QT实现在线流媒体播放平台-编程知识

文章目录

QT实现在线流媒体播放平台
- 简介
- 开发视频
- - ffmpeg下载
  - SimpleVideoPlayer.h
  - SimpleVideoPlayer.cpp
- 开发音频
- 添加功能
- - 打开文件夹
  - 播放暂停
  - 播放上下一首
  - 选择倍速
- 效果展示
- 项目下载

QT实现在线流媒体播放平台

简介

Qt是一种流行的C++开发框架，它提供了用于构建图形用户界面（GUI）和跨平台应用程序的工具和库。Qt具有广泛的应用范围，可以用于开发桌面应用程序、移动应用程序和嵌入式系统等。Qt具有丰富的多媒体功能，包括音频和视频处理能力。

在使用Qt进行在线流媒体开发时，我们可以结合FFmpeg和QMediaPlayer来实现强大的音视频处理和播放功能。首先，可以使用FFmpeg解码音视频文件或流，提取音频和视频数据。然后，可以使用QMediaPlayer加载音频和视频数据，并通过其播放控制接口实现音视频的同步播放。此外，可以使用Qt的图形界面开发能力，创建用户友好的界面，显示视频内容，并提供交互控制。

开发视频

FFmpeg是一个开源的多媒体框架，它提供了一套用于处理音视频的工具和库。FFmpeg支持广泛的音视频格式和编解码器，能够对音视频进行解码、编码、转换和处理等操作。在在线流媒体应用中，FFmpeg通常用于处理音视频文件或流，提取其中的音频和视频数据，进行解码和编码，以及应用特效和滤镜等。

ffmpeg下载

如果你的qt版本是32位，下载的FFmpeg是64位，则可能识别不了函数
在这里我提供了64位和32位的FFmpeg下载链接

32位链接： https://pan.baidu.com/s/1wBAv6yYYa_9n64wzmHdO2w
提取码：0703

64位链接： https://pan.baidu.com/s/1aEHWpbTQkhVA30KtfviYjA
提取码：0703

SimpleVideoPlayer.h

#ifndef SIMPLEVIDEOPLAYER_H
#define SIMPLEVIDEOPLAYER_H#include <QThread>
#include <QMainWindow>
#include <QImage>extern "C"
{#include "libavcodec/avcodec.h"#include "libavformat/avformat.h"#include "libavutil/pixfmt.h"#include "libswscale/swscale.h"#include <libavutil/imgutils.h>
}class SimpleVideoPlayer : public QThread
{Q_OBJECTpublic:explicit SimpleVideoPlayer();~SimpleVideoPlayer();void setVideo(const QString &videoPath){this->_videoPath = videoPath;}inline void play();enum class PlayerState {Playing,Paused,Stopped};void togglePlayPause();void changeState();void setPlaybackSpeed(QString speed);
signals:void sigCreateVideoFrame(QImage image);protected:void run();private:QString _videoPath;PlayerState _state = PlayerState::Playing;QString speedVideo = "1x";
};#endif // SIMPLEVIDEOPLAYER_H

