Linux下的音频采集与回放(转)[@more@]作者: hotfire [文章出自: ]以下假设你对ioctl已有一定的认识及了解sndtools.h代码:#ifndef SNDTOOLS_H#define SNDTOOLS_H#include #define FMT8BITS AFMT_S8_LE #define FMT16BITS AFMT_S16_LE #define FMT8K 8000#define FMT16K 16000#define FMT22K 22000#define FMT44K 44000#define MONO 1#define STERO 2#ifndef VAR_STATICextern int devfd;extern int CapMask;#endif //ifndef VAR_STATIC//Open sound device, return 1 if open success//else return 0int OpenSnd();//Close sound deviceint CloseSnd();//Set record or playback format, return 1 if success//else return 0int SetFormat(int bits, int hz);//Set record or playback channel, return 1 if success//else return 1int SetChannel(int chn);//Recordint Record(char *buf, int size);//Playbackint Play(char *buf, int size);#endif //ifndef SNDTOOLS_Hsndtools.c代码:#include #include #include #include #include #define VAR_STATIC#include "sndtools.h"int devfd = 0;/** Open Sound device* Return 1 if success, else return 0.*/int OpenSnd(/* add by new version */int nWhich){if(devfd > 0)close(devfd);devfd = open("/dev/dsp", O_RDWR);if(devfd < 0)return 0;return 1;}/** Close Sound device* return 1 if success, else return 0.*/int CloseSnd(/* add by new version */int nWhich){close(devfd);devfd = 0;return 1;}/** Set Record an Playback format* return 1 if success, else return 0.* bits -- FMT8BITS(8bits), FMT16BITS(16bits)* hz -- FMT8K(8000HZ), FMT16K(16000HZ), FMT22K(22000HZ), FMT44K(44000HZ)*/int SetFormat(int bits, int hz){int tmp = bits;if( -1 == ioctl(devfd, SNDCTL_DSP_SETFMT, &tmp)){#ifdef DEBUG_WARNprintf("Set fmt to s16_little faile:%d
", nWhich);#endifreturn 0;}tmp = hz;if( -1 == ioctl(devfd, SNDCTL_DSP_SPEED, &tmp)){#ifdef DEBUG_WARNprintf("Set speed to %d:%d
", hz, nWhich);#endifreturn 0;}return 1;}/** Set Sound Card Channel* return 1 if success, else return 0.* chn -- MONO, STERO*/int SetChannel(int chn){int tmp = chn;if(-1 == ioctl(devfd, SNDCTL_DSP_CHANNELS, &tmp)){#ifdef DEBUG_WARNprintf("Set Audio Channel faile:%d
", nWhich);#endifreturn 0;}return 1;}/** Record* return numbers of byte for read.*/int Record(char *buf, int size){return read(devfd, buf, size);}/* * Playback* return numbers of byte for write.*/int Play(char *buf, int size){return write(devfd, buf, size);}test.c代码:// A sample to test record and playback.#include #include #include #include "sndtools.h"int main(){char *buf;int dwSize;if(!OpenSnd()){printf("Open sound device error!
");exit(-1);}SetFormat(FMT16BITS, FMT8K, WAVOUTDEV);SetChannel(MONO, WAVOUTDEV);buf = (char *)malloc(320);if(buf == NULL)exit(-1);for(int i = 0; i <1000; i++){dwSize = Record(buf, 640);dwSize = Play(buf, dwSize); }exit 1;}
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