IssueTracker

Could you please provide additional detail on which TV make and model, and what specific content you have the issue with.

TV set is a 2012 model Samsung UE40D8005YUXXE. And the content is all that
are available on-demand from the national norwegian broadcaster NRK.
All material are 25/50 FPS as is common in Europe.

Both my Chromecast and my MythTV box are powered continiously.
When the TV set is switched on, I have to set the MythTV HDMI framerate to
50Hz manually - every time. I believe that the TV set initializes the HDMI
framerate to 60 Hz at power on.

If you need a tester, I will gladly cooperate with you.
 9. sep. 2014 22:17 skrev <google-cast-sdk@googlecode.com> følgende:

Thanks for the details.
Could please confirm what you have set for the following settings on your TV:
Film Mode (Menu->Picture->Picture Options)
Motion Plus (Menu->Picture->Picture Options)

Also,  could please reboot your Chromecast device, then after 1 min, start the Chromecast app on your mobile device, select your Chromecast device from the list of devices and then use the menu option to submit a feedback report. Please prefix the report feedback title with "Issue 374:" so that we can find it.

Settings are (and have been) as requested and feedback is returned.
Settings have no effect on judder. Judder is most visible when panning.I should wish there were an option to set HDMI framerate in Chromecast.

We got your feedback, but the chromecast device logs is missing. Please make sure that the 'Send device logs' checkbox is checked in the Chromecast app for you device and please resend the feedback with the same title.

This is caused by the fact that Chromecast plays 25fps/50fps content at 60Hz output video refresh rate (as is evident by the fact that the reporter has the same juddered behavior when he plays 25/50 content on his other devices using 60Hz video mode).

Since 25 is not an exact multiple of 60, the frames are played out at an uneven rate:
2-2-3-2-3-2-2-3-2-3
(each number represents an incoming 25p input video content frame and the value is the amount of HDMI output frames that contain the input frame)
For 50p content played back at the Chromecast 60Hz video mode:
1-1-1-1-2-1-1-1-1-2
So every fifth frame is duplicated, while the rest of the frames play too fast, causing a judder effect.

However, my experience is that only about 5-30% of people actually notice such judder (and many of those don't care). This has still come up many times in the Chromecast Help Forums, for example, however.
The judder is especially noticiable in panning shots and sports content.


Similar issue happens with most movie and North American TV series content as well. Both of those are 24p (or 23.976p), and thus playing them back on a 60hz video mode causes the following frame cadence:
2-3-2-3-2-3-2-3-2-3

This is much less noticiable than the 50p/25p issues since the "pattern" is short, but still an issue (you can google for "chromecast 24p" to find people suffering from this).


To fix this, Chromecast should automatically (or add an API to allow the application "manually" to) switch the HDMI video mode to 50Hz output (e.g. CEA-861 VIC 31) for 25/50fps content and 24Hz/23.976Hz (VIC 32) for 24/23.976fps content. Doing this automatically is the behavior of e.g. Samsung blu-ray players (and others) when using Netflix, when playing e.g. British TV content the video mode switches to 50Hz and when playing back movies it goes to 24Hz (as can be seen in the TV UI as video mode), instead of being fixed to 60Hz like on Chromecast.


I'm also experiencing this issue with all of the TV content here in Finland (which is 25p or in some cases 50p). I've tried on LG 55LH5000, LG 42LH2000 (with all motion interpolation related settings off) and on some other models, but this should affect all TV models. I can provide more info if needed.

Please reboot your Chromecast device, then after 1 min, start the Chromecast app on your mobile device and select your Chromecast device from the list of devices. Make sure that the 'Send device logs' checkbox is checked in the Chromecast app for your device, then use the menu option to submit a feedback report. Please prefix the report feedback title with "Issue 374:" so that we can find it.

OK, done.

Hi from Germany,

I an experiencing the same issue with any other TV I have used so far, because chromecast won't switch to 50Hz and all video material in Europe is 50Hz.

MT

Same problem for me. Chromecast is always running in 60Hz causing judder for 50Hz content.
/Andreas

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Same issue here in sweden. Looking on sport gets me dizzy and a bit headache. Chromecast is connected to applicera Yamaha and tv Panasonic. Same issue if i connect direct to tv

Same problem here. I even tried to run Chromecast through the HDMI in on my Xbox One console and forcing 50 Hz output. Yet the judder persisted.

All tv carriers and many content provideres in Europe broadcast in 50 Hz. Thus it's imperative that a viable solution is found.

BR,
Anders

Same issue here (Denmark). Chromecast is basically useless for 25/50Hz and for 24Hz.

I have returned it for a refund.

I didn't notice this behaviour until this evening when I was watching supposedly smooth output from YouTube. The juddering effect on my UK TV (almost the same Samsung model D8000 as above, with Game Mode enabled) is very distracting!

I very much hope this is not a case where 'you get what you pay for' :(

Will this be fixed? Or is that impossible due to hardware limitations? That would be really sad...

Same here. 24p content looks really ugly on Chromecast.

Armchair developer speaking here:

The framerate is a meta-information that comes with the video stream. The Chromecast  firmware should be able to parse this information and then switch the video mode's framerate.

The stick's hardware is probably able to do this (these days it's tough to find SoC video hardware that can't switch to 24/25/50/60 framerates), so it's more a driver/firmware issue.

Please add this feature. Thx.