This file explains how to build picam on low-performance models such as Raspberry Pi 1 or Zero. The whole process takes about 2-3 hours on a standard Linux box.
If you have Raspberry Pi 2 or 3, you can build picam without additional machine. Please refer to BUILDING.md which is much easier than cross compiling.
We need to install some packages used to build crosstool-ng
$ apt-get install flex bison automake gperf libtool patch texinfo ncurses-dev help2man
$ yum install flex bison automake gperf libtool texinfo patch gcc gcc-c++ gmp-devel help2man
$ yum install ncurses-devel ncurses glibc-devel glibc-static libstdc++-static
First we need to install crosstool-ng on a powerful Linux machine (not the Raspberry Pi) to be able to cross-compile ffmpeg.
$ mkdir ~/pi
$ cd ~/pi
$ wget http://crosstool-ng.org/download/crosstool-ng/crosstool-ng-1.22.0.tar.xz
$ tar xvf crosstool-ng-1.22.0.tar.xz
$ cd crosstool-ng
$ ./configure --prefix=/opt/cross
$ make
$ sudo make install
$ export PATH=$PATH:/opt/cross/bin
$ cd ..
$ mkdir ctng
$ cd ctng
$ ct-ng menuconfig
Then we need to configure the cross compiler for our Raspberry Pi version. The following configurations are for crosstool-ng 1.22.0, and they may not be applicable to later versions.
- Paths and misc options
- Check "Try features marked as EXPERIMENTAL"
- Set "Prefix directory" to "/opt/cross/x-tools/${CT_TARGET}"
- (OPTIONAL) Set "Number of parallel jobs" to amount of cores your processor has
- Target options
- Set "Target Architecture" to "arm"
- Set "Endianness" to "Little endian"
- Set "Bitness" to "32-bit"
- Set "Emit assembly for CPU" to "arm1176jzf-s"
- Set "Use specific FPU" to "vfp"
- Set "Floating point" to "hardware (FPU)"
- Set "Default instruction set mode" to "arm"
- Check "Use EABI"
- Toolchain options
- Set "Tuple's vendor string" to "rpi"
- Operating System
- Set "Target OS" to "linux"
- Binary utilities
- Set "Binary format" to "ELF"
- Set "binutils version" to "2.25.1"
- C-library
- Set "C library" to "glibc"
- Set "glibc version" to "2.22"
- C compiler
- Check "Show Linaro versions"
- Set "gcc version" to "linaro-4.9-2015.06"
- Set "gcc extra config" to "--with-float=hard"
- Check "Link libstdc++ statically into the gcc binary"
- Check "C++" under "Additional supported languages"
- Paths and misc options
- Check "Try features marked as EXPERIMENTAL"
- Set "Prefix directory" to "/opt/cross/x-tools/${CT_TARGET}"
- (OPTIONAL) Set "Number of parallel jobs" to amount of cores your processor has
- Target options
- Set "Target Architecture" to "arm"
- Set "Endianness" to "Little endian"
- Set "Bitness" to "32-bit"
- Set "Emit assembly for CPU" to "cortex-a7"
- Set "Use specific FPU" to "neon-vfpv4"
- Set "Floating point" to "hardware (FPU)"
- Set "Default instruction set mode" to "arm"
- Check "Use EABI"
- Toolchain options
- Set "Tuple's vendor string" to "rpi"
- Operating System
- Set "Target OS" to "linux"
- Binary utilities
- Set "Binary format" to "ELF"
- Set "binutils version" to "2.25.1"
- C-library
- Set "C library" to "glibc"
- Set "glibc version" to "2.22"
- C compiler
- Check "Show Linaro versions"
- Set "gcc version" to "linaro-4.9-2015.06"
- Set "gcc extra config" to "--with-float=hard"
- Check "Link libstdc++ statically into the gcc binary"
- Check "C++" under "Additional supported languages"
Save the configuration and build.
$ sudo chown -R $USER /opt/cross
$ ct-ng build
$ export CCPREFIX="/opt/cross/x-tools/arm-rpi-linux-gnueabihf/bin/arm-rpi-linux-gnueabihf-"
We will use $HOME/pi/ as a working directory and put compiled binaries and header files in $HOME/pi/build/. Set the environment variable $PIBUILD.
$ export PIBUILD=$HOME/pi/build
$ mkdir $PIBUILD
$ cd ~/pi
Download fdk-aac-0.1.5.tar.gz (or the latest version) from https://sourceforge.net/projects/opencore-amr/files/fdk-aac/ and run the following commands.
$ tar zxvf fdk-aac-0.1.5.tar.gz
$ cd fdk-aac-0.1.5
$ CC=${CCPREFIX}gcc CXX=${CCPREFIX}g++ ./configure --host=arm-rpi-linux-gnueabi --prefix=$PIBUILD
$ make
$ make install
You can't use ffmpeg that can be installed via apt-get or pacman.
Log in to Raspberry Pi and install libasound2-dev and libssl-dev via apt-get.