SimpleVideoPlayer.cpp

#include "SimpleVideoPlayer.h"
#include <iostream>
#include <QDebug>SimpleVideoPlayer::SimpleVideoPlayer()
{}SimpleVideoPlayer::~SimpleVideoPlayer()
{}void SimpleVideoPlayer::play()
{start();
}void SimpleVideoPlayer::togglePlayPause()
{if (_state == PlayerState::Playing) {_state = PlayerState::Paused;} else {_state = PlayerState::Playing;}
}void SimpleVideoPlayer::changeState()
{if(_state == PlayerState::Playing || _state == PlayerState::Paused){_state = PlayerState::Stopped;}
}void SimpleVideoPlayer::setPlaybackSpeed(QString speed)
{speedVideo = speed;
}void SimpleVideoPlayer::run()
{_state = PlayerState::Playing;if (_videoPath.isNull()){return;}char *file1 = _videoPath.toUtf8().data();//编解码器的注册，最新版本不需要调用//av_register_all();//描述多媒体文件的构成及其基本信息AVFormatContext *pAVFormatCtx = avformat_alloc_context();if (avformat_open_input(&pAVFormatCtx, file1, NULL, NULL) != 0){std::cout<<"open file fail"<<std::endl;avformat_free_context(pAVFormatCtx);return;}//读取一部分视音频数据并且获得一些相关的信息if (avformat_find_stream_info(pAVFormatCtx, NULL) < 0){std::cout<<"avformat find stream fail"<<std::endl;avformat_close_input(&pAVFormatCtx);return;}int iVideoIndex = -1;for (uint32_t i = 0; i < pAVFormatCtx->nb_streams; ++i){//视频流if (pAVFormatCtx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO){iVideoIndex = i;break;}}if (iVideoIndex == -1){std::cout<<"video stream not find"<<std::endl;avformat_close_input(&pAVFormatCtx);return;}//获取视频流的编解码器上下文的数据结构AVCodecContext *pAVCodecCtx = avcodec_alloc_context3(NULL);if (!pAVCodecCtx) {fprintf(stderr, "Could not allocate codec context\n");exit(1);}if (avcodec_parameters_to_context(pAVCodecCtx, pAVFormatCtx->streams[iVideoIndex]->codecpar) < 0) {fprintf(stderr, "Could not copy codec parameters\n");exit(1);}//编解码器信息的结构体const AVCodec *pAVCodec = avcodec_find_decoder(pAVCodecCtx->codec_id);if (pAVCodec == NULL){std::cout<<"not find decoder"<<std::endl;return;}//初始化一个视音频编解码器if (avcodec_open2(pAVCodecCtx, pAVCodec, NULL) < 0){std::cout<<"avcodec_open2 fail"<<std::endl;return;}//AVFrame 存放从AVPacket中解码出来的原始数据AVFrame *pAVFrame = av_frame_alloc();AVFrame *pAVFrameRGB = av_frame_alloc();//用于视频图像的转换,将源数据转换为RGB32的目标数据SwsContext *pSwsCtx = sws_getContext(pAVCodecCtx->width, pAVCodecCtx->height, pAVCodecCtx->pix_fmt,pAVCodecCtx->width, pAVCodecCtx->height, AV_PIX_FMT_RGB32,SWS_BICUBIC, NULL, NULL, NULL);int iNumBytes = av_image_get_buffer_size(AV_PIX_FMT_RGB32, pAVCodecCtx->width, pAVCodecCtx->height,1);uint8_t *pRgbBuffer = (uint8_t *)(av_malloc(iNumBytes * sizeof(uint8_t)));//为已经分配的空间的结构体AVPicture挂上一段用于保存数据的空间av_image_fill_arrays(pAVFrameRGB->data, pAVFrameRGB->linesize, pRgbBuffer, AV_PIX_FMT_RGB32, pAVCodecCtx->width, pAVCodecCtx->height,1);//AVpacket 用来存放解码之前的数据AVPacket packet;av_new_packet(&packet, pAVCodecCtx->width * pAVCodecCtx->height);//读取码流中视频帧while (av_read_frame(pAVFormatCtx, &packet) >= 0){if (_state == PlayerState::Stopped) {qDebug()<<"当前音乐已终止";break;}if (_state == PlayerState::Paused) {QThread::msleep(600); // Sleep for 600ms 线程休息continue;}if (packet.stream_index != iVideoIndex){av_packet_unref(&packet);continue;}// 发送数据包到解码器if (avcodec_send_packet(pAVCodecCtx, &packet) < 0){std::cout << "Error sending packet for decoding." << std::endl;av_packet_unref(&packet);continue;}// 从解码器接收解码后的帧while (avcodec_receive_frame(pAVCodecCtx, pAVFrame) == 0){// 转换像素格式sws_scale(pSwsCtx, (uint8_t const * const *)pAVFrame->data, pAVFrame->linesize, 0, pAVCodecCtx->height, pAVFrameRGB->data, pAVFrameRGB->linesize);// 构造QImageQImage img(pRgbBuffer, pAVCodecCtx->width, pAVCodecCtx->height, QImage::Format_RGB32);// 绘制QImageemit sigCreateVideoFrame(img);}av_packet_unref(&packet);double fps = av_q2d(pAVFormatCtx->streams[iVideoIndex]->r_frame_rate);int delay = 900.0 / fps;if(speedVideo == "2x"){msleep(delay / 2);}else if(speedVideo == "0.5x"){msleep(delay * 2);}else{msleep(delay);}//msleep(15);}//资源回收/*av_free(pAVFrame);av_free(pAVFrameRGB);sws_freeContext(pSwsCtx);avcodec_close(pAVCodecCtx);avformat_close_input(&pAVFormatCtx);*/av_frame_free(&pAVFrame);av_frame_free(&pAVFrameRGB);sws_freeContext(pSwsCtx);avcodec_free_context(&pAVCodecCtx);avformat_close_input(&pAVFormatCtx);}

