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noggin14,378 posts since 26 Jun 2001
AppleTV+ will support 4K HDR playback with HDR10 and Dolby Vision & Dolby Atmos sound.


So same as Amazon Prime and Netflix then. Anything less than HDR10 and/or Dolby Vision, and anything less than Dolby Atmos sound, would leave Apple TV+ as 'second rate' in comparison.

Bit like SkyQ all nice looking but lacks HDR, HLG


Yep - tvOS has framework support for all the three main flavours of HDR out in the wild : HDR10, Dolby Vision and HLG.

I'm not aware of any UK Apple TV app that uses HLG at the moment. (I think there is limited MPEG-DASH support in tvOS - which may be why iPlayer doesn't support UHD HLG iPlayer?)
Last edited by noggin on 5 June 2019 1:31pm
UKnews830 posts since 26 Apr 2011
Amazon are streaming the Queens Tennis in p50 - at least via AppleTV. Looks far far better.

Bit rate could do with being higher as there’s some blocking / lack of detail- for instance on the net when the camera moves, but it’s a vast improvement on the p25 that was offered before.
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noggin14,378 posts since 26 Jun 2001
Yes - Apple TV 4K Developer HUD shows 1920x1080 at 50Hz (i.e. 1080p50) with an average bitrate of around 11.4Mbs AVC (aka h.264) video and 128k AAC audio watching a replay. I guess it's deinterlaced from a 1080i25 feed. It's pretty much as good as watching a regular 1080i DVB linear channel (minus the 5.1 sound on some sport outlets) There are some compression artefacts - but they are relatively minor unless it ramps down to 1280x720 or 960x540.

Huge improvement over the p25 stuff that they used to use, and puts it massively ahead of NowTV. Fingers crossed this is the 'new normal' for Amazon sport coverage.
Last edited by noggin on 23 June 2019 11:20pm
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noggin14,378 posts since 26 Jun 2001
1080p50 is very good indeed why isn’t broadcast tv 1080p50? I mean why is it 1080i25?


The 1080p50 being provided OTT by Amazon Prime is almost certainly a deinterlace from 1080i25 (which has the same motion as p50)

Broadcast outlets aimed at TVs use 1080i because TV has been interlaced since 1936 (the original 405line standard was 377i25) and either display it native interlaced (CRTs and early ALiS Plasmas) or deinterlace from i25 to p50.

Computers, tablets and phones don't always have decent deinterlacing built in (and it takes processing power to do it) so for OTT platforms a progressive format is always preferred. Until recently (iPlayer was the first UK platform to switch from p25 to p50 a couple of years ago) all OTT was p25. This is fine for drama and documentary (which is shot progressive at 25Hz), but terrible for sport and entertainment that is shot at 50Hz.

1080p50 is do-able as a native origination format - but is relatively rare - as there are no major linear broadcast outlets that take it. If an event is being shot primarily for streaming it can be shot 1080p50 (most modern cameras and infrastructure supports the 3G-SDI required for 1080p50 and 1080p59.94)

In Germany and the Netherlands their DVB-T2 platforms are using 1080p50 HEVC/h.265 encoded - but I believe a lot of this is 1080i25 deinterlaced to 1080p50. (HEVC isn't optimised for interlaced content in the same way that h.264 is)

To be honest - the quality difference between 1080i25 deinterlaced well and native 1080p50 is quite small - HDR and UHD make more of an impact (HDR particularly)

The key thing to always remember is that 1080i25 isn't 25 pictures per second. It's 50 - the same number of pictures per second as 1080p50. This is why 1080i25 and 1080p50 have the same fluid motion. The difference is that 1080p50 native has full vertical resolution irrespective of content (as it sends 50 1080 line pictures each second), whereas 1080i25 has reduced vertical motion on moving content, with only static content having the higher vertical resolution (as it sends 50 540 line pictures each second, but the two pairs of 540 line pictures that make up a frame are offset vertically with respect to each other). Motion blur on moving content is entirely normal - so people don't perceive it as a major quality issue. LOTS of people think 1080i25 has the same motion as 1080p25 because it has the same frame rate - ignoring what interlace is and how it works .
Last edited by noggin on 24 June 2019 4:24pm
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DVB Cornwall8,335 posts since 4 Dec 2003
Westcountry Spotlight
Comparing the same match on Prime Video and on the OTT Tennis TV service feed from Eastbourne, yes the AZPV feed has improved. but still for fluid movement the OTT service wins significantly, (Both on Apple TV 4K). Can someone confirm the transmission parameters on the AZPV Eastbourne coverage are identical to those used yesterday from Queens?
noggin14,378 posts since 26 Jun 2001
Eastbourne is obviously 1080p25 on my Apple TV 4K (and reported as such by the Developer HUD) and is also 1080p25 on my nVidia Shield TV. Neither device is running at the 1080p50 I was seeing for Queens on my Apple TV 4K.

My guess is it depends how the Amazon streams are originated, and by whom.
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