Vector3A D3dMatrixMultiply(D3DXMATRIX bonematrix, D3DXMATRIX actormatrix) { Vector3A result; result.X = bonematrix._41 * actormatrix._11 + bonematrix._42 * actormatrix._21 + bonematrix._43 * actormatrix._31 + bonematrix._44 * actormatrix._41; result.Y = bonematrix._41 * actormatrix._12 + bonematrix._42 * actormatrix._22 + bonematrix._43 * actormatrix._32 + bonematrix._44 * actormatrix._42; result.Z = bonematrix._41 * actormatrix._13 + bonematrix._42 * actormatrix._23 + bonematrix._43 * actormatrix._33 + bonematrix._44 * actormatrix._43; return result; }

这是一个用于计算两个 D3D 矩阵相乘后得到的 Vector3A 的函数。其中 bonematrix 和 actormatrix 是两个 D3DXMATRIX 类型的矩阵，包含了矩阵的各个元素（_11, _12, _13, ..., _44）。这个函数的作用是将这两个矩阵相乘后得到的结果再赋值给一个 Vector3A 类型的变量 result，并返回这个变量。具体的计算过程是，先将 bonematrix 的第一行元素和 actormatrix 的第一列元素对应相乘，再将 bonematrix 的第二行元素和 actormatrix 的第二列元素对应相乘，最后将 bonematrix 的第三行元素和 actormatrix 的第三列元素对应相乘，将这三个结果分别赋值给 result 的 X、Y、Z 成员变量。

相关问题

在windows cpp 动态库读取test.mp4视频流到Windows窗口的离屏表面，在Qt调用该动态库。完整源码

以下是一个简单的示例代码，演示如何使用Windows动态库来读取视频流并在Qt中显示：

Windows动态库代码（video_player.cpp）：

#include <windows.h>
#include <d3d9.h>
#include <d3dx9.h>
#include "video_player.h"

#pragma comment(lib, "d3d9.lib")
#pragma comment(lib, "d3dx9.lib")

// 定义窗口宽高
#define WINDOW_WIDTH 640
#define WINDOW_HEIGHT 480

// 定义视频帧缓冲区大小
#define FRAME_SIZE (WINDOW_WIDTH * WINDOW_HEIGHT * 4)

// 全局变量
LPDIRECT3D9 g_pD3D;
LPDIRECT3DDEVICE9 g_pDevice;
LPDIRECT3DSURFACE9 g_pSurface;
BYTE* g_pFrameBuffer = NULL;

// 初始化Direct3D
bool InitD3D(HWND hWnd)
{
    g_pD3D = Direct3DCreate9(D3D_SDK_VERSION);
    if (!g_pD3D)
        return false;

    D3DPRESENT_PARAMETERS d3dpp;
    ZeroMemory(&d3dpp, sizeof(d3dpp));
    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;

    if (FAILED(g_pD3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
        D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &g_pDevice)))
        return false;

    return true;
}

// 释放Direct3D资源
void ReleaseD3D()
{
    if (g_pSurface)
    {
        g_pSurface->Release();
        g_pSurface = NULL;
    }

    if (g_pDevice)
    {
        g_pDevice->Release();
        g_pDevice = NULL;
    }

    if (g_pD3D)
    {
        g_pD3D->Release();
        g_pD3D = NULL;
    }
}

// 创建离屏表面
bool CreateOffscreenSurface()
{
    HRESULT hr = g_pDevice->CreateOffscreenPlainSurface(WINDOW_WIDTH, WINDOW_HEIGHT, D3DFMT_X8R8G8B8,
        D3DPOOL_SYSTEMMEM, &g_pSurface, NULL);

    return SUCCEEDED(hr);
}

// 读取视频帧到离屏表面
bool LoadFrameToSurface(BYTE* pBuffer)
{
    D3DLOCKED_RECT LockedRect;
    HRESULT hr = g_pSurface->LockRect(&LockedRect, NULL, D3DLOCK_DISCARD);

    if (FAILED(hr))
        return false;

