[linux-dvb] Re: SAA7146 Cropping

[Jeremy Jones <jj_gittes5@yahoo.com>]

Ok, so it sounds like the saa7146 scaling features are not currently supported by the linux driver and adding them would not be a trivial task.  I'm not much of a kernel person and know nothing about the saa7146 so I don't think I'll be able to take the option of trying to implement this functionality in the linux driver :-)

 

Thank You

bball

Robert Schlabbach <robert_s@gmx.net> wrote:

Sorry, not for Linux :(

The difference between SAA7146A cropping and using the hardware overlay is
that in the former case, the SAA7146A will do the downscaling, whereas in
the latter case, the graphics card will do it.

While letting the SAA7146A do the downscaling would actually be
preferrable, since it puts less load on the PCI bus (only the downscaled
image would be transferred vs. the full image), this might require writing
a LOT of SAA7146A code to implement use of its High Performance Scaler
(HPS).

In contrast, if hardware overlay support already exists, you would have
much less work implementing what you want.

Regards,
--
Robert Schlabbach
e-mail: robert_s@gmx.net
Berlin, Germany

----- Original Message -----
From: "Jeremy Jones"
To: "Robert Schlabbach"
Sent: Wednesday, July 07, 2004 6:12 PM
Subject: Re: [linux-dvb] Re: SAA7146 Cropping


> I will look into this, I'm still quite new to dvb and mpeg-2. I found
the other example googling for mpeg scaling. I will do some digging on
hardware overlay but would you happen to have any pointers offhand ?
>
> Thank You,
> bball

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