// Recorder.cpp : Defines the entry point for the console application.
//

#include <exception>
#include <iostream>

extern "C" {
#include "common.h"
}

#include "headers_ffmpeg.h"

void capture_screen()
{
    try {
        ffmpeg_register_all();
        ffmpeg_register_devices();

        AVFormatContext *pFormatCtx = avformat_alloc_context();

        const AVInputFormat *ifmt = av_find_input_format("gdigrab");
        avformat_open_input(&pFormatCtx, "desktop", ifmt, NULL);

        if (avformat_find_stream_info(pFormatCtx, NULL) < 0) {
            throw std::exception("could not find stream information");
        }

        int videoIndex = -1;
        for (int i = 0; i < pFormatCtx->nb_streams; i++) {
            if (ffmpeg_get_codec_type(pFormatCtx->streams[i]) == AVMEDIA_TYPE_VIDEO) {
                videoIndex = i;
                break;
            }
        }

        if (videoIndex == -1)
            throw std::exception("could not find a video stream");

        AVCodecContext *pDecoderCtx = ffmpeg_get_codec_context(pFormatCtx->streams[videoIndex]);

        //init decoder
        AVCodec *pDecoder = avcodec_find_decoder(pDecoderCtx->codec_id);

        if (pDecoder == NULL)
            throw std::exception("could not find codec");

        if (avcodec_open2(pDecoderCtx, pDecoder, NULL) != 0) {
            throw std::exception("open codec ffailed");
        }

        //init transfer and buffer
        AVFrame *pFrameRGB, *pFrameYUV;
        pFrameRGB = av_frame_alloc();
        pFrameYUV = av_frame_alloc();

        uint8_t *out_buffer = (uint8_t *) av_malloc(
            avpicture_get_size(AV_PIX_FMT_YUV420P, pDecoderCtx->width, pDecoderCtx->height));
        avpicture_fill((AVPicture *) pFrameYUV,
                       out_buffer,
                       AV_PIX_FMT_YUV420P,
                       pDecoderCtx->width,
                       pDecoderCtx->height);

        int ret, gotPic = 0;

        AVPacket *packet = (AVPacket *) av_malloc(sizeof(AVPacket));

        struct SwsContext *imgConvertCtx = NULL;
        imgConvertCtx = sws_getContext(pDecoderCtx->width,
                                       pDecoderCtx->height,
                                       pDecoderCtx->pix_fmt,
                                       pDecoderCtx->width,
                                       pDecoderCtx->height,
                                       AV_PIX_FMT_YUV420P,
                                       SWS_BICUBIC,
                                       NULL,
                                       NULL,
                                       NULL);

        //init encoder
        AVCodec *pEncoder = avcodec_find_encoder(AV_CODEC_ID_H264);
        if (pEncoder == NULL)
            throw std::exception("could not find encoder");

        AVCodecContext *pEncoderCtx = avcodec_alloc_context3(pEncoder);
        if (pEncoderCtx == NULL)
            throw std::exception("could not alloc context for encoder");

        pEncoderCtx->codec_id = AV_CODEC_ID_H264;
        pEncoderCtx->codec_type = AVMEDIA_TYPE_VIDEO;
        pEncoderCtx->pix_fmt = AV_PIX_FMT_YUV420P;
        pEncoderCtx->width = pDecoderCtx->width;
        pEncoderCtx->height = pDecoderCtx->height;
        pEncoderCtx->time_base.num = 1;
        pEncoderCtx->time_base.den = 20; //֡��(��һ���Ӷ�����ͼƬ)
        pEncoderCtx->bit_rate = 4000000; //������(���������С���Ըı�������Ƶ������)
        pEncoderCtx->gop_size = 12;

        if (pEncoderCtx->flags & AVFMT_GLOBALHEADER)
            pEncoderCtx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;

        AVDictionary *param = 0;

        av_dict_set(&param, "preset", "superfast", 0);
        av_dict_set(&param, "tune", "zerolatency", 0);

        pEncoder = avcodec_find_encoder(pEncoderCtx->codec_id);
        if (pEncoder == NULL)
            throw std::exception("could not find encoder by context");

        if (avcodec_open2(pEncoderCtx, pEncoder, &param) != 0)
            throw std::exception("open encoder failed");

        AVFrame *pFrame264 = av_frame_alloc();
        int frame264Size = avpicture_get_size(pEncoderCtx->pix_fmt,
                                              pEncoderCtx->width,
                                              pEncoderCtx->height);
        uint8_t *frame264Buf = (uint8_t *) av_malloc(frame264Size);
        avpicture_fill((AVPicture *) pFrame264,
                       frame264Buf,
                       pEncoderCtx->pix_fmt,
                       pEncoderCtx->width,
                       pEncoderCtx->height);

