PSA: You can now use FFmpeg's VAAPI-based VP8 and VP9 encoder on Skylake+ systems on Linux: Tested on Ubuntu 16.04LTS

ffmpeg-vp8&9-encode-test-vaapi-intel.md

Build VAAPI with support for VP8/9 decode and encode hardware acceleration on a Skylake validation testbed:

Build platform: Ubuntu 16.04LTS.

First things first:

Install baseline dependencies first

sudo apt-get -y install autoconf automake build-essential libass-dev libtool pkg-config texinfo zlib1g-dev libva-dev cmake mercurial libdrm-dev libvorbis-dev libogg-dev git libx11-dev libperl-dev libpciaccess-dev libpciaccess0 xorg-dev intel-gpu-tools

This presents only one option, building all components from source and installing the latest build dependencies from source.

Then add the Oibaf PPA, needed to install the latest development headers for libva:

sudo add-apt-repository ppa:oibaf/graphics-drivers
sudo apt-get update && sudo apt-get -y upgrade && sudo apt-get -y dist-upgrade

Option 1: Build the latest libva and all drivers from source:

First things first, build the dependency chain:

1. libva:

Libva is an implementation for VA-API (Video Acceleration API)

VA-API is an open-source library and API specification, which provides access to graphics hardware acceleration capabilities for video processing. It consists of a main library and driver-specific acceleration backends for each supported hardware vendor. It is a prerequisite for building the VAAPI driver components below.

git clone https://github.com/01org/libva
cd libva
./autogen.sh --prefix=/usr --libdir=/usr/lib/x86_64-linux-gnu
time make -j$(nproc) VERBOSE=1
sudo make -j$(nproc) install

2. cmrt:

This is the C for Media Runtime GPU Kernel Manager for Intel G45 & HD Graphics family. it's a prerequisite for building the intel-hybrid-driver package.

git clone https://github.com/01org/cmrt
cd cmrt
./autogen.sh --prefix=/usr --libdir=/usr/lib/x86_64-linux-gnu
time make -j$(nproc) VERBOSE=1
sudo make -j$(nproc) install

3. intel-hybrid-driver:

This package provides support for WebM project VPx codecs. GPU acceleration is provided via media kernels executed on Intel GEN GPUs. The hybrid driver provides the CPU bound entropy (e.g., CPBAC) decoding and manages the GEN GPU media kernel parameters and buffers.

This package grants access to the VPX-series hybrid decode capabilities on supported hardware configurations,, namely Haswell and Skylake. Do not build this target on unsupported platforms.

Related, see this commit regarding the hybrid driver initialization failure on platforms where its' not relevant.

git clone https://github.com/01org/intel-hybrid-driver
cd intel-hybrid-driver
./autogen.sh --prefix=/usr --libdir=/usr/lib/x86_64-linux-gnu
time make -j$(nproc) VERBOSE=1
sudo make -j$(nproc) install

4. intel-vaapi-driver:

This package provides the VA-API (Video Acceleration API) user mode driver for Intel GEN Graphics family SKUs. The current video driver back-end provides a bridge to the GEN GPUs through the packaging of buffers and commands to be sent to the i915 driver for exercising both hardware and shader functionality for video decode, encode, and processing.

it also provides a wrapper to the intel-hybrid-driver when called up to handle VP8/9 hybrid decode tasks on supported hardware (when configured with the --enable-hybrid-codec option as shown below:).

git clone https://github.com/01org/intel-vaapi-driver
cd intel-vaapi-driver
./autogen.sh --prefix=/usr --libdir=/usr/lib/x86_64-linux-gnu --enable-hybrid-codec
time make -j$(nproc) VERBOSE=1
sudo make -j$(nproc) install

However, on Kabylake and newer, omit this as shown since its' not needed:

cd ~/vaapi
git clone https://github.com/intel/intel-vaapi-driver
cd intel-vaapi-driver
./autogen.sh --prefix=/usr --libdir=/usr/lib/x86_64-linux-gnu 
time make -j$(nproc) VERBOSE=1
sudo make -j$(nproc) install

