Problems with colour spaces on UHD Ripper

peejay1977

Hi all,

First off, I just want to assure people the 4K HDR10 rips I am referring to in this post are ones I have the original discs for and will be keeping safe under the bed with the rest of my collection.

I currently use Plex to stream to a Samsung UE43K7500 Smart TV which works perfectly. The Plex app for the telly support HDR10 and I can confirm that a full quality rip of Star Trek Beyond (for instance) direct plays to the TV with no visual issues whatsoever.

If I try to compress the file however I am having some issues. I am a long time video encoding nut so I have not encountered issues until now, and I suspect it is due to the BT2020 colour parameters of the original video file.

If I use DVDFab for instance to compress the file, it has a specific profile for HEVC 10bit 4K which compresses the file down just fine. However on playback the colours are dull and washed out. Same thing if I use Staxrip to compress the file.

In both instances the output file definitely is HEVC with 10bit colour and BT2020 colour parameters but using Mediainfo to compare, some of the parameters that are listed for the original file are absent from the converted one.

I have tried to force Staxrip to choose the correct BT2020 profile options but it doesn't seem to be writing them all into the file.

Has anyone encountered this issue?

Thanks

Paul.

peejay1977

It's the MKV profile that is broken in the DVDFab Ripper, if you use M2TS the correct colour space info is retained but not when using the MKV profile. This needs to be fixed :)

Mona

Hello,

Please post DVDFab internal log file, thank you.

Regards,
mona

peejay1977

Hello,

Please post DVDFab internal log file, thank you.

Regards,
mona
Mona

Hi there, apologies for the delay in replying to this. I have managed to fix the colour space issue, it seems once I switched to the M2TS profile and then back to MKV that side of it now works fine. However, although the colour of the video is perfect, there are visual artefacts that appear randomly on the screen once encoded. This occurs on playback no matter what device I use for playback (all are capable of HDR10 support). The artefacts don't appear if I use MKV passthrough to save the movie in full quality. As well as the artefacts I get the brightness of the picture changing like the device is being fed inconsistent information, again this occurs on all playback devices and software.

I have tried to encode using CRF set to 15, and also Fast Encoding. My GPU is capable of H265 hardware acceleration.

Here is a screenshot of the kind of artefacts I see appear and disappear.

IMG_1761 by Paul Jones, on Flickr

I can provide my log file if required.

Thanks

Paul.

peejay1977

Just to add to this, a 2 pass encode does NOT encounter the same issue. So it's only when the GPU is being used for encoding.

peejay1977

I believe I may have resolved this with updating the NVidia driver to 360.95 which suggests the earlier version has an issue.