  We reanalyze the decay constants of s-wave and p-wave mesons and D, B ->M
form factors, where M represents a pseudoscalar meson, a vector meson, a scalar
meson, or an axial vector meson within a covariant light-front quark model. The
parameter \beta for wave-functions of most of s-wave mesons and of a few
axial-vector mesons are fixed with latest experimental information, wherever
available or using the lattice calculations. The treatment of masses and mixing
angles for strange axial vector mesons is improved for the purpose. We extend
our analysis to determine the form factors appearing in the transition of D_s,
B_s->M transitions, and to the isoscalar final state mesons. Numerical results
of the form factors for transitions between a heavy pseudoscalar meson and an
s-wave or p-wave light meson and their momentum dependence are presented in
detail. Further, their sensitivity to uncertainties of beta parameters of the
initial as well as the final mesons is investigated. Some experimental
measurements of the charmed and bottom meson decays are employed to compare the
decay constants and transition form factors obtained in this and other works.