5. libva-utils:

This package provides a collection of tests for VA-API, such as vainfo, needed to validate a platform's supported features (encode, decode & postproc attributes on a per-codec basis by VAAPI entry points information).

git clone https://github.com/intel/libva-utils
cd libva-utils
./autogen.sh --prefix=/usr --libdir=/usr/lib/x86_64-linux-gnu
time make -j$(nproc) VERBOSE=1
sudo make -j$(nproc) install

Platform environment variables:

Check if LIBVA environment variables are correctly configured:

set | grep LIBVA

Should output something like:

LIBVA_DRIVER_NAME=i965
LIBVA_DRIVERS_PATH=/usr/lib/x86_64-linux-gnu/dri

If not (as expected), set them on your system environment variables (/etc/environment) and reboot.

sudo systemctl reboot 

Verification:

When done, test the VAAPI supported featureset by running vainfo:

vainfo

The output on my current testbed is:

libva info: VA-API version 0.40.0
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_0_40
libva info: va_openDriver() returns 0
vainfo: VA-API version: 0.40 (libva 1.7.3)
vainfo: Driver version: Intel i965 driver for Intel(R) Skylake - 1.8.3.pre1 (glk-alpha-58-g5a984ae)
vainfo: Supported profile and entrypoints
      VAProfileMPEG2Simple            :	VAEntrypointVLD
      VAProfileMPEG2Simple            :	VAEntrypointEncSlice
      VAProfileMPEG2Main              :	VAEntrypointVLD
      VAProfileMPEG2Main              :	VAEntrypointEncSlice
      VAProfileH264ConstrainedBaseline:	VAEntrypointVLD
      VAProfileH264ConstrainedBaseline:	VAEntrypointEncSlice
      VAProfileH264ConstrainedBaseline:	VAEntrypointEncSliceLP
      VAProfileH264Main               :	VAEntrypointVLD
      VAProfileH264Main               :	VAEntrypointEncSlice
      VAProfileH264Main               :	VAEntrypointEncSliceLP
      VAProfileH264High               :	VAEntrypointVLD
      VAProfileH264High               :	VAEntrypointEncSlice
      VAProfileH264High               :	VAEntrypointEncSliceLP
      VAProfileH264MultiviewHigh      :	VAEntrypointVLD
      VAProfileH264MultiviewHigh      :	VAEntrypointEncSlice
      VAProfileH264StereoHigh         :	VAEntrypointVLD
      VAProfileH264StereoHigh         :	VAEntrypointEncSlice
      VAProfileVC1Simple              :	VAEntrypointVLD
      VAProfileVC1Main                :	VAEntrypointVLD
      VAProfileVC1Advanced            :	VAEntrypointVLD
      VAProfileNone                   :	VAEntrypointVideoProc
      VAProfileJPEGBaseline           :	VAEntrypointVLD
      VAProfileJPEGBaseline           :	VAEntrypointEncPicture
      VAProfileVP8Version0_3          :	VAEntrypointVLD
      VAProfileVP8Version0_3          :	VAEntrypointEncSlice
      VAProfileHEVCMain               :	VAEntrypointVLD
      VAProfileHEVCMain               :	VAEntrypointEncSlice
      VAProfileVP9Profile0            :	VAEntrypointVLD

On reboot, test the VAAPI supported featureset by running vainfo:

vainfo

Making a usable FFmpeg build to test the encoders:

Now, we will build an FFmpeg binary that can take advantage of VAAPI to test the encode and decode capabilities on Skylake, using a custom prefix because we load FFmpeg via the environment-modules system on the testbed.

Prepare the target directories first:

sudo mkdir -p /apps/ffmpeg/dyn
sudo chown -Rc $USER:$USER /apps/ffmpeg/dyn
mkdir -p ~/ffmpeg_sources

Include extra components as needed:

(a). Build and deploy nasm: Nasm is an assembler for x86 optimizations used by x264 and FFmpeg. Highly recommended or your resulting build may be very slow.

