These registers affect the vertical and horizontal offsets that the 7127
uses for timing etc. I believe (but I may be wrong) that they will affect
the horizontal and vertical offsets of both the OSD and the mpeg playback.
What we really want is something that just moves the OSD.
The chip works by being fed the data on its inputs with the mpeg on the
rising edge of a clock and the osd data on the falling edge (or reversed).
Thus they have to be in step and it also expects 720 pixels per line which I
don't think can be changed.
So programming the 7127 is not as far as I can see ever going to provide a
solution for overscan.
What we really need is to provide the osd data offset from the video data. I
don't thing the itvc15 can do this either so I think we are left with doing
it in software.
My proposed solution is to accept that we need a 720x480/576 frame
buffer but that we should modify the dma code to just fill a defined region
in the middle and leave the border initialized to a particular value. So we
could tell X/Myth/whatever that the frame buffer is 640x480 and make the dma
do the correct offset management for each line to put it in the correct
place in the 720x576 frame buffer.
I almost had this working a while ago and the same code is needed to
allow smaller region updates which is the next way to get a performance
boost for X in any case.
I will try to get back to this next week and see if I can make it
work. This also has the benefit of reducing the frame buffer size exposed to
X etc. which reduces the dma transfer size which will increase the
performance as well.
I would of course like to be proved wrong about all of this but I have read
the 7127 data sheet several times and not found anything that looks helpful.
John
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:mythtv-users-
> [EMAIL PROTECTED] On Behalf Of Jeff Simpson
> Sent: 22 February 2005 16:54
> To: [EMAIL PROTECTED]; Discussion about mythtv
> Subject: Re: [mythtv-users] PVR-350, TVOut Bigger than the TV
>
> Actually, it was on the ivtv list. This was the short little blurb I
> wrote up a couple months ago when I reverse-engineered some of the
> registers. I guess I didn't get any size registers, but I'm fairly
> certain there are some, because I remember adjusting it in that way at
> one point, too.
>
> Your results may vary, make sure to back up the register maps before
> making changes
>
> REG: 0x6C
> VAL: (bits from LSB to MSB): First 3 bits - color. Normal color is 110
> (rightmost digit a 6 or an E). The first bit is the "make it an
> ugly green" flag. I assume the other two are red and blue, but they
> weren't as apparent as the green was. The other 5 bits are the
> horizontal position, larger number is further to the right. I cranked
> it all the way up to get a well-located picture.
>
> ivtvctl -j reg=0x6c,val=0xFE -d/dev/video0
>
> REG: 0x6D
> VAL: (LSB to MSB) first 5 bits - vertical offset (larger number is
> further down). The last three bits are the large adjust for the
> horizontal adjust. So there's a total of 8 bits of horizontal
> adjustment, the lower 5 bits are the low bits of 0x6C and the upper 3
> bits are the upper 3 bits of 0x6C. I'd like to meet the engineers who
> designed this card.....
>
> I went looking for registers that would fix the color problems - I got
> some really weird results from a lot of them. I found some that made
> the picture grainy, some that made it black and white, some that made
> the colors REALLY bright.
>
> On Tue, 22 Feb 2005 11:42:23 -0500, Jeff Simpson <[EMAIL PROTECTED]>
> wrote:
> > There is a way to modify the TV out size and location on the 350.
> > Search the archives for postings by me involving ivtvctl and crazy
> > registry hacks. Some of the hacks change the colors and others resize
> > and move the output on the screen. I have a pretty good description
> > with my findings, but I don't have them anyplace I can find easily
> > right now.
> >
> > That should probably make it to a wiki somewhere, huh?
> >
> > - Jeff
> >
> > On Tue, 22 Feb 2005 11:17:27 -0500, Les Gondor <[EMAIL PROTECTED]>
> wrote:
> > > I am using the 350's TVout and ivtv-0.2.0-64_rc3f.rhfc3.at from Axel's
> > > site. Horizontal scan percentage is 4 and vertical scan percentage is
> 1
> > > (displacements are both zero). Sorry for the delay, I had to ssh into
> my
> > > mythbox to find out.
> > >
> > > Les
> > >
> > > Thom Paine wrote:
> > > > On Tue, 22 Feb 2005 10:36:02 -0500, Les Gondor <[EMAIL PROTECTED]>
> wrote:
> > > >
> > > >>I had the same problem until I experimented with overscan/underscan
> > > >>settings under the 'Appearance' entry in the setup screens. This is
> a
> > > >>separate control from the GUI settings and affects the on screen
> > > >>displays (clock, channel number, progress bar and browse info).
> > > >>
> > > >
> > > >
> > > > Les:
> > > >
> > > > You have the overscan/underscan working with a 350? Are you using
> the
> > > > 350's TVOut or the TVOut with another video card?
> > > >
> > >
> > >
> > > _______________________________________________
> > > mythtv-users mailing list
> > > [email protected]
> > > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> > >
> > >
> > >
> >
> > --
> > email me if you want a gmail invite, I have some invites
> >
>
>
> --
> email me if you want a gmail invite, I have some invites
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