7. Development¶

The main GitHub repository for the project can be found at:

Anyone is more than welcome to open tickets to discuss bugs, new features, or just to ask usage questions (I find this useful for gauging what questions ought to feature in the FAQ, for example).

For anybody wishing to hack on the project, I would strongly recommend reading through the PiCamera class’ source, to get a handle on using the mmalobj layer. This is a layer introduced in picamera 1.11 to ease the usage of libmmal (the underlying library that picamera, raspistill, and raspivid all rely upon).

Beneath mmalobj is a ctypes translation of the libmmal headers but my hope is that most developers will never need to deal with this directly (thus, a working knowledge of C is hopefully no longer necessary to hack on picamera).

Various classes for specialized applications also exist (PiCameraCircularIO, PiBayerArray, etc.)

Even if you don’t feel up to hacking on the code, I’d love to hear suggestions from people of what you’d like the API to look like (even if the code itself isn’t particularly pythonic, the interface should be)!

7.1. Development installation¶

If you wish to develop picamera itself, it is easiest to obtain the source by cloning the GitHub repository and then use the “develop” target of the Makefile which will install the package as a link to the cloned repository allowing in-place development (it also builds a tags file for use with vim/emacs with Exuberant’s ctags utility). The following example demonstrates this method within a virtual Python environment:

$sudo apt-get install lsb-release build-essential git git-core \ > exuberant-ctags virtualenvwrapper python-virtualenv python3-virtualenv \ > python-dev python3-dev libjpeg8-dev zlib1g-dev libav-tools$ cd
$mkvirtualenv -p /usr/bin/python3 picamera$ workon picamera
(picamera) $git clone https://github.com/waveform80/picamera.git (picamera)$ cd picamera
(picamera) $make develop  To pull the latest changes from git into your clone and update your installation: $ workon picamera
(picamera) $cd ~/picamera (picamera)$ git pull
(picamera) $make develop  To remove your installation, destroy the sandbox and the clone: (picamera)$ deactivate
$rmvirtualenv picamera$ rm -fr ~/picamera


7.2. Building the docs¶

If you wish to build the docs, you’ll need a few more dependencies. Inkscape is used for conversion of SVGs to other formats, Graphviz is used for rendering certain charts, and TeX Live is required for building PDF output. The following command should install all required dependencies:

$sudo apt-get install texlive-latex-recommended texlive-latex-extra \ texlive-fonts-recommended graphviz inkscape  Once these are installed, you can use the “doc” target to build the documentation: $ workon picamera
(picamera) $cd ~/picamera (picamera)$ make doc


The HTML output is written to docs/_build/html while the PDF output goes to docs/_build/latex.

7.3. Test suite¶

If you wish to run the picamera test suite, follow the instructions in Development installation above and then make the “test” target within the sandbox:

$workon picamera (picamera)$ cd ~/picamera
(picamera) \$ make test


Warning

The test suite takes a very long time to execute (at least 1 hour on an overclocked Pi 3). Depending on configuration, it can also lockup the camera requiring a reboot to reset, so ensure you are familiar with SSH or using alternate TTYs to access a command line in the event you need to reboot.