Note that we've now switched away from Yasm to nasm, as this is the current assembler that x265,x264, among others, are adopting.

cd ~/ffmpeg_sources
wget wget http://www.nasm.us/pub/nasm/releasebuilds/2.14rc0/nasm-2.14rc0.tar.gz
tar xzvf nasm-2.14rc0.tar.gz
cd nasm-2.14rc0
./configure --prefix="/apps/ffmpeg/dyn" --bindir="/apps/ffmpeg/dyn/bin"
make -j$(nproc) VERBOSE=1
make -j$(nproc) install
make -j$(nproc) distclean

(b). Build and deploy libx264 statically: This library provides a H.264 video encoder. See the H.264 Encoding Guide for more information and usage examples. This requires ffmpeg to be configured with --enable-gpl --enable-libx264.

cd ~/ffmpeg_sources
git clone http://git.videolan.org/git/x264.git -b stable
cd x264/
PATH="/apps/ffmpeg/dyn/bin:$PATH" ./configure --prefix="/apps/ffmpeg/dyn" --bindir="/apps/ffmpeg/dyn/bin" --enable-static --disable-opencl --enable-pic
PATH="/apps/ffmpeg/dyn/bin:$PATH" make -j$(nproc) VERBOSE=1
make -j$(nproc) install VERBOSE=1
make -j$(nproc) distclean

(c). Build and configure libx265: This library provides a H.265/HEVC video encoder. See the H.265 Encoding Guide for more information and usage examples.

cd ~/ffmpeg_sources
hg clone https://bitbucket.org/multicoreware/x265
cd ~/ffmpeg_sources/x265/build/linux
PATH="$/apps/ffmpeg/dyn/bin:$PATH" cmake -G "Unix Makefiles" -DCMAKE_INSTALL_PREFIX="/apps/ffmpeg/dyn" -DENABLE_SHARED:bool=off ../../source
make -j$(nproc) VERBOSE=1
make -j$(nproc) install VERBOSE=1
make -j$(nproc) clean VERBOSE=1

(d). Build and deploy the libfdk-aac library: This provides an AAC audio encoder. See the AAC Audio Encoding Guide for more information and usage examples. This requires ffmpeg to be configured with --enable-libfdk-aac (and --enable-nonfree if you also included --enable-gpl).

cd ~/ffmpeg_sources
wget -O fdk-aac.tar.gz https://github.com/mstorsjo/fdk-aac/tarball/master
tar xzvf fdk-aac.tar.gz
cd mstorsjo-fdk-aac*
autoreconf -fiv
./configure --prefix="/apps/ffmpeg/dyn" --disable-shared
make -j$(nproc)
make -j$(nproc) install
make -j$(nproc) distclean

(e). Build and configure libvpx

   cd ~/ffmpeg_sources
   git clone https://github.com/webmproject/libvpx
   cd libvpx
   ./configure --prefix="/apps/ffmpeg/dyn" --enable-runtime-cpu-detect --enable-vp9 --enable-vp8 \
   --enable-postproc --enable-vp9-postproc --enable-multi-res-encoding --enable-webm-io --enable-better-hw-compatibility --enable-vp9-highbitdepth --enable-onthefly-bitpacking --enable-realtime-only \
   --cpu=native --as=nasm
   time make -j$(nproc)
   time make -j$(nproc) install
   time make clean -j$(nproc)
   time make distclean

(f). Build LibVorbis

   cd ~/ffmpeg_sources
   wget -c -v http://downloads.xiph.org/releases/vorbis/libvorbis-1.3.6.tar.xz
   tar -xvf libvorbis-1.3.6.tar.xz
   cd libvorbis-1.3.6
   ./configure --enable-static --prefix="/apps/ffmpeg/dyn"
   time make -j$(nproc)
   time make -j$(nproc) install
   time make clean -j$(nproc)
   time make distclean