        AVPacket pkt264;
        av_new_packet(&pkt264, frame264Size);

        int Y_size = pEncoderCtx->width * pEncoderCtx->height;

        for (;;) {
            if (av_read_frame(pFormatCtx, packet) < 0) {
                break;
            }

            if (packet->stream_index == videoIndex) {
                ret = avcodec_decode_video2(pDecoderCtx, pFrameRGB, &gotPic, packet);
                if (ret < 0) {
                    throw std::exception("decode error");
                }

                //trans rgb to yuv420 in out_buffer
                if (gotPic) {
                    sws_scale(imgConvertCtx,
                              (const uint8_t *const *) pFrameRGB->data,
                              pFrameRGB->linesize,
                              0,
                              pDecoderCtx->height,
                              pFrameYUV->data,
                              pFrameYUV->linesize);

                    gotPic = 0;
                    pFrame264->data[0] = out_buffer;                  //Y
                    pFrame264->data[1] = out_buffer + Y_size;         //U
                    pFrame264->data[2] = out_buffer + Y_size * 5 / 4; //V

                    ret = avcodec_encode_video2(pEncoderCtx, &pkt264, pFrame264, &gotPic);
                    if (gotPic == 1) {
                        printf("264 packet:%d\r\n", pkt264.size);

                        static FILE *fp = fopen("a.264", "wb+");

                        fwrite(pkt264.data, 1, pkt264.size, fp);

                        av_free_packet(&pkt264);
                    }
                }

                // 移除固定睡眠以降低延迟，依靠事件/时间戳节奏
            }

            av_free_packet(packet);
        } //for(;;��

        av_free(pFrameYUV);
        avcodec_close(pDecoderCtx);
        avformat_close_input(&pFormatCtx);
    } catch (std::exception ex) {
        printf("%s\r\n", ex.what());
    }
}

#include <AudioClient.h>
#include <AudioPolicy.h>
#include <MMDeviceAPI.h>

#define REFTIMES_PER_SEC 10000000
#define REFTIMES_PER_MILLISEC 10000

#define EXIT_ON_ERROR(hres) \
    if (FAILED(hres)) { \
        goto Exit; \
    }
#define SAFE_RELEASE(punk) \
    if ((punk) != NULL) { \
        (punk)->Release(); \
        (punk) = NULL; \
    }

const CLSID CLSID_MMDeviceEnumerator = __uuidof(MMDeviceEnumerator);
const IID IID_IMMDeviceEnumerator = __uuidof(IMMDeviceEnumerator);
const IID IID_IAudioClient = __uuidof(IAudioClient);
const IID IID_IAudioCaptureClient = __uuidof(IAudioCaptureClient);

#define MoveMemory RtlMoveMemory
#define CopyMemory RtlCopyMemory
#define FillMemory RtlFillMemory
#define ZeroMemory RtlZeroMemory

#define min(a, b) (((a) < (b)) ? (a) : (b))

//
//  WAV file writer.
//
//  This is a VERY simple .WAV file writer.
//

//
//  A wave file consists of:
//
//  RIFF header:    8 bytes consisting of the signature "RIFF" followed by a 4 byte file length.
//  WAVE header:    4 bytes consisting of the signature "WAVE".
//  fmt header:     4 bytes consisting of the signature "fmt " followed by a WAVEFORMATEX
//  WAVEFORMAT:     <n> bytes containing a waveformat structure.
//  DATA header:    8 bytes consisting of the signature "data" followed by a 4 byte file length.
//  wave data:      <m> bytes containing wave data.
//
//
//  Header for a WAV file - we define a structure describing the first few fields in the header for convenience.
//
struct WAVEHEADER
{
    DWORD dwRiff;    // "RIFF"
    DWORD dwSize;    // Size
    DWORD dwWave;    // "WAVE"
    DWORD dwFmt;     // "fmt "
    DWORD dwFmtSize; // Wave Format Size
};

//  Static RIFF header, we'll append the format to it.
const BYTE WaveHeader[] = {'R', 'I', 'F', 'F', 0x00, 0x00, 0x00, 0x00, 'W',  'A',
                           'V', 'E', 'f', 'm', 't',  ' ',  0x00, 0x00, 0x00, 0x00};

//  Static wave DATA tag.
const BYTE WaveData[] = {'d', 'a', 't', 'a'};

