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2018-01-20, 02:45
(This post was last modified: 2018-01-20, 02:48 by narenh.)
To clarify a few points: if Atmos is decoded anywhere but a soundbar/receiver, you are left with only the 7.1 core (no object metadata). Therefore, you want Atmos tracks to be bitstreamed (also known as passthrough) from the Shield to your receiver or soundbar. Kodi on the Shield does this flawlessly as long as you set your Kodi audio preferences to bitstream TrueHD tracks.
HDMI-ARC isn't exactly limited to six channels. When you're bitstreaming audio, the only thing that matters is bandwidth. HDMI-ARC doesn't have the bandwidth to bitstream TrueHD or uncompressed 7.1, but you CAN bitstream Dolby Digital Plus (eAC3), which is a supported format for Atmos. This is how internal streaming apps pass Atmos to your sound system—by using a lossy format with object metadata.
If you have Atmos tracks in MKV files, it's a near-certainty they're encoded in TrueHD; therefore, as long as you connect the Shield to your receiver/soundbar and then that to the TV you should have no problems! I can personally verify that I had Atmos working on my Shield before I got rid of it for a better device.
HDR is a whole other can of worms on the Shield, since the Shield does not automatically switch between color spaces (Rec.709 for SDR, BT.2020 for HDR) and Nvidia implemented an incorrect algorithm to map Rec.709 colors into BT.2020. So make sure you manually change the color space on the Shield before playing SDR or HDR content.
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You should have TrueHD checked in Kodi.
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I use a MINIX U9-H running LibreELEC instead of the Shield now. The GUI isn't as snappy as the Shield but all content plays back perfectly.
Re: Shield's color space issue, the answer is yes and no (but mostly no). Here's the problem: Android apps still can't *switch* color spaces on-the-fly. But very few, if any, TVs can actually display the full BT.2020 color space. So when you set the Shield to BT.2020, it (correctly) tone maps the output to what your TV can display. This is all well and good for HDR videos, but the tone-mapping compresses the range of all values in the color space (presumably not linearly but still) including those in the Rec.709 space. Therefore, the Shield is outputting wide color tone-mapped to your TVs capabilities when it doesn't really have to—your TV can absolutely display all of Rec.709 completely unadjusted. Nvidia seems to have improved their tone-mapping algorithm to improve this somewhat, but no matter how much it's improved, there are no APIs to tell the system if the content is 709 or 2020, meaning 709 content will always be needlessly tone-mapped.
LibreELEC gets around this by actually changing the video output when you start/end playback. 709/SDR content isn't tone-mapped at all, and 2020/HDR content is tone-mapped at the hardware level to match your display's capabilities.
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hi, hope u are still following this post; i have several 4k movies in mkv with dolby atmos / dts X, but my sony android oled tv not sending atmos sound to my amplifier. i was planning to purchase the Nvidia Shield, i see that u are using MINIX U9-H, can you please confirm if its better than nvidia for the image quality and also to have my amplifier detect the dolby atmos / dts x sound?
Thanks
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Thanks Bhooshan, that is helpful to know - Does LibreELEC run under the latest version of Android TV ?