I have really terrible problem that makes me almost sick. For 2-3 days, I've been dealing with this protocol issue and i find myself here to get some help from you guys. I hope I'll be solving. Thanks in advance. I had code in Vb that uses Old MsComm Library. So I decided to change all stuff with C#. I'm okey with opening , closing port and sending data etc.
In Vb; I have the following part of code which is for receiving data from Mbus driver via RS485. Once you sent this it responses you to obtain data. It works and no problem.
Dim SendData(19) As Byte
Dim sending As String
SendData(0) = &HFA
SendData(1) = Mid(DriverNo, 1, 2)
SendData(2) = Mid(DriverNo, 3, 2)
SendData(3) = Mid(DriverNo, 5, 2)
SendData(4) = Mid(DriverNo, 7, 2)
SendData(5) = 210
SendData(6) = CheckSum_Temass(5)
SendData(7) = &HFB
sending = ""
For i = 0 To 7
sending= sending + Chr(SendData(i))
Next
SP.Output = sending
So , the code above is working fine in Vb and Vb.Net. However when I convert it to C# like the following ; I cant get response from mbus driver. While sending data via RS485, I can see that yellow led fires. Normally while receiving data, you can see that red led also fires. The Code in C# ;
string sending= "";
byte[] SendData = new byte[8];
SentData[0] = 0xfa;
SendData[1] = Convert.ToByte((Strings.Mid(DriverNo, 1, 2)));
SendData[2] = Convert.ToByte((Strings.Mid(DriverNo, 3, 2)));
SendData[3] = Convert.ToByte((Strings.Mid(DriverNo, 5, 2)));
SendData[4] = Convert.ToByte((Strings.Mid(DriverNo, 7, 2)));
SendData[5] = 210
SendData[6] = CheckSum_Temass(5);
SendData[7] = 0xfb;
for (int i = 0; i <= 7; i++)
{
sending= sending+ ((char)SendData[i]);
}
sp.Write(sending);
I cant see any problem with this but Vb Code works and C# does not.
In c# , the following is the part of my open port function ;
sp.PortName = portName;
sp.BaudRate = baudRate;
sp.DataBits = databits;
sp.Parity = parity;
sp.StopBits = StopBits.One;//stopBits;
sp.PinChanged += SerialPinChangedEventHandler1;
sp.ErrorReceived += SerialErrorReceivedEventHandler1;
sp.DataReceived += new SerialDataReceivedEventHandler(DataReceived);
sp.ReadTimeout = 1000;
sp.WriteTimeout = 1000;
Everything works fine. I can see as I said the flow of data through Mbus via RS485. I can see it from TX led which fires all the time I send data.However, as i said again, RX led does not fires.
I solved the problem which was relasted to parity. In default it is none but in my system it was supposed to be even. So I can receive data right now but the problem is now speed of data.
In Vb. I'm using valveopen function forthtimes to open valve.Therefore I code like ;
valveopen();
valveopen();
valveopen();
valveopen();
However in C# it is like god knows how many times it will operate :). Arbitrarily I'm able to open valve right now. All stuff are the same and no problem. I think data transfer speed of MSComn and Serial Port are different.
I solved the problem by flushing read and send data.
Related
I have been trying to use NDI SDK 4.5, in a Objective-C iOS-13 app, to broadcast camera capture from iPhone device.
My sample code is in public Github repo: https://github.com/bharatbiswal/CameraExampleObjectiveC
Following is how I send CMSampleBufferRef sampleBuffer:
CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
NDIlib_video_frame_v2_t video_frame;
video_frame.xres = VIDEO_CAPTURE_WIDTH;
video_frame.yres = VIDEO_CAPTURE_HEIGHT;
video_frame.FourCC = NDIlib_FourCC_type_UYVY; // kCVPixelFormatType_420YpCbCr8BiPlanarFullRange
video_frame.line_stride_in_bytes = VIDEO_CAPTURE_WIDTH * VIDEO_CAPTURE_PIXEL_SIZE;
video_frame.p_data = CVPixelBufferGetBaseAddress(pixelBuffer);
NDIlib_send_send_video_v2(self.my_ndi_send, &video_frame);
I have been using "NewTek NDI Video Monitor" to receive the video from network. However, even though it shows as source, the video does not play.
