Mailing List Archive

NVDEC: is there something wrong with it?
I just put together a new workstation where I will be watching TV with
Mythtv-frontend when not using it for other things.

It's a 6 core Ryzen 5 3600 with a Nvidia GT-1030 fanless GFX card.

After the initial install of mythtv-frontend I started playing videos
with the default settings of NVDEC.  That worked fine on HD 1080i
content but when I tried a sub-channel where the video was 720x480@30, I
immediately noticed that the video paused and played every few seconds
and never got better.

When I changed the video profile to High Quality OpenGL it worked
perfectly on all video types.

So I'll leave it that way, but why would NVDEC be so bad on 480i content??

Jim A


_______________________________________________
mythtv-users mailing list
mythtv-users@mythtv.org
http://lists.mythtv.org/mailman/listinfo/mythtv-users
http://wiki.mythtv.org/Mailing_List_etiquette
MythTV Forums: https://forum.mythtv.org
Re: NVDEC: is there something wrong with it? [ In reply to ]
On Tue, Nov 10, 2020 at 8:28 AM Jim Abernathy <jfabernathy@gmail.com> wrote:

> I just put together a new workstation where I will be watching TV with
> Mythtv-frontend when not using it for other things.
>
> It's a 6 core Ryzen 5 3600 with a Nvidia GT-1030 fanless GFX card.
>
> After the initial install of mythtv-frontend I started playing videos
> with the default settings of NVDEC. That worked fine on HD 1080i
> content but when I tried a sub-channel where the video was 720x480@30, I
> immediately noticed that the video paused and played every few seconds
> and never got better.
>
> When I changed the video profile to High Quality OpenGL it worked
> perfectly on all video types.
>
> So I'll leave it that way, but why would NVDEC be so bad on 480i content??
>
> Jim A
>

Possibly the same MPEG issue that have plagued other cards too...?
Re: NVDEC: is there something wrong with it? [ In reply to ]
On Tue, Nov 10, 2020 at 10:43 AM Greg Oliver <oliver.greg@gmail.com> wrote:

> On Tue, Nov 10, 2020 at 8:28 AM Jim Abernathy <jfabernathy@gmail.com>
> wrote:
>
>> I just put together a new workstation where I will be watching TV with
>> Mythtv-frontend when not using it for other things.
>>
>> It's a 6 core Ryzen 5 3600 with a Nvidia GT-1030 fanless GFX card.
>>
>> After the initial install of mythtv-frontend I started playing videos
>> with the default settings of NVDEC. That worked fine on HD 1080i
>> content but when I tried a sub-channel where the video was 720x480@30, I
>> immediately noticed that the video paused and played every few seconds
>> and never got better.
>>
>> When I changed the video profile to High Quality OpenGL it worked
>> perfectly on all video types.
>>
>> So I'll leave it that way, but why would NVDEC be so bad on 480i content??
>>
>> Jim A
>>
>
> Possibly the same MPEG issue that have plagued other cards too...?
>
> I've been testing further and I find that High Quality OpenGL is very good
on my system; however, if I'm watching a program that has a text crawl at
the bottom (new, sports) that over time the crawl becomes jittery. This is
on HD 1080i programs. I have not seen that with an NVDEC profile. NVDEC
will definitely not play a 720x480@30 program so I use OpenGL for that.

So is there a way to switch between profiles with a keyboard shortcut? I
have not found one yet. Now I have to use Setup to do this.

Jim A
Re: NVDEC: is there something wrong with it? [ In reply to ]
On Fri, 13 Nov 2020 10:14:32 -0500, you wrote:

