I have been experimenting with different resolutions on the Aura outputing to my LG 4K TV. When I press the S/AD button on remote twice I get the Audio/Video Options pop up and in video resolution I get a little number 1 or 2 in a grey box with alternative resolution. When I press 2 I get 1080p 50hz after a short black screen; and I think it looks a bit sharper. Is that because It’s not being upscaled to 4K making it slightly softer?
My Humax Forum » Freeview HD » Aura UHD
4K or 1080p Which looks best on 4K TV?
(3 posts)-
| Mon 5 Jul 2021 13:45:30 #1 |
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Paul Bton - 3 mins ago »
I have been experimenting with different resolutions on the Aura outputing to my LG 4K TV. When I press the S/AD button on remote twice I get the Audio/Video Options pop up and in video resolution I get a little number 1 or 2 in a grey box with alternative resolution. When I press 2 I get 1080p 50hz after a short black screen; and I think it looks a bit sharper. Is that because It’s not being upscaled to 4K making it slightly softer?All 4K TVs will scale a lower resolution input to 2160p. If it did not you would get a tiny picture.
With Aura Set to output 1080p50 box scales to 1080p and TV then scales this to 2160p. If 1080p looks best than your TV has the best scaler.
IF Aura has a 4K source and output is set to 4K50 on say iplayer UHD. Then Neither the TV or the Box will alter this. IF iplayer 4K HLG HDR content looks wrong with bright green grass your TV has the wrong settings. Typically left in shop mode Vivid.
| Mon 5 Jul 2021 13:55:10 #2 | -
grahamlthompson - 7 hours ago »
Paul Bton - 3 mins ago »
I have been experimenting with different resolutions on the Aura outputing to my LG 4K TV. When I press the S/AD button on remote twice I get the Audio/Video Options pop up and in video resolution I get a little number 1 or 2 in a grey box with alternative resolution. When I press 2 I get 1080p 50hz after a short black screen; and I think it looks a bit sharper. Is that because It’s not being upscaled to 4K making it slightly softer?All 4K TVs will scale a lower resolution input to 2160p. If it did not you would get a tiny picture.
With Aura Set to output 1080p50 box scales to 1080p and TV then scales this to 2160p. If 1080p looks best than your TV has the best scaler.
IF Aura has a 4K source and output is set to 4K50 on say iplayer UHD. Then Neither the TV or the Box will alter this. IF iplayer 4K HLG HDR content looks wrong with bright green grass your TV has the wrong settings. Typically left in shop mode Vivid.Simple primer how digital and especially how 4K TV works which may help. Using a 8 bit screen as an example as the maths are simpler.
The display screen has a matrix of oled pixels with each one having 3 subpixels.
The 3 subpixels make up a square pixel so each is rectangular and are Red Green and Blue.
Each of these is connected by a transistor to a field store with a storage to a identical field store refreshed by the live TV feed.
Taking a 50HZ 4K progressive source. Every 1/50 second the storage has a full screen. The switching transistor transfer this image near instantly to the screen.
Thanks to our eyes you a get moving video image at 50fps.
The number of possible color variations is down to possible variations within the 8 bit limit for each of the primary colours. Red Green and Blue.
8 bits gives you 256 variations from 0 (black) to 256 Red, 256 Green and 256 red.
So 256(red) x 256(green) x 256 (blue). So 6,777,216 colours.
So sadly way beyond the capabilty to transmit this amount of data.
Enter lossy mpeg data compression. HD TV uses an advanced Codec Known as H64/AVC. 4K and even more advance version H265/EHVC.
Both rely on losing lots of video data. Basically you transmit one full frame in a packet known as a group of pictures (Gop). The full frame is labelled as a Iframe. The others just contain what has changed from the iframe allowing the mpeg decoder in the decoding device to recreate the original stream.
SD channels use a inferior DVB-T modulation. HD ones a improved DVB-T2 system
The higher the bitstream frequency the less video info is lost. The more advanced the codec the result is superior.
Both use a analogue carrier to transmit the data so only the modulation is digital.
Hence no such thing as a digital aerial.
| Mon 5 Jul 2021 22:06:18 #3 |
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