Everybody knows, any cd sector in mode1 format contains main useful data 2048 bytes/sect. + ECC-EDC + SUB channel data and everybody knows, ECC-EDC+SUB can be reproduced on the main data. Almost all sectors of any cd disk with commercial protections have matching data of ECC-EDC+SUB to main sectors data. As you see, you don't need to create an rawsub image with full ECC-EDC+SUB data, just for those sectors with mismatched checksums+sub.
Therefore I think, why not to create the smart cd image format???
How I do imagine it, for example, read the image with raw and sub data, count on the fly the check sum of main data, if it matches with readed raw+sub data, just write in the image 2048 bytes of sector. If the sector has mismatched ECC-EDC data and Sub channels, just write the sector in the image as is.
So you may ask, what about storing the data, how the program should know, if the image contains normal data sectors and sectors with advanced data, that have raw+sub data. And that is easy
You could add at end of the image infos about sector number of any sector with additional raw+sub.
As example you could write the sector number as ever in hex 25050h=151632, and so you know, the sector, as example, 151632, contains data+ecc:edc+sub, so you know, if you want to read sectors in the image after this sector, you have to take into account bigger size of this advanced sector. Then you could write entire number of such advanced sectors at the right end of image to know, how much such sectors numbers there are at the end of image. So you don't need to change mds file format for such smart cd image format. Maximal theoretically possible additional size of this info about sector numbers would be not more as 1.5mb. And that, if all 355000 sectors would have such mismatched ecc-edc+sub. In reality impossible, but anyway, so about 0-100-10000 sectors could have such mismatching data.
Now think about, if there are not so many such advanced sectors in image you could fit an image on cd disk as file and in the same time as functional raw+sub image. Anyway the main point is to save space on this smart way.
That's what i want in future Alcohol version. Save the space.