Has anyone used NDI SDK in iOS to build broadcast sender or receiver functionalities? Please help.
You should use kCVPixelFormatType_32BGRA in video settings. And NDIlib_FourCC_type_BGRA as FourCC in NDIlib_video_frame_v2_t.
Are you sure about your VIDEO_CAPTURE_PIXEL_SIZE ?
When I worked with NDI on macos I had the same black screen problem and it was due to a wrong line stride.
Maybe this can help : https://developer.apple.com/documentation/corevideo/1456964-cvpixelbuffergetbytesperrow?language=objc ?
Also it seems the pixel formats from core video and NDI don't match.
On the core video side you are using Bi-Planar Y'CbCr 8-bit 4:2:0, and on the NDI side you are using NDIlib_FourCC_type_UYVY which is Y'CbCr 4:2:2.
I cannot find any Bi-Planar Y'CbCr 8-bit 4:2:0 pixel format on the NDI side.
You may have more luck using the following combination:
core video: https://developer.apple.com/documentation/corevideo/1563591-pixel_format_identifiers/kcvpixelformattype_420ypcbcr8planarfullrange?language=objc
NDI: NDIlib_FourCC_type_YV12
Hope this helps!
In my experience, you have two mistake. To use CVPixelBuffer's CVPixelBufferGetBaseAddress, the CVPixelBufferLockBaseAddress method must be called first. Otherwise, it returns a null pointer.
https://developer.apple.com/documentation/corevideo/1457128-cvpixelbufferlockbaseaddress?language=objc
Secondly, NDI does not support YUV420 biplanar. (The default format for iOS cameras.) More precisely, NDI only accepts one data pointer. In other words, you have to merge the biplanar memory areas into one, and then pass it in NV12 format. See the NDI document for details.
So your code should look like this: And if sending asynchronously instead of NDIlib_send_send_video_v2, a strong reference to the transferred memory area must be maintained until the transfer operation by the NDI library is completed.
CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CVPixelBufferLockBaseAddress(pixelBuffer, 0);
int width = (int)CVPixelBufferGetWidth(pixelBuffer);
int height = (int)CVPixelBufferGetHeight(pixelBuffer);
OSType pixelFormat = CVPixelBufferGetPixelFormatType(pixelBuffer);
NDIlib_FourCC_video_type_e ndiVideoFormat;
uint8_t* pixelData;
int stride;
if (pixelFormat == kCVPixelFormatType_32BGRA) {
ndiVideoFormat = NDIlib_FourCC_type_BGRA;
pixelData = (uint8_t*)CVPixelBufferGetBaseAddress(pixelBuffer); // Or copy for asynchronous transmit.
stride = width * 4;
} else if (pixelFormat == kCVPixelFormatType_420YpCbCr8BiPlanarFullRange) {
ndiVideoFormat = NDIlib_FourCC_type_NV12;
pixelData = (uint8_t*)malloc(width * height * 1.5);
uint8_t* yPlane = (uint8_t*)CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
int yPlaneBytesPerRow = (int)CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0);
int ySize = yPlaneBytesPerRow * height;
uint8_t* uvPlane = (uint8_t*)CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 1);
int uvPlaneBytesPerRow = (int)CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 1);
int uvSize = uvPlaneBytesPerRow * height;
stride = yPlaneBytesPerRow;
memcpy(pixelData, yPlane, ySize);
memcpy(pixelData + ySize, uvPlane, uvSize);
} else {
return;
}
NDIlib_video_frame_v2_t video_frame;
video_frame.xres = width;
video_frame.yres = height;
video_frame.FourCC = ndiVideoFormat;
video_frame.line_stride_in_bytes = stride;
video_frame.p_data = pixelData;
NDIlib_send_send_video_v2(self.my_ndi_send, &video_frame); // synchronous sending.
CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
// For synchrnous sending case. Free data or use pre-allocated memory.
if (pixelFormat == kCVPixelFormatType_420YpCbCr8BiPlanarFullRange) {
free(pixelData);
}
I am having problems communicating FROM the arduino to my Qt application through QSerialPort. I have a listening signal that tells me when there is data ready to be read from the arduino. I expect a value for the number of steps that a stepper motor has undertaken before hitting a limit switch, so only a simple int such as "2005". When the data is available for reading, sometimes I get two separate reads with "200" and "5". Obviously this messes things up when I am parsing the data because it records it as two numbers, both much smaller than the intended number.
