No way to set HDMI framerate to 50Hz causes judder

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What steps will reproduce the problem?
1.Playing any 25/50FPS footage which is normal in Europe.
2.
3.

What is the expected output? What do you see instead?
Dropping frames causing video stuttering, audio is OK.

What version of the product are you using? On what operating system?
Latest Chromecast image.

Please provide any additional information below.
The same stuttering can be observed when the HDMI input MythTV is connected to 
is set to 60Hz. But MythTV is a Linux app and the framerate can be set to 50Hz 
which eliminates the problem. 

Original issue reported on code.google.com by per...@gmail.com on 9 Sep 2014 at 12:35

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

Original comment by lnicho...@google.com on 9 Sep 2014 at 8:17

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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:

Original comment by per...@gmail.com on 10 Sep 2014 at 5:50

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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.

Original comment by lnicho...@google.com on 10 Sep 2014 at 8:32

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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.

Original comment by per...@gmail.com on 11 Sep 2014 at 1:02

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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.

Original comment by lnicho...@google.com on 11 Sep 2014 at 4:35

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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.

Original comment by anssi.hannula@gmail.com on 20 Sep 2014 at 11:38

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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.

Original comment by lnicho...@google.com on 20 Sep 2014 at 11:48

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OK, done.

Original comment by anssi.hannula@gmail.com on 21 Sep 2014 at 12:03

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Original comment by and...@google.com on 25 Sep 2014 at 11:13

• Changed state: Acknowledged

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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

Original comment by IrishFol...@googlemail.com on 1 Oct 2014 at 12:50

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

Original comment by Andreas....@gmail.com on 4 Oct 2014 at 8:18

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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 

Original comment by Eddie.ca...@gmail.com on 5 Oct 2014 at 1:37

Attachments:

• IMG_20141005_153419.jpg

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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

Original comment by aalb1...@gmail.com on 7 Oct 2014 at 8:54

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

I have returned it for a refund.

Original comment by palle....@gmail.com on 7 Oct 2014 at 10:14

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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' :(

Original comment by g...@acentral.co.uk on 11 Oct 2014 at 11:20

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

Original comment by vanrooy...@gmail.com on 17 Oct 2014 at 9:15

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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.

Original comment by zulla.ha...@gmail.com on 20 Oct 2014 at 11:38

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It would be really nice to see this issue solved in the next FW version.
Regards

Original comment by bebo...@gmail.com on 22 Oct 2014 at 9:01

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I am starting to wonder whether this is hardware limitation. This issue has 
been know for a while and there has been no statement from Chromecast team 
whatsoever. It has been discussed several times on user product forum: 
https://productforums.google.com/forum/#!forum/chromecast with no particular 
outcome.

Original comment by ondrejpe...@gmail.com on 23 Oct 2014 at 1:55

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Just guessing:

I doubt it's a hardware limitation, but it could be a usability "feature" in 
favour of KISS.

There are TVs that do not support 24p. By using 60p only, the Chromecast never 
shows a black screen to users who own a TV like that.

Original comment by zulla.ha...@gmail.com on 24 Oct 2014 at 8:28

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This is a feature that has existed in DVD, mediaplayers and set top boxes for 
ages. Even the chinese Android TV sticks can change refresh rates. That Google 
could not get it to work would be astonishing. All HDMI tv sets report which 
resolutions they are capable of. All signs point to laziness from Goggles side.
As mentioned, all European movies, tv shows and especially sport which contain 
camera panning or moving objects are a pain to watch due to stuttering. Until 
this is fixed I could never recommend this product.

Original comment by tmarkl...@gmail.com on 2 Nov 2014 at 10:24

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Same issue confirmed by me watching svtplay (sweden) I bought this device in 
USA and though it might be a different version of the cromecast HW. Seams not 
to be the case. Until this is solved the device has limited usage in my home.

