Other option to set media in Player of Qt

Tejas Virpariya

Hi,

I am able to play .h264 binary file using QMediaPlayer in Qt, but in which I give file from local location using

QMediaPlayer *player;
QString fileName = "C:/username/test.mp4";
player->setmedia(QUrl::fromLocalFile(fileName));

Only for knowledge : Second application get data from camera and put frame by frame in .h264 file, and my application read data from this file, for time saving purpose and for better performance, I want to catch direct data from buffer and show on a player.

Now my requirement I have to show on time video of camera, and data come in buffer, so question is, How can I set buffer as a input source of player->setmedia? I don't want to give file location to player->setmedia.

Thanks.

SGaist

Hi,

Is that camera visible from QCamera ?

Tejas Virpariya

@SGaist : I don't know its visible or not, but in our process, there is RTSP client application which try to get frame from camera and put in a .h264 binary file, now I have to catch frame from RTSP client and show on a player on time.

And ya I can give buffer input to player->setmedia like

mBuffer = new QBuffer(this);
const QByteArray &bytArray;
mBuffer->write(bytArray);
mPlayer->setMedia(QMediaContent(), mBuffer);

Now my question is, can I catch my frame in a bytArray? if yes then will it work continue? means one frame come on bytArray then I have to catch second frame in bytArray again and this process will continue.

SGaist

How are you controlling that RTSP client ? Does it give you access to the frames somehow ?

Tejas Virpariya

@SGaist : Yes, I can control RTSP client, and this process store frame in a buffer (Char Array). Now I want to show this frame on a screen frame by frame.

SGaist

What format is that frame ?

Tejas Virpariya

@SGaist : Char array. its a one type of buffer. and ya every frame has different size.

SGaist

My question was more: are you getting a decoded uncompressed frame ?

Tejas Virpariya

@SGaist : yes I decoded it with system decoder... actually I store buffer in one file, and when I play this file in VLC, it play successfully. but qt show only black screen.

I added some more code...

QMediaPlayer* player[screen];
QVideoWidget* vw[screen];
....
while(1){
    if (NULL != fpFrames)
                {
                    fwrite(u8NAL, 4, 1, fpFrames);
                    fwrite(streamData->dataBuffer, streamData->dataSize, 1, fpFrames);


                    mBuffer->open(QIODevice::ReadWrite);
                    mBuffer->seek(0);
                    mBuffer->setData((char *)streamData->dataBuffer,streamData->dataSize);
                    mBuffer->write((char *)streamData->dataBuffer);
                    mBuffer->seek(0);

                    if(playerFlag == 0){

                        player[0]->setMedia(QMediaContent(), mBuffer);

                        playerFlag = 1;
                        player[0]->play();
                    }
}

In above code I get data from rtsp in streamData->dataBuffer and its type is void*, I store it in QBuffer *mBuffer, and this mBuffer store in one file, which can play in VLC.

Now when I run this application, application out show some message :
Buffer::setData: Buffer is open

*GStreamer; Unable to pause - ""

QBuffer::setData: Buffer is open

QBuffer::setData: Buffer is open........*

Now help to come out this problem....
Thanks...

SGaist

You never close mBuffer, hence the Buffer is open error.