How can I fix this without me putting in a Sleep or QTimer to allow for a bit more time for the data to come in from the arduino? Note: my program is not multithreaded.
Example Qt code:
//Get the data from serial, and let MainWindow know it's ready to be collected.
QByteArray direct = arduino->readAll();
data = QString(direct);
emit dataReady();
return 0;
Arduino:
int count = 2005;
Serial.print(count);
You can add line break to synchronize.
Example Qt code:
//Get the data from serial, and let MainWindow know it's ready to be collected.
QByteArray direct = arduino->readLine();
data = QString(direct);
emit dataReady();
return 0;
Arduino:
int count = 2005;
Serial.print(count);
Serial.println();
If you are going to use QSerialPort::readyRead signal, you need to also use the QSerialPort::canReadLine function, see this.
Thank you for your help Arpegius. The println() function was definitely a good choice to use for the newline delimiter. And following that link, I was able to get a listening function that got everything the arduino sent as seperate strings. The extra if statements in the loop handle any cases where the incoming string does not contain the newline character (I am paranoid :D)
My code for anyone that has the same problem in the future.
int control::read()
{
QString characters;
//Get the data from serial, and let MainWindow know it's ready to be collected.
while(arduino->canReadLine())
{
//String for data to go.
bool parsedCorrectly = 0;
//characters = "";
//Loop until we find the newline delimiter.
do
{
//Get the line.
QByteArray direct = arduino->readLine();//Line();
//If we have found a new line character in any line, complete the parse.
if(QString(direct).contains('\n'))
{
if(QString(direct) != "\n")
{
characters += QString(direct);
characters.remove(QRegExp("[\\n\\t\\r]"));
parsedCorrectly = 1;
}
}
//If we don't find the newline straight away, add the string we got to the characters QString and keep going.
else
characters += QString(direct);
}while(!parsedCorrectly);
//Save characters to data and emit signal to collect it.
data = characters;
emit dataReady();
//Reset characters!
characters = "";
}
return 0;
}
I want to use EVR standalone, but i failed sending IMFSample to it. codes list below,
//create the video render
IMFActivate* pActive = NULL;
hr = MFCreateVideoRendererActivate(m_hWnd, &pActive);
CHECK_HR(hr);
hr = pActive->ActivateObject(IID_IMFMediaSink,(void**)&m_pVideoSink) ;
CHECK_HR(hr);
hr = m_pVideoSink->GetStreamSinkByIndex(0,&m_pVideoStreamSink) ;
CHECK_HR(hr);
//on Sample ready from a custom mft
hr = m_pVideoStreamSink->ProcessSample(pSample) ;
then i got an E_NOTIMPL error. After several hours struggles, i implemented IMFVideoSampleAllocator:
//get IMFVideoSampleAllocator service
hr = MFGetService(m_pVideoStreamSink,MR_VIDEO_ACCELERATION_SERVICE,IID_PPV_ARGS(&m_pAllocator)) ;
CHECK_HR(hr);
//init IMFVideoSampleAllocator,pType is the negotiated type
hr = m_pAllocator->InitializeSampleAllocator(20,pType) ;
//On sample ready,pSample is the IMFSample from mft
IMFSample* pVideoSample = NULL ;
IMFMediaBuffer* pBuffer = NULL ;
LONGLONG hnsTimeStamp = 0 ;
//copy sample data from pSample to pVideoSample
CHECK_HR(hr = m_pAllocator->AllocateSample(&pVideoSample)) ;
CHECK_HR(hr = pSample->GetSampleTime(&hnsTimeStamp)) ;
CHECK_HR(hr = pVideoSample->SetSampleTime(hnsTimeStamp)) ;
CHECK_HR(hr = pSample->GetBufferByIndex(0,&pBuffer)) ;
CHECK_HR(hr = pVideoSample->AddBuffer(pBuffer)) ;
hr = m_pVideoStreamSink->ProcessSample(pVideoSample) ;
now, every thing works great, but i got only a black screen with no any movie picture drawn on it!
besides, i had added SAR to my code, it worked pretty good.
any help, thx!
