csvorbis.Floor1.unpack C# (CSharp) Method

        public override Object unpack(Info vi , csBuffer opb)
        {
            int count=0,maxclass=-1,rangebits;
            InfoFloor1 info=new InfoFloor1();

            /* read partitions */
            info.partitions=opb.read(5);            /* only 0 to 31 legal */
            for(int j=0;j<info.partitions;j++)
            {
                info.partitionclass[j]=opb.read(4); /* only 0 to 15 legal */
                if(maxclass<info.partitionclass[j])
                    maxclass=info.partitionclass[j];
            }

            /* read partition classes */
            for(int j=0;j<maxclass+1;j++)
            {
                info.class_dim[j]=opb.read(3)+1; /* 1 to 8 */
                info.class_subs[j]=opb.read(2);  /* 0,1,2,3 bits */
                if(info.class_subs[j]<0)
                {
                    //goto err_out;
                    info.free();
                    return(null);
                }
                if(info.class_subs[j]!=0)
                {
                    info.class_book[j]=opb.read(8);
                }
                if(info.class_book[j]<0 || info.class_book[j]>=vi.books)
                {
                    //goto err_out;
                    info.free();
                    return(null);
                }
                for(int k=0;k<(1<<info.class_subs[j]);k++)
                {
                    info.class_subbook[j][k]=opb.read(8)-1;
                    if(info.class_subbook[j][k]<-1 || info.class_subbook[j][k]>=vi.books)
                    {
                        //goto err_out;
                        info.free();
                        return(null);
                    }
                }
            }

            /* read the post list */
            info.mult=opb.read(2)+1;     /* only 1,2,3,4 legal now */
            rangebits=opb.read(4);

            for(int j=0,k=0;j<info.partitions;j++)
            {
                count+=info.class_dim[info.partitionclass[j]];
                for(;k<count;k++)
                {
                    int t=info.postlist[k+2]=opb.read(rangebits);
                    if(t<0 || t>=(1<<rangebits))
                    {
                        //goto err_out;
                        info.free();
                        return(null);
                    }
                }
            }
            info.postlist[0]=0;
            info.postlist[1]=1<<rangebits;

            return(info);
            //  err_out:
            //    info.free();
            //    return(null);
        }