I have integrated the NDI SDK from NewTek in the current version 5 into my Qt6.3 widget project.
I copied and included the required DLLs and header files from the NDI SDK installation directory into my project.
To test my build environment I tried to compile a simple test program based on the example from "..\NDI 5 SDK\Examples\C++\NDIlib_Recv".
That was also successful.
I was therefore able to receive or access data from my NDI source.
There is therefore a valid frame in the video_frame of the type NDIlib_video_frame_v2_t. Within the structure I can also query correct data of the frame such as the size (.xres and .yres).
The pointer p_data points to the actual data.
So far so good.
Of course, I now want to display this frame on the Qt6 GUI. In other words, the only thing missing now is the conversion into an appropriate format so that I can display the frame with QImage, QPixmap, QLabel, etc.
But how?
So far I've tried calls like this:
curFrame = QImage(video_frame.p_data, video_frame.xres, video_frame.yres, QImage::Format::Format_RGB888);
curFrame.save("out.jpg");
I'm not sure if the format is correct either.
Here's a closer look at the mentioned frame structure within the Qt debug session:
my NDI video frame in the Qt Debug session, after receiving
Within "video_frame" you can see the specification video_type_UYVY.
This may really be the format as it appears at the source!?
Fine, but how do I get this converted now?
Many thanks and best regards
You mean something like this? :)
https://github.com/NightVsKnight/QtNdiMonitorCapture
Specifically:
https://github.com/NightVsKnight/QtNdiMonitorCapture/blob/main/lib/ndireceiverworker.cpp
Assuming you connect using NDIlib_recv_color_format_best:
NDIlib_recv_create_v3_t recv_desc;
recv_desc.p_ndi_recv_name = "QtNdiMonitorCapture";
recv_desc.source_to_connect_to = ...;
recv_desc.color_format = NDIlib_recv_color_format_best;
recv_desc.bandwidth = NDIlib_recv_bandwidth_highest;
recv_desc.allow_video_fields = true;
pNdiRecv = NDIlib_recv_create_v3(&recv_desc);
Then when you receive a NDIlib_video_frame_v2_t:
void NdiReceiverWorker::processVideo(
NDIlib_video_frame_v2_t *pNdiVideoFrame,
QList<QVideoSink*> *videoSinks)
{
auto ndiWidth = pNdiVideoFrame->xres;
auto ndiHeight = pNdiVideoFrame->yres;
auto ndiLineStrideInBytes = pNdiVideoFrame->line_stride_in_bytes;
auto ndiPixelFormat = pNdiVideoFrame->FourCC;
auto pixelFormat = NdiWrapper::ndiPixelFormatToPixelFormat(ndiPixelFormat);
if (pixelFormat == QVideoFrameFormat::PixelFormat::Format_Invalid)
{
qDebug().nospace() << "Unsupported pNdiVideoFrame->FourCC " << NdiWrapper::ndiFourCCToString(ndiPixelFormat) << "; return;";
return;
}
QSize videoFrameSize(ndiWidth, ndiHeight);
QVideoFrameFormat videoFrameFormat(videoFrameSize, pixelFormat);
QVideoFrame videoFrame(videoFrameFormat);
if (!videoFrame.map(QVideoFrame::WriteOnly))
{
qWarning() << "videoFrame.map(QVideoFrame::WriteOnly) failed; return;";
return;
}
auto pDstY = videoFrame.bits(0);
auto pSrcY = pNdiVideoFrame->p_data;
auto pDstUV = videoFrame.bits(1);
auto pSrcUV = pSrcY + (ndiLineStrideInBytes * ndiHeight);
for (int line = 0; line < ndiHeight; ++line)
{
memcpy(pDstY, pSrcY, ndiLineStrideInBytes);
pDstY += ndiLineStrideInBytes;
pSrcY += ndiLineStrideInBytes;
if (pDstUV)
{
// For now QVideoFrameFormat/QVideoFrame does not support P216. :(
// I have started the conversation to have it added, but that may take awhile. :(
// Until then, copying only every other UV line is a cheap way to downsample P216's 4:2:2 to P016's 4:2:0 chroma sampling.
// There are still a few visible artifacts on the screen, but it is passable.
if (line % 2)
{
memcpy(pDstUV, pSrcUV, ndiLineStrideInBytes);
pDstUV += ndiLineStrideInBytes;
}
pSrcUV += ndiLineStrideInBytes;
}
}
videoFrame.unmap();
foreach(QVideoSink *videoSink, *videoSinks)
{
videoSink->setVideoFrame(videoFrame);
}
}
QVideoFrameFormat::PixelFormat NdiWrapper::ndiPixelFormatToPixelFormat(enum NDIlib_FourCC_video_type_e ndiFourCC)
{
switch(ndiFourCC)
{
case NDIlib_FourCC_video_type_UYVY:
return QVideoFrameFormat::PixelFormat::Format_UYVY;
case NDIlib_FourCC_video_type_UYVA:
return QVideoFrameFormat::PixelFormat::Format_UYVY;
break;
// Result when requesting NDIlib_recv_color_format_best
case NDIlib_FourCC_video_type_P216:
return QVideoFrameFormat::PixelFormat::Format_P016;
//case NDIlib_FourCC_video_type_PA16:
// return QVideoFrameFormat::PixelFormat::?;
case NDIlib_FourCC_video_type_YV12:
return QVideoFrameFormat::PixelFormat::Format_YV12;
//case NDIlib_FourCC_video_type_I420:
// return QVideoFrameFormat::PixelFormat::?
