if(permutation[1]==1) return;
void ff_block_permute(INT16 *block, UINT8 *permutation, const UINT8 *scantable, int last){    int i;    INT16 temp[64];        if(last<=0) return;    if(permutation[1]==1) return; //FIXME its ok but not clean and might fail for some perms    for(i=0; i<=last; i++){        const int j= scantable[i];        temp[j]= block[j];        block[j]=0;    }        for(i=0; i<=last; i++){        const int j= scantable[i];        const int perm_j= permutation[j];        block[perm_j]= temp[j];    }}