DirectShow音频采集pcm，实时编码AAC，附源码

定期送福利，今天给大家送上Windows中利用DirectShow采集microphone音频，并将采集到的pcm数据，利用FAAC库编码成AAC，进行本地存储或者网络传输。

直接贴代码，解析看注释：

/*
	功能描述：	简单实现用DirectShow采集Windows麦克风音频PCM数据
				经过FAAC编码成AAC存储文件，可根据项目修改成直播，对讲
				等实时传输类应用。
				
	From：		http://blog.csdn.net/xiejiashu
	Site:		http://www.easydarwin.org
	时间：		2014/07/28
*/
#include "../DSAudio/General.h"
#include<iostream>
#include<cstring>
#include<windows.h>
#include<conio.h>
#include "../DSAudio/dscapture.h"
#include "DSAudio/FAACEncoder.h"

unsigned char fBitsPerSample, fNumChannels;
unsigned fSamplingFrequency;
unsigned fGranularityInMS;

DSCapture* ds_capture_;
FAACEncoder* faac_encoder_;

unsigned long max_out_bytes;
unsigned char* outbuf;

FILE* f_aac_;

int main()
{

	fBitsPerSample = 16; //单个采样音频信息位数
	fNumChannels = 2; //通道数
	fSamplingFrequency = 44100;//采样率

	faac_encoder_ = new FAACEncoder(); //新建AAC编码对象

	faac_encoder_->Init(fSamplingFrequency,fNumChannels,fBitsPerSample); //初始化AAC编码器

	ds_capture_ = new DSCapture();
	std::map<CString, CString> a_devices = ds_capture_->DShowGraph()->AudioCapDevices();

	if(a_devices.size() == 0 ) ::exit(0);

	DSAudioFormat audio_fmt;
    audio_fmt.samples_per_sec = fSamplingFrequency;
    audio_fmt.channels = fNumChannels;
    audio_fmt.bits_per_sample = fBitsPerSample;

	// 枚举音频采样设备，选择最后一个
	CString audio_device_id;
	for (std::map<CString, CString>::iterator it = a_devices.begin(); it != a_devices.end(); ++it)
    {
		audio_device_id = it->first;
    }

    ds_capture_->Create(audio_device_id, audio_fmt, NULL);
   
	// 开始采集音频数据
    ds_capture_->StartAudio();

	::Sleep(10);

	max_out_bytes = faac_encoder_->MaxOutBytes();
    outbuf = (unsigned char*)malloc(max_out_bytes);

	// 编码后存文件
	f_aac_ = fopen("./audio.aac","wb");
	printf("Recording...");
	while(1)
	{
		int pcmLen = 0;
		// 采集音频pcm数据
		char* pcmBuf = ds_capture_->GetBuffer(pcmLen);
		if(pcmLen > 0)
		{
			unsigned int sample_count = (pcmLen << 3)/fBitsPerSample;
			unsigned int buf_size = 0;
			// 编码AAC
			faac_encoder_->Encode((unsigned char*)pcmBuf, sample_count, (unsigned char*)outbuf, buf_size);	
			if(buf_size > 0)
			{
				printf(".");
				// 存文件或者自定义
				fwrite(outbuf,1,buf_size,f_aac_);
			}			
		}
		// 释放采集的pcm数据
		ds_capture_->ReleaseBuffer(pcmBuf);	
		::Sleep(1);
	}

	free(outbuf);
}

源码下载：http://pan.baidu.com/s/1kTj05Fp

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