how to play a voice from QByteArray in Qt

Question

I want to play a music from QByteArray with so I can use it in many cases as to retrieve a sound from database or transfer it over network using Tcp etc..
So I use these lines of code

QFile file("E:\\amr.mp3");    // sound dir
file.open(QIODevice::ReadOnly);
QByteArray arr = file.readAll(); // change it to QbyteArray
QBuffer buffer(&arr);  
qDebug() << "Buffer error = " << buffer.errorString();  // i get error from here "unkow error"

QMediaPlayer *player = new QMediaPlayer();
player->setMedia(QMediaContent(),&buffer);

player->play();
qDebug() << "Player error = " << player->errorString(); // no error ""

I see many solutions when I search, one of them is on stackoverflow the solution is to make a Qbuffer, pass to it the array and put it in setMedia but it didn't work so I need any help to make this code run or any other way to play a voice or music from QByteArray

Answer 1

You just forgot to open the Buffer with

buffer.open(QIODevice::ReadOnly);

So a full working demo program is this:

#include <QApplication>
#include <QMediaPlayer>
#include <QFile>
#include <QBuffer>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);


    QFile file(R"(C:\test.mp3)");    // sound dir
    file.open(QIODevice::ReadOnly);
    QByteArray arr = file.readAll(); 

    QMediaPlayer *player = new QMediaPlayer(&a);

    QBuffer *buffer = new QBuffer(player);
    buffer->setData(arr);
    buffer->open(QIODevice::ReadOnly);

    player->setMedia(QMediaContent(),buffer);

    player->play();

    return a.exec();
}