Compiling FFMPEG

https://trac.ffmpeg.org/wiki/How%20to%20compile%20FFmpeg%20for%20Raspberry%20Pi%20%28Raspbian%29

PCL cross compilation

This is work in progress..
Compiling PCL on Raspberry Pi gives an internal compiler error because of limited memory, so we need to cross compile it on a Linux PC.
Below are the steps documented for compilation of PCL on Pi that leads to the error.

The Point Cloud Library (or PCL) is a large scale, open project [1] for 2D/3D image and point cloud processing. The PCL framework contains numerous state-of-the art algorithms including filtering, feature estimation, surface reconstruction, registration, model fitting and segmentation http://pointclouds.org/about/

This is a guide of how to compile PCL on Raspberry Pi.

Step 0:
Download version 1.6.0 should be PCL-1.6.0-Source.tar.bz2.
Uncompress the tar-bzip archive, e.g. (replace 1.6.0 with the correct version number):

tar xvfj PCL-1.6.0-Source.tar.bz2

Step 1: Architecture changes

a) Edit src/pcl/cmake/pcl_find_sse.cmake and replace '-march=native' from line 10 with  
'-march=armv6 -mfloat-abi=hard -mfpu=vfp'. for Raspberry Pi
'-march=armv7-a -mtune=cortex-a9 -mfloat-abi=softfp -mfpu=neon' for ARM Cortex 9 CPUs

b) Edit the files
src/pcl/io/include/pcl/io/ply/byte_order.h
src/pcl/common/include/sensor_msgs/PointCloud2.h
and define PLY_LITTLE_ENDIAN, right after it checks if it was already defined:
#if (defined(__powerpc) || defined(__powerpc__) || defined(__POWERPC__) || defined(__ppc__) || defined(_M_PPC) || defined(__ARCH_PPC))
#  define PCL_BIG_ENDIAN
#elif (defined(i386) || defined(__i386__) || defined(__i386) || defined(_M_IX86) || defined(_X86_) || defined(__THW_INTEL__) || defined(__I86__) || defined(__INTEL__)) \
  || (defined(__amd64__) || defined(__amd64) || defined(__x86_64__) || defined(__x86_64) || defined(_M_X64)) \
        || (defined(__ANDROID__))
#  define PCL_LITTLE_ENDIAN
#else
#  define PCL_LITTLE_ENDIAN
#endif

http://www.ros.org/wiki/groovy/Installation/Raspbian/Source

Step 2: Install PCL dependencies:
sudo apt-get install libboost-all-dev  libeigen3-dev libflann-dev libvtk5-dev g++-multilib libusb-1.0-0-dev

Step 3:

1. Change the directory to the PCL-1.6.0-Source (replace 1.6.0 with the correct version number) directory, and create a build directory in there:

   cd PCL-1.6.0-Source && mkdir build && cd build

2. Run the CMake build system using the default options:cmake ..

3. make 

4. make install

http://pointclouds.org/downloads/source.html


Step 4 - Note enough memory?
installing another compiler version gcc 4.7 gives the same internal compiler error as with gcc 4.6 like just like in other places:
http://www.raspberrypi.org/phpBB3/viewtopic.php?f=66&t=7104
sudo apt-get install gcc-4.7
sudo update-alternatives --config gcc
choose gcc 4.7 during config

Step 5: Try another ARM board

Step 6: CUDA support
if you happen to have an ARM board with an NVidia card ;)
you need to to install the CUDA repository package for Ubuntu 12.10 from the CUDA download site - this is the direct link, maybe it still works:
 http://developer.download.nvidia.com/compute/cuda/repos/ubuntu1204/armhf/cuda-repo-ubuntu1204_5.5-0_armhf.deb
 and install it in a terminal:

$ sudo dpkg -i cuda-repo-ubuntu1210_5.5-0_amd64.deb
$ sudo apt-get update 

 $ sudo apt-get install cuda

Some posts about problems compiling on some ARM platforms:
http://www.pcl-users.org/Failure-to-compile-daily-builds-on-Pandaboard-td4020376.html
http://www.pcl-developers.org/unable-to-compile-PCL-for-ARM-Cortex-A9-td5707514.html