QMediaContent and QBuffer

OtisLin

I want to read the video in the buffer.
I think it can faster to change to next video?
Finally I want to combine two video stream.
this is my code

QFile mediaFile("path");
mediaFile.open(QIODevice::ReadyOnly);
QByteArrary *ba = new QByteArrary();
ba->append(mediaFile->readAll());
QBuffer *buffer = new QBuffer(ba);
buffer->open(QIODevice::ReadyOnly);
buffer->seek(0);
MediaPlayer.setMedia(QMediaContent(), buffer);

How to put a buffer in QMediaContent?