Errors when reading a QImage sent through a socket

[volatile_ah]

Hey guys,

First up I'm new to this whole Qt-programming, but it's been a fun challenge thus far.

What I'm trying to do is send a QImage across the network using a QTcpSocket. Let's for a second pretend I don't care about bandwidth, I just want to try and get this working.

Below is my server code (snippet):

QBuffer image_buffer;
QImageWriter writer(&image_buffer, "PNG");
if(!writer.write(captured_image.getImage()))
	qWarning()<<"ERROR: Unable to write image to buffer: "<<writer.errorString();
 
QByteArray data;
QDataStream out(&data, QIODevice::WriteOnly);
out.setVersion(QDataStream::Qt_4_0);
out<<(quint32)image_buffer.data().size();
 
qDebug()<<"Image size = "<<image_buffer.data().size();
 
out<<image_buffer.data();
 
video_socket.write(data);
if(!video_socket.waitForBytesWritten())
	qWarning()<<"ERROR: Unable to send image: "<<video_socket.errorString();

QBuffer image_buffer;
QImageWriter writer(&image_buffer, "PNG");
if(!writer.write(captured_image.getImage()))
	qWarning()<<"ERROR: Unable to write image to buffer: "<<writer.errorString();
				
QByteArray data;
QDataStream out(&data, QIODevice::WriteOnly);
out.setVersion(QDataStream::Qt_4_0);
out<<(quint32)image_buffer.data().size();
			
qDebug()<<"Image size = "<<image_buffer.data().size();
			
out<<image_buffer.data();
			
video_socket.write(data);
if(!video_socket.waitForBytesWritten())
	qWarning()<<"ERROR: Unable to send image: "<<video_socket.errorString();

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My client code (snippet) is as follows:

QDataStream in(&video_socket);
in.setVersion(QDataStream::Qt_4_0);
 
while(video_socket.bytesAvailable() < sizeof(quint32))
{
	qDebug()<<"Waiting for image size...";
	if(!video_socket.waitForReadyRead())
	{
		qWarning()<<"ERROR: Failed to read image size: "<<video_socket.errorString();
		return;
	}
}
 
quint32 image_size;
in>>image_size;
 
qDebug()<<"Image Size = "<<image_size;
 
while(video_socket.bytesAvailable() < image_size)
{
	qDebug()<<"Waiting for image...";
	if(!video_socket.waitForReadyRead())
	{
		qWarning()<<"ERROR: Failed to read image: "<<video_socket.errorString();
		return;
	}
}
 
QByteArray data;
in>>data;
 
qDebug()<<"Data size = "<<data.size();
 
QBuffer image_buffer(&data);
QImageReader reader(&image_buffer, "PNG");	
QImage received_image;
 
if(!reader.read(&received_image))
{
	qWarning()<<"ERROR: Unable to read received image from buffer: "<<reader.errorString();
	return;
}

QDataStream in(&video_socket);
in.setVersion(QDataStream::Qt_4_0);
		
while(video_socket.bytesAvailable() < sizeof(quint32))
{
	qDebug()<<"Waiting for image size...";
	if(!video_socket.waitForReadyRead())
	{
		qWarning()<<"ERROR: Failed to read image size: "<<video_socket.errorString();
		return;
	}
}
		
quint32 image_size;
in>>image_size;
		
qDebug()<<"Image Size = "<<image_size;
		
while(video_socket.bytesAvailable() < image_size)
{
	qDebug()<<"Waiting for image...";
	if(!video_socket.waitForReadyRead())
	{
		qWarning()<<"ERROR: Failed to read image: "<<video_socket.errorString();
		return;
	}
}
		
QByteArray data;
in>>data;
		
qDebug()<<"Data size = "<<data.size();
		
QBuffer image_buffer(&data);
QImageReader reader(&image_buffer, "PNG");	
QImage received_image;
		
if(!reader.read(&received_image))
{
	qWarning()<<"ERROR: Unable to read received image from buffer: "<<reader.errorString();
	return;
}

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However, the client only seems to be able to read the size of the image, then dies.

Below is the output from the qDebug() statements in the server:

Image size = 384387
Data written = 384395

And below is my output from qDebug() statements in the client program:

Waiting for image size...
Image Size = 384387
Waiting for image...
Waiting for image...
Waiting for image...
ERROR: Failed to read image: "The remote host closed the connection"

So I guess my question is, can anyone see why it is doing this? I'm at a loss...

Any help would be terrific!!!

Regards,
Adrian