1.头文件：
sdlqtrgb.h
#pragma once
#include <QtWidgets/QWidget>
#include "ui_sdlqtrgb.h"
#include <thread>
class SdlQtRGB : public QWidget
{
Q_OBJECT
public:
SdlQtRGB(QWidget* parent = Q_NULLPTR);
~SdlQtRGB()
{
is_exit_ = true;
//等待渲染线程退出
th_.join();
}
void timerEvent(QTimerEvent* ev) override;
void resizeEvent(QResizeEvent* ev) override;
//线程函数，用于刷新视频
void Main();
signals:
void ViewS(); //信号函数，将任务放入列表
public slots:
void View(); //显示的槽函数
void Open1();
void Open2();
void Open(int i);
private:
std::thread th_;
bool is_exit_ = false;//处理线程退出
Ui::SdlQtRGBClass ui;
};
xvideoview.h
#ifndef XVIDEO_VIEW_H
#define XVIDEO_VIEW_H
#include <mutex>
#include <fstream>
struct AVFrame;
void MSleep(unsigned int ms);
//获取当前时间戳 毫秒
long long NowMs();
/// 视频渲染接口类
/// 隐藏SDL实现
/// 渲染方案可替代
// 线程安全
class XVideoView
{
public:
enum Format //枚举的值和ffmpeg中一致
{
YUV420P = 0,
ARGB = 25,
RGBA = 26,
BGRA = 28
};
enum RenderType
{
SDL = 0
};
static XVideoView* Create(RenderType type = SDL);
/// 初始化渲染窗口 线程安全 可多次调用
/// @para w 窗口宽度
/// @para h 窗口高度
/// @para fmt 绘制的像素格式
/// @para win_id 窗口句柄，如果为空，创建新窗口
/// @return 是否创建成功
virtual bool Init(int w, int h,
Format fmt = RGBA) = 0;
//清理所有申请的资源，包括关闭窗口
virtual void Close() = 0;
//处理窗口退出事件
virtual bool IsExit() = 0;
//
/// 渲染图像 线程安全
///@para data 渲染的二进制数据
///@para linesize 一行数据的字节数，对于YUV420P就是Y一行字节数
/// linesize<=0 就根据宽度和像素格式自动算出大小
/// @return 渲染是否成功
virtual bool Draw(const unsigned char* data, int linesize = 0) = 0;
virtual bool Draw(
const unsigned char* y, int y_pitch,
const unsigned char* u, int u_pitch,
const unsigned char* v, int v_pitch
) = 0;
//显示缩放
void Scale(int w, int h)
{
scale_w_ = w;
scale_h_ = h;
}
bool DrawFrame(AVFrame* frame);
int render_fps() { return render_fps_; }
//打开文件
bool Open(std::string filepath);
//
/// 读取一帧数据，并维护AVFrame空间
/// 每次调用会覆盖上一次数据
AVFrame* Read();
void set_win_id(void* win) { win_id_ = win; }
protected:
void* win_id_ = nullptr; //窗口句柄
int render_fps_ = 0; //显示帧率
int width_ = 0; //材质宽高
int height_ = 0;
Format fmt_ = RGBA; //像素格式
std::mutex mtx_; //确保线程安全
int scale_w_ = 0; //显示大小
int scale_h_ = 0;
long long beg_ms_ = 0; //计时开始时间
int count_ = 0; //统计显示次数
private:
std::ifstream ifs_;
AVFrame* frame_ = nullptr;
};
#endif
xsdl.h
#pragma once
#include "xvideo_view.h"
struct SDL_Window;
struct SDL_Renderer;
struct SDL_Texture;
class XSDL :public XVideoView
{
public:
void Close() override;
/// 初始化渲染窗口 线程安全
/// @para w 窗口宽度
/// @para h 窗口高度
/// @para fmt 绘制的像素格式
/// @para win_id 窗口句柄，如果为空，创建新窗口
/// @return 是否创建成功
bool Init(int w, int h,
Format fmt = RGBA) override;
//
/// 渲染图像 线程安全
///@para data 渲染的二进制数据
///@para linesize 一行数据的字节数，对于YUV420P就是Y一行字节数
/// linesize<=0 就根据宽度和像素格式自动算出大小
/// @return 渲染是否成功
bool Draw(const unsigned char* data,
int linesize = 0) override;
bool Draw(
const unsigned char* y, int y_pitch,
const unsigned char* u, int u_pitch,
const unsigned char* v, int v_pitch
) override;
bool IsExit() override;
private:
SDL_Window* win_ = nullptr;
SDL_Renderer* render_ = nullptr;
SDL_Texture* texture_ = nullptr;
};2.源文件：
sdlqtrgb.cpp
#include "sdlqtrgb.h"
#include <fstream>
#include <iostream>
#include <QMessageBox>
#include <thread>
#include <sstream>
#include <iostream>
#include <QSpinBox>