//
//  Write the contents of a WAV file.  We take as input the data to write and the format of that data.
//
bool WriteWaveFile(HANDLE FileHandle,
                   const BYTE *Buffer,
                   const size_t BufferSize,
                   const WAVEFORMATEX *WaveFormat)
{
    DWORD waveFileSize = sizeof(WAVEHEADER) + sizeof(WAVEFORMATEX) + WaveFormat->cbSize
                         + sizeof(WaveData) + sizeof(DWORD) + static_cast<DWORD>(BufferSize);
    BYTE *waveFileData = new (std::nothrow) BYTE[waveFileSize];
    BYTE *waveFilePointer = waveFileData;
    WAVEHEADER *waveHeader = reinterpret_cast<WAVEHEADER *>(waveFileData);

    if (waveFileData == NULL) {
        printf("Unable to allocate %d bytes to hold output wave data\n", waveFileSize);
        return false;
    }

    //
    //  Copy in the wave header - we'll fix up the lengths later.
    //
    CopyMemory(waveFilePointer, WaveHeader, sizeof(WaveHeader));
    waveFilePointer += sizeof(WaveHeader);

    //
    //  Update the sizes in the header.
    //
    waveHeader->dwSize = waveFileSize - (2 * sizeof(DWORD));
    waveHeader->dwFmtSize = sizeof(WAVEFORMATEX) + WaveFormat->cbSize;

    //
    //  Next copy in the WaveFormatex structure.
    //
    CopyMemory(waveFilePointer, WaveFormat, sizeof(WAVEFORMATEX) + WaveFormat->cbSize);
    waveFilePointer += sizeof(WAVEFORMATEX) + WaveFormat->cbSize;

    //
    //  Then the data header.
    //
    CopyMemory(waveFilePointer, WaveData, sizeof(WaveData));
    waveFilePointer += sizeof(WaveData);
    *(reinterpret_cast<DWORD *>(waveFilePointer)) = static_cast<DWORD>(BufferSize);
    waveFilePointer += sizeof(DWORD);

    //
    //  And finally copy in the audio data.
    //
    CopyMemory(waveFilePointer, Buffer, BufferSize);

    //
    //  Last but not least, write the data to the file.
    //
    DWORD bytesWritten;
    if (!WriteFile(FileHandle, waveFileData, waveFileSize, &bytesWritten, NULL)) {
        printf("Unable to write wave file: %d\n", GetLastError());
        delete[] waveFileData;
        return false;
    }

    if (bytesWritten != waveFileSize) {
        printf("Failed to write entire wave file\n");
        delete[] waveFileData;
        return false;
    }
    delete[] waveFileData;
    return true;
}

//
//  Write the captured wave data to an output file so that it can be examined later.
//
void SaveWaveData(BYTE *CaptureBuffer, size_t BufferSize, const WAVEFORMATEX *WaveFormat)
{
    HRESULT hr = NOERROR;

    SYSTEMTIME st;
    GetLocalTime(&st);
    char waveFileName[_MAX_PATH] = {0};
    sprintf(waveFileName,
            ".\\WAS_%04d-%02d-%02d_%02d_%02d_%02d_%02d.wav",
            st.wYear,
            st.wMonth,
            st.wDay,
            st.wHour,
            st.wMinute,
            st.wSecond,
            st.wMilliseconds);

    HANDLE waveHandle = CreateFile(waveFileName,
                                   GENERIC_WRITE,
                                   FILE_SHARE_READ,
                                   NULL,
                                   CREATE_ALWAYS,
                                   FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN,
                                   NULL);
    if (waveHandle != INVALID_HANDLE_VALUE) {
        if (WriteWaveFile(waveHandle, CaptureBuffer, BufferSize, WaveFormat)) {
            printf("Successfully wrote WAVE data to %s\n", waveFileName);
        } else {
            printf("Unable to write wave file\n");
        }
        CloseHandle(waveHandle);
    } else {
        printf("Unable to open output WAV file %s: %d\n", waveFileName, GetLastError());
    }
}

static int check_sample_fmt(const AVCodec *codec, enum AVSampleFormat sample_fmt);
static int select_sample_rate(const AVCodec *codec);

BOOL AdjustFormatTo16Bits(WAVEFORMATEX *pwfx)
{
    BOOL bRet(FALSE);

    if (pwfx->wFormatTag == WAVE_FORMAT_IEEE_FLOAT) {
        pwfx->wFormatTag = WAVE_FORMAT_PCM;
        pwfx->wBitsPerSample = 16;
        pwfx->nBlockAlign = pwfx->nChannels * pwfx->wBitsPerSample / 8;
        pwfx->nAvgBytesPerSec = pwfx->nBlockAlign * pwfx->nSamplesPerSec;