Maybe a little late to answer to your question, but anyway ...
I was in a similar situation and I solved it by using a Stream Reader configured with MF_SOURCE_READER_D3D_MANAGER. I took the IDirect3DDeviceManager9 from the Stream Sink the same way you took the allocator:
hr = MFGetService(m_pVideoStreamSink,MR_VIDEO_ACCELERATION_SERVICE,IID_PPV_ARGS(&pD3DManager);
and set it as IUnknown to MF_SOURCE_READER_D3D_MANAGER attribute above.
If you cannot use IMFSourceReader then maybe this link will be helpful:
https://code.google.com/p/webrtc4all/source/browse/trunk/gotham/MFT_WebRTC4All/test/test_evr.cc?r=15
When the pVideoSample is allocated, it already has a buffer for your use; you don't need to add any other buffers.
In your case, my guess is that the originally allocated buffer was used to render the output - which is this case is empty, and hence there's no image.
I am tring to send a screenshot of a desktop over winsock.
As such, there are four tasks:
Save bitmap to buffer
Write data across wire using a socket
Read data from wire using a socket
Load a bitmap from a buffer
I have saved the bitmap to a char array using GetDIBits.
Writing the data to the server, I have done but I have questions.
For writing data over from server to the client, do I need to use only 1 recv() call (I am using TCP), or do i need to split it up into multiple parts? Ive read that TCP is stream concept and that I wouldnt have to worry about packets because that is abstracted for me?
How would I go about loading the information from GetDIBits into a bitmap and displaying it on the main window?
I am guessing I have to use SetDIBits, but into which device contexts do i use?
The Server screenshot capturer is here:
HDC handle_ScreenDC = GetDC(NULL);
HDC handle_MemoryDC = CreateCompatibleDC(handle_ScreenDC);
BITMAP bitmap;
int x = GetDeviceCaps(handle_ScreenDC, HORZRES);
int y = GetDeviceCaps(handle_ScreenDC, VERTRES);
HBITMAP handle_Bitmap = CreateCompatibleBitmap(handle_ScreenDC, x, y);
SelectObject(handle_MemoryDC, handle_Bitmap);
BitBlt(handle_MemoryDC, 0, 0, x, y, handle_ScreenDC, 0, 0, SRCCOPY);
GetObject(handle_Bitmap, sizeof(BITMAP), &bitmap);
BITMAPFILEHEADER bmfHeader;
BITMAPINFOHEADER bi;
bi.biSize = sizeof(BITMAPINFOHEADER);
bi.biWidth = bitmap.bmWidth;
bi.biHeight = bitmap.bmHeight;
bi.biPlanes = 1;
bi.biBitCount = 16;
bi.biCompression = BI_RGB;
bi.biSizeImage = 0;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biClrUsed = 0;
bi.biClrImportant = 0;
//std::cout<< bitmap.bmWidth;
DWORD dwBmpSize =((bitmap.bmWidth * bi.biBitCount + 5) / 32) * 4 * bitmap.bmHeight;
//int i = bitmap.bmWidth;
//DWORD dwBmpSize = 99;
HANDLE hDIB = GlobalAlloc(GHND, dwBmpSize);
char* bufptr = (char *)GlobalLock(hDIB);
GetDIBits(handle_ScreenDC, handle_Bitmap, 0, (UINT)bitmap.bmHeight, bufptr, (BITMAPINFO *)&bi, DIB_RGB_COLORS);
send(clientsock, bufptr , GlobalSize((char *)GlobalLock(hDIB)), 0);
/*Do i need to packetize/split it up? Or 1 send() is good for the matching Recv on the client?*/
/*I am assuming i must send bi structure over winsock also correct?*/
And The receiveing client code:
case WM_PAINT:{
//Im a Gdi beginner so I dont have a clue what im doing here as far as blitting the recved bits, this is just some stuff i tried myself before asking for help
PAINTSTRUCT paintstruct;
HDC handle_WindowDC = BeginPaint(hwnd, &paintstruct);
handle_MemoryDC = CreateCompatibleDC(handle_WindowDC);
handle_Bitmap = CreateCompatibleBitmap(handle_WindowDC, 640, 360);
std::cout << SetDIBits(handle_MemoryDC, handle_Bitmap, 0, bi.biHeight, buffer, (BITMAPINFO *)&bi, DIB_RGB_COLORS);
SelectObject(handle_MemoryDC, handle_Bitmap);
StretchBlt(handle_WindowDC, 50, 50, 640, 360, handle_MemoryDC, 0, 0, x, y, SRCCOPY);
EndPaint(hwnd, &paintstruct);
}
Sockets do have limited buffer sizes at both ends, typically around 4000 bytes. So if you dump a large block of data (like a full screendump) in one call to a non-blocking send, you will likely get errors, and you will need to manage your own buffers, calling multiple sends. However, if you are using non-blocking socket, you should be OK, as send() will simply block until all the data is sent.