开发音频

QMediaPlayer是Qt自带的多媒体播放器类，它提供了简单易用的接口，用于播放音频和视频文件。QMediaPlayer支持多种音视频格式，并且可以通过网络流式传输音视频内容。它具有播放、暂停、停止、跳转和调整音量等常见的播放控制功能。此外，QMediaPlayer还提供了信号和槽机制，可用于捕获播放状态的变化和处理用户交互事件。

MainWindow::MainWindow(QWidget *parent) :QMainWindow(parent),ui(new Ui::MainWindow)
{ui->setupUi(this);this->setWindowTitle("在线播放平台");//comboBox 数据居中ui->comboBox->setStyleSheet("QComboBox QAbstractItemView { text-align: center; }");/*QMediaPlayer * m_player;m_player = new QMediaPlayer(this);QString strPlayer = "D:/QT.study/onlinePlay/qiFengLe";m_player->setMedia(QUrl::fromLocalFile(strPlayer));m_player->setVolume(50);m_player->play();*///QPushButton *openFileButton = new QPushButton("打开文件", this);//setCentralWidget(openFileButton);connect(ui->openFileButton, &QPushButton::clicked, this, &MainWindow::openFileDialog);_simpleVp = new SimpleVideoPlayer();// 创建媒体播放器player = new QMediaPlayer;//_simpleAp = new audioPlayer();connect(_simpleVp,SIGNAL(sigCreateVideoFrame(QImage)),this,SLOT(sigGetVideoFrame(QImage)));connect(ui->Slider,&QSlider::valueChanged,this,&MainWindow::changeAudio);connect(ui->startBtn,&QPushButton::clicked,this,&MainWindow::startPlay);connect(ui->pauseButton , &QPushButton::clicked, this->_simpleVp, &SimpleVideoPlayer::togglePlayPause);connect(ui->boxBS, &QComboBox::currentTextChanged, this, &MainWindow::onSpeedChanged);//下一首歌曲connect(ui->nextButton,&QPushButton::clicked,this->_simpleVp,&SimpleVideoPlayer::changeState);connect(ui->nextButton,&QPushButton::clicked,this,&MainWindow::nextVideo);//上一首歌曲connect(ui->previousBtn,&QPushButton::clicked,this->_simpleVp,&SimpleVideoPlayer::changeState);connect(ui->previousBtn,&QPushButton::clicked,this,&MainWindow::previousVideo);//暂停播放connect(ui->pauseButton,&QPushButton::clicked,this,&MainWindow::pauseAudio);//增加MV曲目ui->comboBox->addItem("起风了----------买辣椒也用券");ui->comboBox->addItem("悬溺------------葛东琪");ui->comboBox->addItem("平凡之路--------朴树");ui->comboBox->addItem("把回忆拼好给你---------王贰浪");ui->comboBox->addItem("带我去找夜生活---------告五人");//增加倍速ui->boxBS->addItem("1x");ui->boxBS->addItem("0.5x");ui->boxBS->addItem("2x");connect(this, &MainWindow::speedChanged, _simpleVp, &SimpleVideoPlayer::setPlaybackSpeed);//视频文件路径videoStr["起风了----------买辣椒也用券"] = "D:/QT.music/video/qifengle.mkv";videoStr["平凡之路--------朴树"] = "D:/QT.music/video/pingfanzhilu.mkv";videoStr["带我去找夜生活---------告五人"] = "D:/QT.music/video/yeshenghuo.mkv";videoStr["把回忆拼好给你---------王贰浪"] = "D:/QT.music/video/huiyi.mkv";videoStr["悬溺------------葛东琪"] = "D:/QT.music/video/xuanni.mkv";//音乐文件路径audioStr["起风了----------买辣椒也用券"] = "D:/QT.music/audio/qifengle1.mp3";audioStr["平凡之路--------朴树"] = "D:/QT.music/audio/pingfanzhilu.mp3";audioStr["带我去找夜生活---------告五人"] = "D:/QT.music/audio/yeshenghuo.mp3";audioStr["把回忆拼好给你---------王贰浪"] = "D:/QT.music/audio/huiyi.mp3";audioStr["悬溺------------葛东琪"] = "D:/QT.music/audio/xuanni.mp3";QIcon icon;icon.addFile(tr(":/qrs/4.png"));ui->pauseButton->setIconSize(QSize(120,40));ui->pauseButton->setIcon(icon);
}MainWindow::~MainWindow()
{delete ui;delete _simpleVp;delete player;
}void MainWindow::startPlay()
{//获得当前选择歌曲QString Str = ui->comboBox->currentText();qDebug()<<Str;// 加载音乐文件QString currentAudio = audioStr[Str];// player->setMedia(QUrl::fromLocalFile(currentAudio));//0~100音量范围,默认是100ui->Slider->setValue(50);player->setVolume(50);// 加载视频文件QString currentVideo = videoStr[Str];//_simpleVp->setVideo(currentVideo);/*_simpleAp->setAudio("D:/QT.study/onlinePlay/qifengle1.mp3");开始播放，QThread类的成员函数_simpleAp->start();*///开始播放player->play();_simpleVp->start();}

