Pôle de Diffusion des Savoirs » ENVeMeDiS

h1. Installation d'un FFmpeg OpenCL

h2. Préparation de la Debian Wheezy

* Installation de quoi compiler un paquet

<pre>

apt-get install pbuilder

</pre>

* Installation de git pour le téléchargement des sources

<pre>

apt-get install git

</pre>

* Installation des dépendances nécessaires pour compiler le ffmpeg de la Debian

<pre>

apt-get build-dep ffmpeg

</pre>

* Installation de l'OpenCL AMD utilisable sur le processeur

<pre>

apt-get install amd-opencl-icd amd-opencl-dev amd-libopencl1 amd-clinfo

</pre>

h2. Vérification de la disponibilité OpenCL

Le lancement de la commande clinfo

<pre>

Number of platforms:				 1

  Platform Profile:				 FULL_PROFILE

  Platform Version:				 OpenCL 1.2 AMD-APP (938.2)

  Platform Name:				 AMD Accelerated Parallel Processing

  Platform Vendor:				 Advanced Micro Devices, Inc.

  Platform Extensions:				 cl_khr_icd cl_amd_event_callback cl_amd_offline_devices

  Platform Name:				 AMD Accelerated Parallel Processing

Number of devices:				 1

  Device Type:					 CL_DEVICE_TYPE_CPU

  Device ID:					 4098

---

  Name:						 QEMU Virtual CPU version 1.1.2

  Vendor:					 AuthenticAMD

  Device OpenCL C version:			 OpenCL C 1.2 

  Driver version:				 2.0 (sse2)

  Profile:					 FULL_PROFILE

  Version:					 OpenCL 1.2 AMD-APP (938.2)

  Extensions:					 cl_khr_fp64 cl_amd_fp64 cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_byte_addressable_store cl_khr_gl_sharing cl_ext_device_fission cl_amd_device_attribute_query cl_amd_vec3 cl_amd_printf cl_amd_media_ops cl_amd_popcnt 

</pre>

h2. Récupération des sources par git

<pre>

git clone git://source.ffmpeg.org/ffmpeg.git ffmpeg

</pre>

h2. Préparation de la compilation

Nous supposons que nous allons placer toute notre archive compilée FFmpeg dans @/opt/ffmpeg@ :<pre>

cd ffmpeg

./configure --prefix=/opt/ffmpeg --extra-cflags="-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security " --extra-ldflags="-Wl,-z,relro" --cc="ccache cc" --enable-shared --enable-libmp3lame --enable-gpl --enable-nonfree --enable-libvorbis --enable-pthreads --enable-libfaac --enable-libxvid --enable-postproc --enable-x11grab --enable-libgsm --enable-libtheora --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264 --enable-libspeex --enable-nonfree --disable-stripping --enable-libvpx --enable-libschroedinger --disable-encoder=libschroedinger --enable-version3 --enable-libopenjpeg --enable-librtmp --enable-avfilter --enable-libfreetype --enable-libvo-aacenc --disable-decoder=amrnb --enable-libvo-amrwbenc --enable-libaacplus --libdir=/opt/ffmpeg/lib --disable-vda --enable-libbluray --enable-libcdio --enable-gnutls --enable-frei0r --enable-openssl --enable-libass --enable-libopus --enable-fontconfig --enable-opencl --enable-libdc1394 --enable-libfdk-aac --disable-altivec --disable-armv5te --disable-armv6 --disable-vis --shlibdir=/opt/ffmpeg/lib/

</pre>

h2. Compilation

<pre>

time make

</pre>

<pre>

STRIP	ffserver

skipping strip ffserver

real	16m43.162s

user	14m53.112s

sys	1m15.065s

</pre>

h2. Installation

<pre>

time make install

</pre>

h2. Vérification des dépendances OpenCL

<pre>

cd /opt/ffmpeg

find /opt/ffmpeg/ -executable -exec ldd {} \; 2>/dev/null | grep -i opencl

</pre>

<pre>

	libOpenCL.so.1 => /usr/lib/x86_64-linux-gnu/libOpenCL.so.1 (0x00007f021c24b000)

	libOpenCL.so.1 => /usr/lib/x86_64-linux-gnu/libOpenCL.so.1 (0x00007fbaeba83000)

	libOpenCL.so.1 => /usr/lib/x86_64-linux-gnu/libOpenCL.so.1 (0x00007f5a182eb000)

	libOpenCL.so.1 => /usr/lib/x86_64-linux-gnu/libOpenCL.so.1 (0x00007f5a9173d000)

	libOpenCL.so.1 => /usr/lib/x86_64-linux-gnu/libOpenCL.so.1 (0x00007f848b776000)

	libOpenCL.so.1 => /usr/lib/x86_64-linux-gnu/libOpenCL.so.1 (0x00007f892615a000)

</pre>

Nous découvrons que 6 exécutables ou librairies disposent d'une dépendance à OpenCL.

h2. Test de compression