Hi,
>> But the TV does nasty things: looks like it scales the 1280 down to
>> 1024, and then back to 1280 when switched to 16x9 :-( Ihave to
>> investigate this further....
> Many people would be interested by your findings (including me). Did you
> try read-edid to get what the TV advertises via DDC
I did some more tests yesterday, and I created lots of test pictures in
1024x768 and 1280x768 resolution. (Is there a place where I could
provide them to the public?)
First the bad news: I cannot read/decode the DDC data with read-edid:
artus.reinelt:~ # get-edid | parse-edid
get-edid: get-edid version 1.4.1
Performing real mode VBE call
Interrupt 0x10 ax=0x4f00 bx=0x0 cx=0x0
Function supported
Call successful
VBE version 300
VBE string at 0xc52c8 "VIA CLE266"
VBE/DDC service about to be called
Report DDC capabilities
Performing real mode VBE call
Interrupt 0x10 ax=0x4f15 bx=0x0 cx=0x0
Function supported
Call successful
Monitor and video card combination does not support DDC1 transfers
Monitor and video card combination supports DDC2 transfers
0 seconds per 128 byte EDID block transfer
Screen is not blanked during DDC transfer
Reading next EDID block
VBE/DDC service about to be called
Read EDID
Performing real mode VBE call
Interrupt 0x10 ax=0x4f15 bx=0x1 cx=0x0
Function supported
Call successful
parse-edid: parse-edid version 1.4.1
parse-edid: EDID checksum passed.
# EDID version 1 revision 1
Section "Monitor"
# Block type: 2:0 3:0
# Block type: 2:0 3:0
# Block type: 2:0 3:fc
Identifier "TCL LCD3026T"
VendorName "TCL"
ModelName "TCL LCD3026T"
# Block type: 2:0 3:0
# Block type: 2:0 3:0
# Block type: 2:0 3:fc
# Block type: 2:0 3:0
# DPMS capabilities: Active off:no Suspend:no Standby:yes
# Block type: 2:0 3:0
# Block type: 2:0 3:0
# Block type: 2:0 3:fc
# Block type: 2:0 3:0
EndSection
Maybe parse-edid cannot decode DDC2 data? I remember reading something
in the manual....
But I'm shure the TV does provide this data, along with a mode of
1280x768: I've been booting some "system info CD" from the german
computer magazine "c't" yesterday, some of the test programs did report
a lot of modes (but no further timing information).
Is there any other possibility to get the DDC data with linux?
Next I played around with modes for viafb: I get a 1280x768 mode with
this options:
modprobe viafb mode=1280x768 bpp=32 refresh=60 TVon=0
I get a quite good picture where the 1280x768 fit exactly onto the
screen (after some fine-tunig in the TV setup). But as I feared: the
horizontal resolution isn't that good. I get a sharp resolution
vertically, I can see that one pixel on the TV directly corresponds to
one pixel in the test image. Horizontally, the pixels are blurred over
2-3 pixels. I have to switch the TV into 16:9 mode, in 4:3 mode the
image is scaled down to 1024 pixels. I'm afraid the TV does *always*
scale down to 1024, and then back up to 1280. Who the hell did design
this braindamadged thing???
Next I tried to play around with 1024x768. Now for the bad news: I
couldn't get a good picture here. First, the only way to get a signal on
the TV is
modprobe viafb mode=1024x768 bpp=32 refresh=50 TVon=1 TVtype=1 TVoverscan=1
(note the TVon=1!!)
As soon as I set TVon to 0, I get "no signal" or "not receiving" on the
TV. Maybe some of the modes in viafb are wrong?
But even with the TVon=1 mode, the resulting image isn't 1024x768, but
somewhat smaller ( I suppose about 800x600 or so). I think here are some
wrong mode values, too.
Next I will play with softdevice and try to get VDR on viafb up and running.
Last questions: is this the right ML for this stuff, or is it a bit OT
here?
bye, Michael
--
Michael Reinelt <reinelt@xxxxxxxx>
http://home.pages.at/reinelt
GPG-Key 0xDF13BA50
ICQ #288386781