(g). Build FFmpeg:

cd ~/ffmpeg_sources
git clone https://github.com/FFmpeg/FFmpeg -b master
cd FFmpeg
PATH="/apps/ffmpeg/dyn/bin:$PATH" PKG_CONFIG_PATH="/apps/ffmpeg/dyn/lib/pkgconfig:/usr/local/lib/pkgconfig" ./configure \
  --pkg-config-flags="--static" \
  --prefix="/apps/ffmpeg/dyn" \
  --extra-cflags="-I/apps/ffmpeg/dyn/include" \
  --extra-ldflags="-L/apps/ffmpeg/dyn/lib" \
  --extra-cflags="-I/usr/local/include" \
  --extra-ldflags="-L/usr/local/lib" \
  --bindir="/apps/ffmpeg/dyn/bin" \
  --enable-debug=3 \
  --enable-vaapi \
  --enable-libvorbis \
  --enable-libvpx \
  --enable-gpl \
  --cpu=native \
  --enable-opengl \
  --enable-libfdk-aac \
  --enable-libx264 \
  --enable-libx265 \
  --extra-libs=-lpthread \
  --enable-nonfree 
PATH="/apps/ffmpeg/dyn/bin:$PATH" make -j$(nproc) 
make -j$(nproc) install 
make -j$(nproc) distclean 
hash -r

Note: To get debug builds, omit the distclean step and you'll find the ffmpeg_g binary under the sources subdirectory.

We only want debug builds when an issue crops up and a gdb trace may be required for debugging purposes.

The environment-modules file for FFmpeg (edit as necessary if your prefixes differ, and to add conflicts if needed):

less /usr/share/modules/modulefiles/ffmpeg/vaapi


#%Module1.0#####################################################################
##
## ffmpeg media transcoder modulefile
## By Dennis Mungai <[email protected]>
## February, 2018
##

# for Tcl script use only
set     appname         ffmpeg
set     version         dyn
set     prefix          /apps/${appname}/${version}
set     exec_prefix     ${prefix}/bin

conflict        ffmpeg/git

prepend-path    PATH            ${exec_prefix}
prepend-path    LD_LIBRARY_PATH ${prefix}/lib

To load and test, run:

module load ffmpeg/vaapi

Confirm all is sane via:

which ffmpeg

Expected output:

/apps/ffmpeg/dyn/bin/ffmpeg

Sample snippets to test the new encoders:

Confirm that the VAAPI encoders have been built successfully:

ffmpeg  -hide_banner -encoders | grep vaapi 

 V..... h264_vaapi           H.264/AVC (VAAPI) (codec h264)
 V..... hevc_vaapi           H.265/HEVC (VAAPI) (codec hevc)
 V..... mjpeg_vaapi          MJPEG (VAAPI) (codec mjpeg)
 V..... mpeg2_vaapi          MPEG-2 (VAAPI) (codec mpeg2video)
 V..... vp8_vaapi            VP8 (VAAPI) (codec vp8)

See the help documentation for each encoder in question:

ffmpeg -hide_banner -h encoder='encoder name'

Making a usable FFmpeg build without the module system:

Now, we will build an FFmpeg binary that can take advantage of VAAPI to test the encode and decode capabilities on the test platform.

Prepare the target directories first:

mkdir -p $HOME/bin
chown -Rc $USER:$USER $HOME/bin
mkdir -p ~/ffmpeg_sources

Include extra components as needed:

(a). Build and deploy nasm: Nasm is an assembler for x86 optimizations used by x264 and FFmpeg. Highly recommended or your resulting build may be very slow.

