Roku Developer Program

[EnTerr]

Nigh hijacked the "image easing" thread with peripheral issue, so trying to pull it separate:

"TheEndless" wrote:

"EnTerr" wrote:

"TheEndless" wrote:
The output refresh rate is always 60Hz (in the US), regardless of how long it takes you to draw a single roScreen frame.

How do you know that? You say it with conviction, is there a spec (radical idea) i can find? My censored Sony TV shows resolution but not Hz.

Primarily because the video framerate isn't affected when drawing overlays to the roScreen. If you break into the debugger, for instance, video continues to play, while the last frame of your roScreen is also displayed. But also because the monitor I use for development does display the refresh rate, and it's always 60Hz, with or without video playing, even for the SD resolutions.

I'd have sworn they listed that online in the detailed specs on the comparison chart at one time, but I can't find it now.

Drawing overlays has no reason to affect refresh rate, SwapBuffers() only changes (conceptually) the pointer that video output generator uses at its own pace (be it 24, 50, 60Hz). Shan't doubt the monitor though. Frequency does not change if playing one of the "Example Short 23.976 fps" clips on Netflix either?

It seams likely Roku player always outputs at 60Hz. RokuCo probably forgot the spec info when re-designing the http://www.roku.com/products/compare page with big checkboxes + small fonts, though conspiracy theorists can go with "trying to hide lack of native support for 1080p24 BD video and 50fps UK/EU content". Now I see AppleTV supports both 50Hz and 60Hz - and Chromecast dongle seems to be 60Hz only - but can't find streamers doing native 24fps.

That would mean for 24fps video player pulls a 3:2 pull-down by making up every 5th frame as "dirty" (by combining two neighbors, A A (A+B) B B) - or maybe just by showing movie frames in AAABB pattern. 24/60=2/5, so pattern is ends up synced after every 2nd input and 5th output frame. There would be "judder", wonder if noticeable.

[TheEndless]

"EnTerr" wrote:
Drawing overlays has no reason to affect refresh rate, SwapBuffers() only changes (conceptually) the pointer that video output generator uses at its own pace (be it 24, 50, 60Hz).

I know. That was my point when I said they were independent of each other... 😉

"EnTerr" wrote:
Shan't doubt the monitor though. Frequency does not change if playing one of the "Example Short 23.976 fps" clips on Netflix either?

Nope, never changes.

"EnTerr" wrote:
It seams likely Roku player always outputs at 60Hz. RokuCo probably forgot the spec info when re-designing the http://www.roku.com/products/compare page with big checkboxes + small fonts, though conspiracy theorists can go with "trying to hide lack of native support for 1080p24 BD video and 50fps UK/EU content". Now I see AppleTV supports both 50Hz and 60Hz - and Chromecast dongle seems to be 60Hz only - but can't find streamers doing native 24fps.

Per Joel in the other thread, he said he believes it outputs at 50Hz in the UK. Not sure if that was definitive or not.

If I'm not mistaken, I believe the MHL version of the streaming stick supports 1080p24 (sources: http://en.wikipedia.org/wiki/Roku_Streaming_Player and http://www.missingremote.com/news/2012- ... d-app-upda).

[EnTerr]

"TheEndless" wrote:
Per Joel in the other thread, he said he believes it outputs at 50Hz in the UK. Not sure if that was definitive or not.

He said "probably", no problem with an honest guess.
But if i google NowTV and 50Hz, things come up:

"James Pullicino, Programme Manager at BSkyB" wrote:
The NOW TV Box is based on the Roku device, which is an American product that outputs in NTSC which is 60Hz. In the UK, we use the PAL standard which outputs at 50 Hz. This difference is negligible, especially when watching on more modern TVs over an HDMI connection.

"NowTV users" wrote:

The NowTV box only outputs at 60Hz, meaning anything intended for UK broadcast (eg. NowTV, Sky News, BBC iPlayer and Demand 5 - ie. everything the box comes pre-installed with) does not play back smoothly.
[...] converting 50Hz to display at 60Hz will invariably result in some loss of quality... does! Duplicating frames to get up to the 60Hz results in a 10Hz or 5Hz judder on smooth motion from 50Hz/25Hz source material. I do see exactly this kind of judder on sources like iPlayer - I'm using a PC monitor with the box without any additional processing.

"RaspberryPi forum post" wrote:
It uses the same CPU/GPU as the RPi but the firmware only supports 60Hz field rate. That has two potential drawbacks. [...]
2. Even if your TV is OK with 60 Hz video, much of the content from the NOW TV box was shot at 50 Hz. Motion, especially panning shots and scrolling credits, is not smooth.

So theoretically maybe NowTV can run on 50Hz - but it doesn't. And probably won't, if i am guessing right that BSkyB is already doing server-side the 50-to-60Hz pull-down. Also if you have written a channel doing 30fps (or 60fps) animation and player outputs at 50Hz, that may give some eery strobe effects.

"TheEndless" wrote:
If I'm not mistaken, I believe the MHL version of the streaming stick supports 1080p24 (sources: http://en.wikipedia.org/wiki/Roku_Streaming_Player and http://www.missingremote.com/news/2012- ... d-app-upda).

Depends what you call "support". I said "native support", which would be if player pushes out video over HDMI at 24Hz. Can it decode 1080p24 file - sure. Can it output that video as 1080p24 over HDMI - nobody ever said it can (incl. the two links).

[EnTerr]

Can i get answer from Roku*, please?
The question is well summarized in the thread subject, rest is discussion.