webrtc（二） ns

版本对应的commit

commit 99f8566524b3764bf84b7f4cbd8232bdf6c142a5
Author: kjellander <kjellander@webrtc.org>
Date:   Sun Nov 29 20:50:44 2015 -0800

由于缺少说明文档和参考文献，这里简单罗列一下使用的例子

int nsTest(char *filename, char *outfilename, int mode)
{
//alloc
FILE *infp=fopen(filename,"r");
int nBands = 1;
int frameSize = 160;//10ms对应于160个short
short *temp = (short*)malloc(frameSize*sizeof(short));
float **pData = (float**)malloc(nBands*sizeof(float*));
pData[0] = (float*)malloc(frameSize*sizeof(float));

float **pOutData = (float**)malloc(nBands*sizeof(float*));
pOutData[0] = (float*)malloc(frameSize*sizeof(float));
int offset = 0;

//init
NsHandle *handle = 0;
int ret = 0;
handle=WebRtcNs_Create();
ret= WebRtcNs_Init(handle,16000);
if(ret==-1){
printf("%s","init failure!");
return -1;
}
ret = WebRtcNs_set_policy(handle,2);

//process
FILE *outfp = fopen(outfilename,"w");
int len = frameSize;
while(len > 0)
{
memset(temp, 0, frameSize*sizeof(short));
len = fread(temp, sizeof(short), frameSize, infp);
int i;
for(i = 0; i < frameSize; i++)
{
pData[0][i] = (float)temp[i];
//fprintf(stdout, "ns:%d\n", temp[i]);
}
WebRtcNs_AnalyzeCore((NoiseSuppressionC*)handle,pData[0]);
WebRtcNs_Process(handle,pData,nBands,pOutData);

for(i = 0; i < frameSize; i++)
{
temp[i] = (short)pOutData[0][i];
//fprintf(stderr, "ns:%d\n", temp[i]);
}
//write file
len = fwrite(temp,sizeof(short),len,outfp);
}
fclose(infp);
fclose(outfp);

WebRtcNs_Free(handle);
free(temp);
free(pData[0]);
free(pData);
free(pOutData[0]);
free(pOutData);
}

代码使用流程参考webrtc/modules/audio_processing/noise_suppression_impl.cc