Comb Filters

What's the state of comb filters in capture cards today?

Are they much better than the comb filters present in the laserdisc players of yesteryear? If so, would it be wise to get a laserdisc player that doesn't have its own comb filter (assuming that it's an otherwise excellent player) and rely on the comb filter in my capture card?

My current, and preferred, capture card is a Hauppauge 610 USB-Live2.

I might be showing my ignorance, but if you use the composite connections (Video, Audio L & R), you wouldn't be using the comb filter.

The comb filter is only used for the S-Video connection.........right?

:?

Davnes007 said:

I might be showing my ignorance, but if you use the composite connections (Video, Audio L & R), you wouldn't be using the comb filter.

The comb filter is only used for the S-Video connection.........right?

:?

Well, a comb filter can be applied to any signal. There are even software comb filters available in AviSynth; e.g., TComb.

However, it's my understanding that, in hardware, it's usually the opposite of what you mentioned. That is, comb filters are applied to composite video sources because the luma and chroma aren't separated (unlike S-Video), which results in dot crawl and rainbowing artifacts.

The S-Video signal is already separated by the LD player.

The composite signal will be separated by the capture card.

Davnes007 said:

The S-Video signal is already separated by the LD player.

The composite signal will be separated by the capture card.

This is technically true, but it's my understanding that most LD players do a poor job at separating luma from chroma for S-Video output.

AntcuFaalb said:

Davnes007 said:

The S-Video signal is already separated by the LD player.

The composite signal will be separated by the capture card.

This is technically true, but it's my understanding that most LD players do a poor job at separating luma from chroma for S-Video output.

No argument there.

AntcuFaalb said:

What's the state of comb filters in capture cards today?

Normally difficult to get the relevant specs. Analogue capture is becoming a dying art. ;-)

Are they much better than the comb filters present in the laserdisc players of yesteryear?

Probably. But are they better than the high-end comb filters of yesteryear, for example Faroudja VS-50 or VP-100, or Crystal Vision VPS-1?

If so, would it be wise to get a laserdisc player that doesn't have its own comb filter (assuming that it's an otherwise excellent player) and rely on the comb filter in my capture card?

Well, that's the real trick, isn't it?

I used to think that was the way to go, but I was reliably informed that most good players (i.e. those that have an s-video out) pass the signal through their internal comb filter regardless. The composite output is then just the s-video's luma and chroma recombined.

There are a few good players that do apparently output an untouched composite signal: the X0, for example, and some industrial models such as the LD-V8000.

But you also need to consider what difference the comb filter makes in the final result. As an example, I've shown that dot crawl caused by a poor comb filter is non-existent in a multi-capture average.

Thanks for the information, Moth3r!

There are a few good players that do apparently output an untouched composite signal: the X0, for example, and some industrial models such as the LD-V8000.

What about a Pioneer CLD-V2800?

From info here it looks like an industrial composite-only model, but not much info on whether it's any good or not.

Useful places to try and find details & specs are the forum on lddb.com, the Google Groups archive of alt.video.laserdisc, and old posts on here by Aleksbmw or Laserman.

I discovered my capture card, using the Philips SAA 7134 chipset, has a four line comb filtes... following this specs, it seems it's better than Pioneer HLD-X9 S-Video out, which uses a "mere" three lines...