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HEVC HDR not transcoding/downscaling with hable


Wynter

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Wynter

I have many items encoded with 4K HDR10 with a low bitrate.  I also have several TVs that are 1080p.   If I select 1080p4mbps on those sets the Roku direct streams the video and it looks faded.   I have to go all the way down to 720p2mbps for it to transcode and therefore apply the hable table to correct the colour.  It seems like it only takes the bitrate into account (4mbps isn’t low enough to trigger the transcode but is the lowest 1080p bitrate selectable) and not just that I selected 1080p which should be enough?

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Right. Presently the MaxHeight associated to the Resolution is only when transcoding. If the bitrate is high enough the resolution is not checked. You are correct. The Roku supports downscale in hardware on the Roku device itself. It can be sent resolutions larger than the display and the Roku will downscale itself to match your TV. This is why you buy a Roku. Some older Roku do not support downscale. RokuTV under 43 inches do not support downscale. Our device detection handles all that. You just press play.

To get the behavior you are after you only need to press DOWN on the Roku remote while the video is playing to open the On Screen Display. Find the Cog/Gear and click it to open Playback Settings. Inside Playback Settings is the Attempt Playback Correction button. You can press that button multiple times and it will fallback through each playback method.

You do not need to reduce bitrate and affect your playback quality. Just use the Attempt Playback Correction as many times as needed until you get the desired playback. ;)

Edited by speechles
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We need to improve this to allow a transcode to be triggered based on hdr support. Thanks.

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Brightscript Debugger> print device.getdisplayproperties()
<Component: roAssociativeArray> =
{
    DolbyVision: false
    EDID: <Component: roByteArray>
    Hdr10: true
    Hdr10Plus: false
    HdrSeamless: false
    headless: false
    height: 62
    HLG: true
    internal: false
    width: 111
}

@Luke Does the server have fields in capabilities for DV, HLG, HDRS, HDR10 and HDR10+?

Edited by speechles
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  • 4 weeks later...

I have noticed that this behavior also causes issues with android devices.  The devices will play the full HDR10 file even if the device doesn't support it (lots of delay and stuttering and washed out colours) unless you select something really low like 720p2mbps to force a transcode.

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The files are quite low bitrate HEVC with HDR10 which is probably why it needs the bitrate set so low to make it transcode and 1080p only goes down to 4mbps so I'm forced to drop to 720p2mbps.  Could this be done automatically or could there be a check box in the settings to always transcode media for HDR10?

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  • 3 weeks later...
  • 1 month later...

There is still no improvement on this issue... is it possible to have certain users have a flag that will force conversion of any HDR content regardless of resolution and bitrate so that the colour correction will take place?  Like SDR only or something similar?

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7 minutes ago, Wynter said:

There is still no improvement on this issue... is it possible to have certain users have a flag that will force conversion of any HDR content regardless of resolution and bitrate so that the colour correction will take place?  Like SDR only or something similar?

HI, yes we'll likely end up adding that sort of option. Thanks for the feedback.

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  • 1 month later...

The new beta Roku app seems to have fixed the hable conversion when a Roku is not attached to an HDR TV.  Thankfully won’t have to “attempt playback correction” twice on every play, or worry about family members that don’t understand!!  Can’t express how awesome that is..  I found one file out of many it didn’t work on, but there may be an issue with that particular file so I’ll check that first.  

  • Thanks 1
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  • 1 month later...
1 hour ago, Wynter said:

Has this been looked at yet?  In the works?

Hi, I thought you said there was improvement, no? What are you asking for at this point?

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There was an improvement but it was actually a bug that was helping the issue I had as per this thread...

What was happening since I said that was that all video was failing playback twice (a bug?) therefore causing a transcode and therefore the tone mapping to be applied.  I don't believe any logic was being applied and therefore the issue of HDR content not being converted properly for SDR devices was just accidentally happening.

 

Currently with the most recent roku beta I have to press down on the remote to get the menu, press right 2 times to get to the gear, up several times and select "attempt playback correction" and wait for the video to start again... then go through the whole thing again maybe even 2 times more to get the video to transcode and have tone mapping applied... this still happens even if I have selected 1080p4mbit from the settings menu as the default playback quality.  This is for most of my content (it doesn't actually even play 1080p when you select it).  If i select from the 720p quality then I get a super low quality playback so there is no in between...  You had discussed early in this post (last July) whether it was possible for the app to see HDR and play based on that.

 

"Presently the MaxHeight associated to the Resolution is only when transcoding. If the bitrate is high enough the resolution is not checked."

"We need to improve this to allow a transcode to be triggered based on hdr support. Thanks. "

 

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  • 4 months later...
Wynter

I went to JellyFin for over a year and came back to test this and it is still broken.  Small HDR files (below 4mbps) when played on a 1080p SDR TV with a Roku still don't trigger the video to be converted with tone mapping it just passes them through.  I think I first posted about this starting May 2021 and was told you're working on it and it would be done soon...

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Hi.  We still need to implement a mechanism for the apps to tell the server that tone-mapping is needed.  That will be coming.

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  • 2 weeks later...

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