        bRet = TRUE;
    } else if (pwfx->wFormatTag == WAVE_FORMAT_EXTENSIBLE) {
        PWAVEFORMATEXTENSIBLE pEx = reinterpret_cast<PWAVEFORMATEXTENSIBLE>(pwfx);
        if (IsEqualGUID(KSDATAFORMAT_SUBTYPE_IEEE_FLOAT, pEx->SubFormat)) {
            pEx->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
            pEx->Samples.wValidBitsPerSample = 16;
            pwfx->wBitsPerSample = 16;
            pwfx->nBlockAlign = pwfx->nChannels * pwfx->wBitsPerSample / 8;
            pwfx->nAvgBytesPerSec = pwfx->nBlockAlign * pwfx->nSamplesPerSec;

            bRet = TRUE;
        }
    }

    return bRet;
}

#define DEF_CAPTURE_MIC

HRESULT capture_audio()
{
    HRESULT hr;
    REFERENCE_TIME hnsRequestedDuration = REFTIMES_PER_SEC;
    REFERENCE_TIME hnsActualDuration;
    UINT32 bufferFrameCount;
    UINT32 numFramesAvailable;
    IMMDeviceEnumerator *pEnumerator = NULL;
    IMMDevice *pDevice = NULL;
    IAudioClient *pAudioClient = NULL;
    IAudioCaptureClient *pCaptureClient = NULL;
    WAVEFORMATEX *pwfx = NULL;
    UINT32 packetLength = 0;
    BOOL bDone = FALSE;
    BYTE *pData;
    DWORD flags;

    /*CoTaskMemFree(pwfx);
	SAFE_RELEASE(pEnumerator)
		SAFE_RELEASE(pDevice)
		SAFE_RELEASE(pAudioClient)
		SAFE_RELEASE(pCaptureClient)*/

    hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);

    hr = CoCreateInstance(CLSID_MMDeviceEnumerator,
                          NULL,
                          CLSCTX_ALL,
                          IID_IMMDeviceEnumerator,
                          (void **) &pEnumerator);
    EXIT_ON_ERROR(hr)

    hr = pEnumerator->GetDefaultAudioEndpoint(eRender, eConsole, &pDevice);
    EXIT_ON_ERROR(hr)

    hr = pDevice->Activate(IID_IAudioClient, CLSCTX_ALL, NULL, (void **) &pAudioClient);
    EXIT_ON_ERROR(hr)

    hr = pAudioClient->GetMixFormat(&pwfx);
    EXIT_ON_ERROR(hr)

    //AdjustFormatTo16Bits(pwfx);

    hr = pAudioClient->Initialize(AUDCLNT_SHAREMODE_SHARED,
                                  AUDCLNT_STREAMFLAGS_LOOPBACK | AUDCLNT_STREAMFLAGS_EVENTCALLBACK,
                                  hnsRequestedDuration,
                                  0,
                                  pwfx,
                                  NULL);
    EXIT_ON_ERROR(hr)

    size_t persample_size = (pwfx->wBitsPerSample / 8) * pwfx->nChannels;

    // Get the size of the allocated buffer.
    hr = pAudioClient->GetBufferSize(&bufferFrameCount);
    EXIT_ON_ERROR(hr)

    hr = pAudioClient->GetService(IID_IAudioCaptureClient, (void **) &pCaptureClient);
    EXIT_ON_ERROR(hr)

    // Calculate the actual duration of the allocated buffer.
    hnsActualDuration = (double) REFTIMES_PER_SEC * bufferFrameCount / pwfx->nSamplesPerSec;

    av_register_all();

    AVIOContext *output_io_context = NULL;
    AVFormatContext *output_format_context = NULL;
    AVCodecContext *output_codec_context = NULL;
    AVStream *output_stream = NULL;
    AVCodec *output_codec = NULL;

    const char *out_file = "tdjm.aac";

    if (avio_open(&output_io_context, out_file, AVIO_FLAG_READ_WRITE) < 0) {
        printf("Failed to open output file!\n");
        return -1;
    }

    output_format_context = avformat_alloc_context();
    if (output_format_context == NULL) {
        return -1;
    }

    output_format_context->pb = output_io_context;

    output_format_context->oformat = av_guess_format(NULL, out_file, NULL);

    output_format_context->url = av_strdup(out_file);

    if (!(output_codec = avcodec_find_encoder(AV_CODEC_ID_AAC)))
        return -1;

    int is_support = check_sample_fmt(output_codec, AV_SAMPLE_FMT_S16);
    int selected_sample = select_sample_rate(output_codec);

    output_stream = avformat_new_stream(output_format_context, NULL);
    if (!output_stream)
        return -1;

    output_codec_context = avcodec_alloc_context3(output_codec);
    if (output_codec_context == NULL)
        return -1;

