Calculating the number of needed error correction words in QR code

Question

I like to encode QR codes. Therefore I need to know, how much error correction words are needed by an specified version and correction level. For QR version 1 in combination with ec-level Q there must be 13 error correction words and 13 data words. I know there are some tables (table 7,8,9) in the ISO/IEC 18004 where this information is stored. But I like to know if it's possible to calculate the amount of needed error correction words.

Greets, Raffi

Answer 1

Yes, you need ISO 18004. I suppose you could also look at the source code from zxing that calculates this. It happens around the method interleaveWithECBytes.