I need help understanding the C1/C2 scan results I get from data or audio CD burns, using PlexTools Professional. I have gotten partial answers by studying this forum and by contacting Plextor, but I have some unanswered questions that are still bugging me.
As I understand it, the C1 stage of error checking normally counts up all the E11 + E21 + E31 and reports this sum. This would seem to be indicating the total block error rate. As I understand it, the E11 and E21 are corrected at this stage, and the E31 are passed along to the next stage.
After the interleaving shuffle, the C2 stage normally counts up all the E12 + E22 + E32. Again, as I understand it, the E12 and E22 are corrected at this stage and - - in most cases - - the E32 are not correctable at this stage and are registered as CU (uncorrectable).
The PlexTools “Help” file says that PlexTools reports E11 + E21 + E31 as C1. It further says that it reports only E22 as C2. This explanation leaves me puzzling over some of my results: In many cases of defective media, I have max C2 values that are bigger than my max C1 values. For example, I have one scan where C1max = 33 and C2max = 195.
So I am confused. If the C1 stage reports ALL the occurrences of read errors and corrects most of these, it should be passing a much smaller number to the second stage. Shouldn’t C2 therefore always be smaller than C1?
On top of that, PlexTools supposedly only reports the E22 portion of C2. This should make the reported C2 even smaller.
So how can I be getting results like C2max = 195 while C1max = 33???
And - - while we’re on the subject - - why does PlexTools only report E22 under C2? I can see the value in knowing E22, since it is the closest thing to the usually uncorrectable E32 without actually going there. But I’d like to know about E12 as well.
Now that I’m thinking about it - - does CD Speed report C2 differently from PlexTools? Would there be some advantage of using that instead?