    output_codec_context->channels
        = 2; //av_get_channel_layout_nb_channels(pEncoderCtx->channel_layout);
    output_codec_context->channel_layout = ffmpeg_get_default_channel_layout(2); //AV_CH_LAYOUT_STEREO;
    output_codec_context->sample_rate = pwfx->nSamplesPerSec;                //48000
    output_codec_context->sample_fmt = AV_SAMPLE_FMT_FLTP;
    output_codec_context->bit_rate = 96000;

    output_codec_context->strict_std_compliance = FF_COMPLIANCE_EXPERIMENTAL;

    output_codec_context->time_base.den = pwfx->nSamplesPerSec;
    output_codec_context->time_base.num = 1;

    if (output_format_context->oformat->flags & AVFMT_GLOBALHEADER) {
        output_format_context->oformat->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
    }

    if (avcodec_open2(output_codec_context, output_codec, NULL) < 0)
        throw std::exception("open audio encoder failed");

    if (avcodec_parameters_from_context(output_stream->codecpar, output_codec_context) < 0)
        return -1;

    AVFrame *resampled_frame = av_frame_alloc();
    resampled_frame->nb_samples = output_codec_context->frame_size;
    resampled_frame->channel_layout = output_codec_context->channel_layout;
    resampled_frame->format = output_codec_context->sample_fmt;
    resampled_frame->sample_rate = output_codec_context->sample_rate;

    int resampled_size = av_samples_get_buffer_size(NULL,
                                                    output_codec_context->channels,
                                                    output_codec_context->frame_size,
                                                    output_codec_context->sample_fmt,
                                                    0);

    uint8_t *resampled_buf = (uint8_t *) av_malloc(resampled_size);
    if (avcodec_fill_audio_frame(resampled_frame,
                                 output_codec_context->channels,
                                 output_codec_context->sample_fmt,
                                 resampled_buf,
                                 resampled_size,
                                 0)
        < 0)
        return -1;

    AVFrame *sample_frame = av_frame_alloc();
    sample_frame->nb_samples = 1024;
    sample_frame->channel_layout = ffmpeg_get_default_channel_layout(pwfx->nChannels);
    sample_frame->format = AV_SAMPLE_FMT_FLT;
    sample_frame->sample_rate = pwfx->nSamplesPerSec;

    int sample_size = av_samples_get_buffer_size(NULL, pwfx->nChannels, 1024, AV_SAMPLE_FMT_FLT, 0);
    uint8_t *sample_buf = (uint8_t *) av_malloc(sample_size);

    avcodec_fill_audio_frame(sample_frame,
                             pwfx->nChannels,
                             AV_SAMPLE_FMT_FLT,
                             sample_buf,
                             sample_size,
                             0);

    AVPacket pkt;

    HANDLE hAudioSamplesReadyEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
    if (hAudioSamplesReadyEvent == NULL) {
        printf("Unable to create samples ready event: %d.\n", GetLastError());
        goto Exit;
    }

    hr = pAudioClient->SetEventHandle(hAudioSamplesReadyEvent);
    if (FAILED(hr)) {
        printf("Unable to set ready event: %x.\n", hr);
        return false;
    }

    //init resampler
    SwrContext *resample_ctx = swr_alloc_set_opts(NULL,
                                                  AV_CH_LAYOUT_STEREO,
                                                  AV_SAMPLE_FMT_FLTP,
                                                  48000,
                                                  AV_CH_LAYOUT_STEREO,
                                                  AV_SAMPLE_FMT_FLT,
                                                  48000,
                                                  0,
                                                  NULL);
    int error = swr_init(resample_ctx);
    if (error < 0)
        return false;

    //init FIFO buffer

    //start recording

    avformat_write_header(output_format_context, NULL);

    hr = pAudioClient->Start();
    EXIT_ON_ERROR(hr)

    int pcmInBuffer = 0;
    int copiedPcm = 0;
    int gotPacket = 0;
    int index = 0;

    HANDLE waitArray[3];
    waitArray[0] = hAudioSamplesReadyEvent;

    uint64_t nextptx = 0;

    while (bDone == false) {
        DWORD waitResult = WaitForMultipleObjects(1, waitArray, FALSE, INFINITE);
        switch (waitResult) {
        case WAIT_OBJECT_0 + 0: // _AudioSamplesReadyEvent
            hr = pCaptureClient->GetNextPacketSize(&packetLength);

            while (packetLength != 0) {
                // Get the available data in the shared buffer.
                hr = pCaptureClient->GetBuffer(&pData, &numFramesAvailable, &flags, NULL, NULL);

                if (flags & AUDCLNT_BUFFERFLAGS_SILENT) {
                    pData = NULL; // Tell CopyData to write silence.
                }

