之前用qt寫了一個在windows下播放視頻的軟件，具體介紹參見qt編寫的視頻播放器，windows下使用，精致小巧_GreenHandBruce的博客-CSDN博客

后來發現有些視頻沒有內嵌字幕，需要外掛字幕，這時候，我就想著把加載外掛字幕的功能加上。如下圖：

這里先做了解析.srt字幕文件的功能。具體實現如下

1.先在窗口放一個label，將label調整到界面底部，設置字體，顏色

//顯示字幕用的label;labelSubTitle = new myLabel(this);
//    labelSubTitle->setText("這里顯示字幕文件");QFont font("微軟雅黑",15,QFont::Bold);QPalette palette = labelSubTitle->palette();palette.setColor(QPalette::WindowText,Qt::white);labelSubTitle->setPalette(palette);labelSubTitle->setFont(font);labelSubTitle->setAlignment(Qt::AlignCenter);

2.在打開視頻文件的時候找到同文件夾下的.srt文件

    int nIndex = fileName.lastIndexOf('.');//尋找‘.’符號在字符串中的idnIndex++;QString srtfile =fileName.mid(0,nIndex); //截取‘.’符號后面的字符串，這是為了獲取文件后綴名srtfile +="srt";EncodingFormat code = FileCharacterEncoding(srtfile);QFile file(srtfile);if(!file.open(QIODevice::ReadOnly)) {qDebug()<<"未找到外掛字幕文件："<<srtfile<<endl;}

3.解析.srt文件，先看一下.srt字幕文件格式如下：

然后寫個結構體用來存放解析之后的srt內容，如下：

struct SrtInfo
{qint16 Num;QTime dtStart;QTime dtEnd;QString strSubTitle;
};

然后解析，在解析的時候要注意.srt的編碼格式，（編碼格式這塊參見我上一篇文章qt按照不同編碼格式讀取文字(UTF-16LE,UTF-8,UTF-8BOM,UTF-16BE)-CSDN博客）

void VideoPlayer::ParseSubTitle(QString fileName)
{int nIndex = fileName.lastIndexOf('.');//尋找‘.’符號在字符串中的idnIndex++;QString srtfile =fileName.mid(0,nIndex); //截取‘.’符號后面的字符串，這是為了獲取文件后綴名srtfile +="srt";EncodingFormat code = FileCharacterEncoding(srtfile);QFile file(srtfile);if(!file.open(QIODevice::ReadOnly)) {qDebug()<<"未找到外掛字幕文件："<<srtfile<<endl;}m_SrtInfoLst.clear();QTextCodec::ConverterState state;QTextCodec *codec = QTextCodec::codecForName("UTF-8");if(code==EncodingFormat::UTF16LE){codec = QTextCodec::codecForName("UTF-16LE");}else if(code==EncodingFormat::UTF8){codec = QTextCodec::codecForName("UTF-8");}else if(code==EncodingFormat::UTF8BOM){codec = QTextCodec::codecForName("UTF-8");}else if(code==EncodingFormat::UTF16BE){codec = QTextCodec::codecForName("UTF-16BE");}QTextStream stream_src(&file);stream_src.setCodec(codec);while(!stream_src.atEnd()) {QString str = stream_src.readLine();str = str.replace('\r',"");//替換回車符str = str.replace('\n',"");//替換換行符bool ok;qint16 nID = str.toInt(&ok,10);if(ok){SrtInfo info;info.Num = nID;if(stream_src.atEnd())break;QString str2=stream_src.readLine();str2 = str2.replace('\r',"");//替換回車符str2 = str2.replace('\n',"");//替換換行符str2 = str2.replace(' ',"");//替換空格符if(str2=="")continue;info.dtStart = QTime::fromString(str2.split('-').first(),"hh:mm:ss,zzz");info.dtEnd = QTime::fromString(str2.split('>').last(),"hh:mm:ss,zzz");QString str3=stream_src.readLine();if(str3=="")continue;str3 = str3.replace('\r',"");//替換回車符str3 = str3.replace('\n',"");//替換換行符info.strSubTitle = str3;QString str4=stream_src.readLine();if(str4=="")continue;str4 = str4.replace('\r',"");//替換回車符str4 = str4.replace('\n',"");//替換換行符info.strSubTitle.append('\n');info.strSubTitle.append(str4);m_SrtInfoLst.append(info);}}file.close();
}

然后就是在播放視頻的時候，找到當前時刻對應的字幕并顯示在label上，如下：

void VideoPlayer::positionChanged(qint64 position)
{m_positionSlider->setValue(position);QTime timeCrt = QTime(0,0,0);timeCrt = timeCrt.addMSecs(position);QTime timeTotal =QTime(0,0,0);timeTotal = timeTotal.addMSecs(m_mediaPlayer->duration());QString str = timeCrt.toString("hh:mm:ss")+"/"+timeTotal.toString("hh:mm:ss");
//    m_labelTiem->setFont(QFont::gra);m_labelTiem->setText(str);if(m_mediaPlayer->duration()>0&&position>=m_mediaPlayer->duration()){//圖標變成playQImage img;img.load(":/play");m_labelPlay->setPixmap(QPixmap::fromImage(img));}bool bShow = false;foreach(const SrtInfo item,m_SrtInfoLst){if(item.dtStart<timeCrt && item.dtEnd>timeCrt){labelSubTitle->setText(item.strSubTitle);bShow = true;break;}}if(!bShow){labelSubTitle->setText("");}
}

完整代碼參見

https://download.csdn.net/download/weixin_43935474/88561361