Note that we've now switched away from Yasm to nasm, as this is the current assembler that x265,x264, among others, are adopting.

cd ~/ffmpeg_sources
wget wget http://www.nasm.us/pub/nasm/releasebuilds/2.14rc0/nasm-2.14rc0.tar.gz
tar xzvf nasm-2.14rc0.tar.gz
cd nasm-2.14rc0
./configure --prefix="$HOME/bin" --bindir="$HOME/bin"
make -j$(nproc) VERBOSE=1
make -j$(nproc) install
make -j$(nproc) distclean

(b). Build and deploy libx264 statically: This library provides a H.264 video encoder. See the H.264 Encoding Guide for more information and usage examples. This requires ffmpeg to be configured with --enable-gpl --enable-libx264.

cd ~/ffmpeg_sources
git clone http://git.videolan.org/git/x264.git -b stable
cd x264/
PATH="$HOME/bin:$PATH" ./configure --prefix="$HOME/bin" --bindir="$HOME/bin" --enable-static --disable-opencl --enable-pic
PATH="$HOME/bin:$PATH" make -j$(nproc) VERBOSE=1
make -j$(nproc) install VERBOSE=1
make -j$(nproc) distclean

(c). Build and configure libx265: This library provides a H.265/HEVC video encoder. See the H.265 Encoding Guide for more information and usage examples.

sudo apt-get install cmake mercurial
cd ~/ffmpeg_sources
hg clone https://bitbucket.org/multicoreware/x265
cd ~/ffmpeg_sources/x265/build/linux
PATH="$HOME/bin:$PATH" cmake -G "Unix Makefiles" -DCMAKE_INSTALL_PREFIX="$HOME/bin" -DENABLE_SHARED:bool=off ../../source
make -j$(nproc) VERBOSE=1
make -j$(nproc) install VERBOSE=1
make -j$(nproc) clean VERBOSE=1

(d). Build and deploy the libfdk-aac library: This provides an AAC audio encoder. See the AAC Audio Encoding Guide for more information and usage examples. This requires ffmpeg to be configured with --enable-libfdk-aac (and --enable-nonfree if you also included --enable-gpl).

cd ~/ffmpeg_sources
wget -O fdk-aac.tar.gz https://github.com/mstorsjo/fdk-aac/tarball/master
tar xzvf fdk-aac.tar.gz
cd mstorsjo-fdk-aac*
autoreconf -fiv
./configure --prefix="$HOME/bin" --disable-shared
make -j$(nproc)
make -j$(nproc) install
make -j$(nproc) distclean

(e). Build and configure libvpx:

cd ~/ffmpeg_sources
git clone https://github.com/webmproject/libvpx/
cd libvpx
./configure --prefix="$HOME/bin" --enable-runtime-cpu-detect --enable-vp9 --enable-vp8 \
--enable-postproc --enable-vp9-postproc --enable-multi-res-encoding --enable-webm-io --enable-vp9-highbitdepth --enable-onthefly-bitpacking --enable-realtime-only \
--cpu=native --as=yasm
time make -j$(nproc)
time make -j$(nproc) install
time make clean -j$(nproc)
time make distclean

(f). Build LibVorbis:

   cd ~/ffmpeg_sources
   wget -c -v http://downloads.xiph.org/releases/vorbis/libvorbis-1.3.6.tar.xz
   tar -xvf libvorbis-1.3.6.tar.xz
   cd libvorbis-1.3.6
   ./configure --enable-static --prefix="$HOME/bin"
   time make -j$(nproc)
   time make -j$(nproc) install
   time make clean -j$(nproc)
   time make distclean

(g). Build FFmpeg:

cd ~/ffmpeg_sources
git clone https://github.com/FFmpeg/FFmpeg -b master
cd FFmpeg
PATH="$HOME/bin:$PATH" PKG_CONFIG_PATH="$HOME/bin/lib/pkgconfig:/usr/local/lib/pkgconfig" ./configure \
  --pkg-config-flags="--static" \
  --prefix="$HOME/bin" \
  --extra-cflags="-I$HOME/bin/include" \
  --extra-ldflags="-L$HOME/bin/lib" \
  --extra-cflags="-I/usr/local/include" \
  --extra-ldflags="-L/usr/local/lib" \
  --bindir="$HOME/bin" \
  --enable-debug=3 \
  --enable-vaapi \
  --enable-libvorbis \
  --enable-libvpx \
  --disable-debug \
  --enable-gpl \
  --cpu=native \
  --enable-opengl \
  --enable-libfdk-aac \
  --enable-libx264 \
  --enable-libx265 \
  --extra-libs=-lpthread \
  --enable-nonfree 
PATH="$HOME/bin:$PATH" make -j$(nproc) 
make -j$(nproc) install 
make -j$(nproc) distclean 
hash -r

Note: To get debug builds, omit the distclean step and the --disable-debug configure flag and you'll find the ffmpeg_g binary under the sources subdirectory.

