./ffmpeg -re -hwaccel cuvid -c:v hevc_cuvid -i /data/public/media/HEVC4K60.ts -ac 2 -ar 48000 -f decklink -vf hwdownload,format=nv12 -pix_fmt uyvy422 'DeckLink 8K Pro (1)' -v verbose
ffmpeg version N-94012-ge62f625 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 4.6.4 (crosstool-NG 1.18.0) 20130102 (prerelease)
  configuration: --prefix=/usr/local/ffmpeg --enable-shared --enable-libfdk-aac --enable-librtmp --disable-libvorbis --disable-encoder=vorbis --disable-decoder=vorbis --enable-libmp3lame --disable-debug --enable-nonfree --enable-gpl --disable-ffplay --enable-pthreads --enable-ffmpeg --enable-avresample --disable-vdpau --disable-vaapi --disable-libmfx --enable-libx264 --enable-openssl --enable-decklink --enable-nvdec --enable-nvenc --enable-libnpp --enable-cuda --extra-cflags=-I/root/X/tmp/cuda_dev/include --extra-ldflags=-L/root/X/tmp/cuda_dev/lib
  libavutil      56. 28.100 / 56. 28.100
  libavcodec     58. 52.102 / 58. 52.102
  libavformat    58. 27.103 / 58. 27.103
  libavdevice    58.  7.100 / 58.  7.100
  libavfilter     7. 55.100 /  7. 55.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  4.101 /  5.  4.101
  libswresample   3.  4.100 /  3.  4.100
  libpostproc    55.  4.100 / 55.  4.100
Input #0, mpegts, from '/data/public/media/HEVC4K60.ts':
  Duration: 00:10:30.40, start: 0.602033, bitrate: 12384 kb/s
  Program 1
    Metadata:
      service_name    : Big Buck Bunny, Sunflower version
      service_provider: FFmpeg
    Stream #0:0[0x100]: Video: hevc (Main), 1 reference frame ([36][0][0][0] / 0x0024), yuv420p(tv), 3840x2160 [SAR 1:1 DAR 16:9], 60 fps, 60 tbr, 90k tbn, 60 tbc
    Stream #0:1[0x101](und): Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 201 kb/s
[hevc_cuvid @ 0x6a1d80] Initializing cuvid hwaccel
[AVBSFContext @ 0x1076d80] The input looks like it is Annex B already
[hevc_cuvid @ 0x6a1d80] CUVID capabilities for hevc_cuvid:
[hevc_cuvid @ 0x6a1d80] 8 bit: supported: 1, min_width: 144, max_width: 8192, min_height: 144, max_height: 8192
[hevc_cuvid @ 0x6a1d80] 10 bit: supported: 1, min_width: 144, max_width: 8192, min_height: 144, max_height: 8192
[hevc_cuvid @ 0x6a1d80] 12 bit: supported: 1, min_width: 144, max_width: 8192, min_height: 144, max_height: 8192
Stream mapping:
  Stream #0:0 -> #0:0 (hevc (hevc_cuvid) -> wrapped_avframe (native))
  Stream #0:1 -> #0:1 (aac (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
[hevc_cuvid @ 0x6a1d80] Initializing cuvid hwaccel
[hevc_cuvid @ 0x6a1d80] Formats: Original: cuda | HW: cuda | SW: nv12
[graph 0 input from stream 0:0 @ 0x16d2500] w:3840 h:2160 pixfmt:cuda tb:1/90000 fr:60/1 sar:1/1 sws_param:flags=2
[auto_scaler_0 @ 0x16d4bc0] w:iw h:ih flags:'bicubic' interl:0
[format @ 0x16d3900] auto-inserting filter 'auto_scaler_0' between the filter 'Parsed_format_1' and the filter 'format'
[auto_scaler_0 @ 0x16d4bc0] w:3840 h:2160 fmt:nv12 sar:1/1 -> w:3840 h:2160 fmt:uyvy422 sar:1/1 flags:0x4
[graph_1_in_0_1 @ 0x114b5c0] tb:1/48000 samplefmt:fltp samplerate:48000 chlayout:0x3
[format_out_0_1 @ 0x114bf00] auto-inserting filter 'auto_resampler_0' between the filter 'Parsed_anull_0' and the filter 'format_out_0_1'
[auto_resampler_0 @ 0x114eb00] ch:2 chl:stereo fmt:fltp r:48000Hz -> ch:2 chl:stereo fmt:s16 r:48000Hz
[decklink @ 0x6f33c0] Found Decklink mode 3840 x 2160 with rate 60.00
Output #0, decklink, to 'DeckLink 8K Pro (1)':
  Metadata:
    encoder         : Lavf58.27.103
    Stream #0:0: Video: wrapped_avframe, 1 reference frame, uyvy422(progressive), 3840x2160 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 60 fps, 60 tbn, 60 tbc
    Metadata:
      encoder         : Lavc58.52.102 wrapped_avframe
    Stream #0:1(und): Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
    Metadata:
      encoder         : Lavc58.52.102 pcm_s16le
[decklink @ 0x6f33c0] There are not enough buffered video frames. Video may misbehave!
    Last message repeated 1 times
[decklink @ 0x6f33c0] There's no buffered audio. Audio will misbehave!
    Last message repeated 10 times
[decklink @ 0x6f33c0] There are not enough buffered video frames. Video may misbehave!
[decklink @ 0x6f33c0] There's no buffered audio. Audio will misbehave!
[decklink @ 0x6f33c0] There are not enough buffered video frames. Video may misbehave!
[decklink @ 0x6f33c0] There's no buffered audio. Audio will misbehave!
    Last message repeated 9 times
[decklink @ 0x6f33c0] There are not enough buffered video frames. Video may misbehave!
[decklink @ 0x6f33c0] There's no buffered audio. Audio will misbehave!
[decklink @ 0x6f33c0] There are not enough buffered video frames. Video may misbehave!
[decklink @ 0x6f33c0] There's no buffered audio. Audio will misbehave!
    Last message repeated 10 times
[decklink @ 0x6f33c0] There are not enough buffered video frames. Video may misbehave!
[decklink @ 0x6f33c0] There's no buffered audio. Audio will misbehave!
[decklink @ 0x6f33c0] There are not enough buffered video frames. Video may misbehave!
[decklink @ 0x6f33c0] There's no buffered audio. Audio will misbehave!
[decklink @ 0x6f33c0] There are not enough buffered video frames. Video may misbehave!
    Last message repeated 1 times
frame=  133 fps= 19 q=-0.0 Lsize=N/A time=00:00:02.21 bitrate=N/A speed=0.314x
video:70kB audio:308kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
Input file #0 (/data/public/media/HEVC4K60.ts):
  Input stream #0:0 (video): 137 packets read (3108108 bytes); 134 frames decoded;
  Input stream #0:1 (audio): 77 packets read (40015 bytes); 77 frames decoded (78848 samples);
  Total: 214 packets (3148123 bytes) demuxed
Output file #0 (DeckLink 8K Pro (1)):
  Output stream #0:0 (video): 133 frames encoded; 133 packets muxed (71288 bytes);
  Output stream #0:1 (audio): 77 frames encoded (78848 samples); 77 packets muxed (315392 bytes);
  Total: 210 packets (386680 bytes) muxed
[AVIOContext @ 0x6a4700] Statistics: 10088880 bytes read, 3 seeks