ubuntu-x-swat team mailing list archive

[Hans-Juergen Mauser <670790@xxxxxxxxxxxxxxxxxx>]

Hello Tormod,

thanks for your comments and tests! Are you more deeply involved into
the calculation methods for these savage drivers?

In fact, on my system I had to remove the 7-pixel offset to get the
screen full in width.

I'm sorry, at the moment I don't have a lot of time for doing an
official commit - but if it may take some time, I can keep an eye on it.

I'd like to improve the driver further, there are several open issues:

- when switching to TV output, similar clipping as I had experienced
(and resolved) it on the LCD occurs again, depending on the video source
resolution --> maybe an intermediate calculation similar to the
expansion code should be applied? Additionally, there is NO resolution
that fits TV out perfectly. 800x600 is closest, but the right and bottom
ends are not displayed. This looks like even the basic image buffer
might need scaling.

- the driver (or the HW) is not able to scale a video DOWN. If there is
a display window smaller than the source resolution, it is clipped.
Maybe an integer/float issue?

- when using the s3switch tool to use TV mode, this setting is not
stored correctly / permanently in any way. Power management
interventions or even players like VLC (which I need due to performance
issues) disable the TV out and put garbage on the LCD. I have to enter
"s3switch lcd" blindly to regain anything visual from the system. The
current workaround with VLC is to start and pause a video while still
using LCD or CRT, then switch to TV. The simple "play" command from stop
state in VLC results in the garbage mentioned...

- I have a little bit of hope to be able to boost the XVideo source
window limit from 1024x1024 up to something larger, at least 1280x1280
to allow larger images (which are only data bloat and often the added
"resolution" is decreased by compression artifacts,  but can sometimes
be found) to be displayed.

It would be great if we could improve this driver. The machines using
the hardware are great tools, very power-saving and quiet, and the basic
acceleration of the savage as well as the TV out rendering are quite
nice.

Do you have access to any specs of the S3 chips? And/or can you explain
the data formats to me, especially this integer/float issue and
"artificial" floats created by dividing an integer data type to a
fraction? I searched the internet a lot, but could not find a definite
clue. Often such formats are no "standards" but simply a way to resolve
a problem - I work a lot with controllers which are only able to use
integers, often enough only 16 bit embedded systems... but in these
application I can look at the code and see how the numbers are used. X11
is also open source, but a big bunch... so it would be great if you
could help me here.

Best regards,

Hans-Juergen

-- 
You received this bug notification because you are a member of Ubuntu-X,
which is subscribed to xserver-xorg-video-savage in Ubuntu.
https://bugs.launchpad.net/bugs/670790

Title:
  Xv / XVideo accelerated video width is limited by / depending on the
  screen resolution on S3 Savage, but only if the laptop LCD is the
  primary screen