We only want debug builds when an issue crops up and a gdb trace may be required for debugging purposes.

Test the encoders;

Using GNU parallel, we will encode some mp4 files (4k H.264 test samples, 40 minutes each, AAC 6-channel audio) on the ~/src path on the system to VP8 and HEVC respectively using the examples below. Note that I've tuned the encoders to suit my use-cases, and re-scaling to 1080p is enabled. Adjust as necessary.

To VP8, launching 10 encode jobs simultaneously:

parallel -j 10 --verbose 'ffmpeg -loglevel debug -threads 4 -hwaccel vaapi -i "{}"  -vaapi_device /dev/dri/renderD129 -c:v vp8_vaapi -loop_filter_level:v 63 -loop_filter_sharpness:v 15 -b:v 4500k -maxrate:v 7500k -vf 'format=nv12,hwupload,scale_vaapi=w=1920:h=1080' -c:a libvorbis -b:a 384k -ac 6 -f webm "{.}.webm"' ::: $(find . -type f -name '*.mp4')

To HEVC with GNU Parallel:

To HEVC Main Profile, launching 10 encode jobs simultaneously:

parallel -j 4 --verbose '/apps/ffmpeg/dyn/bin/ffmpeg -loglevel debug -threads 4 -hwaccel vaapi -i "{}"  -vaapi_device /dev/dri/renderD129 -c:v hevc_vaapi -qp:v 19 -b:v 2100k -maxrate:v 3500k -vf 'format=nv12,hwupload,scale_vaapi=w=1920:h=1080' -c:a libvorbis -b:a 384k -ac 6 -f matroska "{.}.mkv"' ::: $(find . -type f -name '*.mp4')

Some notes:

1. Intel's QuickSync is very efficient. See the power utilization traces and average system loads with 10 encodes running simultaneously here.
2. Skylake's HEVC encoder is very slow, and I suspect that on my hardware, may be slower than the software-based x265 encoder and kvazaar's HEVC encoders. However, its' quality, when well tuned, is significantly superior to other hardware-based encoders such as the Nvidia NVENC HEVC encoder on Maxwell GM200-series SKUs. The NVENC encoder on Pascal is however faster and superior to the one on Intel's Skylake HEVC encoder implementation.
3. Unlike Nvidia's NVENC, there are no simultaneous encodes limitations on the consumer SKUs. I was able to run 10 encode sessions siumultaneously with VAAPI, whereas with NVENC, I'd have been limited to two maximum simultaneous encodes on the GeForce GTX series GPUs on the testbeds. Good work, Intel.

VP9 hardware-accelerated encoding is now available for FFmpeg. However, you'll need an Intel Kabylake-based Integrated GPU to take advantage of this feature.

And now, with the new vp9_vaapi encoder, here's what we get.

Encoder options now available:

ffmpeg -h vp9_vaapi

Output:

Encoder vp9_vaapi [VP9 (VAAPI)]:
    General capabilities: delay 
    Threading capabilities: none
    Supported pixel formats: vaapi_vld
vp9_vaapi AVOptions:
  -loop_filter_level <int>        E..V.... Loop filter level (from 0 to 63) (default 16)
  -loop_filter_sharpness <int>        E..V.... Loop filter sharpness (from 0 to 15) (default 4)

What happens when you try to pull this off on unsupported hardware, say Skylake?

