[mythtv] Relationship of XVideo to V4L

[Michael J. Hammel]

On Tue, 2003-07-08 at 15:51, Fredrik Söderqvist wrote:
> since you've now had a tough beating at the MythTV list, you know the small errors in your mail :-)

Its funny that I got all that wrong too since I once worked on a simple
Xv app for Xi Graphics back around '95 or '96.  I've just forgotten it
all since then.

> While there does exist drivers fro saa7110 and saa7111 (and some more saa71xx), 
> there does not - at least not to my knowledge - exist any driver for saa7114 
> (but maybe that was the original problem...).

Ivtv has a 7115 driver and the source actually mentions the 7114H in the
header (and that the 7114 driver came from LinuxMediaLabs and was open
source).  The docs for ivtv mention that the 7114 driver was included at
one time but the only related source now seems to be for the 7115.  I
also found in the V4l arcvhives notes about this driver - that there
were no non-NDA docs for it at the time (back in Feb 2003, I think).

> There _do_ seem to be datasheets available though, at
> http://www.semiconductors.philips.com/acrobat/datasheets/SAA7114H_1.pdf

I'll see if the ivtv guys know about this one.

> So if you want to write the driver, that should probably suffice.

I'd love to work on it.  I haven't had a real reason to dig into a
driver like this for about 12 years now, so I'm essentially starting
over.  I may get a lot more wrong before I get it right with the code
too.  But its worth digging in to it.

> If you feel that it would be of any help, I could offer some help. I
>  don't have any saa7114 hardware, so I guess I could be supportive with 
> peer-review and such (I do have an interest in low-level and kernel code).

I'll be happy to post any code or updates I make.  The first step,
though, is to find out how compatible that 7115 code from ivtv might be
with the 7114.  Even if its not, it sounds like they might know if the
former is a good starting point for a new 7114 driver.

> Any replies are most welcome,

Same here.  Thanks for the tips and offers of support.

-- 
Michael J. Hammel <mythtv at graphics-muse.com>
Graphics Muse