>On Tue, Nov 10, 2020 at 10:43 AM Greg Oliver <oliver.greg@gmail.com> wrote:
>
>> On Tue, Nov 10, 2020 at 8:28 AM Jim Abernathy <jfabernathy@gmail.com>
>> wrote:
>>
>>> I just put together a new workstation where I will be watching TV with
>>> Mythtv-frontend when not using it for other things.
>>>
>>> It's a 6 core Ryzen 5 3600 with a Nvidia GT-1030 fanless GFX card.
>>>
>>> After the initial install of mythtv-frontend I started playing videos
>>> with the default settings of NVDEC. That worked fine on HD 1080i
>>> content but when I tried a sub-channel where the video was 720x480@30, I
>>> immediately noticed that the video paused and played every few seconds
>>> and never got better.
>>>
>>> When I changed the video profile to High Quality OpenGL it worked
>>> perfectly on all video types.
>>>
>>> So I'll leave it that way, but why would NVDEC be so bad on 480i content??
>>>
>>> Jim A
>>>
>>
>> Possibly the same MPEG issue that have plagued other cards too...?
>>
>> I've been testing further and I find that High Quality OpenGL is very good
>on my system; however, if I'm watching a program that has a text crawl at
>the bottom (new, sports) that over time the crawl becomes jittery. This is
>on HD 1080i programs. I have not seen that with an NVDEC profile. NVDEC
>will definitely not play a 720x480@30 program so I use OpenGL for that.
>
>So is there a way to switch between profiles with a keyboard shortcut? I
>have not found one yet. Now I have to use Setup to do this.
>
>Jim A

You should be able to set up playback profiles to match specific frame
sizes and frame rates. Create a new profile and add a new entry under
that profile. Fill in the width and height range and frame rate range
fields.
_______________________________________________
mythtv-users mailing list
mythtv-users@mythtv.org
http://lists.mythtv.org/mailman/listinfo/mythtv-users
http://wiki.mythtv.org/Mailing_List_etiquette
MythTV Forums: https://forum.mythtv.org
Re: NVDEC: is there something wrong with it? [ In reply to ]
>> So is there a way to switch between profiles with a keyboard shortcut? I have not found one yet. Now I have to use Setup to do this.

I'm still on 29, so things may have changed; has VDPAU been depreciated?

Doug
_______________________________________________
mythtv-users mailing list
mythtv-users@mythtv.org
http://lists.mythtv.org/mailman/listinfo/mythtv-users
http://wiki.mythtv.org/Mailing_List_etiquette
MythTV Forums: https://forum.mythtv.org
Re: NVDEC: is there something wrong with it? [ In reply to ]
On Fri, Nov 13, 2020 at 10:29 AM Stephen Worthington <
stephen_agent@jsw.gen.nz> wrote:

>
>
> You should be able to set up playback profiles to match specific frame
> sizes and frame rates. Create a new profile and add a new entry under
> that profile. Fill in the width and height range and frame rate range
> fields.
>

That works great. My first entry is for NVDEC but only for widths >=1280
and heights >=720.
My second entry is for High Quality OpenGL software but only for 720 width
and 480 height.

Thanks,

Jim A
Re: NVDEC: is there something wrong with it? [ In reply to ]
On Fri, 13 Nov 2020 10:29:31 -0500 (EST), you wrote:

>>> So is there a way to switch between profiles with a keyboard shortcut? I have not found one yet. Now I have to use Setup to do this.
>
>I'm still on 29, so things may have changed; has VDPAU been depreciated?
>
>Doug

The word you want is "deprecated", and it looks like things are
trending towards VDPAU eventually being deprecated in favour of NVDEC,
but it will be a long time before we get there. It is up to Nvidia
and they do publish their plans for stopping support for older
drivers.
_______________________________________________
mythtv-users mailing list
mythtv-users@mythtv.org
http://lists.mythtv.org/mailman/listinfo/mythtv-users
http://wiki.mythtv.org/Mailing_List_etiquette
MythTV Forums: https://forum.mythtv.org
Re: NVDEC: is there something wrong with it? [ In reply to ]
On 13/11/2020 15:29, Doug Lytle wrote:
>>> So is there a way to switch between profiles with a keyboard shortcut? I have not found one yet. Now I have to use Setup to do this.
>
> I'm still on 29, so things may have changed; has VDPAU been depreciated?
>

Yes, by NVidia. All new cards are supported by the new drivers which do
NVDEC (and a subset of profiles via VDPAU), and "legacy" cards are
supported by the old driver which only does VDPAU.


