???? ????? ??? ??? ?? ??? ???? ?? C++ ?? ??

??:
??? ??? ?? ???? ???? ?? ??? ?? ? ?????? ???, ?? ?? ???, ??? ?? ? ??. ??? ??? ?? ??, ??? ?? ?? ?? ?? ???? ????? ??? ??? ???. ? ????? C++ ??? ???? ???? ????? ??? ??? ?? ??? ???? ??? ???? ?? ??? ?????.

1. ??? ???? ???? ?????
???? ???? ???? ???? ???? ???? ??? ??? ??? ???? ???? ???? ?? ?? ?????. ???? ??, ??? ??, ?? ?? ?? ?? ??? ???? ???. ARM Cortex-A ???? ?? ?? ??? ???? ????? ??? ? ????. ?? I2S, PCM ?? ?? ??? ??? ?? ? ?? ?????? ???? ?? ???? ???.

2. ??? ??? ?? ????? ??
C++ ?? ???? ??? ?? ??? ???? ?? ???? ??? ??? ?? ?????? ???? ???. ????? ???? ??? ?? ?????? ??? ????.

1. PortAudio: ?? ? ?? ??? ???? ???? ????? ??? ? ?? ??? ??? ??? IO ????????.
2. Essentia: ????? ???? ??? ?? ????? ?? ??? ?? ?? ??? ?? ????????.
3. FFTW: ??? ??? ??? ?? ??? ??? ? ?? ??? ??? ????????.

?? ?????? ?? ??? ?? ??? ?????? ???? ?? ???? ???? ?????. ?? ?? ??? PortAudio ?????? ???? ??? ?? ? ?? ??? ?????.

#include <stdio.h>
#include "portaudio.h"

#define SAMPLE_RATE (44100)
#define CHANNEL_COUNT (2)
#define FRAMES_PER_BUFFER (1024)

// 錄制回調(diào)函數(shù)
int recordCallback(const void *inputBuffer, void *outputBuffer,
                    unsigned long framesPerBuffer,
                    const PaStreamCallbackTimeInfo *timeInfo,
                    PaStreamCallbackFlags statusFlags,
                    void *userData)
{
    // 處理錄制的音頻數(shù)據(jù)
    // ...

    return 0;
}

// 播放回調(diào)函數(shù)
int playCallback(const void *inputBuffer, void *outputBuffer,
                unsigned long framesPerBuffer,
                const PaStreamCallbackTimeInfo *timeInfo,
                PaStreamCallbackFlags statusFlags,
                void *userData)
{
    // 生成播放的音頻數(shù)據(jù)
    // ...

    return 0;
}

int main()
{
    PaStream *recordingStream;
    PaStream *playingStream;
    PaError err;

    // 初始化PortAudio庫
    err = Pa_Initialize();
    if (err != paNoError)
    {
        printf("Failed to initialize PortAudio
");
        return 0;
    }

    // 打開錄制流
    err = Pa_OpenDefaultStream(&recordingStream, CHANNEL_COUNT, 0, paFloat32,
                                SAMPLE_RATE, FRAMES_PER_BUFFER,
                                recordCallback, NULL);
    if (err != paNoError)
    {
        printf("Failed to open recording stream
");
        return 0;
    }

    // 打開播放流
    err = Pa_OpenDefaultStream(&playingStream, 0, CHANNEL_COUNT, paFloat32,
                                SAMPLE_RATE, FRAMES_PER_BUFFER,
                                NULL, playCallback);
    if (err != paNoError)
    {
        printf("Failed to open playing stream
");
        return 0;
    }

    // 啟動錄制流
    err = Pa_StartStream(recordingStream);
    if (err != paNoError)
    {
        printf("Failed to start recording stream
");
        return 0;
    }

    // 啟動播放流
    err = Pa_StartStream(playingStream);
    if (err != paNoError)
    {
        printf("Failed to start playing stream
");
        return 0;
    }

    // 等待用戶按下回車鍵停止程序
    getchar();

    // 停止錄制流
    err = Pa_StopStream(recordingStream);
    if (err != paNoError)
    {
        printf("Failed to stop recording stream
");
        return 0;
    }

    // 停止播放流
    err = Pa_StopStream(playingStream);
    if (err != paNoError)
    {
        printf("Failed to stop playing stream
");
        return 0;
    }

    // 關(guān)閉錄制流
    err = Pa_CloseStream(recordingStream);
    if (err != paNoError)
    {
        printf("Failed to close recording stream
");
        return 0;
    }

    // 關(guān)閉播放流
    err = Pa_CloseStream(playingStream);
    if (err != paNoError)
    {
        printf("Failed to close playing stream
");
        return 0;
    }

    // 終止PortAudio庫
    err = Pa_Terminate();
    if (err != paNoError)
    {
        printf("Failed to terminate PortAudio
");
        return 0;
    }

    return 0;
}

3. ??? ???? ? ??
???? ?????? ???? ???? ??? ???? ????? ???? ??? ?? ????? ???. ?? ??? ?????. ????? ??? ?? ??? ?? ???? ? ????.

1. ?? ??? ?? ??: ???? ???? ??? ???? ??? ?? ??? ??? ???? ?? ??? ???? ?????. ??? ????? ?? ??? ??? ?? ???? ??? ? ????.
2. ???? ??? ???? ??: ???? ??? ????? ???? ???? ??? ???? ?? ? ????. ?? ?? FFT(Fast Fourier Transform) ????? ??? ?? ??? ??? ???? ? ?????.
3. ??? ?? ??: ??? ?? ?? ??? ???? ???? ???? ????, ?? ???? ?? ??? ??? ???, ???? ????.

??:
? ???? ???? ????? ??? ??? ?? ??? ???? ?? C++ ??? ??? ?????. ??? ???? ???? ??? ?? ?????? ???? ????? ??? ????? ??? ????? ???? ??? ?? ??? ??? ? ????. ? ??? ???? ???? ??? ?? ?????? ??? ??? ????.

?? ??:

1. PortAudio ?? ??: http://www.portaudio.com/
2. Essentia ?? ??: http://essentia.upf.edu/
3. FFTW ?? ??: http://www.fftw .org/

? ??? C++ ??? ??? ???? ????? ??? ??? ?? ??? ???? ??? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!