Hi Frank,

On Wed, Jun 4, 2008 at 11:41 AM, Frank Neuber <[EMAIL PROTECTED]> wrote:
> Hi Markus,
>
> Am Mittwoch, den 04.06.2008, 11:21 +0200 schrieb Markus Rechberger:
>> Implementing rawvbi in the driver isn't difficult, the problem is
>> getting applications work with the delivered data.
> Yes that is clear, we can do the slicer in software. But with the YuY2
> data it is also impossible to decode teletext. Did you ever teletext
> running with the Cinergy?
>

The data can be considered Y8, there's a slicer implemented in the
driver which dumps the top VBI data to /dev/vbi0
with the Cinergy Hybrid XS (not FM) and zapping yes, osc which is part
of the libzvbi package also dumps some decoded data.

>> There are specs available for the cx25843, this one has to be
> Yes I read this and set the bit 0x404[3] = VBIHACTRAW_EN and 0x424 to
> 0x434 = 0 in the cx25843. But the YuY2 data does not change to rawvbi.
>
>> configured properly (this is not covered by the em28xx specs anyway,
> In the em28xx datasheet (from linuxtv) I read that there is a
> possebility to enable raw vbi data. Because I don't know how is the
> Cinergy wired I had the hope that this helps.
>> it's more about reading through those specs - understanding them and
>> implementing it the right way).
>
>> Enabling VBI for the em28xx is just setting a bit of the 0x11 register
>> and this is already implemented in the em28xx.
> You mean R11_VINCTRL_REG = 0x51 is slicer off? Which Bit is it exactly?
>

I don't have the specs here, although enabling rawvbi in the em28xx is
already fine, setting the correct parameters wich get passed forward
to userspace migth need some adjustment in the driver.

A description what rawvbi is actually:

http://img134.imageshack.us/my.php?image=00000008kk3.png

this frame directly includes the rawvbi data ontop of the video.
The em28xx driver on mcentral.de is capable of slicing this part and
dumping it to /dev/vbi0

This data needs to be demodulated, (eg by libzvbi).
One drawback I noticed when using libzvbi it's not very accurate. With
the old cinergy hybrid xs, which used a texas instruments tvp5150 chip
it was possible to oversample the vbi data which result in twice as
big waveforms and libzvbi seemed to work better with that data.

Markus

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