[Kwintv] Some other issues

Andras Mantia amantia at freemail.hu
Tue Mar 16 00:07:20 CET 2004


Dirk Ziegelmeier wrote:

> On Monday 15 March 2004 13:32, Andras Mantia wrote:
>> - the whole screen is redrawn every time you change a channel, resulting
>> in an annoying flicker.
> Yes. Cannot be changed. The overlay draws straght into the graphics
> memory, no matter whether there is the TV screen or a window bar. The
> flicker is a window that is opened shortly and closed again to trigger a
> redraw.

But the old KWinTV works alright and does not trigger the redraw...


>> - with v4l/overlay101 works, but as I already said no transparency is
>> supported.
> Can't be.
Ok, this is minor, I just listed here as I wrote about the teletext plugin.


>> - v4l/grab+display, it works very stangely (or better does not work). I
>> enter some number, but the searching is very slow, the update of the
>> number looks something like: 150 -> 197-> 605->406 (totally random), and
>> simply does not find the page (in my case page 100).
> I notice this with 2.4.X kernels, too. 
Yes, I have 2.4.21.

> Upgrading to 2.6.X solves it. I 
> think it comes from a very heavy usage of mutexes (grabber thread <-> GUI
> thread). The 2.4 mutex implementation seems to be quite slow compared to
> 2.6...
I will try with 2.6 and report back.

> Yes this could solve the issue, but will create another: You need to
> center the visible area of the tv screen on the monitor. Whenever the user
> moves the mouse, he will move the visible window of the virtual screen,
> resulting in the annoying effect of constantly moving the tv widget out of
> sight... 
Yes, but this is still better than the messed up windows when you return
from the fullscreen. I've tried to implement this with my little (almost 0)
knowledge about the X and XRANDR, but I failed. :-( 
My old KWintv does not want to switch resolution when going fullscreen now,
but IIRC it handled the above issue in a way (not so good, but acceptable
way): when the mouse was moved outside of the visible area, it was quickly
moved back to the center of the area. So even if you had a larger virtual
screen, you could always see only a part of it. This solution resulted in a
flicker, but is acceptable.


> Overlay is simply broken and a hack when it's not done from 
> inside the X server (like XVIDEO does).

It might be, but as I said, the XVIDEO scaling results in a badly looking
picture here. I know this is not QtVision's fault.

Andras

> 
> Dirk



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