Re: [AG-TECH] linux video capture

[Robert Olson <olson@mcs.anl.gov>]

What you might be seeing is this:

On linux, vic captures via v4l at 352x288. On a BT848-flavored card (I 
think the Ospreys fall in this class as well as the Hauppauge cards), 
capturing at more than 240 lines causes teh capture to happen from both 
fields, as NTSC video is two fields of 240 lines each. Hence, you get 
interlacing effects.

As I recall with vic on windows, it captures at 320x240, so the data 
comes from a single field and hence has no interface artifacts.

Thus, one solution would be to modify the vic capture code to use 
320x240 (or 640x240 if you wanted  more horizontal resolution, and 
resample to 352x288).

--bob

On Mar 16, 2005, at 12:25 PM, Gavin W. Burris aka 86 wrote:

> Looks like Osprey cards do have Linux support.  Has anyone tested an
> Osprey card with AGTk?  Can you also use multiple Osprey cards under
> Linux with AGTk?
>
> Gavin W. Burris aka 86 wrote (on Wed, 16 Mar 2005 at 12:54):
> > Does anyone have a suggestion for better video capture devices under
> > Linux?  The three Hauppauge WinTV PCI cards I am using are great,
> > except that the video is interlaced.  I was looking at an Osprey card
> > on Windows and there is a big difference in the quality sans the
> > interlacing.
> >
> > Cheers,
> > --
> > Gavin W. Burris aka 86
> > Senior Systems Programmer
> > Penn State Visualization Group
> > http://viz.aset.psu.edu/ga5in
> --
> Gavin W. Burris aka 86
> Senior Systems Programmer
> Penn State Visualization Group
> http://viz.aset.psu.edu/ga5in