case NDIlib_FourCC_video_type_NV12:
return QVideoFrameFormat::PixelFormat::Format_NV12;
case NDIlib_FourCC_video_type_BGRA:
return QVideoFrameFormat::PixelFormat::Format_BGRA8888;
case NDIlib_FourCC_video_type_BGRX:
return QVideoFrameFormat::PixelFormat::Format_BGRX8888;
case NDIlib_FourCC_video_type_RGBA:
return QVideoFrameFormat::PixelFormat::Format_RGBA8888;
case NDIlib_FourCC_video_type_RGBX:
return QVideoFrameFormat::PixelFormat::Format_RGBX8888;
default:
return QVideoFrameFormat::PixelFormat::Format_Invalid;
}
}
I have a recursive function which iterates though directory trees listing the file names located in them.
Here is the function:
void WINAPI SearchFile(PSTR Directory)
{
HANDLE hFind;
WIN32_FIND_DATA FindData;
char SearchName[1024],FullPath[1024];
memset(SearchName,0,sizeof(SearchName));
memset(&FindData,0,sizeof(WIN32_FIND_DATA));
sprintf(SearchName,"%s\\*",Directory);
hFind=FindFirstFile(SearchName,&FindData);
if(hFind!=INVALID_HANDLE_VALUE)
{
while(FindNextFile(hFind,&FindData))
{
if(FindData.cFileName[0]=='.')
{
continue;
}
memset(FullPath,0,sizeof(FullPath));
sprintf(FullPath,"%s\\%s",Directory,FindData.cFileName);
if(FindData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
{
MessageBoxA(NULL, FullPath, "Directory", MB_OK);
SearchFile(FullPath);
}
else
{
MessageBoxA(NULL, FullPath, "File", MB_OK);
}
}
FindClose(hFind);
}
}
There are obviously differences between both functions but I don't understand what's making them act differently. Does anyone know why I am having this problem?
for fast understand error need look for line
goto label;
//SearchFile(FullPath);
at this point hFind containing valid data and FindClose(hFind); need be called for it. but after goto label; executed - your overwrite hFind with hFind = FindFirstFile(SearchName, &FindData); - so you already never close original hFind, never can return to iterate folder after such go to sub-folder. this is key point - need save original hFind before go to sub directory and restore it after. when you do recursive function call - this is done auto - because every sub directory in this case enumerated in self stack frame, which have separate hFind. this is native solution use recursion here.
but possible convert recursion to loop here because we call self always from the single place and as result to this single place. so we can not save return address in stack but do unconditional jump (goto) to known place.
then code have some extra errors, you never check for string buffers overflow, why 1024 as max length is hard-coded when file path can be up to 32768 chars, you not check for reparse point as result can enter to infinite loop, use FindFirstFile instead FindFirstFileEx, etc.
correct code for enumerate sub-folder in loop can be next
void DoEnum(PCWSTR pcszRoot)
{
SIZE_T FileNameLength = wcslen(pcszRoot);
// initial check for . and ..
switch (FileNameLength)
{
case 2:
if (pcszRoot[1] != '.') break;
case 1:
if (pcszRoot[0] == '.') return;
}
static const WCHAR mask[] = L"\\*";
WCHAR FileName[MAXSHORT + 1];
if (_countof(FileName) < FileNameLength + _countof(mask))
{
return;
}
ULONG dwError;
HANDLE hFindFile = 0;
WIN32_FIND_DATA FindData{};
enum { MaxDeep = 0x200 };
//++ stack
HANDLE hFindFileV[MaxDeep];
PWSTR pszV[MaxDeep];
char prefix[MaxDeep+1];
//--stack
ULONG Level = MaxDeep;
memset(prefix, '\t', MaxDeep);
prefix[MaxDeep] = 0;
PWSTR psz = FileName;
goto __enter;
__loop:
hFindFile = FindFirstFileEx(FileName, FindExInfoBasic, &FindData, FindExSearchNameMatch, 0, FIND_FIRST_EX_LARGE_FETCH);
if (hFindFile != INVALID_HANDLE_VALUE)
{
do
{
pcszRoot = FindData.cFileName;
// skip . and ..
