porting ffmpeg's problem , A/V sync

[denny.tang]

when porting the libavcodec/libavformat to stagefright, the A/V sync
problem happlened.
my way to set the kKetTime is :
video_packet->pts*av_q2d(time_base) : video keytime
audio_packet->pts*av_q2d(time_base) : audio keytime

when i play the video(640*280) , stagefright lost 6 frames everytime.
is it normal ?

please give me some suggestions,

thanks
Best Regard