    BYTE* pDest = (BYTE*)LockedRect.pBits;
    int nDestPitch = LockedRect.Pitch;

    for (int y = 0; y < WINDOW_HEIGHT; ++y)
    {
        memcpy(pDest, pBuffer, WINDOW_WIDTH * 4);
        pBuffer += WINDOW_WIDTH * 4;
        pDest += nDestPitch;
    }

    hr = g_pSurface->UnlockRect();
    return SUCCEEDED(hr);
}

// 在窗口中显示离屏表面
void PresentOffscreenSurface(HWND hWnd)
{
    RECT rect;
    GetClientRect(hWnd, &rect);

    D3DXMATRIX matProj;
    D3DXMatrixOrthoOffCenterLH(&matProj, 0, (FLOAT)WINDOW_WIDTH, (FLOAT)WINDOW_HEIGHT, 0, 0, 1);
    g_pDevice->SetTransform(D3DTS_PROJECTION, &matProj);

    g_pDevice->StretchRect(g_pSurface, NULL, g_pDevice->GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO), &rect, D3DTEXF_NONE);
}

// 打开视频文件，读取视频流并显示
bool PlayVideo(HWND hWnd, const char* szFileName)
{
    // 打开视频文件
    FILE* file = fopen(szFileName, "rb");
    if (!file)
        return false;

    fseek(file, 0, SEEK_END);
    int nFileSize = ftell(file);
    fseek(file, 0, SEEK_SET);

    // 初始化视频帧缓冲区
    g_pFrameBuffer = new BYTE[FRAME_SIZE];

    // 初始化Direct3D
    if (!InitD3D(hWnd))
        return false;

    // 创建离屏表面
    if (!CreateOffscreenSurface())
        return false;

    // 读取视频流
    while (true)
    {
        int nFrameSize;
        if (fread(&nFrameSize, sizeof(nFrameSize), 1, file) != 1)
            break;

        if (fread(g_pFrameBuffer, nFrameSize, 1, file) != 1)
            break;

        // 将视频帧加载到离屏表面
        if (!LoadFrameToSurface(g_pFrameBuffer))
            break;

        // 在窗口中显示离屏表面
        PresentOffscreenSurface(hWnd);

        // 等待一段时间，以便视频流显示更流畅
        Sleep(33);
    }

    // 释放资源
    delete[] g_pFrameBuffer;
    ReleaseD3D();
    fclose(file);

    return true;
}

Windows动态库头文件（video_player.h）：

#ifndef VIDEO_PLAYER_H
#define VIDEO_PLAYER_H

#include <windows.h>

// 播放视频
bool PlayVideo(HWND hWnd, const char* szFileName);

#endif // VIDEO_PLAYER_H

Qt代码（mainwindow.cpp）：

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "video_player.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    // 创建按钮
    QPushButton* btnPlay = new QPushButton("Play", this);
    btnPlay->setGeometry(10, 10, 80, 30);
    connect(btnPlay, SIGNAL(clicked()), this, SLOT(OnBtnPlayClicked()));
}

MainWindow::~MainWindow()
{
    delete ui;
}

// 点击播放按钮
void MainWindow::OnBtnPlayClicked()
{
    PlayVideo((HWND)winId(), "test.mp4");
}

请注意，此示例代码仅演示了如何在Windows和Qt中使用动态库读取视频流并在窗口中显示。实际应用中，您需要根据您的需求进行修改和调整。

ffmepg6.0录屏推流c++示例

以下是在 Windows 平台上，使用 FFmpeg 6.0 实现录屏推流的 C++ 示例代码：

#include <iostream>
#include <Windows.h>
#include <d3d9.h>
#include <d3dx9.h>
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavutil/opt.h>

#pragma comment(lib, "d3d9.lib")
#pragma comment(lib, "d3dx9.lib")
#pragma comment(lib, "avcodec.lib")
#pragma comment(lib, "avformat.lib")
#pragma comment(lib, "avutil.lib")

