DVD Playback Dot Crawl?

[darkdream787]

I just bought a new DVD to watch with a relative but I am seeing something I have had no issue with before. Encoding DVD's into H.264 or DIVX for PC playback this would be called Dot Crawl but I have never had this problem when playing a DVD on my television before.


Im guessing this is just my DVD player but Im not sure because I have no other TV to test it on.


During playblack I notice these blocks kind of like a checkerboard running along the edges of the video like an escalator. Even when paused they keep moving. Here are some pictures of it. You will notice them most on the right side of her face in the pictures. This is very strong during playback and cant be ignored no matter how hard I try. Its very annoying!!

http://img694.imageshack.us/img694/7527/photo0345h.jpg

http://img13.imageshack.us/img13/1971/photo0342v.jpg

http://img401.imageshack.us/img401/7571/photo0343u.jpg


Am I right about this being dot crawl? and if so why have I never had this problem with any other DVD I have played up untill now? And believe me I have played several hundred of them. This is the first DVD that I have noticed this happen on when being played. Is it my DVD player like I suspect or the DVD itself? Can I get rid of this problem?


If it helps any to know the information about the DVD this is what was bought.

http://www.amazon.com/Pocahontas-Two-Disc-Anniversary-Irene-Bedard/dp/B0007KTBIU/ref=c...pr_product_top

[poisondeathray]

Am I right about this being dot crawl? and if so why have I never had this problem with any other DVD I have played up untill now? And believe me I have played several hundred of them. This is the first DVD that I have noticed this happen on when being played. Is it my DVD player like I suspect or the DVD itself? Can I get rid of this problem?

It looks like dot crawl, but it's hard to say definitively without a video sample

If the DVD itself was derived from an analog source, you can get dot crawl from analog crosstalk

You can try tcomb , checkmate, dedot , guavacomb in avisynth, a few others

[dragonkeeper]

Hard to say with out a sample the video but it looks like a combination of the two, looks like the edges are over sharpened. DVD production houses are notorious for over-sharpening edges

[edDV]

Looks to me like NTSC routed to Y with no chroma separation.

Explain how you captured and the interconnections.

[jagabo]

Stop using composite. Use s-video, component, or HDMI.

There's no way the commercial release of Pocahontas 10 Anniversary Edition was made from an analog composite source.

[dragonkeeper]

Stop using composite. Use s-video, component, or HDMI.

Good catch i should have realized that from the pic.

[darkdream787]

Stop using composite. Use s-video, component, or HDMI.

There's no way the commercial release of Pocahontas 10 Anniversary Edition was made from an analog composite source.

I would love to use S-Video but my TV doesn't have it. its only a standard definition CRT TV that was gotten about 2008 or so just before they were phased out of stores and replaced with HDTV's

It looks fine when I stick the DVD into my computer, its only this 1 DVD out of them all and I only see it on my TV.

[darkdream787]

Am I right about this being dot crawl? and if so why have I never had this problem with any other DVD I have played up untill now? And believe me I have played several hundred of them. This is the first DVD that I have noticed this happen on when being played. Is it my DVD player like I suspect or the DVD itself? Can I get rid of this problem?

It looks like dot crawl, but it's hard to say definitively without a video sample

If the DVD itself was derived from an analog source, you can get dot crawl from analog crosstalk

You can try tcomb , checkmate, dedot , guavacomb in avisynth, a few others

Im not trying to encode this to an MKV or AVI or anything like that Poison. I know how to fix it with avisynth if Im encoding it for PC playback, this is a problem with my DVD player and my TV. This video is coming from the actual purchased DVD, not one that I encoded and or made myself.

[edDV]

Am I right about this being dot crawl? and if so why have I never had this problem with any other DVD I have played up untill now? And believe me I have played several hundred of them. This is the first DVD that I have noticed this happen on when being played. Is it my DVD player like I suspect or the DVD itself? Can I get rid of this problem?

It looks like dot crawl, but it's hard to say definitively without a video sample

If the DVD itself was derived from an analog source, you can get dot crawl from analog crosstalk

You can try tcomb , checkmate, dedot , guavacomb in avisynth, a few others

Im not trying to encode this to an MKV or AVI or anything like that Poison. I know how to fix it with avisynth if Im encoding it for PC playback, this is a problem with my DVD player and my TV. This video is coming from the actual purchased DVD, not one that I encoded and or made myself.

Its possible to do much better from composite source. How did you capture this?

[jagabo]

He's not capturing it, he's just wants to watch it on TV without all the dotcrawl artifacts.

Unless the TV has a good comb filter you're not going to get rid of the dot crawl artifacts when using a composite cable. The TV does that with all material it's just that it's much more noticeable with highly saturated, sharp, animated content.

[darkdream787]

He's not capturing it, he's just wants to watch it on TV without all the dotcrawl artifacts.

Unless the TV has a good comb filter you're not going to get rid of the dot crawl artifacts when using a composite cable. The TV does that with all material it's just that it's much more noticeable with highly saturated, sharp, animated content.

Well that makes sense and thats about what I get from reading up on it. But how come out of all the hundreds of DVD's I've played and watched, this is the first to do that to me?

[edDV]

He's not capturing it, he's just wants to watch it on TV without all the dotcrawl artifacts.

Unless the TV has a good comb filter you're not going to get rid of the dot crawl artifacts when using a composite cable. The TV does that with all material it's just that it's much more noticeable with highly saturated, sharp, animated content.

Well that makes sense and thats about what I get from reading up on it. But how come out of all the hundreds of DVD's I've played and watched, this is the first to do that to me?

So those pictures you showed are photos off the screen? If so it has nothing to do with the video on the DVD. It reflects YCbCr to NTSC encoding in your DVD player and notch filter or no filter chroma separation in your TV.

NTSC (or PAL) video encodes chroma using quadrature modulation about a subcarrier. In the case of NTSC this is at 3.58 MHz. If a composite NTSC source is viewed directly with no Y/C separation, you will see the chroma modulation affecting luma as small dots.


Unfiltered cross color (zoomed).

With a notch filter, the effect is more noticeable on edge transitions like you are seeing in your pictures. The more chroma saturation, the more dot crawl from chroma bleed into luma especially at transitions from one saturated color to another saturated color. The disadvantage of the notch filter technique is lower luma resolution (detail).

A higher end TV will use a 2D or 3D comb filter to separate chroma from luma while preserving luminance detail around 3.58 MHz and above. Four wire S-Video avoids the problem by keeping luma and chroma on separate wires. Luma is on one wire pair, modulated subcarrier is on the other wire pair.

Examples -- from http://home.earthlink.net/~tacosalad/video/dotcrawl.html


Before someone in PAL land blames NTSC, the issue is the same for PAL. The only difference is PAL subcarrier is at a slightly higher 4.43 MHz frequency so the cross color artifacts are somewhat smaller.

This shows PAL chroma to luminance artifacts (unfiltered and zoomed).

Composite PAL output from Cyberhome DVD player, monochrome capture.

[darkdream787]

Actually its just my tv, i tried this on many other tv's with the same dvd player and old crt tv's and mines the only one doing it. Must be the type or make of it.

thanks for the info pplz