We theoretically study the properties of quasi-stationary light pulses, formed by simultaneously switching on two counter-propagating coupling fields of imbalanced intensities, in the retrieval of stored photonic information, in a room-temperature or hot media of gaseous atoms or molecules. An analytical solution is obtained, and its predictions are in good agreement with the results from the numerical calculation. With the analytical solution, we discuss the propagation, broadening, and energy decay of quasi-stationary light pulses.