_samtaylor
Posts: 2
Joined: Fri Mar 06, 2015 4:00 pm

access edid data of monitor; tvservice --dumpedid unreadable

Fri Mar 06, 2015 4:09 pm

Hi,
So as part of a project I'm working on for uni I need to be able to access the edid data of a monitor I connect to, and then decode this to display the information about the monitor. I have begun writing the code to do the decoding and am making good progress, but as of yet I am unable to access the edid data as desired from the pi - So far I have been using data that was given to me, along with the spec of said TV so I can check I am getting the right values.

I've seen the "tvservice --dumpedid <filename>" command which seems to be close to what I want, but I can't read the output (presumably due to the encoding??).
Any help in being able to get the edid data in the following using the pi would be appreciated:

00 FF FF FF FF FF FF 00 4C 2D 90 0B 01 00 00 00
02 18 01 03 80 79 44 78 0A EE 91 A3 54 4C 99 26
0F 50 54 BD EF 80 71 4F 81 C0 81 00 81 80 95 00
A9 C0 B3 00 01 01 08 E8 00 30 F2 70 5A 80 B0 58
8A 00 50 1D 74 00 00 1E 02 3A 80 18 71 38 2D 40
58 2C 45 00 50 1D 74 00 00 1E 00 00 00 FD 00 18
4B 0F 87 3C 00 0A 20 20 20 20 20 20 00 00 00 FC
00 53 41 4D 53 55 4E 47 0A 20 20 20 20 20 01 1E

Thanks

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AndyD
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Joined: Sat Jan 21, 2012 8:13 am
Location: Melbourne, Australia
Contact: Website

Re: access edid data of monitor; tvservice --dumpedid unread

Fri Mar 06, 2015 11:05 pm

To see the edid data as a hexadecimal output, you could use the xxd command. For example:-

Code: Select all

tvservice --dumpedid edid.dat
xxd -g 1 edid.dat
But, I am not sure that I understand the question. What programming language are you using? The EDID format appears to be available online (e.g. on Wikipedia), it shouldn't be too difficult to parse the binary file.

gkreidl
Posts: 5952
Joined: Thu Jan 26, 2012 1:07 pm
Location: Germany

Re: access edid data of monitor; tvservice --dumpedid unread

Fri Mar 06, 2015 11:12 pm

run

Code: Select all

editparser edid.dat
Minimal Kiosk Browser (kweb)
Slim, fast webkit browser with support for audio+video+playlists+youtube+pdf+download
Optional fullscreen kiosk mode and command interface for embedded applications
Includes omxplayerGUI, an X front end for omxplayer

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AndyD
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Joined: Sat Jan 21, 2012 8:13 am
Location: Melbourne, Australia
Contact: Website

Re: access edid data of monitor; tvservice --dumpedid unread

Sat Mar 07, 2015 12:18 am

gkreidl wrote:run

Code: Select all

editparser edid.dat
A much better idea!

_samtaylor
Posts: 2
Joined: Fri Mar 06, 2015 4:00 pm

Re: access edid data of monitor; tvservice --dumpedid unread

Fri Mar 13, 2015 10:07 am

Thanks - this is exactly what I was looking for!
Yes, parsing it is fine, I just wasn't sure how to get the data on a pi - on a lubuntu machine I was running "xrandr --verbose" which did the trick there.
AndyD wrote:To see the edid data as a hexadecimal output, you could use the xxd command. For example:-

Code: Select all

tvservice --dumpedid edid.dat
xxd -g 1 edid.dat
But, I am not sure that I understand the question. What programming language are you using? The EDID format appears to be available online (e.g. on Wikipedia), it shouldn't be too difficult to parse the binary file.

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