#include <QFileDialog>
#include "xvideo_view.h"
#include <vector>
#include <sstream>
using namespace std;
static std::vector<XVideoView*> views;
SdlQtRGB::SdlQtRGB(QWidget* parent)
: QWidget(parent)
{
ui.setupUi(this);
//绑定渲染信号槽
connect(this, SIGNAL(ViewS()), this, SLOT(View()));
views.push_back(XVideoView::Create());// 创建一个对象并用vector 存储
views.push_back(XVideoView::Create());
views[0]->set_win_id((void*)ui.video1->winId());//将video1的窗口句柄赋值给xvideoview对象的窗口句柄
views[1]->set_win_id((void*)ui.video2->winId());
th_ = std::thread(&SdlQtRGB::Main, this);
}
void SdlQtRGB::timerEvent(QTimerEvent* ev)
{
}
void SdlQtRGB::View()
{
static int last_pts[32] = { 0 };//last_pts 用于存放每个视图上次渲染的时间戳,lase_pts[0]表示第一个播放窗口
static int fps_arr[32] = { 0 };//用于存放每个视图的帧率值。
fps_arr[0] = ui.set_fps1->value();//获取第一个播放窗口的fps，用fps_arr[0]存储
fps_arr[1] = ui.set_fps2->value();
for (int i = 0; i < views.size(); i++)//依次渲染容器中的xvideoview对象
{
if (fps_arr[i] <= 0) continue;//invaluable data then pass
//需要间隔时间
int ms = 1000 / fps_arr[i];// video1's fps = 100,then ms = 10,意思是100fps，一秒渲染100次，每10ms渲染一次
//判断是否到了可渲染时间
if (NowMs() - last_pts[i] < ms)//一秒渲染100次，每10ms渲染一次，若时间没达到10ms那么不继续进行渲染
continue;
last_pts[i] = NowMs();//记录下此次的渲染时间
auto frame = views[i]->Read();//read()执行完后 返回读取了yuv数据的avframe对象给frame，此时frame中已经进行了文件读取有了yuv数据，参考read函数即可
if (!frame)continue;
views[i]->DrawFrame(frame);//计算了当前帧率并且进行了渲染
//显示fps
stringstream ss;
ss << "fps:" << views[i]->render_fps();
if (i == 0)
ui.fps1->setText(ss.str().c_str());
else
ui.fps2->setText(ss.str().c_str());
}
}
void SdlQtRGB::Main()
{
while (!is_exit_)
{
ViewS();//调用一次view槽函数,再没进行Open函数之前是不能把view槽函数执行完的，因为进行draw之前要进行材质的初始化 Init函数，在Open函数之中
//一旦执行了Open函数，Init即进行完毕，则一直在执行的线程函数Main则会调用view函数，此时view函数中的draw函数可以进行渲染了
MSleep(10);//每调用一次槽函数就休眠10ms，用于控制帧率
}
}
void SdlQtRGB::Open1()
{
Open(0);
}
void SdlQtRGB::Open2()
{
Open(1);
}
void SdlQtRGB::Open(int i)
{
QFileDialog fd;
auto filename = fd.getOpenFileName();
if (filename.isEmpty())return;
cout << filename.toLocal8Bit().data() << endl;
//打开文件
if (!views[i]->Open(filename.toLocal8Bit().toStdString()))
{
return;
}
int w = 0;
int h = 0;
QString pix = 0; //YUV420P RGBA
if (i == 0)//下拉框的下标0，表示YUV420P，下标1表示RGBA以此类推
{
w = ui.width1->value();
h = ui.height1->value();
pix = ui.pix1->currentText(); //像素格式
}
else
{
w = ui.width2->value();
h = ui.height2->value();
pix = ui.pix2->currentText();
}
XVideoView::Format fmt = XVideoView::YUV420P;
if (pix == "YUV420P")
{
}
else if (pix == "RGBA")
{
fmt = XVideoView::RGBA;
}
else if (pix == "ARGB")
{
fmt = XVideoView::ARGB;
}
else if (pix == "BGRA")
{
fmt = XVideoView::BGRA;
}
//初始化窗口和材质
views[i]->Init(w, h, fmt);
}
void SdlQtRGB::resizeEvent(QResizeEvent* ev)
{
//ui.label->resize(size());
//ui.label->move(0, 0);
//view->Scale(width(), height());
}xvideoview.cpp
#include "xsdl.h"
#include <thread>
#include <iostream>
using namespace std;
extern "C"
{
#include <libavcodec/avcodec.h>
}
#pragma comment(lib,"avutil.lib")
void MSleep(unsigned int ms)
{
auto beg = clock();
for (int i = 0; i < ms; i++)
{
this_thread::sleep_for(1ms);
if ((clock() - beg) / (CLOCKS_PER_SEC / 1000) >= ms)
break;
}
}
long long NowMs()
{
return clock() / (CLOCKS_PER_SEC / 1000);//获取当前时间戳 毫秒