Original comment by leif.eng...@telia.com on 4 Nov 2014 at 11:16

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Same Issue with my TV (LG 42LM620S) when streaming YouTube or from the Plex 
Media-Server.

Original comment by andre.he...@gmail.com on 12 Nov 2014 at 9:16

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Same problem here in Germany with my Sony KDL 46NX715, for example when 
streaming from Plex - movies are not watchable. Don't use the chromecast any 
more until this issue is fixed.....

Original comment by Tobias.N...@gmail.com on 12 Nov 2014 at 9:53

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Samsung UE55ES7090 

Chromecast ruckelt bei Kameraschwenks... (ansonsten ruckelt der TV nicht !)

Original comment by andron.f...@gmail.com on 12 Nov 2014 at 10:23

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Same issue for me (Germany).
Brought back to the shop after 10 minutes of usage.
Could not believe it.
My prediction: It will NOT be fixed.

Original comment by jochen.f...@gmail.com on 12 Nov 2014 at 10:32

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I think the best way to raise the awareness at Google is to use the feedback, 
like described in reply #7. If Google would get like a million feedbacks 
concerning this issue 374, I'm sure it would get better attention.

Original comment by twuimo...@gmail.com on 15 Nov 2014 at 12:14

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This issue is the reason why I will not buy Chromecast or recommend it to 
anyone. Smooth framerate, and matching of hdmi frequency to video content is a 
must have for a video player. 

Original comment by mikaelva...@gmail.com on 16 Nov 2014 at 10:28

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Same problem - chromecast and android hdmi output does not switch to the 50p or 
24p Video framerate and this produces extreme stuttering. This needs to get 
fixed!

Original comment by mjmeierh...@gmail.com on 16 Nov 2014 at 11:19

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http://www.minixforum.com/threads/autoframerate-detection-switching-output-hd-au
dio-passthrough-licenses.158/
...for more info

Original comment by mjmeierh...@gmail.com on 16 Nov 2014 at 11:27

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We appreciate everybody's input on this issue. Our engineers have spent some 
time investigating the issue and have worked with our hardware partners to 
consider various solutions. Our conclusion is that the TV is in the best 
position to handle HDMI refresh rates. Chromecast cannot attempt to handle 
changes in HDMI refresh rates since it is very hard to accurately identify the 
incoming frame rate. Also, every time there is a HDMI mode change, it usually 
leads to flashing or loss of picture for a few seconds. Blu-ray players can 
handle this issue because discs have extra metadata that would allow players to 
output at the most suitable rate. This is very hard to pull off with streaming 
content.

Original comment by lnicho...@google.com on 26 Nov 2014 at 3:16

• Changed state: WontFix

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Then why are you not providing a MANUAL setting through Chromecast app, or are 
we forced to buy an AppleTV, which actually works in 50hz?

Original comment by tmarkl...@gmail.com on 26 Nov 2014 at 6:39

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unbelievable....

Original comment by Tobias.N...@gmail.com on 26 Nov 2014 at 7:07

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@lnicho:  That's a joke, isn't it?  **head shake**

Original comment by andre.he...@gmail.com on 26 Nov 2014 at 7:08

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How can Inicho... say that the TV is in the best position to handle HDMI 
refresh rate when the Chromecast is only outputting 60hz??? 

Come on, please provide at MANUAL setting then in the app if you cant fix it 
other wise. We need this baaaadly in Europe.

Original comment by Gerst...@gmail.com on 26 Nov 2014 at 8:23

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They won't read any new comment, I think. This issues status is "closed", so 
they will ignore this thread from this moment.
They will never fix this issue (or rather offer an manual setting) as the US 
are the center point of the Universe, and they are not interested in problems 
around them.

Original comment by andre.he...@gmail.com on 26 Nov 2014 at 8:31

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The refresh rate really only needs to be changed when playback is started,
at the point the app will know what refers rate is required. The app needs
a way to tell the Chromecast what to do. The Chromecast doesn't need to
figure out anything.

