Roku Developer Program

[EnTerr]

"kmayur" wrote:
I am not using "roScreen" in my application and I am not using any openGL APIs. I am not controlling rendering as well. So, I don't know how V-sync is getting affected. Is there any settings for choosing V-sync mode?

"It doesn't matter" 🙂 I mean Vsync-ing is a very low level thing in producing video signal (below roScreen, OGL, video decoding). It's not configurable. And if it's that and there were a way to disable the "adaptive" mode of Vsync - mind you that would be worse overall because it will decrease effective FPS.

"EnTerr" wrote:
Can you provide the Co a URL to a sample video that causes the effect?

This issue is reproducible with any 4K@60fps stream.

I understand the annoyance when asked to provide sample for something "obvious" but it may help your case. Metaphorically, you know how "class lawsuits" cover everyone from a group? Well they still need a few real humans as "representatives" in the court proceedings, to represent the plaintiff class. The picture you showed is a simulated("fake") image from wikipedia, not the real effect - it would be good if there is something tangible for a Co' person to look at.

Also, I am more interested about the "GetVideoMode" output. Why it is detecting the HDMI as 30fps? I think that is the root cause of the issue.

That is a good question, though that by itself would not cause tearing.

[kmayur]

Hi @EnTerr,

EnTerr:
"It doesn't matter" [img=15x15]https://forums.roku.com/images/smilies/icon_smile.gif[/img] I mean Vsync-ing is a very low level thing in producing video signal (below roScreen, OGL, video decoding). It's not configurable. And if it's that and there were a way to disable the "adaptive" mode of Vsync - mind you that would be worse overall because it will decrease effective FPS.

As per my understanding, Adaptive V-sync will be turned ON if the stream has variable frame rate. But my streams have fixed 60fps frame rate, so I don't think it is turned ON. However, as you mentioned it is not configurable and hence I don't think that is the issue I am facing.

"EnTerr" wrote:
I understand the annoyance when asked to provide sample for something "obvious" but it may help your case. Metaphorically, you know how "class lawsuits" cover everyone from a group? Well they still need a few real humans as "representatives" in the court proceedings, to represent the plaintiff class. The picture you showed is a simulated("fake") image from wikipedia, not the real effect - it would be good if there is something tangible for a Co' person to look at.

I am using some customer's stream stream for testing. I have checked with them and I am not able to share them with you. According to me, the issues are reproducible with any 4K@60fps stream.

"EnTerr" wrote:
That is a good question, though that by itself would not cause tearing.

 I think this is the issue because display is configured for 30fps and rendering is at 60fps. Decoder might be writing to a buffer when the buffer is being used by the display. 

[kmayur]

"kmayur" wrote:

"RokuMarkn" wrote:
What do you have selected under Settings > Display Type?

--Mark

Thank you, @Mark 🙂 . We have tested with both 4K-8bit and 4K-10bit options under Settings > Display type. Please note, we are using 4K-8bit content for testing.

To give a brief note on our testing,
1) We have tested by connecting Roku to a different HDMI ports on the TV and also tested with different HDMI cables.
2) We have played the same 4K@60fps content on the same TV with a different media player device (Not Roku). It plays without any issues. So, it is not the issue with the HDMI port or HDMI cable.
3) We have also tried rebooting Roku while TV is switched ON.

Please let me know if you think any other tests to be done.

Hi @Mark,
Any update on this issue?
As I mentioned, I expected "GetVideoMode" would return "2160p60" for 8-bit and "2160p60b10" for 10-bit display type selection. I am not sure what is going wrong here. Also please let me know if you need any other information.

[RokuJoel]

After chatting with @RokuMarkN I've filed a bug with the media team on your issue, linking to this thread.

 - Joel

[kmayur]

"RokuJoel" wrote:
After chatting with @RokuMarkN I've filed a bug with the media team on your issue, linking to this thread.

 - Joel

Thank you, RokuJoel[/url:2lv0k0ki].

Regards,
Mayur

[kmayur]

Hi @RokuJoel, I just wanted to know if there is any update from your side on this issue. Is Roku media team able to reproduce the issue? Is it a bug in the the system or some configuration issue in my application? Please let me know if you need any information from my side.

Regards,
Mayur

[kmayur]

Hi @RokuJoel, Please let me know if there any updates. Do you think it is a bug in Roku player?

[RokuJoel]

This bug is still under investigation, and currently believed to be specific to the Roku 4 platform (i.e software bug on that hardware).

 - Joel

[kmayur]

Hi Joel,
Thanks for the update!

I have some questions. 
1) Are you able to reproduce the issue on your Roku-4 device? If that is the case, I think I can stop debugging my application.
2) Is there any workaround for this issue?

Regards,
Mayur

[kmayur]

Joel,
Are there any updates?

Regards,
Mayur