}
AVFrame* XVideoView::Read()
{
if (width_ <= 0 || height_ <= 0 || !ifs_)return NULL;
//AVFrame空间已经申请，如果参数发生变化，需要释放空间
if (frame_)//若分配了
{
if (frame_->width != width_
|| frame_->height != height_
|| frame_->format != fmt_)
{
//释放AVFrame对象空间，和buf引用计数减一
av_frame_free(&frame_);
}
}
if (!frame_)//若没分配则分配
{
//分配对象空间和像素空间
frame_ = av_frame_alloc();
frame_->width = width_;
frame_->height = height_;
frame_->format = fmt_;
frame_->linesize[0] = width_ * 4;
if (frame_->format == AV_PIX_FMT_YUV420P)//YUV420P单独处理，因为他不是平面存储是多层存储需要三个数组存储三个平面
{
frame_->linesize[0] = width_; // Y
frame_->linesize[1] = width_ / 2;//U
frame_->linesize[2] = width_ / 2;//V
}
//生成AVFrame空间，使用默认对齐
auto re = av_frame_get_buffer(frame_, 0);
if (re != 0)
{
char buf[1024] = { 0 };
av_strerror(re, buf, sizeof(buf) - 1);
cout << buf << endl;
av_frame_free(&frame_);
return NULL;
}
}
if (!frame_)return NULL;
//读取一帧数据
if (frame_->format == AV_PIX_FMT_YUV420P)
{
ifs_.read((char*)frame_->data[0],
frame_->linesize[0] * height_); //Y
ifs_.read((char*)frame_->data[1],
frame_->linesize[1] * height_ / 2); //U
ifs_.read((char*)frame_->data[2],
frame_->linesize[2] * height_ / 2); //V
}//执行完后 avframe中就保存了从2.yuv中读取的yuv数据了
else //RGBA ARGB BGRA 32
{
ifs_.read((char*)frame_->data[0], frame_->linesize[0] * height_);
}
if (ifs_.gcount() == 0)
return NULL;
return frame_;
}
//打开文件
bool XVideoView::Open(std::string filepath)
{
if (ifs_.is_open())
{
ifs_.close();
}
ifs_.open(filepath, ios::binary);
return ifs_.is_open();//ifs_绑定了所选的文件 如 2.yuv
}
XVideoView* XVideoView::Create(RenderType type)
{
switch (type)
{
case XVideoView::SDL:
return new XSDL();
break;
default:
break;
}
return nullptr;
}
bool XVideoView::DrawFrame(AVFrame* frame)
{
if (!frame || !frame->data[0])return false;
count_++;
if (beg_ms_ <= 0)
{
beg_ms_ = clock();
}
//计算显示帧率
else if ((clock() - beg_ms_) / (CLOCKS_PER_SEC / 1000) >= 1000) //一秒计算一次fps
{
render_fps_ = count_;
count_ = 0;
beg_ms_ = clock();
}
switch (frame->format)
{
case AV_PIX_FMT_YUV420P:
return Draw(frame->data[0], frame->linesize[0],//Y
frame->data[1], frame->linesize[1], //U
frame->data[2], frame->linesize[2] //V
);
case AV_PIX_FMT_BGRA:
case AV_PIX_FMT_ARGB:
case AV_PIX_FMT_RGBA:
return Draw(frame->data[0], frame->linesize[0]);
default:
break;
}
return false;
}xsdl.cpp
#include "xsdl.h"
#include "sdl/SDL.h"
#include <iostream>
using namespace std;
#pragma comment(lib,"SDL2.lib")
static bool InitVideo()
{
static bool is_first = true;
static mutex mux;
unique_lock<mutex> sdl_lock(mux);
if (!is_first)return true;
is_first = false;
if (SDL_Init(SDL_INIT_VIDEO))
{
cout << SDL_GetError() << endl;
return false;
}
//设定缩放算法，解决锯齿问题,线性插值算法
SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "1");
return true;
}
bool XSDL::IsExit()
{
SDL_Event ev;
SDL_WaitEventTimeout(&ev, 1);
if (ev.type == SDL_QUIT)
return true;
return false;
}
void XSDL::Close()
{
//确保线程安全
unique_lock<mutex> sdl_lock(mtx_);
if (texture_)
{
SDL_DestroyTexture(texture_);
texture_ = nullptr;
}
if (render_)
{
SDL_DestroyRenderer(render_);
render_ = nullptr;
}
if (win_)
{
SDL_DestroyWindow(win_);
win_ = nullptr;
}
}
bool XSDL::Init(int w, int h, Format fmt)
{
if (w <= 0 || h <= 0)return false;