See the sample output below:

[Parsed_format_0 @ 0x42cb500] compat: called with args=[nv12]
[Parsed_format_0 @ 0x42cb500] Setting 'pix_fmts' to value 'nv12'
[Parsed_scale_vaapi_2 @ 0x42cc300] Setting 'w' to value '1920'
[Parsed_scale_vaapi_2 @ 0x42cc300] Setting 'h' to value '1080'
[graph 0 input from stream 0:0 @ 0x42cce00] Setting 'video_size' to value '3840x2026'
[graph 0 input from stream 0:0 @ 0x42cce00] Setting 'pix_fmt' to value '0'
[graph 0 input from stream 0:0 @ 0x42cce00] Setting 'time_base' to value '1/1000'
[graph 0 input from stream 0:0 @ 0x42cce00] Setting 'pixel_aspect' to value '1/1'
[graph 0 input from stream 0:0 @ 0x42cce00] Setting 'sws_param' to value 'flags=2'
[graph 0 input from stream 0:0 @ 0x42cce00] Setting 'frame_rate' to value '24000/1001'
[graph 0 input from stream 0:0 @ 0x42cce00] w:3840 h:2026 pixfmt:yuv420p tb:1/1000 fr:24000/1001 sar:1/1 sws_param:flags=2
[format @ 0x42cba40] compat: called with args=[vaapi_vld]
[format @ 0x42cba40] Setting 'pix_fmts' to value 'vaapi_vld'
[auto_scaler_0 @ 0x42cd580] Setting 'flags' to value 'bicubic'
[auto_scaler_0 @ 0x42cd580] w:iw h:ih flags:'bicubic' interl:0
[Parsed_format_0 @ 0x42cb500] auto-inserting filter 'auto_scaler_0' between the filter 'graph 0 input from stream 0:0' and the filter 'Parsed_format_0'
[AVFilterGraph @ 0x42ca360] query_formats: 6 queried, 4 merged, 1 already done, 0 delayed
[auto_scaler_0 @ 0x42cd580] w:3840 h:2026 fmt:yuv420p sar:1/1 -> w:3840 h:2026 fmt:nv12 sar:1/1 flags:0x4
[hwupload @ 0x42cbcc0] Surface format is nv12.
[AVHWFramesContext @ 0x42ccbc0] Created surface 0x4000000.
[AVHWFramesContext @ 0x42ccbc0] Direct mapping possible.
[AVHWFramesContext @ 0x42c3e40] Created surface 0x4000001.
[AVHWFramesContext @ 0x42c3e40] Direct mapping possible.
[AVHWFramesContext @ 0x42c3e40] Created surface 0x4000002.
[AVHWFramesContext @ 0x42c3e40] Created surface 0x4000003.
[AVHWFramesContext @ 0x42c3e40] Created surface 0x4000004.
[AVHWFramesContext @ 0x42c3e40] Created surface 0x4000005.
[AVHWFramesContext @ 0x42c3e40] Created surface 0x4000006.
[AVHWFramesContext @ 0x42c3e40] Created surface 0x4000007.
[AVHWFramesContext @ 0x42c3e40] Created surface 0x4000008.
[AVHWFramesContext @ 0x42c3e40] Created surface 0x4000009.
[AVHWFramesContext @ 0x42c3e40] Created surface 0x400000a.
[vp9_vaapi @ 0x409da40] Encoding entrypoint not found (19 / 6).
Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
[AVIOContext @ 0x40fdac0] Statistics: 0 seeks, 0 writeouts
[aac @ 0x40fcb00] Qavg: -nan
[AVIOContext @ 0x409f820] Statistics: 32768 bytes read, 0 seeks
Conversion failed!

The interesting bits are the entrypoint warnings for VP9 encoding being absent on this particular platform, as confirmed by vainfo's output:

