mainline kernel hardware acceleration

[xmixahlx]

mpeg2video hwaccel is tested working.

testing requirements:
patched kernel (libreelec; optionally kwiboo v4l2 5.5 wip and rkvdec, plus bbrezillon patches)
patched libva (plus pulls 332,340)
patched libva-v4l2-request (plus pulls 28,29,30)
patched ffmpeg (v4l2-request-hwaccel) -- recommend 4.2.2 or -master
> build with --enable-v4l2-request --enable-libdrm --enable-libudev --enable-pic --enable-shared (plus optional config)

determine video decoder:
dmesg | grep rk3399-vpu-dec
note video device (i.e. /dev/video1)

export variables:
export LIBVA_DRIVER_NAME=v4l2_request
export LIBVA_V4L2_REQUEST_VIDEO_PATH=/dev/video1

vainfo output:

libva info: VA-API version 1.6.1
libva info: User environment variable requested driver 'v4l2_request'
libva info: Trying to open /usr/local/lib/aarch64-linux-gnu/dri/v4l2_request_drv_video.so
libva info: Found init function __vaDriverInit_1_6
libva info: va_openDriver() returns 0
vainfo: VA-API version: 1.6 (libva 2.6.0)
vainfo: Driver version: v4l2-request
vainfo: Supported profile and entrypoints
     VAProfileMPEG2Simple            : VAEntrypointVLD
     VAProfileMPEG2Main              : VAEntrypointVLD
     VAProfileH264Main               : VAEntrypointVLD
     VAProfileH264High               : VAEntrypointVLD
     VAProfileH264ConstrainedBaseline: VAEntrypointVLD
     VAProfileH264MultiviewHigh      : VAEntrypointVLD
     VAProfileH264StereoHigh         : VAEntrypointVLD

vlc abbreviated output:
> opengl video, vaapi hwaccel

libva info: VA-API version 1.6.1
libva info: User environment variable requested driver 'v4l2_request'
libva info: Trying to open /usr/local/lib/aarch64-linux-gnu/dri/v4l2_request_drv_video.so
libva info: Found init function __vaDriverInit_1_6
libva info: va_openDriver() returns 0
[0000ffff5cc19640] avcodec decoder: Using v4l2-request for hardware decoding

ffmpeg -decoders | grep v4l2request output:

V..... h263_v4l2request h263 (v4l2request) (codec h263)
V..... h264_v4l2request h264 (v4l2request) (codec h264)
V..... hevc_v4l2request hevc (v4l2request) (codec hevc)
V..... mpeg1_v4l2request mpeg1 (v4l2request) (codec mpeg1video)
V..... mpeg2_v4l2request mpeg2 (v4l2request) (codec mpeg2video)
V..... mpeg4_v4l2request mpeg4 (v4l2request) (codec mpeg4)
V..... vc1_v4l2request vc1 (v4l2request) (codec vc1)
V..... vp8_v4l2request vp8 (v4l2request) (codec vp8)
V..... vp9_v4l2request vp9 (v4l2request) (codec vp9)

screenshot eye candy