//初始化SDL 视频库
InitVideo();
//确保线程安全
unique_lock<mutex> sdl_lock(mtx_);
width_ = w;
height_ = h;
fmt_ = fmt;
if (texture_)
SDL_DestroyTexture(texture_);
if (render_)
SDL_DestroyRenderer(render_);
///1 创建窗口
if (!win_)
{
if (!win_id_)
{
//新建窗口
win_ = SDL_CreateWindow("",
SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,
w, h, SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE
);
}
else
{
//渲染到控件窗口
win_ = SDL_CreateWindowFrom(win_id_);
}
}
if (!win_)
{
cerr << SDL_GetError() << endl;
return false;
}
/// 2 创建渲染器
render_ = SDL_CreateRenderer(win_, -1, SDL_RENDERER_ACCELERATED);
if (!render_)
{
cerr << SDL_GetError() << endl;
return false;
}
//创建材质 （显存）
unsigned int sdl_fmt = SDL_PIXELFORMAT_RGBA8888;
switch (fmt)
{
case XVideoView::RGBA:
sdl_fmt = SDL_PIXELFORMAT_RGBA32;
break;
case XVideoView::BGRA:
sdl_fmt = SDL_PIXELFORMAT_BGRA32;
break;
case XVideoView::ARGB:
sdl_fmt = SDL_PIXELFORMAT_ARGB32;
break;
case XVideoView::YUV420P:
sdl_fmt = SDL_PIXELFORMAT_IYUV;
break;
default:
break;
}
texture_ = SDL_CreateTexture(render_,
sdl_fmt, //像素格式
SDL_TEXTUREACCESS_STREAMING, //频繁修改的渲染（带锁）
w, h //材质大小
);
if (!texture_)
{
cerr << SDL_GetError() << endl;
return false;
}
return true;
}
bool XSDL::Draw(
const unsigned char* y, int y_pitch,
const unsigned char* u, int u_pitch,
const unsigned char* v, int v_pitch
)
{
//参数检查
if (!y || !u || !v)return false;
unique_lock<mutex> sdl_lock(mtx_);
if (!texture_ || !render_ || !win_ || width_ <= 0 || height_ <= 0)
return false;
//复制内存到显显存
auto re = SDL_UpdateYUVTexture(texture_,
NULL,
y, y_pitch,
u, u_pitch,
v, v_pitch);
if (re != 0)
{
cout << SDL_GetError() << endl;
return false;
}
//清空屏幕
SDL_RenderClear(render_);
//材质复制到渲染器
SDL_Rect rect;
SDL_Rect* prect = nullptr;
if (scale_w_ > 0) //用户手动设置缩放
{
rect.x = 0; rect.y = 0;
rect.w = scale_w_;//渲染的宽高，可缩放
rect.h = scale_w_;
prect = ▭
}
re = SDL_RenderCopy(render_, texture_, NULL, prect);
if (re != 0)
{
cout << SDL_GetError() << endl;
return false;
}
SDL_RenderPresent(render_);
return true;
}
bool XSDL::Draw(const unsigned char* data, int linesize)
{
if (!data)return false;
unique_lock<mutex> sdl_lock(mtx_);
if (!texture_ || !render_ || !win_ || width_ <= 0 || height_ <= 0)
return false;
if (linesize <= 0)
{
switch (fmt_)
{
case XVideoView::RGBA:
case XVideoView::ARGB:
linesize = width_ * 4;
break;
case XVideoView::YUV420P:
linesize = width_;
break;
default:
break;
}
}
if (linesize <= 0)
return false;
//复制内存到显显存
auto re = SDL_UpdateTexture(texture_, NULL, data, linesize);
if (re != 0)
{
cout << SDL_GetError() << endl;
return false;
}
//清空屏幕
SDL_RenderClear(render_);
//材质复制到渲染器
SDL_Rect rect;
SDL_Rect* prect = nullptr;
if (scale_w_ > 0) //用户手动设置缩放
{
rect.x = 0; rect.y = 0;
rect.w = scale_w_;//渲染的宽高，可缩放
rect.h = scale_w_;
prect = ▭
}
re = SDL_RenderCopy(render_, texture_, NULL, prect);
if (re != 0)
{
cout << SDL_GetError() << endl;
return false;
}
SDL_RenderPresent(render_);
return true;
}main.cpp
#include "sdlqtrgb.h"
#include <QtWidgets/QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
SdlQtRGB w;
w.show();
return a.exec();
}
3.运行结果：
![[C++数据结构之看懂就这一篇]图(上)](https://img-blog.csdnimg.cn/img_convert/d6a4016ed68d8491e43827dfddb79e79.png)
