Acquisition issues

Using Aravis
1

Hello, I am currently using aravis-0.4 on a QT project.
I use a callback to display the live vidéo, but the image is blinking and there are artifacts on it (see the image).

im
im1296×972 441 KB

Did wrong parameters can make an image look like that ?
Here is my functions to start aquire and my callback:

void AcquisitionThread::startAcquire()
{
	if(canCapture && camera != NULL && device != NULL)
	{
		cameraStream = arv_camera_create_stream(camera, NULL, NULL);
		if(cameraStream != NULL)
		{
			arv_stream_push_buffer (cameraStream, arv_buffer_new (arv_camera_get_payload (camera), NULL));


			/* Connect the new-buffer signal */
			g_signal_connect (cameraStream, "new-buffer", G_CALLBACK (&AcquisitionThread::acquireFrame), this);

			/* And enable emission of this signal (it's disabled by default for performance reason) */
			arv_stream_set_emit_signals (cameraStream, TRUE);

			/* Connect the control-lost signal */
			g_signal_connect (device, "control-lost", G_CALLBACK (&AcquisitionThread::controlLostCallback), this);

			/* Start the video stream */
			arv_camera_start_acquisition (camera);
			isRunning = true;
		}
		else
		{
			isRunning = false ;
		}
	}
	else
	{
		qDebug() << tr("%1 The acquisition thread isn't able to capture.").arg("<KAT0x9>");
	}
}

void KAcquisitionThread::acquireFrame(ArvStream *pStream, void *instance)
{
	AcquisitionThread* instanceClasse =static_cast<AcquisitionThread*>( instance);
	ArvBuffer *pBuffer;
	pBuffer = arv_stream_try_pop_buffer(pStream);
	qDebug() << "TRY POP BUFFER";
	if (pBuffer != NULL)
	{
		qDebug() << "BUFFER NON NULL";
		ArvBufferStatus status = arv_buffer_get_status (pBuffer);
		if(status  == ARV_BUFFER_STATUS_SUCCESS)
		{
			qDebug() << "BUFFER SUCCES";
			int width = arv_buffer_get_image_width(pBuffer);
			int height = arv_buffer_get_image_height(pBuffer);
			QImage im( instanceClasse->image.scaled(width, height));
			size_t nDim = width*height;
			memcpy(im.bits(), (unsigned char*)arv_buffer_get_data (pBuffer, &nDim ), (size_t)im.byteCount());

			Q_EMIT instanceClasse->updateImage(im.mirrored( instanceClasse->camID == 2,  instanceClasse->camID == 1)); //??
		}
		else
		{
			instanceClasse->ShowErrormessage(status);
		}
		unsigned int payload;
		payload = arv_camera_get_payload (instanceClasse->camera);
		g_object_unref(pBuffer);
		g_mutex_lock(instanceClasse->mutex);
		pBuffer = arv_buffer_new (payload, NULL);
		g_mutex_unlock(instanceClasse->mutex);
		arv_stream_push_buffer (pStream, pBuffer);
	}
	else
	{
		qDebug() << "Buffer is null" ;
	}
}

Did you see a probleme ?

I also try to download the frame, same probleme. Thats why I think I have a acquisition issue.

Ty for your help.

Romain

3

Blinking/pumping might be due to auto exposure, specially for colour cameras.

Try to set a fixed exposure.