DRI_PRIME=1 LIBVA_DRIVER_NAME=radeonsi ffmpeg -framerate 25 -vaapi_device /dev/dri/renderD129 -device /dev/dri/card1 -f kmsgrab -i - -f lavfi -i anullsrc=channel_layout=stereo:r=48000 -vf 'hwmap=derive_device=vaapi' -c:v h264_vaapi -b:v 2000k -bf 0 -profile:v constrained_baseline -quality:v 0 -level:v 4.1 -coder:v cavlc -acodec aac -ar 48000 -b:a 128k test.mkv
ffmpeg version N-91697-g45499e557c Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 7.3.0 (Gentoo Hardened 7.3.0-r3 p1.4)
  configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --docdir=/usr/share/doc/ffmpeg-9999/html --mandir=/usr/share/man --enable-shared --cc=x86_64-pc-linux-gnu-gcc --cxx=x86_64-pc-linux-gnu-g++ --ar=/usr/bin/ar --optflags='-O3 -ftree-vectorize -march=native -mtune=native' --disable-static --enable-avfilter --enable-avresample --disable-stripping --enable-nonfree --enable-version3 --disable-indev=oss --disable-outdev=oss --disable-outdev=sdl --enable-version3 --enable-version3 --enable-nonfree --enable-bzlib --disable-runtime-cpudetect --disable-debug --disable-gcrypt --disable-gnutls --enable-gmp --enable-gpl --enable-hardcoded-tables --disable-iconv --disable-libtls --enable-lzma --enable-network --enable-opencl --enable-openssl --enable-postproc --disable-libsmbclient --disable-ffplay --disable-sdl2 --enable-vaapi --enable-vdpau --enable-xlib --enable-libxcb --enable-libxcb-shm --enable-libxcb-xfixes --enable-zlib --enable-libcdio --disable-libiec61883 --disable-libdc1394 --disable-libcaca --enable-openal --enable-opengl --enable-libv4l2 --enable-libpulse --disable-libdrm --enable-libopencore-amrwb --enable-libopencore-amrnb --disable-libcodec2 --enable-libfdk-aac --enable-libopenjpeg --enable-libbluray --enable-libcelt --disable-libgme --enable-libgsm --disable-mmal --disable-libmodplug --enable-libopus --disable-libilbc --enable-librtmp --enable-libssh --enable-libspeex --enable-librsvg --disable-ffnvcodec --enable-libvorbis --enable-libvpx --disable-libzvbi --disable-appkit --disable-libbs2b --enable-chromaprint --disable-libflite --disable-frei0r --disable-libfribidi --enable-fontconfig --enable-ladspa --enable-libass --enable-lv2 --enable-libfreetype --disable-librubberband --disable-libzmq --disable-libzimg --disable-libsoxr --enable-pthreads --disable-omx --disable-omx-rpi --disable-mmal --enable-libvo-amrwbenc --enable-libmp3lame --enable-libkvazaar --enable-libaom --enable-libopenh264 --enable-libsnappy --enable-libtheora --enable-libtwolame --disable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --disable-nvenc --enable-libdrm --disable-cuda --disable-cuvid --disable-gnutls --disable-armv5te --disable-armv6 --disable-armv6t2 --disable-neon --disable-vfp --disable-vfpv3 --disable-armv8 --disable-mipsdsp --disable-mipsdspr2 --disable-mipsfpu --disable-altivec --disable-amd3dnow --disable-amd3dnowext --disable-fma4 --disable-xop --cpu=host --disable-doc --disable-htmlpages --enable-manpages
  libavutil      56. 19.100 / 56. 19.100
  libavcodec     58. 25.100 / 58. 25.100
  libavformat    58. 17.103 / 58. 17.103
  libavdevice    58.  4.101 / 58.  4.101
  libavfilter     7. 26.100 /  7. 26.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  2.100 /  5.  2.100
  libswresample   3.  2.100 /  3.  2.100
  libpostproc    55.  2.100 / 55.  2.100
[kmsgrab @ 0x556dde4f1840] Using plane 42 to locate framebuffers.
[kmsgrab @ 0x556dde4f1840] Template framebuffer is 100: 1920x1080 32bpp 24b depth.
Input #0, kmsgrab, from 'pipe:':
  Duration: N/A, start: 1535421298.192447, bitrate: N/A
    Stream #0:0: Video: wrapped_avframe, drm_prime, 1920x1080, 24.92 tbr, 1000k tbn, 1000k tbc
Input #1, lavfi, from 'anullsrc=channel_layout=stereo:r=48000':
  Duration: N/A, start: 0.000000, bitrate: 768 kb/s
    Stream #1:0: Audio: pcm_u8, 48000 Hz, stereo, u8, 768 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (wrapped_avframe (native) -> h264 (h264_vaapi))
  Stream #1:0 -> #0:1 (pcm_u8 (native) -> aac (native))
[h264_vaapi @ 0x556dde514700] Warning: some packed headers are not supported (want 0xd, got 0).
Segmentation fault (core dumped)