LD_LIBRARY_PATH=/usr/local/cuda-8.0/lib64/  ffmpeg -f lavfi -i nullsrc -c:v h264_nvenc -gpu list -f null - -v trace
ffmpeg version N-83034-gf48b6b8 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.4) 20160609
  configuration: --prefix=/root/ffmpeg_build --pkg-config-flags=--static --extra-cflags=-I/root/ffmpeg_build/include --extra-ldflags=-L/root/ffmpeg_build/lib --bindir=/root/bin --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-nonfree --disable-shared --enable-nvenc --enable-cuda --enable-cuvid --enable-libnpp --extra-cflags=-Ilocal/include --extra-cflags=-I../nv_sdk --extra-ldflags=-L../nv_sdk
  libavutil      55. 43.100 / 55. 43.100
  libavcodec     57. 71.100 / 57. 71.100
  libavformat    57. 62.100 / 57. 62.100
  libavdevice    57.  2.100 / 57.  2.100
  libavfilter     6. 68.100 /  6. 68.100
  libswscale      4.  3.101 /  4.  3.101
  libswresample   2.  4.100 /  2.  4.100
  libpostproc    54.  2.100 / 54.  2.100
Successfully parsed a group of options.
Parsing a group of options: input url nullsrc.
Applying option f (force format) with argument lavfi.
Successfully parsed a group of options.
Opening an input file: nullsrc.
detected 12 logical cores
[Parsed_nullsrc_0 @ 0x3d609e0] size:320x240 rate:25/1 duration:-1.000000 sar:1/1
[AVFilterGraph @ 0x3d5efe0] query_formats: 2 queried, 1 merged, 0 already done, 0 delayed
[lavfi @ 0x3d5e740] All info found
[lavfi @ 0x3d5e740] stream 0: start_time: 0.000 duration: -368934881474191040.000
[lavfi @ 0x3d5e740] format: start_time: 0.000 duration: -9223372036854.775 bitrate=0 kb/s
Input #0, lavfi, from 'nullsrc':
  Duration: N/A, start: 0.000000, bitrate: N/A
    Stream #0:0, 1, 1/25: Video: rawvideo, 1 reference frame (I420 / 0x30323449), yuv420p, 320x240 [SAR 1:1 DAR 4:3], 0/1, 25 tbr, 25 tbn, 25 tbc
Successfully opened the file.
Parsing a group of options: output url -.
Applying option c:v (codec name) with argument h264_nvenc.
Applying option f (force format) with argument null.
Successfully parsed a group of options.
Opening an output file: -.
Successfully opened the file.
Initializing cuvid transcoding
[graph 0 input from stream 0:0 @ 0x3d5e3c0] Setting 'video_size' to value '320x240'
[graph 0 input from stream 0:0 @ 0x3d5e3c0] Setting 'pix_fmt' to value '0'
[graph 0 input from stream 0:0 @ 0x3d5e3c0] Setting 'time_base' to value '1/25'
[graph 0 input from stream 0:0 @ 0x3d5e3c0] Setting 'pixel_aspect' to value '1/1'
[graph 0 input from stream 0:0 @ 0x3d5e3c0] Setting 'sws_param' to value 'flags=2'
[graph 0 input from stream 0:0 @ 0x3d5e3c0] Setting 'frame_rate' to value '25/1'
[graph 0 input from stream 0:0 @ 0x3d5e3c0] w:320 h:240 pixfmt:yuv420p tb:1/25 fr:25/1 sar:1/1 sws_param:flags=2
[format @ 0x3da42e0] compat: called with args=[yuv420p|nv12|p010le|yuv444p|yuv444p16le|bgr0|rgb0|cuda]
[format @ 0x3da42e0] Setting 'pix_fmts' to value 'yuv420p|nv12|p010le|yuv444p|yuv444p16le|bgr0|rgb0|cuda'
[AVFilterGraph @ 0x3da2980] query_formats: 4 queried, 3 merged, 0 already done, 0 delayed
Loaded lib: libcuda.so.1
Loaded sym: cuInit
Loaded sym: cuDeviceGetCount
Loaded sym: cuDeviceGet
Loaded sym: cuDeviceGetName
Loaded sym: cuDeviceComputeCapability
Loaded sym: cuCtxCreate_v2
Loaded sym: cuCtxPushCurrent_v2
Loaded sym: cuCtxPopCurrent_v2
Loaded sym: cuCtxDestroy_v2
Loaded sym: cuMemAlloc_v2
Loaded sym: cuMemFree_v2
Loaded sym: cuMemcpy2D_v2
Loaded sym: cuGetErrorName
Loaded sym: cuGetErrorString
Loaded lib: libnvidia-encode.so.1
Loaded sym: NvEncodeAPICreateInstance
Loaded sym: NvEncodeAPIGetMaxSupportedVersion
[h264_nvenc @ 0x3d9f0a0] Loaded Nvenc version 7.1
[h264_nvenc @ 0x3d9f0a0] Nvenc initialized successfully
[h264_nvenc @ 0x3d9f0a0] 2 CUDA capable devices found
[h264_nvenc @ 0x3d9f0a0] [ GPU #0 - < Tesla M60 > has Compute SM 5.2 ]
[h264_nvenc @ 0x3d9f0a0] supports NVENC
[h264_nvenc @ 0x3d9f0a0] [ GPU #1 - < Tesla M60 > has Compute SM 5.2 ]
[h264_nvenc @ 0x3d9f0a0] supports NVENC
[h264_nvenc @ 0x3d9f0a0] Nvenc unloaded
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (h264_nvenc))