[mythtvnz] Fwd: Re: 18.04.1 upgrade and old Nvidia drivers

[Stephen Worthington]

On Fri, 17 Aug 2018 11:53:33 +1200, you wrote:

>
>How critical is this really, for watching recordings?
>
>I just found out I've been using the nouveau driver on my desktop pc
>(forgot to download the propriety drivers after the last upgrade) and I
>haven't seen any problems.
>
>In fact, since installing propriety drivers yesterday, I've seen some
>stuttering on youtube that I've never seen before. My desktop has a
>GT430 and my mythbox has a GT710.Both use the Nvidia 390 driver.
>
>-Paul

If your CPU is doing all the decoding and is powerful enough, the
Nouveau drivers are now likely to be fine (I have not actually tried
them myself for many years).  Your power bill will suffer a little
though - the CPU will jump from 10% to nearly 100% on one core at
least.  Lots of systems with older GPUs (like my mother's) also have
older CPUs and are totally incapable of doing the decoding for 1080i
in real time.  They also often have problems with 720p and only work
with SD video, unless they can offload to the GPU.

The biggest problem with not being able to use the Nvidia drivers
would be if you need 3D for 3D software or particularly gaming.
Nouveau does not do optimised 3D.  But the situation now is much
better than it used to be, as last time I looked at Nouveau there was
no 3D support at all - now there may well be enough for most
non-gaming uses.  Fortunately MythTV does not need 3D for anything, so
that can be ignored for a box that is only used for MythTV.

If you are getting stuttering after changing to the Nvidia drivers,
you probably have not adjusted MythTV to use them - it needs to be set
to use VDPAU and also to change the refresh rate to match the video
file's refresh rate.  On a laptop, the screens often are fixed
frequency these days, so you may not be able to have the refresh rate
match the video, and that will cause problems even with full CPU
decoding.  It is normally most visible in panning and high speed
movement.