libva info: VA-API version 0.40.0
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/local/lib/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_0_40
libva info: va_openDriver() returns 0
vainfo: VA-API version: 0.40 (libva 1.7.3)
vainfo: Driver version: Intel i965 driver for Intel(R) Skylake - 1.8.4.pre1 (glk-alpha-71-gc3110dc)
vainfo: Supported profile and entrypoints
      VAProfileMPEG2Simple            :	VAEntrypointVLD
      VAProfileMPEG2Simple            :	VAEntrypointEncSlice
      VAProfileMPEG2Main              :	VAEntrypointVLD
      VAProfileMPEG2Main              :	VAEntrypointEncSlice
      VAProfileH264ConstrainedBaseline:	VAEntrypointVLD
      VAProfileH264ConstrainedBaseline:	VAEntrypointEncSlice
      VAProfileH264ConstrainedBaseline:	VAEntrypointEncSliceLP
      VAProfileH264Main               :	VAEntrypointVLD
      VAProfileH264Main               :	VAEntrypointEncSlice
      VAProfileH264Main               :	VAEntrypointEncSliceLP
      VAProfileH264High               :	VAEntrypointVLD
      VAProfileH264High               :	VAEntrypointEncSlice
      VAProfileH264High               :	VAEntrypointEncSliceLP
      VAProfileH264MultiviewHigh      :	VAEntrypointVLD
      VAProfileH264MultiviewHigh      :	VAEntrypointEncSlice
      VAProfileH264StereoHigh         :	VAEntrypointVLD
      VAProfileH264StereoHigh         :	VAEntrypointEncSlice
      VAProfileVC1Simple              :	VAEntrypointVLD
      VAProfileVC1Main                :	VAEntrypointVLD
      VAProfileVC1Advanced            :	VAEntrypointVLD
      VAProfileNone                   :	VAEntrypointVideoProc
      VAProfileJPEGBaseline           :	VAEntrypointVLD
      VAProfileJPEGBaseline           :	VAEntrypointEncPicture
      VAProfileVP8Version0_3          :	VAEntrypointVLD
      VAProfileVP8Version0_3          :	VAEntrypointEncSlice
      VAProfileHEVCMain               :	VAEntrypointVLD
      VAProfileHEVCMain               :	VAEntrypointEncSlice
      VAProfileVP9Profile0            :	VAEntrypointVLD

The VLD (for Variable Length Decode) entry point for VP9 profile 0 is the furthest that Skylake comes to in terms of VP9 hardware-acceleration.

These with Kabylake test beds, run these encode tests and report back :-)

@Aaron2550 that's because your VAAPI implementation doesn't support the requested encoding entry points.
For encoding, as explained earlier, you're looking at Slice and SliceLP entry points for VAAPI.
What you posted above from vainfo doesn't indicate these entry points for VP8 and VP9.

For anyone with problem loading hybrid driver with latest libva (2.18 on my laptop), you need the following patch to intel-hybrid-driver:

diff --git a/src/media_drv_output_dri.c b/src/media_drv_output_dri.c
index 42299b8..1eab11e 100644
--- a/src/media_drv_output_dri.c
+++ b/src/media_drv_output_dri.c
@@ -105,11 +105,11 @@ media_output_dri_init (VADriverContextP ctx)
   struct dri_vtable *dri_vtable;

   static const struct dso_symbol symbols[] = {
-    {"dri_get_drawable",
+    {"va_dri_get_drawable",
      offsetof (struct dri_vtable, get_drawable)},
-    {"dri_get_rendering_buffer",
+    {"va_dri_get_rendering_buffer",
      offsetof (struct dri_vtable, get_rendering_buffer)},
-    {"dri_swap_buffer",
+    {"va_dri_swap_buffer",
      offsetof (struct dri_vtable, swap_buffer)},
     {NULL,}
   };
diff --git a/src/media_drv_output_dri.h b/src/media_drv_output_dri.h
index 0d6ccf0..91adee8 100644
--- a/src/media_drv_output_dri.h
+++ b/src/media_drv_output_dri.h
@@ -30,7 +30,7 @@
 #define _MEDIA__DRIVER_OUT_DRI_H
 #include <stdbool.h>
 #include "media_drv_defines.h"
-#define LIBVA_X11_NAME "libva-x11.so.1"
+#define LIBVA_X11_NAME "libva-x11.so.2"
 VOID media_output_dri_terminate (VADriverContextP ctx);
 BOOL media_output_dri_init (VADriverContextP ctx);