> Does anyone have a working ntsc mode for the linux-viafb from cvs?  I
> had ntsc from the viaarena framebuffer but no hardware acceleration so I
> switched to linux-viafb from directfb cvs and managed to get
> acceleration using libcle266mpegdec-0.2, but now I'm stuck with PAL output.

I haven't tried NTSC myself but I would expect you to be able to get
some picture from it (though not a nice unscaled unfiltered one).

Some things that might help:

You'll need the TVon=1 option when you load the framebuffer module in
order to enable the TV encoder.  You'll also need TVtype=1 (NTSC); the
default is 2 (PAL).  With that done, the exact timings you put in the
fb.modes files are fairly academic because the timing is then
determined by what's needed for the TV encoder.  However, you do need
a definition for the resolution that you're going to use (e.g.
720x480).

The actual timings can be found in the via_tv3.h or via_vt1622a.h
files (depending on which TV encoder you have.  Do you know which it
is?)

Unfortunately, the data in those files is not in any way readable but
there is a utility that can help you create the tables.  I'd need to
look that out.  If it's licence is suitable I could pop it in with
linux-viafb.

I created an optimised 720x576 PAL mode for the VT1622A and Nicolas
Huillard did the same for the VT1622.  Perhaps you'd like to make the
NTSC versions?

There are, however, existing NTSC modes that should get you a picture.

> I've also tried with combinations of the bcast and laced options without
> success.

Two different modes are supported for the resolutions supported by the
TV encoder, one with overscan and one without.  You get the overscan
version by putting 'bcast true' in your fb.modes file.

The laced option should not be used.  The interlace is created by the
TV encoder and not by the graphics chip's CRTC (which should be
generating a 720x480p60 picture).

> Ideally I'd like to see a configure option for default output (NTSC, PAL
> or SECAM) at compile time but I have no idea what's involved with that.

The driver doesn't support SECAM.

The defaults are set by the 10 or so lines following the comment
'video mode' in via_fbobj.c.

Regards,

Mark

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