#define SCREEN_WIDTH 1920
#define SCREEN_HEIGHT 1080
#define FPS 30
#define BIT_RATE 4000000
#define STREAM_URL "rtmp://localhost/live/stream"

int main()
{
    // 初始化 D3D9
    IDirect3D9Ex* pD3D = nullptr;
    if (FAILED(Direct3DCreate9Ex(D3D_SDK_VERSION, &pD3D)))
    {
        std::cerr << "Failed to create IDirect3D9Ex object" << std::endl;
        return -1;
    }

    // 枚举显示器适配器
    UINT adapterCount = pD3D->GetAdapterCount();
    if (adapterCount == 0)
    {
        std::cerr << "No display adapter found" << std::endl;
        return -1;
    }

    // 获取第一个适配器的显示模式
    D3DDISPLAYMODE displayMode;
    if (FAILED(pD3D->EnumAdapterModes(0, D3DFMT_X8R8G8B8, 0, &displayMode)))
    {
        std::cerr << "Failed to enumerate display adapter modes" << std::endl;
        return -1;
    }

    // 创建 D3D 设备
    D3DPRESENT_PARAMETERS d3dpp = {};
    d3dpp.Windowed = TRUE;
    d3dpp.BackBufferFormat = D3DFMT_X8R8G8B8;
    d3dpp.BackBufferWidth = SCREEN_WIDTH;
    d3dpp.BackBufferHeight = SCREEN_HEIGHT;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    IDirect3DDevice9Ex* pD3DDevice = nullptr;
    if (FAILED(pD3D->CreateDeviceEx(
        D3DADAPTER_DEFAULT,
        D3DDEVTYPE_HAL,
        GetDesktopWindow(),
        D3DCREATE_HARDWARE_VERTEXPROCESSING,
        &d3dpp,
        nullptr,
        &pD3DDevice)))
    {
        std::cerr << "Failed to create IDirect3DDevice9Ex object" << std::endl;
        return -1;
    }

    // 初始化 FFmpeg
    av_register_all();
    avcodec_register_all();
    avformat_network_init();

    // 创建输出流
    AVFormatContext* pFormatCtx = nullptr;
    if (avformat_alloc_output_context2(&pFormatCtx, nullptr, "flv", STREAM_URL) < 0)
    {
        std::cerr << "Failed to allocate output context" << std::endl;
        return -1;
    }

    // 创建视频流
    AVCodec* pCodec = nullptr;
    AVStream* pStream = avformat_new_stream(pFormatCtx, pCodec);
    if (!pStream)
    {
        std::cerr << "Failed to allocate video stream" << std::endl;
        return -1;
    }

    // 设置编码器参数
    AVCodecContext* pCodecCtx = pStream->codec;
    pCodecCtx->codec_id = AV_CODEC_ID_H264;
    pCodecCtx->codec_type = AVMEDIA_TYPE_VIDEO;
    pCodecCtx->width = SCREEN_WIDTH;
    pCodecCtx->height = SCREEN_HEIGHT;
    pCodecCtx->pix_fmt = AV_PIX_FMT_YUV420P;
    pCodecCtx->bit_rate = BIT_RATE;
    pCodecCtx->gop_size = FPS;
    pCodecCtx->time_base = { 1, FPS };
    pCodecCtx->level = 31;
    pCodecCtx->profile = FF_PROFILE_H264_MAIN;
    av_opt_set(pCodecCtx->priv_data, "preset", "ultrafast", 0);
    av_opt_set(pCodecCtx->priv_data, "tune", "zerolatency", 0);

    // 打开编码器
    pCodec = avcodec_find_encoder(pCodecCtx->codec_id);
    if (!pCodec)
    {
        std::cerr << "Failed to find video encoder" << std::endl;
        return -1;
    }
    if (avcodec_open2(pCodecCtx, pCodec, nullptr) < 0)
    {
        std::cerr << "Failed to open video encoder" << std::endl;
        return -1;
    }

    // 打开输出流
    if (avio_open(&pFormatCtx->pb, STREAM_URL, AVIO_FLAG_WRITE) < 0)
    {
        std::cerr << "Failed to open output stream" << std::endl;
        return -1;
    }

    // 写入文件头
    if (avformat_write_header(pFormatCtx, nullptr) < 0)
    {
        std::cerr << "Failed to write file header" << std::endl;
        return -1;
    }

