Speech Warning System Based on DirectSound Technique

For impelling to emergency linkage of city and making all kinds of related resource get valid integrating,a solution for speech warning system based on DirectSound technique is presented.It can assort the management section of police,fire fight and transportations,is for the demand of unifying the conductor,being good for harmony.The structure of hardware is discussed.Based on DirectSound technique,the capturing and playback of speech is described.The empirical work confirms that it impraves real-time ability of system by using stream buffer which size is 0.3 second.The compressed encoding of speech is implemented with G.729A coding arithmetic.Comparing with compression ration of 8 to 1,it saves 50% of space of magnetic disk by compression ratio of 16 to 1.