[mythtv-users] [ G400 ] Hotwo enable flicker filters
Bernd Müller
caret at gmx.de
Fri Mar 18 15:35:20 UTC 2005
Hello;
Ahhhhh, it seems to me like an enlightment in my mind. I will give the "X on TV"
circuit an third chance (i've tried it two times before). To make sure i've
understand you correctly: The cable looks for the Matrox G400 like this:
VGA SCART
1 -O------------------------------------------O- 15 R
2 -O------------------------------------------O- 11 G
3 -O------------------------------------------O- 7 B
6 -O------------------------------------------O- 13 R Gnd
7 -O------------------------------------------O- 9 G Gnd
8 -O------------------------------------------O- 5 B Gnd
5 -O-+
|
11 -O-+
10 -O------------------------------------------O- 17
Gnd
14 -O------------------------+
-VS |
|
13 -O------------------------+-----------------o- 20
-HS -CS
5,6,7,8,Shell ------------------------------------ 5,9,13,17,21,Shell
Doing the math for the geometry and the timings should be no problem. The thing
i'm not clear about is what the flags csync, hsync, vsync, bcast and so an are
to be used for. At this point I would understand if you say RTFM and i will do,
but maybe you can wrote some words in general. I know what the hsync and vsync
signals are for. But what will the options in the XF86Config modline will do?
A simple enable/disable?
The 736x575i modeline i wrote about is the one which is recommendet at the "X on
TV" homepage for european PAL users. I was also wondering about the resolution
but i've thought the author would know better than me what is right or not.
A seconed time: Thank you very much for help. I don't know how many hours i've
spent in configuring tv-out.
(c; bernd
Cory Papenfuss schrieb:
>> o.k i think i will try this.
>>
> I doubt it will work, but you never know.
>
>> Hm, maybe this isn't an idea that is realizable. I thought of enabling
>> and disabling flicker filter while X is running.
>>
> I think I get what you're trying to do now, and I'm pretty sure it
> won't work. If you're using the SCART cable, then tvout isn't used.
> The flicker filter on the card will be an option on the tvout chip, not
> on the VGA output (second head, even). Now, it's slightly possible that
> it will work, since it's a matrox with an adapter kind of setup. What
> you're really doing is using the tvout function, but tapping off RGB
> directly. You're treading on Matroxisms here, so I've no idea.
>
>> The TruType fonts dosn't look so bad. Problem are the on lined borders
>> around the selection lists in mythmusic and mythvideo. Someone wrote
>> in an other thread about simply bluring all images from the
>> mythtv-theme. This works for the buttons. But the line around the
>> selection list seems to be generated by mythtv itself. So bluring the
>> theme dosn't help.
>>
> Again, it seems like it would be a worthwhile project to fixup the
> GUI of MythTV to do this. If it's drawing lines, then maybe either
> double or triple (...0%-0%-50%-100%-50%-0%-0%...). I guess that's what
> apple used to call their "Convolution flicker filter."
>
>> - has two heads, first is accelerated and seconed has tv-out but is not
>> accelerated
>> - the original Matrox driver for X supports accelerated first head and
>> tv-out
>> on seconed head. Problem is: Not both at the same time, on one head.
>> This
>> menas: I wasn't able to get accelerated video on tv.
>> - workaround: Using the kernel matroxfb which clones first head to
>> seconed head.
>> X runs with the original Matrox drivers but with the "UseFBDev" option
>> enabled. So i'm not able to use the heads seperately 'cause both
>> heads show
>> all the time the same image but i'm able to get accelerated video on tv.
>>
> It sounds like a mess. Keep in mind that there are different kind
> of "accelerated" video. I'm sure someone who knows more can correct
> errors, but normal accelerated video just has to do with the vid card
> doing DMA on chunks of memory, as well as drawing lines, etc with
> primitives and not having to have it's bits calculated and manually
> entered into the VRAM by the CPU. The more applicable acceleration for
> MythTV is whether or not the card can do hardware-accelerated color
> transformations and scaling... called Xv for XVideo. It's almost a
> necessity for making video playback not chew up a bunch of CPU.
>
>> Please note: I'm using the VGA to SCART cabel as described on
>> http://www.myhtpc.de/showtopic.php?threadid=1214
>> connected to the seconed head of the G400. (The page is in german but
>> the important thing, the circuit, is shown in an image.)
>>
> Funky. Again, it looks like a matroxism. I would seriously
> consider ignoring this oddball contraption and just use a regular VGA
> type of SCART connector such as:
>
>> I know about the other VGA to SCART cable as described on
>> http://www.sput.nl/hardware/tv-x.html
>
>
> You don't need the transistor garbage though. All that's doing is
> combining HSYNC and VSYNC into a composite CSYNC. The Matrox cards (as
> well as some, but not all others) can do CSYNC with a driver flag.
> Generally, its done by adding "+csync" or "-csync" at the end of the
> modeline, IIRC.
>
>> but this didn't worked for me. Maybe i do not exactliy know how to use
>> this with
>> my G400. Where it will be connected? First head, seconed head? Do i
>> need the kernel matroxfb? Which drivers i've to use? Original Matrox
>> or Xorg mga? I remember trying to use the G400 without the kernel
>> matroxfb in combination with the original Matrox X driver. But i
>> didn't find any modline which was accepted.
>> Especially the recommended PAL mode
>> "736x575i" 14.16 736 760 824 904 575 580 585 625 interlace -hsync -vsync
>> was not accepted.
>>
> This is the way to do it, but I don't think I believe your
> modeline. Isn't PAL 768x575? The above is only 736 so it's going to
> force scaling. A bit of quick math can convert the fb.modes timing into
> an Xorg timing. The one you said before seems good:
>
> mode "768x576-50"
> # D: 14.766 MHz, H: 15.625 kHz, V: 50.001 Hz
> geometry 768 576 768 576 32
> timings 67723 106 1 44 1 70 4
> csync high
> bcast true
> laced true
> accel true
> rgba 8/16,8/8,8/0,8/24
> endmode
>
> Doing some conversion, the following modeline follows from the above
> data:
>
> Modeline "corypali" 14.766 768 769 839 945 576 577 581 625 interlace -csync
>
> Do a 'man fb.modes' to see how to interpret the fb.modes style of
> defining a modeline.
>
> If you get an "Hsync out of range" in your /var/log/xorg.conf when
> you try this, you probably need to change the hsync range of your
> monitor to be 15kHz minimum. Most likely it's 31kHz minimum now.
> That's why it didn't work before.
>
> -Cory
>
> *************************************************************************
> * Cory Papenfuss *
> * Electrical Engineering candidate Ph.D. graduate student *
> * Virginia Polytechnic Institute and State University *
> *************************************************************************
>
>
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