option -l

I want to know the compressed size of the reads, but only of the bp's (i.e., without quality values, IDs or other info).

I used the option -l with the output.qp file, and I get the number of reads, the number of bp's, the uncompressed size and the compressed size. Does this compressed size correspond to only the compressed size of the bp's? If not, is there an easy way of getting this info?

thanks a lot!