Video playback not truly full-screen on ultra wide display, macOS Sonoma

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Video playback not truly full-screen on ultra wide display, macOS Sonoma

Hello,

I have a LG 29WK600-W ultrawide monitor connected to my Macbook Pro 14" 2021 Sonoma 14.1 thru HDMI. Almost 100% of the times, the monitor displays image using 100% of the screen size. But when I play a ultrawide resolution video (21:9) in full screen mode, it displays black bars on all sides (including top/bottom), instead of filling the whole screen.

Don't think this is related to one or another software, as I already tried different browsers (like Opera, Chrome and Safari), different websites (YouTube, Facebook) and even Apple built-in apps like App TV+, but all of them has the same issue when entering full screen mode.

PS: No black bars appears in top/bottom when displaying a wide (16:9) video. The problem only happens on ultrawide.

Can someone help?

Thanks!

[Re-Titled by Moderator]

MacBook Pro 14″, macOS 14.1

Posted on Oct 31, 2023 10:26 AM

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Answer 1

Top-ranking reply

MKlys

Level 1

5 points

Jun 1, 2024 12:55 PM in response to murilofb

Same problem here. Can someone help us?

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Answer 2

Jun 3, 2024 04:36 PM in response to murilofb

there is not enough bandwidth to support fill screen at 10 bits/color. 8 bits color is already billions of unique colors, more than enough for full-motion video.

Choose one or the other.

The other issue with full motion Video being Streamed, is that the data stream is strongly compressed. It must be uncompressed to a "regular' size easily, but if it then needs to be Scaled to fit the full screen, that takes more compute power and more TIME per frame than may be available.

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Answer 3

murilofb Author

Level 1

4 points

Jun 3, 2024 01:57 PM in response to Grant Bennet-Alder

Thanks for the answer!

I tested and my monitor allows up 75Hz refresh rate on the color mode I'm using. I switched between 75, 60 and 50Hz and all of those have the same problem. Also, as you can see in the image bellow, is not the entire screen that was cut, it was only the video, all the rest of the content is still full screen.

It makes no sense at all :(

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Answer 4

Jun 1, 2024 07:10 PM in response to murilofb

that appears to be a 2560 by 1080 display capable of 10-Bit color

Interfaces:

HDMI

Yes x 2

DisplayPort

Yes (ver. 1.4)

MacBook Pro 14-in 2021 features HDMI 2.0 which supports 2560 (by 1440) at up to 144 Hz refresh rate.

However, if you have selected 10-bit/pixel color, the highest that can be supported is 50 Hz, without compromising something, such as showing black bars or dropping the number of colors actually in the picture.

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Answer 5

murilofb Author

Level 1

4 points

Jun 7, 2024 04:30 PM in response to Grant Bennet-Alder

I tried multiple things. Changing refresh rate, changing color schema, HDMI cable, etc. nothing works. Hardly think it is a processing problem. Specially because it happens with 2160p, 1080p and 720p videos exactly the same way. Also, M1 pro is an extremely powerful processor, it shouldn't have problems to display full ultra wide screen, just like it has no problems on displaying full wide screen.

If you still consider this is the problem, please describe exactly what I need to do to make it work.

Thanks again!

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Video playback not truly full-screen on ultra wide display, macOS Sonoma

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