On the receiving side, it is a similar case - a blocking receive can just keep waiting until it has the full data size that you asked for, but a non-blocking receive will return with whatever data is available at that time, which will result in the data filtering through bit by bit, and you will need to reassemble the data from multiple recv() calls.
I have heard of issues with sending really large blocks of data in one hit, so if you are sending 5 megabytes of data in one hit, be aware there might be other issues coming into play as well.
I'm a newbie in QT and C++, I'm trying to create a QTcpserver using QThreadpools so it can handle multiple clients. Multiple clients are able to connect without any issues. But I'm trying to send an image from an android phone, with a footer "IMGPNG", indicating the end of image data. Now the issue when the readyRead signal is emitted I'm tring to read all the data available data and then perform some string operation later and reconstruct the image. I'm not sure how to receive the complete image for each client and then process it accordingly.
void VireClients::readyRead()//read ready
{
int nsize = socket->bytesAvailable();//trying to check the available bytes
qDebug()<< "Bytes Available" << nsize;
while(socket->bytesAvailable() < nsize){
QByteArray data = socket->readAll();//how to receive all the data and then process it
}
/*!These lines call the threadpool instance and reimplement run*/
imageAnalysis = new VireImageAnalysis(); //creating a new instance of the QRunnable
imageAnalysis->setAutoDelete(true);
connect(imageAnalysis,SIGNAL(ImageAnalysisResult(int)),this,SLOT(TaskResult(int)),Qt::QueuedConnection);
QThreadPool::globalInstance()->start(imageAnalysis);
}
Now i'm not sure how to get the data completely or save the received data in an image format. i want to know how to completely receive the image data. Please help.
A call to readAll() will not always read the complete image as it obviously cannot know the size of the image. It will only read all currently available bytes which might be less than your whole file, or more if the sender is really fast and you cannot catch up reading. The same way readyRead() only informs you that there are bytes available but not that a whole file has been received. It could be a single byte or hundreds of bytes.
Either you know the size of your image in the first place because it is always fixed or the sender has to tell the receiver the number of bytes he wants to sent.
Then you can either just ignore all readyRead() signals until bytesAvailable() matches your image size and call readAll() to read the whole image at once. Or you read whenever there are available bytes and fill up your buffer until the number of bytes read matches the bytes the receiver told you he will send.
Solved saving image issue by collecting, the string in temp variable and finally, used opencv imwrite to save the image, this solved this issue:
while(iBytesAvailable > 0 )
{
if(socket->isValid())
{
char* pzBuff = new char[iBytesAvailable];
int iReadBytes = socket->read(pzBuff, iBytesAvailable);
if( iReadBytes > 0 )
{
result1 += iReadBytes;
str += std::string(reinterpret_cast<char const *>(pzBuff), iReadBytes);
if(str.size() > 0){
search = str.find("IMGPNG");
if(search == result1-6){
finalID = QString::fromStdString(str);
Singleton_Global *strPtr = Singleton_Global::instance();
strPtr->setResult(finalID);
/*!Process the received image here*/
SaveImage= new VSaveImage();
SaveImage->setAutoDelete(false);
connect(SaveImage,SIGNAL(SaveImageResult(QString)),this,SLOT(TaskResult(QString)),Qt::QueuedConnection);
threadPool->start(SaveImage);
}
}
}
Finally did the image saving on the run method -->SaveImage, #DavidSchwartz you were a great help thanks. Thanks all for your help.