OpenMaxIL-cpp

OpenMaxIL-cpp is a library specifically designed for Raspberry Pi, making easier C++ access to camera board and encoders / decoders.

Building

There are no external dependencies except VCOS and IL headers and libraries already pre-shipped in Raspbian images (should be in /opt/vc folder)

mkdir build && cd build
cmake ..
make
sudo make install

Cross compile

It should be compatible with any raspberry cross compilation toolchain. VC headers and libraries are needed on the host system, the preferred way is to copy them from a Raspberry Pi image (i.e. copy from rPi /opt/vc to PC /opt/vc).

The make install command will also install OpenMaxIL-cpp files in this directory.

mkdir build && cd build
cmake -Dcross=1 ..
make
sudo make install

The library is statically linked, so there is no need to install anything on the target Raspberry image.

Usage

Components

Underlying components and port numbers can be found here :

• http://www.jvcref.com/files/PI/documentation/ilcomponents/
• https://github.com/raspberrypi/firmware/tree/master/documentation/ilcomponents

Basic usage

For best performance and usability, OpenMaxIL-cpp is built around OpenMAX components system. Most of the components have one or more input and output ports which can be connected either to another component or to a buffer for manual handling.

Here is a simple example using Camera and VideoRender components connected together :

  // Setup camera 0 (can be 1 on Compute Module, which have two camera ports) with 1280x720 resolution
  Camera* camera = new Camera( 1280, 720, 0 );
  // Create video renderer
  VideoRender* render = new VideoRender();

  // Connect camera continuous video output to renderer input
  camera->SetupTunnelVideo( render );

  // Set both components in idle state, this tells OpenMAX that they should be ready to use
  camera->SetState( Component::StateIdle );
  render->SetState( Component::StateIdle );

  // Start both components, then start camera capture
  camera->SetState( Component::StateExecuting );
  render->SetState( Component::StateExecuting );
  camera->SetCapturing( true );

Complete example can be found in samples/camera_live.cpp file