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orangeteal
Topic Author
Posts: 3
Joined: Wed Nov 09, 2011 3:22 pm

Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Sat Nov 12, 2011 6:11 pm

I have done a search but couldn't find a topic on this issue.

I would like to report a bug: Roku 2 outputs at 60.000Hz refresh rate instead of the standard 59.94Hz rate required to play back 29.97 fps video content from Netflix and Amazon without judder.

This is similar to the problem that Intel Sandybridge processors had, only that was 24.000 vs 23.976, resulting in a stutter every 41.66 seconds. In this case it's 1 / (60.000 - 59.940) = 1 frame repeated every 16.7 seconds.

I was thinking that perhaps this is also the reason some people are still experiencing issues with the video levels after the latest update. Maybe some displays assume that a 60.0 fps integer framerate would only come from a PC and apply PC levels rather than TV levels.

To reproduce the problem on Roku 2 connected by HDMI to an HDTV with no "motion smoothing" functions enabled:
1. Add the private channel "1080p Showcase"
2. Open 1080p Showcase on the Roku and choose Search
3. Type in "rokutest" and hit Search
4. Play "rokutest 1080p HD" and focus on the white bar at the bottom moving from left to right

Image

This is a 20 second clip, so depending on what point in time you start playing the video, you should see the bar stutter either once or twice.

Roku 1 set to output at 720p (59.94) is able to play this video with zero stutters (there are multiple stutters if 1080p30 output is enabled on Roku 1; I'm not sure the reason for that). On Roku 2 it doesn't matter what resolution you choose because it will always output at 60.0 fps.

I am using firmware 4.1 build 2667 with a Roku 2 XD.
 
wxman2003
Posts: 55
Joined: Fri Apr 23, 2010 6:20 pm

Re: Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Sat Nov 12, 2011 8:51 pm

I see it too when 1080p showcase set to 30 fps. I set up 1080p showcase to 24fps and the same with my Pioneer. Judder occurs there too but not as noticeable. Don't know how ROKU could mess something up that simple.
 
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RokuShawnS
Roku Engineering
Posts: 6625
Joined: Thu Mar 10, 2011 2:21 pm

Re: Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Sat Nov 12, 2011 9:37 pm

I forwarded this thread over to an engineer tonight after doing my evening rounds of spam cleanup. I'll let you know if anything comes of it that I can say publicly.

C. Shawn Smith
C. Shawn Smith
Community Liaison

------------
The Cosmos is all that is, and all that was, and ever will be. -- Carl Sagan
 
vandergraff
Posts: 186
Joined: Fri Aug 19, 2011 11:50 am

Re: Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Sun Nov 13, 2011 2:30 am

Yes I see this as well on the showcase 1080P channel 'rokutest'.

Also try the the Netflix 23.976 examples (search '23.976' on Netflix).

They judder badly on my ROKU 2. On my LG BD390 Blu-Ray Player they are smooth. I assumed it was because the BD390 can output 24P while the ROKU 2 only does 60P - but maybe there is something more subtle going on here.
 
__5
** Valued Community Member **
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Joined: Tue Dec 23, 2008 7:51 pm

Re: Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Sun Nov 13, 2011 3:18 am

Roku2 needs 24P, (for Netflix contents).

cheers!
 
themew
Posts: 25
Joined: Sun Oct 16, 2011 10:20 am

Re: Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Sun Nov 13, 2011 11:48 am

This is what we were discussing on the NHL threads. Because of the framerate problem, panning across the ice creates a horrible judder effect.

Thanks for forwarding it Shawn -- maybe we can finally get this fixed and enjoy a smooth hockey game :)
 
wxman2003
Posts: 55
Joined: Fri Apr 23, 2010 6:20 pm

Re: Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Sun Nov 13, 2011 2:04 pm

The NHL judder is a seperate issue. Its noticeable on the Roku 1 as well as Apple TV.
 
wchillman
Posts: 71
Joined: Tue Jan 25, 2011 2:34 pm

Re: Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Sun Nov 13, 2011 2:16 pm

Roku 2 XS: firmware 4.1 build 2667
Sharp Aquos LC-C5262U

I too watched the rokutest on the 1080p Showcase Channel and was unable to see any “jutter or stutter” but I may just not notice any subtleties. Previously, when I used the Roku 1 XDS I was unable to get a 1080p picture at all. Now the picture is incredible. :D
 
mallwalker
Posts: 35
Joined: Sat May 07, 2011 6:41 pm

Re: Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Sun Nov 13, 2011 3:28 pm

Gee, isn't there something in the video composition called Vertical & Horizontal Sync pulses to correct for just this type of thing ?
 
vandergraff
Posts: 186
Joined: Fri Aug 19, 2011 11:50 am

Re: Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Sun Nov 13, 2011 3:44 pm

mallwalker wrote:
Gee, isn't there something in the video composition called Vertical & Horizontal Sync pulses to correct for just this type of thing ?


??????

In the old analog world the vertical sync was the frame rate (progressive) or field rate (interlaced).

The theory being proposed here is that the framerate from the ROKU 2 is wrong causing it to stutter as it tries to stay in sync with the source frame rate.
 
wxman2003
Posts: 55
Joined: Fri Apr 23, 2010 6:20 pm

Re: Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Sun Nov 13, 2011 5:30 pm

wchillman wrote:
Roku 2 XS: firmware 4.1 build 2667
Sharp Aquos LC-C5262U

I too watched the rokutest on the 1080p Showcase Channel and was unable to see any “jutter or stutter” but I may just not notice any subtleties. Previously, when I used the Roku 1 XDS I was unable to get a 1080p picture at all. Now the picture is incredible. :D


If you blink you might miss it. It only happens once in the test. The white bar looks like it takes a step back, or pauses for a split second.
 
lts
Posts: 1
Joined: Wed Nov 30, 2011 10:20 pm

Re: Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Wed Nov 30, 2011 10:23 pm

Also: will it be possible to fix this with a firmware update or will new hardware be required?
 
vandergraff
Posts: 186
Joined: Fri Aug 19, 2011 11:50 am

Re: Roku 2 outputs at 60.0Hz instead of the correct 59.94Hz

Thu Dec 01, 2011 9:39 pm

I would also like to know. Does ROKU confirm this issue - and if so will it be fixed.

Thanks

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