h265 硬解码
Intel QSV
Intel QSV (Quick Sync Video) is a technology which allows decoding and encoding using recent Intel CPU and integrated GPU, supported on recent Intel CPUs. Note that the (CPU)GPU needs to be compatible with both QSV and OpenCL. Some (older) QSV -enabled GPUs aren't compatible with OpenCL. See: http://www.intel.com/content/www/us/en/architecture-and-technology/quick-sync-video/quick-sync-video-general.html https://software.intel.com/en-us/articles/intel-sdk-for-opencl-applications-2013-release-notes
To enable QSV support, you need the Intel Media SDK integrated in the Intel Media Server Studio: https://software.intel.com/en-us/intel-media-server-studio
The Intel Media Server studio is available for both Linux and Windows, and contains the libva and libdrm libraries, the libmfx dispatcher library and the intel drivers. libmfx is the library which selects the codec depending on the system capabilities, falling back to a software implementation if the hardware accelerated codec is not available).
FFmpeg QSV support relies on libmfx, but the library provided by Intel does not come with pkg-config files and a proper installer. Thus the easiest to install the library is to use the libmfx version packaged by lu_zero here: https://github.com/lu-zero/mfx_dispatch
Requirements on Windows: install the Intel Media SDK packaged in the Intel Media Server Studio, which comes with a graphic installer, and a MinGW compilation enviroment (for example provided by MSYS2 with a corresponding Mingw-w64 package). Then you need to build libmfx and install it in a path recognized by pkg-config. For example if you install in /usr/local then you need the update the$PKG_CONFIG_PATH environment variable to make it point to /usr/local/lib/pkgconfig.
Requriments on Linux: you need either to rely on the Intel Media Server Studio for Linux, or use a recent enough supported system, with the libva and libdrm libraries, the libva Intel drivers, and the libmfx library packaged by lu_zero. Note: in case you use the Intel Media Server Studio generic installation script, the installation script may overwrite your system libraries and break the system.
Check the following website for updated information about the Intel Graphics stack on the various Linux platforms: https://01.org/linuxgraphics
To enable QSV support in the FFmpeg build, configure with --enable-libmfx.
Support for decoding and encoding is integrated in FFmpeg through several codecs identified by the _qsv suffix. In particular, it currently supports MPEG2 video, VC1 (decoding only), H.264 and H.265.
For example to encode to H.264 using h264_qsv, you can use the command:
ffmpeg -i INPUT -c:v h264_qsv -preset:v faster out.qsv.mp4