因为需要里面需要打开的文件位置，所以打开时需要更改位置
在这里插入图片描述

添加功能

我们目前只是完成了打开视频和音频的功能，还需要完善一下功能：

打开文件夹
播放暂停
播放下一首歌曲
开启倍速模式
开启调节音量模式

打开文件夹

void MainWindow::openFileDialog()
{//QString filePath = QFileDialog::getOpenFileName(this, "Open Song", "", "Audio Files (*.mp3 *.wav);;All Files (*)");QString filePath = QFileDialog::getOpenFileName(this, "Open Video", "", "Video Files (*.mp4 *.avi *.mkv *.mov);;All Files (*)");ui->openFilePath->setText(filePath);if (!filePath.isEmpty()){// 这里处理用户选择的歌曲，例如将其传递给播放器等。qDebug() << "Selected song:" << filePath;_simpleVp->setVideo(filePath);QString str;for(auto it = videoStr.begin();it != videoStr.end();it++){if(it->second == filePath){str = it->first;break;}}player->setMedia(QUrl::fromLocalFile(audioStr[str]));}
}

播放暂停

void MainWindow::pauseAudio()
{QIcon icon;if (player->state() == QMediaPlayer::PlayingState) {icon.addFile(tr(":/qrs/3.png"));player->pause();//ui->pauseButton->setText("Play");ui->pauseButton->setIconSize(QSize(120,40));ui->pauseButton->setStyleSheet("background-color: transparent;");ui->pauseButton->setFlat(true);ui->pauseButton->setIcon(icon);} else {icon.addFile(tr(":/qrs/4.png"));player->play();//ui->pauseButton->setText("Pause");ui->pauseButton->setIconSize(QSize(120,40));ui->pauseButton->setStyleSheet("background-color: transparent;");ui->pauseButton->setFlat(true);ui->pauseButton->setIcon(icon);}
}

播放上下一首

void MainWindow::nextVideo() //播放下一首歌曲
{int idx = 0;QString fileStr = ui->openFilePath->text();for(auto it = videoStr.begin();it != videoStr.end();it++){if(it->second == fileStr){break;}idx++;}idx = (idx + 1) % 5;int idx1 = idx;QString videoFile;                 //= (videoStr.begin() + idx)->second;QString audioFile;                 //= (audioStr.begin() + idx)->second;for(auto it = videoStr.begin();it != videoStr.end();it++){if(idx == 0){videoFile = it->second;break;}idx--;}for(auto it = audioStr.begin();it != audioStr.end();it++){if(idx1 == 0){audioFile = it->second;break;}idx1--;}ui->openFilePath->setText(videoFile);_simpleVp->setVideo(videoFile);player->setMedia(QUrl::fromLocalFile(audioFile));_simpleVp->start();player->play();
}//实现上一首歌曲功能
void MainWindow::previousVideo()
{int idx = 0;QString fileStr = ui->openFilePath->text();for(auto it = videoStr.begin();it != videoStr.end();it++){if(it->second == fileStr){break;}idx++;}idx = (idx - 1 + 5) % 5;int idx1 = idx;QString videoFile;                 //= (videoStr.begin() + idx)->second;QString audioFile;                 //= (audioStr.begin() + idx)->second;for(auto it = videoStr.begin();it != videoStr.end();it++){if(idx == 0){videoFile = it->second;break;}idx--;}for(auto it = audioStr.begin();it != audioStr.end();it++){if(idx1 == 0){audioFile = it->second;break;}idx1--;}ui->openFilePath->setText(videoFile);_simpleVp->setVideo(videoFile);player->setMedia(QUrl::fromLocalFile(audioFile));_simpleVp->start();player->play();
}

选择倍速

void MainWindow::onSpeedChanged() //选择不同倍速时，会给视频和音频发射信号
{QString SpeedStr = ui->boxBS->currentText();if(SpeedStr == "2x"){player->setPlaybackRate(2.0);}else if(SpeedStr == "0.5x"){player->setPlaybackRate(0.5);}else {player->setPlaybackRate(1.0);}emit speedChanged(SpeedStr);
}