HEVC Main 10 not supported by latest libvdpau (ubuntu 16.04)

I have installed version 390.25 of drivers, and it still says that only HEVC main profile is supported. This is with a geforce gtx 1050ti card, which as far as I can find anecdotally online should support up through 444. I am writing an ATSC3 stream analyzer on ubuntu, and ATSC3 mandates main 10.

output of vdpauinfo:
display: :0 screen: 0
API version: 1
Information string: NVIDIA VDPAU Driver Shared Library 390.25 Wed Jan 24 19:28:27 PST 2018

Video surface:

name width height types

420 8192 8192 NV12 YV12
422 8192 8192 UYVY YUYV

Decoder capabilities:

name level macbs width height

MPEG1 0 65536 4096 4096
MPEG2_SIMPLE 3 65536 4096 4096
MPEG2_MAIN 3 65536 4096 4096
H264_BASELINE 41 65536 4096 4096
H264_MAIN 41 65536 4096 4096
H264_HIGH 41 65536 4096 4096
VC1_SIMPLE 1 8190 2048 2048
VC1_MAIN 2 8190 2048 2048
VC1_ADVANCED 4 8190 2048 2048
MPEG4_PART2_SP 3 8192 2048 2048
MPEG4_PART2_ASP 5 8192 2048 2048
DIVX4_QMOBILE 0 8192 2048 2048
DIVX4_MOBILE 0 8192 2048 2048
DIVX4_HOME_THEATER 0 8192 2048 2048
DIVX4_HD_1080P 0 8192 2048 2048
DIVX5_QMOBILE 0 8192 2048 2048
DIVX5_MOBILE 0 8192 2048 2048
DIVX5_HOME_THEATER 0 8192 2048 2048
DIVX5_HD_1080P 0 8192 2048 2048
H264_CONSTRAINED_BASELINE 41 65536 4096 4096
H264_EXTENDED 41 65536 4096 4096
H264_PROGRESSIVE_HIGH 41 65536 4096 4096
H264_CONSTRAINED_HIGH 41 65536 4096 4096
H264_HIGH_444_PREDICTIVE 41 65536 4096 4096
HEVC_MAIN 153 262144 8192 8192
HEVC_MAIN_10 — not supported —
HEVC_MAIN_STILL — not supported —
HEVC_MAIN_12 — not supported —
HEVC_MAIN_444 — not supported —

There’re already numerous threads about the issue here.

10-bit HEVC was never supported by VDPAU.
And probably never will be (as well as VP9, btw), since Nvidia seems competely moved to NVDEC.
(Nvidia officials can prove me wrong here, but they haven’t so far.)
You could try mpv with cuda or nvdec hw decoders.
PS. https://devtalk.nvidia.com/default/topic/1003387/vdpau-not-functional-at-4k

OK, so assuming I just want to use ffmpeg to transcode video, what do I need to do to get NVDEC acceleration working?

I downloaded the cuda developer’s kit
I downloaded ffmpeg 3.4
I set CC=nvcc and built ffmpeg 3.4

when I try to transcode hevc video to h264 I get the error “[h264_nvenc @ 0x3ac2620] No NVENC capable devices found”

I realize that once someone has been through this it is deadly obvious, but frankly this is ludicrous even by linux standards

DOES ANYONE AT NVIDIA PAY ATTENTION TO THIS FORUM???

enabling verbose mode, it appears that the problem is once again a 10 bit stream. Enabling verbose output in ffmpeg:
hevc_cuvid @ 0x354f060] Initializing cuvid hwaccel
[hevc_cuvid @ 0x354f060] Formats: Original: cuda | HW: cuda | SW: p010le
[graph 0 input from stream 0:0 @ 0x3a63000] w:3840 h:2160 pixfmt:cuda tb:1/15360 fr:60/1 sar:1/1 sws_param:flags=2
[Parsed_scale_cuda_0 @ 0x359ca40] w:3840 h:2160 -> w:1280 h:720
[h264_nvenc @ 0x35a1420] Loaded Nvenc version 8.1
[h264_nvenc @ 0x35a1420] Nvenc initialized successfully
[h264_nvenc @ 0x35a1420] 10 bit encode not supported
[h264_nvenc @ 0x35a1420] Provided device doesn’t support required NVENC features
[h264_nvenc @ 0x35a1420] Nvenc unloaded

YOur verbose output shows h264_nvenc. No hardware supports 10bit h264, not even decoding, let alone encoding.