Mailing List Archive

Alternatives to Xvideo?
Hi,

On the Via forums, in a discussion about using the EPIA M as a settop box,
a comment was made that X/XVideo is a poor choice when your target display
is a TV. The argument, if I understand it correctly, was that X/Xv was
designed for non-interlaced displays. There wasn't a suggestion for a
better way, but I'm guessing maybe framebuffer. I'm a total novice when
it comes to this stuff so I'm seeking comments from the experts on this
list.

So my question in a nutshell is, "what would be an alternative to Xv that
would be light on resources and not be difficult to port Myth to, etc.".

I realize that the outcome of this discussion won't benefit very many
people, but the main reason I am working on this is to learn about the
world of multimedia so all comments are welcome and appreciated.

Here is the link to the thread:
http://forums.viaarena.com/messageview.cfm?catid=28&threadid=31641

Thanks,
Larry
Re: Alternatives to Xvideo? [ In reply to ]
It's of value to me, Larry, I've just about got my EPIA-M 1Ghz unit up
and running and will be heading down this same path shortly!

Mark
-------------------------
http://www.lorimarksolutions.com/MythTv/Mark's_LinTV_Project.html

Larry Matter wrote:
>
> I realize that the outcome of this discussion won't benefit very many
> people, but the main reason I am working on this is to learn about the
> world of multimedia so all comments are welcome and appreciated.
>
Re: Alternatives to Xvideo? [ In reply to ]
At 18-2-03 21:24, Larry Matter wrote:
>On the Via forums, in a discussion about using the EPIA M as a settop box,
>a comment was made that X/XVideo is a poor choice when your target display
>is a TV. The argument, if I understand it correctly, was that X/Xv was
>designed for non-interlaced displays. There wasn't a suggestion for a
>better way, but I'm guessing maybe framebuffer. I'm a total novice when
>it comes to this stuff so I'm seeking comments from the experts on this
>list.

Very untechnical explanation: when displaying on TV control over which line
goes where is important, you only have a handful. If you start scaling you
lose information. And you started off with the same TV resolution input
anyway, so there is no need to scale with any ugly factor, not on grabbing
and not on displaying.

>So my question in a nutshell is, "what would be an alternative to Xv that
>would be light on resources and not be difficult to port Myth to, etc.".
Framebuffer.

Will be offered in the medium-distant future when the new output widget is
in place, which I am writing to support runtime configurable keybindings.
(For the logic between thet connection read the source of MythTV and QT :-)

>I realize that the outcome of this discussion won't benefit very many
>people...
More people have asked for it. Real TV-only output is one reason,
non-XV-able VGA cards another.

Erik
Re: Alternatives to Xvideo? [ In reply to ]
> Very untechnical explanation: when displaying on TV control over which
> line goes where is important, you only have a handful. If you start
> scaling you lose information. And you started off with the same TV
> resolution input anyway, so there is no need to scale with any ugly
> factor, not on grabbing and not on displaying.

Thanks. I don't mind technical btw, if you don't mind typing it. I'm
trying to learn all about this stuff.

>>So my question in a nutshell is, "what would be an alternative to Xv
>> that would be light on resources and not be difficult to port Myth to,
>> etc.".
> Framebuffer.
>
> Will be offered in the medium-distant future when the new output widget
> is in place, which I am writing to support runtime configurable
> keybindings. (For the logic between thet connection read the source of
> MythTV and QT :-)

Cool! I'm willing to help, but as you have guessed, I am not experienced
in this area. However, if you need someone else to try stuff, let me
know. And yes, I plan on diving into the source soon.

Thanks,
Larry
Re: Alternatives to Xvideo? [ In reply to ]
At 19-2-03 18:39, Larry Matter wrote:
> > Very untechnical explanation:
>> ...
> Thanks. I don't mind technical btw, if you don't mind typing it. I'm
>trying to learn all about this stuff.
I did mind typing it :-) Is very long story if you really want to get all
the details right, just google around and read up on broadcast quality
video, de-interlacing and such. Unfortunately no single place has all the
answers, but you could start at http://www.epanorama.net/links/video.html

> > Framebuffer.
> >
> > Will be offered in the medium-distant future when the new output widget
> > is in place, which I am writing to support runtime configurable
> > keybindings. (For the logic between that connection read the source of
> > MythTV and QT :-)
>
>Cool! I'm willing to help, but as you have guessed, I am not experienced
>in this area. However, if you need someone else to try stuff, let me
>know. And yes, I plan on diving into the source soon.

I'm afraid this is more of a "it just works or is just doesn't" issues.
<frustrated ranting>
At the moment I am fighting the eventhandling of QT, het lower level widget
stuff is not multi-threading resistant even if you use the qt-mt lib, and
Isaac really tricked the QT lib into dancing his way. Unfortunately this
means the videowindow gets instantiated outside the main thread, which is
illegal if it is going to be a QT-widget.
</frustrated ranting>

If you could follow the above, mail me privately for some backgroudtalk, if
not, just believe me when I say it sucks :-) But not all of the source is
this complicated, so don't let me scare you from diving in.

Erik