$ sudo apt-get install libasound2-dev libssl-dev
Return to the compiling machine. Set an environment variable $PIUSR, and copy ALSA headers and libs from Raspberry Pi.
$ export PIUSR=$HOME/pi/usr
$ mkdir $PIUSR
$ cd $PIUSR
$ mkdir include lib
$ rsync -rav pi@raspberrypi:/usr/include/alsa/ $PIUSR/include/alsa/
$ rsync -rav pi@raspberrypi:/usr/lib/arm-linux-gnueabihf/libasound.so* $PIUSR/lib/
$ tree --charset=ascii
.
|-- include
| `-- alsa
| |-- alisp.h
: : :
| |-- sound
| | |-- asound_fm.h
: : : :
| | `-- type_compat.h
| |-- timer.h
| |-- use-case.h
| `-- version.h
`-- lib
|-- libasound.so -> libasound.so.2.0.0
|-- libasound.so.2 -> libasound.so.2.0.0
`-- libasound.so.2.0.0
4 directories, 39 files
Log in to Raspberry Pi and install alsa-lib and alsa-utils via pacman.
$ sudo pacman -S alsa-lib alsa-utils
Return to the compiling machine. Set an environment variable $PIUSR, and copy ALSA headers and libs from Raspberry Pi.
$ export PIUSR=$HOME/pi/usr
$ mkdir $PIUSR
$ cd $PIUSR
$ mkdir include lib
$ rsync -rav pi@raspberrypi:/usr/include/alsa/ $PIUSR/include/alsa/
$ rsync -rav pi@raspberrypi:/usr/lib/libasound.so* $PIUSR/lib/
$ tree --charset=ascii
.
|-- include
| `-- alsa
| |-- alisp.h
: : :
| |-- sound
| | |-- asound_fm.h
: : : :
| | `-- type_compat.h
| |-- timer.h
| |-- use-case.h
| `-- version.h
`-- lib
|-- libasound.so -> libasound.so.2.0.0
|-- libasound.so.2 -> libasound.so.2.0.0
`-- libasound.so.2.0.0
4 directories, 39 files
Fetch ffmpeg source and configure it:
$ cd ~/pi
$ git clone git://source.ffmpeg.org/ffmpeg.git
$ cd ffmpeg
$ PKG_CONFIG_PATH=$PKG_CONFIG_PATH:$PIBUILD/lib/pkgconfig CC=${CCPREFIX}gcc CXX=${CCPREFIX}g++ ./configure --enable-cross-compile --cross-prefix=${CCPREFIX} --arch=armel --target-os=linux --prefix=$PIBUILD --extra-cflags="-I$PIBUILD/include -I$PIUSR/include -fPIC" --extra-ldflags="-L$PIBUILD/lib -L$PIUSR/lib -fPIC" --enable-libfdk-aac --pkg-config=`which pkg-config`
In the output of configure, make sure that:
- "Enabled indevs" has "alsa"
- "Enabled encoders" has "libfdk_aac"
If all goes well, build ffmpeg.
$ make
$ make install
If you are running on a system with multiple cores you can invoke make with the -j option. You get the number of cores with the first command.
$ cat /proc/cpuinfo | grep processor | wc -l
$ make -j <num cores>
$ make install
Transfer the contents of $PIBUILD directory to Raspberry Pi.
$ rsync -rav $PIBUILD/ pi@raspberrypi:build/
Then, put those files into /usr/local/ so that you have /usr/local/bin/ffmpeg.
(on Raspberry Pi)
$ cd ~/build
$ ls
bin include lib share
$ sudo rsync -rav ./ /usr/local/
We are done with the powerful machine which we used for cross compiling.
If you don't have /etc/ld.so.conf.d/libc.conf on Raspberry Pi, create that file with the following contents. On Raspbian, /etc/ld.so.conf.d/libc.conf is installed by default.
/usr/local/lib
Run ldconfig.
$ sudo ldconfig
Run ffmpeg -codecs | grep fdk and make sure that the output has this line:
DEA.L. aac AAC (Advanced Audio Coding) (decoders: aac libfdk_aac ) (encoders: aac libfdk_aac )
From now on, all steps are performed on Raspberry Pi.
$ cd /opt/vc/src/hello_pi/libs/ilclient
$ make
If you do not have the /opt/vc/src/ directory, download the firmware from https://github.com/raspberrypi/firmware and put all the contents under /opt/vc/src/. On Raspbian, /opt/vc/src/ is installed by default.
Install libfontconfig1-dev and libharfbuzz-dev via apt-get.
$ sudo apt-get install libfontconfig1-dev libharfbuzz-dev
$ cd (to anywhere you like)
$ git clone https://github.com/iizukanao/picam.git
$ cd picam
$ chmod +x whichpi
$ make
If you want to save some disk space, strip the binary.
$ strip picam
Check that picam runs without errors.
$ ./picam --help
If you are using Arch Linux, you need to have these two lines in /boot/config.txt.
start_file=start_x.elf
fixup_file=fixup_x.dat
Also, assign at least 128MB for GPU memory.
gpu_mem_512=128
Reboot the Raspberry Pi for the changes to take effect.