[alsa-devel] Noise in begnning of alsa application

I have ALSA driver for capture device which works fine with VLC. when I try to capture and render using own application having some issues. When I start play, it has some noise in beginning and audio is discontinuous in between. Discontinuous means, some audio frame are getting dropped in between. cut cut sound for sine wave. I have tried snd_pcm_drop and snd_pcm_drain but no use. Kindly suggest how to remove the starting noise in ALSA.