Re: [Discuss-gnuradio] Fresh NTSC samples needed

[mgray]

I've just posted a wide variety of NTSC captures from a signal generator.  
Included are black (sync only), SMPTE color bars, solid color raster (red, 
green, and blue), ramps, and a cross hatch pattern.  Each also includes 
the sound carrier with a 1KHz test tone.

http://www.kd7lmo.net/ground_gnuradio_ota.html


Also a utility for capturing USRP signal to a file:

http://www.kd7lmo.net/ground_gnuradio_software.html


The RF output of the signal generator was used (channel 4) and down
converted to 10.7MHz for processing by the USRP.  The generator output is
an AM DSB signal, where as OTA NTSC signals are VSB where the lower side
band is supressed 1.25 MHz below the video carrier.  This shouldn't effect
the demodulator as I would guess it is a standard AM demodulator and
doesn't so any kind of LSB filtering (matched filtering).

Enjoy....


On Wed, 30 Mar 2005, Prateek Dayal wrote:

> Hi,
> 
> I think that the color bars should help ... specially since we know what
> to expect. A capture of a soap or something makes a nice demonstration
> :-)
> 
> When Eric gave me the samples, he took the tuner output at 5.75 Mhz
> (center of the 6 Mhz band) and then quadrature sampled it. Therefore in
> the final samples, the video carrier was at -2.75 Mhz, Audio carrier at
> 1.75 Mhz. I think you get the picture.
> 
> Please capture may be a sec of video using a test signal generator and a
> sec of video showing some program. The color bars that Krzysztof pointed
> should help. Otherwise anything you can generate; as long as I know what
> they should look like :-)
> 
> Regards
> 
> PMD
> 
> 
> On Tue, 29 Mar 2005 13:54:42 -0700 (MST), address@hidden
> <address@hidden> wrote:
> > Would it be helpful to capture NTSC color bars or other test signals?
> > 
> > I have an USRP and TEK signal generator.
> > 
> > Where is 0Hz IF when you capture video?
> > 
> > 
> > On Tue, 29 Mar 2005, Prateek Dayal wrote:
> > 
> > > Hi,
> > >
> > > I am testing my NTSC color decoding algorithm currently. The problem
> > > that I am facing is that the NTSC samples that I have downloaded from
> > > comsec.... have only a text message displayed on the screen, so it is
> > > very dificult to make out if the colors that I am getting make any
> > > sense or not.
> > >
> > > It would be very very helpful if someone could cut about 2 seconds of
> > > video with some humans or something in it so that I can make some
> > > sense out of the image or colors.
> > >
> > > Please help me out ....
> > >
> > > Regards
> > >
> > >
> > 
> > 
> 
> 
>