udev - udev rules for usb cameras, see Udev
│   └── uvc-extensions - description files for UVC extension units, see UVC
├── doc - documentation infrastructure
│   ├── images
│   ├── pages
│   │   ├── images
│   │   ├── _static
│   │   └── _templates
├── examples - code examples to help with understanding
│   ├── c
│   └── python
├── external - third party software
│   ├── aravis
│   ├── catch - C++ test framework
│   ├── CLI11
│   ├── fmt-7.1.3
│   ├── json
│   ├── outcome
│   └── PugiXml
│   ├── spdlog
├── libs - collection of helper libraries, not external projects
│   ├── dutils_image - simplified version of tiscamera-dutils algorithms
│   ├── gst-helper - helper libraries for gstreamer elements
│   └── tcam-property - tcam-property GObject library
├── packaging - resources for the creation of binary distributions
│   └── deb
├── scripts - helper scripts, see Scripts
├── src - general source directory
│   ├── aravis - aravis backend
│   ├── gstreamer-1.0 - gstreamer modules
│   │   ├── tcamconvert - files related to the tcamconvert gstreamer plugin
│   │   ├── tcamgstbase - collection of shared gstreamer functionality
│   │   └── tcamsrc - files related to the tcamconvert gstreamer plugin
│   ├── libusb - libusb-1.0 backend
│   ├── tcam-network - network helper library
│   └── v4l2 - v4l2 backend
├── tests - verification code, see Tests
│   ├── integration
│   │   └── start_stop
│   └── unit
│   ├── gstreamer-1.0
│   └── tcam-network
└── tools - directory for applications
├── tcam-capture
├── tcam-ctrl
├── tcam-gige-daemon
├── tcam-gigetool
└── tcam-uvc-extension-loader

Libraries

This section describes the purpose behind the different libraries.

libtcam

The main library. Device indexing, property mappings, etc. is done here. The backends are also contained in this library.

libtcam-property

gobject-introspection library. Used by all gstreamer modules.

libtcam-network

Common network functionality. Used by tcam-gige-daemon and tcam-gigetool

libtcam-uvc-extension

uvc extension loading functionality. Used by tcam-uvc-extension-loader.

libtcamgstbase

Common functionality that is shared between the tcam gstreamer elements.

Threading

Tiscamera will start multiple threads in the background. The following is an overview over these.

  • Indexing An internal device indexing thread will run periodically to ensure all potential devices are known and accessible to the user.
  • Internal capture thread This thread is responsible for image acquisition. It will call the auto algorithms for further processing.
  • Auto algorithms This thread checks for exposure corrections, white balance and other before passing the image buffer to gstreamer.
  • Streaming thread This is the thread tcamsrc and internal elements reside in. It will wait for a new image buffer to be given and pass it to downstream elements.
  • GStreamer thread The main gstreamer thread. Responsible for message handling and state changes. Typically implicitly started by the user application.
  • Device lost thread Security thread for the propagation of device lost events. Idle unless such an event occurs.