Regards
Stuart
_______________________________________________
mythtv-users mailing list
mythtv-users@mythtv.org
http://lists.mythtv.org/mailman/listinfo/mythtv-users
http://wiki.mythtv.org/Mailing_List_etiquette
MythTV Forums: https://forum.mythtv.org
Re: NVDEC: is there something wrong with it? [ In reply to ]
On Tue, 10 Nov 2020 at 14:27, Jim Abernathy <jfabernathy@gmail.com> wrote:
>
> I just put together a new workstation where I will be watching TV with
> Mythtv-frontend when not using it for other things.
>
> It's a 6 core Ryzen 5 3600 with a Nvidia GT-1030 fanless GFX card.
>
> After the initial install of mythtv-frontend I started playing videos
> with the default settings of NVDEC. That worked fine on HD 1080i
> content but when I tried a sub-channel where the video was 720x480@30, I
> immediately noticed that the video paused and played every few seconds
> and never got better.
>
> When I changed the video profile to High Quality OpenGL it worked
> perfectly on all video types.
>
> So I'll leave it that way, but why would NVDEC be so bad on 480i content??
>

Jim

A little late to the party but, thinking about it, there are 3 possible issues:-

- as others have mentioned the 'old' nvidia mpeg2 decoding problem.
You don't mention what the source material is other than the
resolution - but I would expect that to present itself as corrupted
video frames rather performance issues.
- deinterlacer. NVDEC has an awkward deinterlacer setup and there is
also the possibility it is falling over on a particular stream. I
would try going into the details of the video display profile and
disable the 'Prefer driver deinterlacers' option. That should give you
nvdec decoding with OpenGL shader deinterlacers - if that works then
the problem is in the deinterlacers.
- Stuarta A noticed an issue recently with some NVDEC problems which
we tracked down to the number of video buffers in use. We didn't
really finish the conversation but my testing with a 1030 works with
just about everything I can throw at it - whereas Stuart (with a
different nvidia card) had to make some source code adjustments to get
playback to work smoothly.

Can you post some 'mythfrontend -v playback' logs for a stream that
does not play well?

Thanks and regards
Mark
_______________________________________________
mythtv-users mailing list
mythtv-users@mythtv.org
http://lists.mythtv.org/mailman/listinfo/mythtv-users
http://wiki.mythtv.org/Mailing_List_etiquette
MythTV Forums: https://forum.mythtv.org
Re: NVDEC: is there something wrong with it? [ In reply to ]
On Sun, Nov 15, 2020 at 12:20 PM Mark Kendall <mark.kendall@gmail.com>
wrote:

> On Tue, 10 Nov 2020 at 14:27, Jim Abernathy <jfabernathy@gmail.com> wrote:
> >
> > I just put together a new workstation where I will be watching TV with
> > Mythtv-frontend when not using it for other things.
> >
> > It's a 6 core Ryzen 5 3600 with a Nvidia GT-1030 fanless GFX card.
> >
> > After the initial install of mythtv-frontend I started playing videos
> > with the default settings of NVDEC. That worked fine on HD 1080i
> > content but when I tried a sub-channel where the video was 720x480@30, I
> > immediately noticed that the video paused and played every few seconds
> > and never got better.
> >
> > When I changed the video profile to High Quality OpenGL it worked
> > perfectly on all video types.
> >
> > So I'll leave it that way, but why would NVDEC be so bad on 480i
> content??
> >
>
> Jim
>
> A little late to the party but, thinking about it, there are 3 possible
> issues:-
>
> - as others have mentioned the 'old' nvidia mpeg2 decoding problem.
> You don't mention what the source material is other than the
> resolution - but I would expect that to present itself as corrupted
> video frames rather performance issues.
> - deinterlacer. NVDEC has an awkward deinterlacer setup and there is
> also the possibility it is falling over on a particular stream. I
> would try going into the details of the video display profile and
> disable the 'Prefer driver deinterlacers' option. That should give you
> nvdec decoding with OpenGL shader deinterlacers - if that works then
> the problem is in the deinterlacers.
>

This had no effect.


