Re: [Mjpeg-users] Composite vs. S-Video [was: DC30+ is leaving me]...

[Bernhard P. <sha...@ut...>]

Hallo

(I was offline for some time)

> at last I can capture again with my DC30+, but using a S-Video cable 
> only. As Bernhard suggested, the RCA connector of the card must be 
> damaged, while the S-Video connector works fine.
Do you have a picture of what you see, can you record something ?

> Somewhere, a long time ago, I must have read that S-Video is not as good 
> as composite, but that sounded strange to me at that time, and probably 
> I misunderstood.
Normaly you should get a better picture because S-Video has one wire for 
the luma, and one for the croma. That will normaly give you a better 
quality than a cable where you have both on one wire (like you vae it on 
  a composite cable)

> But just to be sure, are S-Video and composite video really equivalent? 
> Or are there some difference that could affect quality? Finally, does 
> lavrec capture exactly with the same quality whatever cable is used?
The picture should look the same, and lavrec sould also work if you 
select the correct input.

the 2nd mail from you:
> The only changes appear on October 27, when I got rid of my GeForce (I 
> never had xawtv working with it) to use the internal i810 (it works very 
> fine for me).
> 
> Finally, I got xawtv working (with -noxv option), and lavrec was working 
> as usual. I mean, I had no reason to think that something was going to 
> break...
That sound s good. But from the other mail it seems as if it is not 
working reliable again.

>  From Oct 27, logs show regularly the lines below:
> 
> DC30plus[0]: zoran_open(Xorg, pid=[3064]), users(-)=0
> DC30plus[0]: UNKNOWN ioctl cmd: 0x800476c6
> DC30plus[0]: VIDIOCSPICT - Invalid palette 9
> DC30plus[0]: UNKNOWN ioctl cmd: 0x80287610
> DC30plus[0]: zoran_close(Xorg, pid=[3064]), users(+)=1
That two ioclt cmd seem to be normal. Means they also appear on my 
machine. And there the card is working.

> just every time Xorg starts. The lines in my first post concerning xawtv 
> appear from Oct 27, but xawtv and lavrec have been working fine till Nov 
> 1, the last day I captured an old Video8 (but also some cartoons from a 
> satellite receiver). On Nov 2, no changes in the kern.logs (the messages 
> are the same as on preceeding days), but that was the day I could not 
> get anything but a black movie from both lavrec and xawtv.
That sounds like a hardware problem.

> I checked that the  video composite cable is working, by using it to 
> connect the videocamera to the TV set in order to playback a tape, and 
> it works.
That sounds more like a connector problem.

> At present, I suspect that the RCA plug for the video composite input of 
> the card is damaged. I should try the S-Video plug, but it seems 
> difficult to find a cable that converts RCA to S-Video. At least, in all 
> of the stores I know, I could not find one. I should made it by myself, 
> I only I knew how to do it.
You can't split Composite to S-Video. You need something like a comb 
filter. The other way (From S-Video to Composite) it can be "converted 
using a simple 470pF capacitor.

auf hoffentlich bald,

Berni the Chaos of Woodquarter

Email: sha...@ut...
www: http://www.lysator.liu.se/~gz/bernhard