[FFmpeg-user] Nvenc Fails with Cannot Init CUDA

[Fabian Russell]

Hello,

On my linux system I have an Nvidia GT 730 card:

# lspci | grep -i nvidia
01:00.0 VGA compatible controller: NVIDIA Corporation GK208B [GeForce GT
730] (rev a1)

This GPU is supposed to support nvenc using the latest proprietary Nvidia
drivers
yet when I attempt to record or transcode a video nvenc will fail.  Here is
one example
of the many possible command lines:

ffmpeg -i input.mp4 -c:v h264_nvenc output.mkv

[h264_nvenc @ 0xb10d00] Cannot init CUDA

Using the strace utility I can get a little more information on the error:

strace ffmpeg -i input.mp4 -c:v h264_nvenc output.mkv

stat("/dev/nvidia-uvm", {st_mode=S_IFCHR|0666, st_rdev=makedev(249, 0),
...}) = 0
stat("/dev/nvidia-uvm-tools", {st_mode=S_IFCHR|0666, st_rdev=makedev(249,
1), ...}) = 0
openat(AT_FDCWD, "/dev/nvidia-uvm", O_RDWR|O_CLOEXEC) = -1 EIO
(Input/output error)
openat(AT_FDCWD, "/dev/nvidia-uvm", O_RDWR) = -1 EIO (Input/output error)
ioctl(-5, _IOC(0, 0x00, 0x01, 0x3000), 0x7ffd8ccc67e0) = -1 EBADF (Bad file
descriptor)
ioctl(-5, _IOC(0, 0x00, 0x02, 0x3000), 0) = -1 EBADF (Bad file descriptor)
close(-5)                               = -1 EBADF (Bad file descriptor)
write(2, "\33[48;5;0m\33[38;5;51m[h264_nvenc @"..., 47[h264_nvenc @
0xf33d00] ) = 47
write(2, "\33[48;5;0m\33[38;5;196mCannot init "..., 41Cannot init CUDA
) = 41

What is the problem here?  How can I debug this further?

Is it necessary to install the complete Nvidia SDK package?