[TESTING] 4K HDR playback with banding & flickering fixes


#102

Yes, it’s not used in the latest fix.


#103

Since the last update from yesterday (vero4k 3.14.29-80), my iptv is displaying tearing…
All other video’s play correct though.


#104

Nothing obvious that would cause this off the top of my head.
Same channels / provider as before?


#105

Yeah nothing changed, watched with it on sunday the F1 race.
Got it with 576p, 720p and 1080p.

Changed the accelerate to HD and up for h264, but the SD channel was still showing tearing :frowning:


#106

Try downgrading Kodi.

sudo apt-get update
sudo apt-get install --reinstall vero3-mediacenter-osmc/stretch


#107

Did a reboot this morning, but just rebooted again and it doesn’t tear anymore… kinda weird but looks to be resolved for now :thinking:


#108

Just did a few HDR-detection tests, as my new AVR shows me exactly what’s going on.
I am on 3.14.29-81-osmc

All my UHD-HDR remux documentaries were correctly detected, Vero switches to 10 bit.

Then I tried a 4K reencoded movie.
Here the Vero outputs 8bit and BT.2020
Seems the detection is not completely working yet.

Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format_Commercial_IfAny                  : HDR10
Format-Profil                            : Main 10@L5.1@High
Codec-ID                                 : V_MPEGH/ISO/HEVC
ColorSpace                               : YUV
ChromaSubsampling/String                 : 4:2:0 (Type 2)
BitDepth/String                          : 10 bits
colour_range                             : Limited
colour_primaries                         : BT.2020
transfer_characteristics                 : PQ
matrix_coefficients                      : BT.2020 non-constant
MasteringDisplay_ColorPrimaries          : BT.709

#109

I only added some basic detection yesterday. Did you update yesterday?

Actually, looks like the Vero 4K is doing the right job.


#110

Hmm, but Vero outputs 8bit and BT.2020
The source is 10 bit

Yes, it’s the update from yesterday evening


#111

Btw. this is from planet earth II, where the detection switches to 10 bit:

Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format_Commercial_IfAny                  : HDR10
Format-Profil                            : Main 10@L5.1@High
Codec-ID                                 : V_MPEGH/ISO/HEVC
ColorSpace                               : YUV
ChromaSubsampling/String                 : 4:2:0 (Type 2)
BitDepth/String                          : 10 bits
colour_range                             : Limited
colour_primaries                         : BT.2020
transfer_characteristics                 : PQ
matrix_coefficients                      : BT.2020 non-constant
MasteringDisplay_ColorPrimaries          : BT.709

It’s exactly the same!


#112

What I’ve found is that the switching to 10 bit 444 only sometimes triggers despite playing the same video or movie.

You can pretty easily see what the Vero is doing by using:
sudo cat /sys/class/amhdmitx/amhdmitx0/attr

Before and then after you start playing a 10 bit HDR file and then again when you press stop.


#113

using sudo watch cat /sys/class/amhdmitx/amhdmitx0/attr may make that job easier :wink:


#114

Am I missing something?
Is there an auto bit depth switching atm?


#115

Yes, in the display settings
(from developer repo)


#116

Thanks for the info, been waiting for this for ages!

It kinda works indeed, quite often the 444,10bit isn’t set, but nice there is progress :slight_smile:


#117

Maybe it would be good to use “colorBits” besides “color_primaries” to determine wether to switch to “444,10bit” or not. Or am I on the wrong track?


#118

Same here. Only sometimes switches to 10 bit when playing 10 bit hdr movie.

Completely random. More times than not playback stays at 8 bit.


#119

Thanks Sam, this fix seems to work fine as long as I force 10-bit output.

Out of curiosity - I haven’t seen this answered elsewhere - what was the cause of this in the first place? I know it was an unintended side effect of whatever the HDR flickering fix was, but can you go into a bit more depth on it?

Second question for the floor - does forcing 10-bit output negatively impact movies that aren’t 10-bit? I haven’t really noticed any issues myself, but I like to know how things work.


#120

Hey @sam_nazarko,
will there be an updated build for better 10bit detection?
Thanks,
Marc


#121

Yes — there is already some work on this