[SOLVED]HDMI handshake issues with Philips TV- magenta/green

Post Reply
evilmf
Posts: 8
Joined: Mon Jun 06, 2016 6:08 pm
languages_spoken: english
ODROIDs: C2
Has thanked: 0
Been thanked: 0
Contact:

[SOLVED]HDMI handshake issues with Philips TV- magenta/green

Unread post by evilmf » Tue Jun 07, 2016 6:49 am

Hi,

I have a problem with my new C2 due to an issue with some Philips/Sony TVs made 5+ years ago. They have a bug in their HDMI implementation that sometimes trigger the selection of the wrong colorspace resulting in a magenta/green display. This happens both in the Kodi GUI and during playback (any video mode).

The problem has been analyzed multiple times, and there is a workaround to resolve it which consist into forcing the output from the devices to Full RGB. A recent patch for the Minix NEO U1 (same chipset as the C2, as far as I know) was created exactly for this purpose, so I know that it is possible to force Full RGB output on this chipset, but I don't know where to start to do it myself :|

See a thread with all the relevant information here: http://www.minixforum.com/threads/solve ... ple.10154/

The description of the problem:
That issue has to do with the color space the HDMI driver uses for displaying video content. I've seen this before with my Open Hour Chameleon Android based media player and there it was only resolved after the developers gave us the option to select the color space to use. By default they were using YUV444 which isn't the preferred color space of my TV (which seems to use RGB). So when the color space information in the HDMI data stream is missed somehow during display (temporary hickup or timing mismatch) the TV picks the color space it prefers (in my case RGB) and displays the YUV444 stream as a RGB stream. Since the Y component (Luminance or brightness information) is mapped to Red and U and V (which normally encode the color components) are mapped to Green and Blue the picture starts looking like its rendered in Green and Purple shades.
The only solution for this issue (as de OHC devs discovered) is to give us the options to set the color space used by the HDMI driver. There are no other solutions for this problem for TV's/Displays that use RGB color space by default.
This issue was also a major problem for UPC's Horizon media boxes and TV's from all major manufacturers (Sony, Philips, Samsung etc) were hit by this until they did the same as the OHC devs.
I have been running both LibreELEC and the official linux image that came with the C2, with the same results. Would it be possible to have a patch to fix the Colorspace to RGB and provide a solution for the unlucky bunch of people that are stuck with this issue ?

As I said, for the Minix they introduced a "Force RGB" settings that does exactly that, so I am hoping the same is possible in our Odroid C2.

I am available of course to run any diagnostics or try any patch and report the results...

Thanks!

endecotp
Posts: 230
Joined: Sun May 08, 2016 12:30 am
languages_spoken: english
ODROIDs: c2
Has thanked: 0
Been thanked: 0
Contact:

Re: HDMI handshake issues with Philips TV - magenta/green sc

Unread post by endecotp » Tue Jun 07, 2016 8:43 am

I believe RGB is used for the HDMI output in most cases. What mode have you selected in boot.ini? Have you tried other modes?

Gazeko
Posts: 30
Joined: Wed Mar 16, 2016 6:13 am
languages_spoken: english, german
Has thanked: 0
Been thanked: 0
Contact:

Re: HDMI handshake issues with Philips TV - magenta/green sc

Unread post by Gazeko » Tue Jun 07, 2016 8:02 pm

Hello, check this http://forum.odroid.com/viewtopic.php?f=141&t=20697. There is a workarround if you have an external sound card. If you enable DVI-Mode in boot.ini the magenta screen won´t come again but you also wont have audio from hdmi. For me this workarround works, I had the same problem.

evilmf
Posts: 8
Joined: Mon Jun 06, 2016 6:08 pm
languages_spoken: english
ODROIDs: C2
Has thanked: 0
Been thanked: 0
Contact:

Re: HDMI handshake issues with Philips TV - magenta/green sc

Unread post by evilmf » Wed Jun 08, 2016 2:19 am

@endecotp, I have this in the boot.ini file:

Code: Select all

setenv video_output "1080p60hz"
setenv video_mode   "hdmi"
setenv video_bpp    "32"
setenv hdmihotplug  "1"
setenv hdmioutput   "1"
setenv vpu          "1"
@Gazeko -- I don't need or want HDMI audio (I use the SPDIF interface on my HiFi Shield); I was actually looking into a solution to turn it off!! So if this works will solve two problems with one change :) I guess it is just a matter of configuring setenv video_mode "dvi" in my boot.ini, correct?
Will try it later.

Thanks a million for your help!

Gazeko
Posts: 30
Joined: Wed Mar 16, 2016 6:13 am
languages_spoken: english, german
Has thanked: 0
Been thanked: 0
Contact:

Re: HDMI handshake issues with Philips TV - magenta/green sc

Unread post by Gazeko » Wed Jun 08, 2016 4:05 am

I´m using the newest ubuntu version and in my boot.ini its "setenv vout "dvi"". Probably the same.

evilmf
Posts: 8
Joined: Mon Jun 06, 2016 6:08 pm
languages_spoken: english
ODROIDs: C2
Has thanked: 0
Been thanked: 0
Contact:

Re: HDMI handshake issues with Philips TV - magenta/green sc

Unread post by evilmf » Wed Jun 08, 2016 6:07 am

@Gazeko

problem sorted -- thanks a lot for your help! :)

Post Reply

Return to “Issues”

Who is online

Users browsing this forum: No registered users and 1 guest