edid-decode(1) [centos man page]

edid-decode(1)						      General Commands Manual						    edid-decode(1)

NAME

       edid-decode - Decode EDID data in human-readable format

SYNOPSIS

       edid-decode [in] [out]

DESCRIPTION

       edid-decode  decodes  EDID  monitor  description  data in human-readable format.  It takes zero, one, or two arguments.	If invoked with no
       arguments it reads from standard input and writes to standard output.  With one argument, the file named by the argument is  read  instead.
       With two arguments, normal output is suppressed, and the binary EDID blob is written to the file named by the second argument.

       Input  files  may  be  raw binaries or ASCII text.  ASCII input is scanned for hex dumps; heuristics are included to search for hexdumps in
       xrandr(1) property output and Xorg(1) log file formats, otherwise the data is treated as a raw hexdump.	EDID blocks for connected monitors
       can be found in /sys/class/drm/*/edid on modern Linux systems with kernel modesetting support.

NOTES

       Not  all  fields  are decoded, or decoded completely.  Some fields' decoding may appear to corrupt the output (for example, detailed string
       sections have their contents printed literally).  edid-decode does attempt to validate its input against the relevant  standards,  but  its
       opinions  have  not  been double-checked with the relevant standards bodies, so they may be wrong.  Do not rely on the output format, as it
       will likely change in future versions of the tool as additional fields and extensions are added.

SEE ALSO

       Xorg(1), xrandr(1)

AUTHORS

       edid-decode was written by Adam Jackson, with contributions from Eric Anholt, Damien Lespiau, and others.  For  complete  history  and  the
       latest version, see http://cgit.freedesktop.org/xorg/app/edid-decode/

																    edid-decode(1)

DDC(9)							   BSD Kernel Developer's Manual						    DDC(9)

NAME

     ddc -- VESA Display Data Channel V2

SYNOPSIS

     #include <dev/i2c/ddcvar.h>

     int
     ddc_read_edid(i2c_tag_t tag, uint8_t *dest, size_t len);

DESCRIPTION

     The ddc_read_edid() reads a VESA Extended Display Identification Data block (EDID) via VESA Display Data Channel (DDCv2).	DDCv2 is a proto-
     col for data exchange between display devices (such as monitors and flat panels) and host machines using an I2C bus.

     The tag argument is a machine-dependent tag used to specify the I2C bus on which the DDCv2 device is located.  The dest argument is a pointer
     to a buffer where the EDID data will be stored.  The len argument is the amount of data to read into the buffer.  (The buffer must be large
     enough.)  Typically, this value will be 128, which is the size of a normal EDID data block.

     Normally the EDID data block will be post-processed with the edid_parse() function.

RETURN VALUES

     The ddc_read_edid() function returns zero on success, and non-zero otherwise.

ENVIRONMENT

     The ddc_read_edid() function is part of the ddc(4) driver, and is only included in the kernel if that driver is also included.

EXAMPLES

     The following code uses ddc_read_edid() to retrieve and print information about a monitor:

	     struct edid_info info;
	     i2c_tag_t	      tag;
	     char	      buffer[128];

	     ...
	     /* initialize i2c tag... */
	     ...
	     if ((ddc_read_edid(tag, buffer, 128) == 0) &&
		 (edid_parse(buffer, &info) == 0))
		     edid_print(info);
	     ...

     Note that this must be called before the PCI bus is attached during autoconfiguration.

SEE ALSO

     ddc(4), edid(9), iic(9)

HISTORY

     DDCv2 support was added in NetBSD 4.0.

AUTHORS

     Garrett D'Amore <gdamore@NetBSD.org>

BSD
								   May 11, 2006 							       BSD