Plenty of networked media players do this automatically, perhaps Google
engineers could have a look at the many open-source projects that are
available?

Original comment by simbl...@gmail.com on 26 Nov 2014 at 8:32

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I expect that statement be should be enough to get a refund under consumer 
protection laws but personally I'm disappointed that Google is incapable of 
finding a solution which means I won't be looking to Google for any future 
media playback devices.

Google knows the origin of the apps, set the default refresh appropriately. For 
multinational content providers like Netflix offer a selection option which 
could be hidden in the settings menu, or just add a switch refresh rate option 
in the Chromecast app as suggested above.

I understand why Google wants friction free viewing, but for those of us who 
know what the problem is and its causes and who are bothered enough to complain 
is there really going to be no fix or workaround.

With the Chromecast references to H2G2-42 and MST3K there must be someone in 
Google smart enough to find a solution :P 

Original comment by ianjorda...@gmail.com on 26 Nov 2014 at 8:39

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Unbelievable ignorance.
Just a manual setting of the frame rate would satisfy most here.

Original comment by jochen.f...@gmail.com on 26 Nov 2014 at 8:46

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Quote : Our conclusion is that the TV is in the best position to handle
HDMI refresh rates
That is correct, our TVs are capable of handling all different refresh
rates, but the Chromecast forces all input to 60hz!!!
So please Google give us at least a workaround by means of a manual setting
or whatever.
There is more than only 60Hz in the world :(

2014-11-26 9:46 GMT+01:00 <google-cast-sdk@googlecode.com>:

Original comment by vanrooy...@gmail.com on 26 Nov 2014 at 9:02

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Approx 30 people have complained about this - how many Chromecasts have been 
sold? That, regrettably, is the reason this is a 'wontfix.'

A shame, but there you go. Perhaps the next generation of Chromecast hardware 
will address this. <shrug> 

Original comment by g...@acentral.co.uk on 26 Nov 2014 at 9:03

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This response does not make much sense.

"It is very hard to accurately identify the incoming frame rate."

Obviously, the video mode's refresh rate should only be changed when the video 
stream's meta data contain the refresh rate information. Otherwise, using a 
60Hz default should be fine.

"Also, every time there is a HDMI mode change, it usually leads to flashing or 
loss of picture for a few seconds."

Then make the ability for video mode refresh rate change an optional and 
disable it by default. (That's how my blu ray player does it, too.)

"Our conclusion is that the TV is in the best position to handle HDMI refresh 
rates."

Yes. But the Chromecast uses 60Hz, only. The TV or the user both cannot 
override that.

Original comment by zulla.ha...@gmail.com on 26 Nov 2014 at 11:19

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Simple explanation why this is "no issue" for most is basically described here: 
https://www.change.org/p/hdtv-manufacturers-please-stop-making-smooth-motion-the
-default-setting-on-all-hdtvs. As long as hardware manufacturers rely on IFC 
and similar systems, mass users will not see any difference with Chromecast 
outputting on 60hz, as any judder (including the natural "film look" of 24p) 
gets washed away by SDK. The artifacts and unpleasantness of resulting image 
goes unnoticed by most, unfortunately.

I still, however, do not see a point in not including this setting in dev mode 
or in SDK for the respective apps to instruct Chromecast (e.g. BBC to output in 
50hz etc.).

Original comment by ondrejpe...@gmail.com on 26 Nov 2014 at 11:21

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Sorry for beating the dead horse, but please search for

XBox One 50Hz

with your favourite search engine.

Microsoft's game console was affected by this problem, as well, and it resulted 
in quite a stink, see 
<http://www.theguardian.com/technology/2013/nov/26/xbox-one-juddering-plagues-uk
-tv-watchers> as an example.

The guys at Microsoft have been able to fix this with a later firmware update, 
so I wonder what's stopping the Chromecast team.

Original comment by zulla.ha...@gmail.com on 26 Nov 2014 at 7:34

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