Mailing List Archive: Raspberry Pi 4B jitter

Raspberry Pi 4B jitter

Sep 20, 2019, 10:31 AM

Post #1 of 4 (681 views)

Hey, all. I just set up my new Raspberry Pi 4 4GB as a frontend, and I'm a
bit disappointed in performance. You can notice jitter easily on sports
programs of all sorts (most often during camera panning), in news crawls at
the bottom of the screen (most of the time, but you'll occasionally get a
second of smooth performance), and so on. In fact, it's pretty similar to
an old post of mine when I described the same behavior on a then-new
Raspberry Pi 3B: https://lists.gt.net/mythtv/users/603845

I'm using mythtv-light on Raspbian, with a 256MB GPU memory split (though
I'm led to believe this doesn't matter anymore), and OpenMAX Normal for
playback. (There is no OpenMAX High available.) Of note is that there is
plenty of free memory and idle CPU capacity while the playback is jittering!

My questions are:

1. Does anyone see better performance on their Raspberry Pi, and if so,
what are you doing differently?

2. Does anyone see better performance using one of the other "standard
hardware" solutions, such as the Shield or the Fire Stick 4K? If so, do you
think it's worth buying that hardware? Have you ever compared it to RPi
performance?

I'm really trying to move off of the cheap slim-form-factor PC I bought off
ebay a few years ago, but at least that PC has VDPAU, which is the only
thing I've ever used for consistently smooth playback.

Thanks!
Josh
mythtv@desh.info

Re: Raspberry Pi 4B jitter [ In reply to ]

jfabernathy at gmail

Sep 20, 2019, 11:39 AM

Post #2 of 4 (681 views)

Permalink

On 9/20/19 1:31 PM, Josh Rosenberg wrote:
> Hey, all. I just set up my new Raspberry Pi 4 4GB as a frontend, and
> I'm a bit disappointed in performance. You can notice jitter easily on
> sports programs of all sorts (most often during camera panning), in
> news crawls at the bottom of the screen (most of the time, but you'll
> occasionally get a second of smooth performance), and so on. In fact,
> it's pretty similar to an old post of mine when I described the same
> behavior on a then-new Raspberry Pi 3B:
> https://lists.gt.net/mythtv/users/603845
>
> I'm using mythtv-light on Raspbian, with a 256MB GPU memory split
> (though I'm led to believe this doesn't matter anymore), and OpenMAX
> Normal for playback. (There is no OpenMAX High available.) Of note is
> that there is plenty of free memory and idle CPU capacity while the
> playback is jittering!
>
> My questions are:
>
> 1. Does anyone see better performance on their Raspberry Pi, and if
> so, what are you doing differently?
>
> 2. Does anyone see better performance using one of the other "standard
> hardware" solutions, such as the Shield or the Fire Stick 4K? If so,
> do you think it's worth buying that hardware? Have you ever compared
> it to RPi performance?
>
> I'm really trying to move off of the cheap slim-form-factor PC I
> bought off ebay a few years ago, but at least that PC has VDPAU, which
> is the only thing I've ever used for consistently smooth playback.
>
> Thanks!
> Josh
> mythtv@desh.info <mailto:mythtv@desh.info>
>
I'm using 320MB GPU memory split and I don't notice much of any problems
on my 4GB RP4.

Jim A

Re: Raspberry Pi 4B jitter [ In reply to ]

jksjdevelop at gmail

Sep 21, 2019, 12:15 AM

Post #3 of 4 (673 views)

Permalink

On 20/09/2019 19:39, James Abernathy wrote:
>
>
> On 9/20/19 1:31 PM, Josh Rosenberg wrote:
>> Hey, all. I just set up my new Raspberry Pi 4 4GB as a frontend, and
>> I'm a bit disappointed in performance. You can notice jitter easily
>> on sports programs of all sorts (most often during camera panning),
>> in news crawls at the bottom of the screen (most of the time, but
>> you'll occasionally get a second of smooth performance), and so on.
>> In fact, it's pretty similar to an old post of mine when I described
>> the same behavior on a then-new Raspberry Pi 3B:
>> https://lists.gt.net/mythtv/users/603845
>>
>> I'm using mythtv-light on Raspbian, with a 256MB GPU memory split
>> (though I'm led to believe this doesn't matter anymore), and OpenMAX
>> Normal for playback. (There is no OpenMAX High available.) Of note is
>> that there is plenty of free memory and idle CPU capacity while the
>> playback is jittering!
>>
>> My questions are:
>>
>> 1. Does anyone see better performance on their Raspberry Pi, and if
>> so, what are you doing differently?
>>
>> 2. Does anyone see better performance using one of the other
>> "standard hardware" solutions, such as the Shield or the Fire Stick
>> 4K? If so, do you think it's worth buying that hardware? Have you
>> ever compared it to RPi performance?
>>
>> I'm really trying to move off of the cheap slim-form-factor PC I
>> bought off ebay a few years ago, but at least that PC has VDPAU,
>> which is the only thing I've ever used for consistently smooth playback.
>>
>> Thanks!
>> Josh
>> mythtv@desh.info <mailto:mythtv@desh.info>
>>
> I'm using 320MB GPU memory split and I don't notice much of any
> problems on my 4GB RP4.
>
> Jim A
>
Using high quality software decode with linear de-interlace gives me
smoother playback than using Openmax but it suffers from slight tearing.
I am sure things will get better when the graphics drivers on the Pi4
get updated. Currently though I agree that the Pi4 is a great backend
but at present 1080i 50Hz is not perfect.

Re: Raspberry Pi 4B jitter [ In reply to ]

lists at glidos

Sep 21, 2019, 2:38 AM

Post #4 of 4 (670 views)

Permalink

On 20/09/2019 18:31, Josh Rosenberg wrote:
> 2. Does anyone see better performance using one of the other "standard
> hardware" solutions, such as the Shield or the Fire Stick 4K? If so, do
> you think it's worth buying that hardware? Have you ever compared it to
> RPi performance?

Not if you're looking for 1080i50 playback as good as vdpau on nvidia
ion, say. The mythfrontend app is very impressive, but not perfect. I'd
love to dump my ZBox and just use the app, but I couldn't use it to
watch Strictly. :-)

I should mention that I don't have the very latest hardware. I have the
second generation Fire TV box, which is 4K capable, but the latest Fire
Stick may perform better for all I know.

Cheers,
Paul.
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