    // 创建缓冲区
    const auto buffer_size = av_image_get_buffer_size(pCodecCtx->pix_fmt, SCREEN_WIDTH, SCREEN_HEIGHT, 1);
    auto buffer = static_cast<uint8_t*>(av_malloc(buffer_size));
    AVFrame* pFrame = av_frame_alloc();
    if (!pFrame)
    {
        std::cerr << "Failed to allocate video frame" << std::endl;
        return -1;
    }
    av_image_fill_arrays(pFrame->data, pFrame->linesize, buffer, pCodecCtx->pix_fmt, SCREEN_WIDTH, SCREEN_HEIGHT, 1);

    // 设置 D3D 设备参数
    IDirect3DSurface9* pSurface = nullptr;
    D3DXMATRIX matrix;
    D3DLOCKED_RECT lockedRect;
    pD3DDevice->CreateOffscreenPlainSurface(SCREEN_WIDTH, SCREEN_HEIGHT, D3DFMT_A8R8G8B8, D3DPOOL_SYSTEMMEM, &pSurface, nullptr);
    D3DXMatrixIdentity(&matrix);

    // 循环推流
    bool running = true;
    while (running)
    {
        // 从 D3D 设备中读取屏幕数据
        if (SUCCEEDED(pD3DDevice->GetFrontBufferData(0, pSurface)))
        {
            if (SUCCEEDED(pSurface->LockRect(&lockedRect, nullptr, D3DLOCK_READONLY)))
            {
                // 将屏幕数据转换为 YUV420P 格式
                for (int y = 0; y < SCREEN_HEIGHT; y++)
                {
                    auto dest = buffer + y * pFrame->linesize[0];
                    auto src = static_cast<uint8_t*>(lockedRect.pBits) + y * lockedRect.Pitch;
                    memcpy(dest, src, SCREEN_WIDTH * 4);
                }
                av_frame_set_pts(pFrame, av_rescale_q(av_gettime(), { 1, AV_TIME_BASE }, pCodecCtx->time_base));

                // 编码并写入数据
                AVPacket packet;
                av_init_packet(&packet);
                packet.data = nullptr;
                packet.size = 0;
                int result = avcodec_send_frame(pCodecCtx, pFrame);
                if (result == 0)
                {
                    while (result >= 0)
                    {
                        result = avcodec_receive_packet(pCodecCtx, &packet);
                        if (result == 0)
                        {
                            packet.stream_index = pStream->index;
                            av_interleaved_write_frame(pFormatCtx, &packet);
                            av_packet_unref(&packet);
                        }
                        else if (result == AVERROR(EAGAIN) || result == AVERROR_EOF)
                        {
                            break;
                        }
                        else
                        {
                            std::cerr << "Failed to encode video frame" << std::endl;
                            running = false;
                        }
                    }
                }
                else
                {
                    std::cerr << "Failed to send video frame for encoding" << std::endl;
                    running = false;
                }

                pSurface->UnlockRect();
            }
        }

        // 限制帧率
        Sleep(1000 / FPS);
    }

    // 写入文件尾
    av_write_trailer(pFormatCtx);

    // 释放资源
    if (pSurface)
    {
        pSurface->Release();
    }
    if (pD3DDevice)
    {
        pD3DDevice->Release();
    }
    if (pD3D)
    {
        pD3D->Release();
    }
    if (pCodecCtx)
    {
        avcodec_close(pCodecCtx);
    }
    if (pFrame)
    {
        av_frame_free(&pFrame);
    }
    if (pFormatCtx)
    {
        avio_close(pFormatCtx->pb);
        avformat_free_context(pFormatCtx);
    }
    if (buffer)
    {
        av_free(buffer);
    }

    return 0;
}

在这个示例中，我们使用了 Windows 平台上的 DirectX 9 API 来捕获屏幕数据，然后使用 FFmpeg 6.0 的编码器将数据编码为 H.264 格式，并通过 RTMP 协议推流到本地的流服务器。您需要根据具体的情况修改 STREAM_URL、SCREEN_WIDTH、SCREEN_HEIGHT、FPS 和 BIT_RATE 等参数。