                // Copy the available capture data to the audio sink.

                if (pData != NULL) {
                    copiedPcm = min(sample_size - pcmInBuffer, numFramesAvailable * persample_size);
                    if (copiedPcm > 0) {
                        memcpy(sample_buf + pcmInBuffer, pData, copiedPcm);
                        pcmInBuffer += copiedPcm;
                    }

                    if (pcmInBuffer == sample_size) { //got one frame ,encode

                        int ret = swr_convert(resample_ctx,
                                              resampled_frame->data,
                                              output_codec_context->frame_size,
                                              (const uint8_t **) sample_frame->data,
                                              1024);
                        if (ret <= 0)
                            return -1;

                        av_init_packet(&pkt);
                        resampled_frame->pts = nextptx;
                        nextptx += resampled_frame->nb_samples;

                        int error = avcodec_send_frame(output_codec_context, resampled_frame);

                        if (error == 0) {
                            error = avcodec_receive_packet(output_codec_context, &pkt);
                            if (error == 0) {
                                av_write_frame(output_format_context, &pkt);

                                index++;

                                printf("index:%d\r\n", index);
                            }
                            av_packet_unref(&pkt);
                        }
                        pcmInBuffer = 0;
                    }

                    if (numFramesAvailable * persample_size - copiedPcm > 0) {
                        memcpy(sample_buf + pcmInBuffer,
                               pData + copiedPcm,
                               numFramesAvailable * persample_size - copiedPcm);

                        pcmInBuffer += numFramesAvailable * persample_size - copiedPcm;
                    }

                    if (index > 2000) {
                        printf("pcm still in buffer:%d\r\n", pcmInBuffer);
                        bDone = true;
                        break;
                    }
                }

                hr = pCaptureClient->ReleaseBuffer(numFramesAvailable);
                EXIT_ON_ERROR(hr)

                hr = pCaptureClient->GetNextPacketSize(&packetLength);
                EXIT_ON_ERROR(hr)
            }

            break;
        } // end of 'switch (waitResult)'

    } // end of 'while (stillPlaying)'

    av_write_trailer(output_format_context);

    if (output_codec_context)
        avcodec_free_context(&output_codec_context);
    if (output_format_context) {
        avio_closep(&output_format_context->pb);
        avformat_free_context(output_format_context);
    }

    hr = pAudioClient->Stop(); // Stop recording.
    EXIT_ON_ERROR(hr)

Exit:
    CoTaskMemFree(pwfx);
    SAFE_RELEASE(pEnumerator)
    SAFE_RELEASE(pDevice)
    SAFE_RELEASE(pAudioClient)
    SAFE_RELEASE(pCaptureClient)

    return hr;
}

HRESULT cpature_wave()
{
    HRESULT hr;

    IMMDeviceEnumerator *pEnumerator = NULL;
    IMMDevice *pDevice = NULL;
    IAudioClient *pAudioClient = NULL;
    IAudioCaptureClient *pCaptureClient = NULL;
    WAVEFORMATEX *pwfx = NULL;

    REFERENCE_TIME hnsRequestedDuration = REFTIMES_PER_SEC;
    UINT32 bufferFrameCount;
    UINT32 numFramesAvailable;

    BYTE *pData;
    UINT32 packetLength = 0;
    DWORD flags;

    hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);
    if (FAILED(hr)) {
        printf("Unable to initialize COM in thread: %x\n", hr);
        return hr;
    }

    hr = CoCreateInstance(CLSID_MMDeviceEnumerator,
                          NULL,
                          CLSCTX_ALL,
                          IID_IMMDeviceEnumerator,
                          (void **) &pEnumerator);
    EXIT_ON_ERROR(hr)

#ifdef DEF_CAPTURE_MIC
    hr = pEnumerator->GetDefaultAudioEndpoint(eCapture, eCommunications, &pDevice);
    //hr = pEnumerator->GetDefaultAudioEndpoint(eCapture,  eMultimedia, &pDevice);
#else
    hr = pEnumerator->GetDefaultAudioEndpoint(eRender, eConsole, &pDevice);
#endif

    EXIT_ON_ERROR(hr)

    hr = pDevice->Activate(IID_IAudioClient, CLSCTX_ALL, NULL, (void **) &pAudioClient);
    EXIT_ON_ERROR(hr)

    hr = pAudioClient->GetMixFormat(&pwfx);
    EXIT_ON_ERROR(hr)

    AdjustFormatTo16Bits(pwfx);