> - Stuarta A noticed an issue recently with some NVDEC problems which
> we tracked down to the number of video buffers in use. We didn't
> really finish the conversation but my testing with a 1030 works with
> just about everything I can throw at it - whereas Stuart (with a
> different nvidia card) had to make some source code adjustments to get
> playback to work smoothly.
>
> Can you post some 'mythfrontend -v playback' logs for a stream that
> does not play well?
>
> Thanks and regards
> Mark
>

When I looked at the logging I saw a lot of video behind audio and I went
in and changed the audio read ahead to 400ms and that fixed it. Not sure
why putting in a faster CPU and Motherboard made any difference when the
Nvidia card remained the same??

Thanks.

Jim A
Re: NVDEC: is there something wrong with it? [ In reply to ]
On Sun, Nov 15, 2020 at 3:30 PM James Abernathy <jfabernathy@gmail.com>
wrote:

>
>
> On Sun, Nov 15, 2020 at 12:20 PM Mark Kendall <mark.kendall@gmail.com>
> wrote:
>
>> On Tue, 10 Nov 2020 at 14:27, Jim Abernathy <jfabernathy@gmail.com>
>> wrote:
>> >
>> > I just put together a new workstation where I will be watching TV with
>> > Mythtv-frontend when not using it for other things.
>> >
>> > It's a 6 core Ryzen 5 3600 with a Nvidia GT-1030 fanless GFX card.
>> >
>> > After the initial install of mythtv-frontend I started playing videos
>> > with the default settings of NVDEC. That worked fine on HD 1080i
>> > content but when I tried a sub-channel where the video was 720x480@30,
>> I
>> > immediately noticed that the video paused and played every few seconds
>> > and never got better.
>> >
>> > When I changed the video profile to High Quality OpenGL it worked
>> > perfectly on all video types.
>> >
>> > So I'll leave it that way, but why would NVDEC be so bad on 480i
>> content??
>> >
>>
>> Jim
>>
>> A little late to the party but, thinking about it, there are 3 possible
>> issues:-
>>
>> - as others have mentioned the 'old' nvidia mpeg2 decoding problem.
>> You don't mention what the source material is other than the
>> resolution - but I would expect that to present itself as corrupted
>> video frames rather performance issues.
>> - deinterlacer. NVDEC has an awkward deinterlacer setup and there is
>> also the possibility it is falling over on a particular stream. I
>> would try going into the details of the video display profile and
>> disable the 'Prefer driver deinterlacers' option. That should give you
>> nvdec decoding with OpenGL shader deinterlacers - if that works then
>> the problem is in the deinterlacers.
>>
>
> This had no effect.
>
>
>> - Stuarta A noticed an issue recently with some NVDEC problems which
>> we tracked down to the number of video buffers in use. We didn't
>> really finish the conversation but my testing with a 1030 works with
>> just about everything I can throw at it - whereas Stuart (with a
>> different nvidia card) had to make some source code adjustments to get
>> playback to work smoothly.
>>
>> Can you post some 'mythfrontend -v playback' logs for a stream that
>> does not play well?
>>
>> Thanks and regards
>> Mark
>>
>
> When I looked at the logging I saw a lot of video behind audio and I went
> in and changed the audio read ahead to 400ms and that fixed it. Not sure
> why putting in a faster CPU and Motherboard made any difference when the
> Nvidia card remained the same??
>
> Thanks.
>
> Jim A
>

Everytime I go through one of these video playback issues with mythfrontend
I start getting really picky, so I'm testing everything with a critical
eye. There is still something that is bothering me about what I'm seeing
on the GT-1030 on my new system. My test case today is NFL football. On the
closeup action shots the motion is just not perfectly smooth. If I'm just
watching then I don't care, but when watching with a critical eye, it's not
perfect. The only visual effect I can describe is on the sports new crawl
at the bottom of the screen. It will scroll along perfectly and then the
text will be jerky just a little, then go back to a perfectly smooth scroll.

I've tried High and Normal OpenGL, NVDEC, and VDPAU. All about the same..

My goal standard at this time is my Nvidia Shield TV. None of the issues I
tried to describe above exist at all on mythfrontend on the Shield TV or on
Leanfront on the Shield TV.

So I have a workable solution for my Mythtv frontend on my main TV, but It
just bothers me that a 6 core Ryzen 5 3600 and a GT-1030 aren't as good as
a $150 Android streaming box.

Jim A