How to get data off cd disk with black dots ?

[Danial129]

Hi everyone, not sure if this is the right place for this question but I have a very old  compact disk with important video on it, however there are some black dots on it(see pic attach) and some video  not playing. 
 

is there a solution for it to get as much of data as possible out of the cd as the whole video probably not gone on physical cd, as there are very few black dots on cd. 
 

so is there a software to get as much data as possible 

 

and 

Is there even a way to fix the physical cd itself

[SupaKomputa]

Those are corrosion, and i think it's dead.

There's no way you can get data from that spot as the metal part is gone.

[porina]

Interesting. I've not seen rot on a CD before, but have heard of it.

 

What format is the CD in? It is a CD not a DVD for example? CD allows for multiple levels of error correction, so it should be able to copy with some quite big errors if it were a data CD format. CD audio however increases capacity by using less error correction, and I suspect native video formats may do similar.

 

If it were CD Audio, then I know EAC would be a good choice, but I don't think it is designed to copy with video or other data formats.

[HowardYing]

I found this forum thread from another community, some agree that it's damage you can not recover from because they eat from the aluminum side first. 

[DigitalGoat]

It depends if the spots are on the surface or are in the dye layer, if surface then water + mild soap and rub gently in a circular fashion, repeat until gone. If disk rot then pretty much any data on those areas is gone as the reading laser will not be able to determine where the pits are.

[Danial129]

5 minutes ago, porina said:

Interesting. I've not seen rot on a CD before, but have heard of it.

 

What format is the CD in? It is a CD not a DVD for example? CD allows for multiple levels of error correction, so it should be able to copy with some quite big errors if it were a data CD format. CD audio however increases capacity by using less error correction, and I suspect native video formats may do similar.

 

If it were CD Audio, then I know EAC would be a good choice, but I don't think it is designed to copy with video or other data formats.

It’s says on back CDR 80 ,1x-32x

[porina]

3 minutes ago, Danial129 said:

It’s says on back CDR 80 ,1x-32x

I'm more interested in the data format. For example, is it VCD, or some files that someone saved on it as a data CD?

[Moonzy]

it is a data rot where the aluminum reacts with oxygen and turns black

oxygen seeps in from the protective layer that's on top of the CD and starts reacting with the raw aluminum

 

afaik, CD have data error correction, so you might be able to pull some data off of it still

 

i remember watching somewhere where a guy drilled a 2mm hole into his CD and still able to play the data

larger hole would be corrupted. (very very old video)

[porina]

2 minutes ago, Moonzy said:

afaik, CD have data error correction, so you might be able to pull some data off of it still

This is the hope essentially. It's been a LOT of years since I did it, but even for music CDs I think there were two interleaved layers of ECC, and data has another layer on top of that. So there will be two steps here, one is to get as much data off as possible, and secondly to make best use of that remaining data where possible.

[JP!]

3 hours ago, DigitalGoat said:

It depends if the spots are on the surface or are in the dye layer, if surface then water + mild soap and rub gently in a circular fashion, repeat until gone. If disk rot then pretty much any data on those areas is gone as the reading laser will not be able to determine where the pits are.

I have no idea about the rotting, i have never seen it before.

 

However, for a scratched / dirty CD / DVD / BD, what usually works for me is non abrasive toothpaste. Soap works as well, but toothpaste works better when there are (mild) scratches.

 

JP