#ifdef DEF_CAPTURE_MIC
    hr = pAudioClient->Initialize(AUDCLNT_SHAREMODE_SHARED,
                                  AUDCLNT_STREAMFLAGS_EVENTCALLBACK | AUDCLNT_STREAMFLAGS_NOPERSIST,
                                  hnsRequestedDuration,
                                  0,
                                  pwfx,
                                  NULL);
#else
    /*
	The AUDCLNT_STREAMFLAGS_LOOPBACK flag enables loopback recording.
	In loopback recording, the audio engine copies the audio stream
	that is being played by a rendering endpoint device into an audio endpoint buffer
	so that a WASAPI client can capture the stream.
	If this flag is set, the IAudioClient::Initialize method attempts to open a capture buffer on the rendering device.
	This flag is valid only for a rendering device
	and only if the Initialize call sets the ShareMode parameter to AUDCLNT_SHAREMODE_SHARED.
	Otherwise the Initialize call will fail.
	If the call succeeds,
	the client can call the IAudioClient::GetService method
	to obtain an IAudioCaptureClient interface on the rendering device.
	For more information, see Loopback Recording.
	*/
    hr = pAudioClient->Initialize(AUDCLNT_SHAREMODE_SHARED,
                                  AUDCLNT_STREAMFLAGS_EVENTCALLBACK | AUDCLNT_STREAMFLAGS_LOOPBACK,
                                  hnsRequestedDuration,
                                  0,
                                  pwfx,
                                  NULL);
#endif
    EXIT_ON_ERROR(hr)

    int nFrameSize = (pwfx->wBitsPerSample / 8) * pwfx->nChannels;

    REFERENCE_TIME hnsStreamLatency;
    hr = pAudioClient->GetStreamLatency(&hnsStreamLatency);
    EXIT_ON_ERROR(hr)

    REFERENCE_TIME hnsDefaultDevicePeriod;
    REFERENCE_TIME hnsMinimumDevicePeriod;
    hr = pAudioClient->GetDevicePeriod(&hnsDefaultDevicePeriod, &hnsMinimumDevicePeriod);
    EXIT_ON_ERROR(hr)

    hr = pAudioClient->GetBufferSize(&bufferFrameCount);
    EXIT_ON_ERROR(hr)
    std::cout << std::endl << "GetBufferSize        : " << bufferFrameCount << std::endl;

    // SetEventHandle
    //////////////////////////////////////////////////////////////////////////
    HANDLE hAudioSamplesReadyEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
    if (hAudioSamplesReadyEvent == NULL) {
        printf("Unable to create samples ready event: %d.\n", GetLastError());
        goto Exit;
    }

    hr = pAudioClient->SetEventHandle(hAudioSamplesReadyEvent);
    if (FAILED(hr)) {
        printf("Unable to set ready event: %x.\n", hr);
        return false;
    }
    //////////////////////////////////////////////////////////////////////////

    hr = pAudioClient->GetService(IID_IAudioCaptureClient, (void **) &pCaptureClient);

    EXIT_ON_ERROR(hr)

    hr = pAudioClient->Start(); // Start recording.
    EXIT_ON_ERROR(hr)

    printf("\nAudio Capture begin...\n\n");

    int nCnt = 0;

    size_t nCaptureBufferSize = 8 * 1024 * 1024;
    size_t nCurrentCaptureIndex = 0;

    BYTE *pbyCaptureBuffer = new (std::nothrow) BYTE[nCaptureBufferSize];

    HANDLE waitArray[3];
    waitArray[0] = hAudioSamplesReadyEvent;

    bool stillPlaying = true;

    // Each loop fills about half of the shared buffer.
    while (stillPlaying) {
        DWORD waitResult = WaitForMultipleObjects(1, waitArray, FALSE, INFINITE);
        switch (waitResult) {
        case WAIT_OBJECT_0 + 0: // _AudioSamplesReadyEvent
            hr = pCaptureClient->GetNextPacketSize(&packetLength);
            EXIT_ON_ERROR(hr)

            printf("%06d # _AudioSamplesReadyEvent packetLength:%06u \n", nCnt, packetLength);

            while (packetLength != 0) {
                // Get the available data in the shared buffer.
                hr = pCaptureClient->GetBuffer(&pData, &numFramesAvailable, &flags, NULL, NULL);
                EXIT_ON_ERROR(hr)

                nCnt++;

                // test flags
                //////////////////////////////////////////////////////////////////////////
                if (flags & AUDCLNT_BUFFERFLAGS_SILENT) {
                    printf("AUDCLNT_BUFFERFLAGS_SILENT \n");
                }

                if (flags & AUDCLNT_BUFFERFLAGS_DATA_DISCONTINUITY) {
                    printf("%06d # AUDCLNT_BUFFERFLAGS_DATA_DISCONTINUITY \n", nCnt);
                }
                //////////////////////////////////////////////////////////////////////////

                UINT32 framesToCopy = min(numFramesAvailable,
                                          static_cast<UINT32>(
                                              (nCaptureBufferSize - nCurrentCaptureIndex)
                                              / nFrameSize));
                if (framesToCopy != 0) {
                    //
                    //  The flags on capture tell us information about the data.
                    //
                    //  We only really care about the silent flag since we want to put frames of silence into the buffer
                    //  when we receive silence.  We rely on the fact that a logical bit 0 is silence for both float and int formats.
                    //
                    if (flags & AUDCLNT_BUFFERFLAGS_SILENT) {
                        //
                        //  Fill 0s from the capture buffer to the output buffer.
                        //
                        ZeroMemory(&pbyCaptureBuffer[nCurrentCaptureIndex],
                                   framesToCopy * nFrameSize);
                    } else {
                        //
                        //  Copy data from the audio engine buffer to the output buffer.
                        //
                        CopyMemory(&pbyCaptureBuffer[nCurrentCaptureIndex],
                                   pData,
                                   framesToCopy * nFrameSize);

                        printf("Get: %d\r\n", framesToCopy * nFrameSize);
                    }
                    //
                    //  Bump the capture buffer pointer.
                    //
                    nCurrentCaptureIndex += framesToCopy * nFrameSize;
                }

                hr = pCaptureClient->ReleaseBuffer(numFramesAvailable);
                EXIT_ON_ERROR(hr)

                hr = pCaptureClient->GetNextPacketSize(&packetLength);
                EXIT_ON_ERROR(hr)

                UINT32 ui32NumPaddingFrames;
                hr = pAudioClient->GetCurrentPadding(&ui32NumPaddingFrames);
                EXIT_ON_ERROR(hr)
                if (0 != ui32NumPaddingFrames) {
                    printf("GetCurrentPadding : %6u\n", ui32NumPaddingFrames);
                }
                //////////////////////////////////////////////////////////////////////////

                if (nCnt == 1000) {
                    stillPlaying = false;
                    break;
                }

            } // end of 'while (packetLength != 0)'

            break;
        } // end of 'switch (waitResult)'

    } // end of 'while (stillPlaying)'

    //
    //  We've now captured our wave data.  Now write it out in a wave file.
    //
    SaveWaveData(pbyCaptureBuffer, nCurrentCaptureIndex, pwfx);

    printf("\nAudio Capture Done.\n");

    hr = pAudioClient->Stop(); // Stop recording.
    EXIT_ON_ERROR(hr)

Exit:
    CoTaskMemFree(pwfx);
    SAFE_RELEASE(pEnumerator)
    SAFE_RELEASE(pDevice)
    SAFE_RELEASE(pAudioClient)
    SAFE_RELEASE(pCaptureClient)

    CoUninitialize();

    if (pbyCaptureBuffer) {
        delete[] pbyCaptureBuffer;
        pbyCaptureBuffer = NULL;
    }

    if (hAudioSamplesReadyEvent) {
        CloseHandle(hAudioSamplesReadyEvent);
        hAudioSamplesReadyEvent = NULL;
    }
}

/* check that a given sample format is supported by the encoder */
static int check_sample_fmt(const AVCodec *codec, enum AVSampleFormat sample_fmt)
{
    const enum AVSampleFormat *p = codec->sample_fmts;

    while (*p != AV_SAMPLE_FMT_NONE) {
        if (*p == sample_fmt)
            return 1;
        p++;
    }
    return 0;
}

/* just pick the highest supported samplerate */
static int select_sample_rate(const AVCodec *codec)
{
    const int *p;
    int best_samplerate = 0;

    if (!codec->supported_samplerates)
        return 44100;

    p = codec->supported_samplerates;
    while (*p) {
        if (!best_samplerate || abs(44100 - *p) < abs(44100 - best_samplerate))
            best_samplerate = *p;
        p++;
    }
    return best_samplerate;
}

/* select layout with the highest channel count */
static int select_channel_layout(const AVCodec *codec)
{
    const uint64_t *p;
    uint64_t best_ch_layout = 0;
    int best_nb_channels = 0;

    if (!codec->channel_layouts)
        return AV_CH_LAYOUT_STEREO;

    p = codec->channel_layouts;
    while (*p) {
        int nb_channels = av_get_channel_layout_nb_channels(*p);

        if (nb_channels > best_nb_channels) {
            best_ch_layout = *p;
            best_nb_channels = nb_channels;
        }
        p++;
    }
    return best_ch_layout;
}

int main1()
{
    //capture_audio();
    //test_transcode();
    cpature_wave();

    system("pause");

    return 0;
}