switch (FileNameLength = wcslen(pcszRoot))
{
case 2:
if (pcszRoot[1] != '.') break;
case 1:
if (pcszRoot[0] == '.') continue;
}
if (FindData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
{
if ((SIZE_T)(FileName + _countof(FileName) - psz) < FileNameLength + _countof(mask))
{
continue;
}
__enter:
memcpy(psz, pcszRoot, (1 + FileNameLength) * sizeof(WCHAR));
if (FindData.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)
{
DbgPrint("%sreparse point: <%S>\n", prefix + Level, pcszRoot);
}
else
{
if (Level)
{
DbgPrint("%s<%S>\n", prefix + Level, psz);
hFindFileV[--Level] = hFindFile;
pszV[Level] = psz;
memcpy(psz += FileNameLength, mask, sizeof(mask));
psz++;
goto __loop;
__return:
*--psz = 0;
psz = pszV[Level];
hFindFile = hFindFileV[Level++];
DbgPrint("%s</%S>\n", prefix + Level, psz);
}
}
}
else
{
DbgPrint("%s[%u%u] %S\n", prefix + Level, FindData.nFileSizeLow, FindData.nFileSizeHigh, pcszRoot);
}
if (!hFindFile)
{
// top level exit
return ;
}
} while (FindNextFile(hFindFile, &FindData));
if ((dwError = GetLastError()) == ERROR_NO_MORE_FILES)
{
dwError = NOERROR;
}
FindClose(hFindFile);
}
else
{
dwError = GetLastError();
}
if (dwError)
{
DbgPrint("<%S> err = %u\n", FileName, dwError);
}
goto __return;
}
The reason for the difference is actually the confusion brought to you by goto label.If you are using the recursive version, after the recursive execution is completed, it will return to the recursive place to continue execution.
In your code, you continue to execute while (FindNextFile(hFind, &FindData)), but when you use goto label, it will jump out of the original loop and restart the program from the label, which leads to what you said list a single directory tree before ending.
If you modify the modified code to the following iterative version, you can understand why there is such a problem.
void fun()
{
char* Directory = "D:\\test";
HANDLE hFind;
WIN32_FIND_DATA FindData;
char SearchName[1024], FullPath[1024];
char LastName[1024] = "";
while (1)
{
memset(SearchName, 0, sizeof(SearchName));
memset(&FindData, 0, sizeof(WIN32_FIND_DATA));
sprintf(SearchName, "%s\\*", Directory);
if (strcmp(SearchName, LastName) == 0)
{
return;
}
strcpy(LastName, SearchName);
hFind = FindFirstFile(SearchName, &FindData);
if (hFind != INVALID_HANDLE_VALUE)
{
while (FindNextFile(hFind, &FindData))
{
if (FindData.cFileName[0] == '.')
{
continue;
}
memset(FullPath, 0, sizeof(FullPath));
sprintf(FullPath, "%s\\%s", Directory, FindData.cFileName);
if (FindData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
{
MessageBoxA(NULL, Directory, "Directory", MB_OK);
char cArray[1024];
memset(cArray, 0, sizeof(cArray));
sprintf(cArray, "%s", FullPath);
Directory = cArray;
break;
}
else
{
MessageBoxA(NULL, FullPath, "File", MB_OK);
}
}
FindClose(hFind);
}
}
}
So you cannot achieve the same purpose as recursion by using goto, here you can only use recursion. Of course, I have provided a way to traverse directories non-recursively using queues, which is a more scientific way.
One of the key things that you obtain from recursion is a separate set of local variables for each call to the recursive function. When a function calls itself, and in the recursive call modifies local variables, those local-variable changes do not (directly) affect the local variables of the caller. In your original program, this applies to variables hFind, FindData, SearchName, and FullPath.
If you want similar behavior in a non-recursive version of the function then you need to manually preserve the state of your traversal of one level of the tree when you descend to another level. The goto statement doesn't do any such thing -- it just redirects the control flow of your program. Although there are a few good use cases for goto in C, they are uncommon, and yours is not one of them.
There are several ways to implement manually preserving state, but I would suggest
creating a structure type in which to store those data that characterize the state of your traversal of a particular level. Those appear to be only hFind and FindData -- it looks like the other locals don't need to be preserved. Maybe something like this, then:
struct dir_state {
HANDLE hFind;
WIN32_FIND_DATA FindData;
};
Dynamically allocating an array of structures of that type.
unsigned depth_limit = DEFAULT_DEPTH_LIMIT;
struct dir_state *traversal_states
= malloc(depth_limit * sizeof(*traversal_states));
if (traversal_states == NULL) // ... handle allocation error ...
Tracking the depth of your tree traversal, and for each directory you process, using the array element whose index is the relative depth of that directory.
// For example:
traversal_states[depth].hFind
= FindFirstFile(SearchName, &traversal_states[depth].FindData);
// etc.
Remembering the size of the array, so as to be able to reallocate it larger if the traversal descends too deep for its current size.
// For example:
if (depth >= depth_limit) {
depth_limit = depth_limit * 3 / 2;
struct dir_state *temp
= realloc(traversal_states, depth_limit * sizeof(*traversal_states));
if (temp == NULL) {
// handle error, discontinuing traversal
}
traversal_states = temp;
}
Also, use an ordinary for, while, or do loop instead of a backward-jumping goto. There will be a few details to work out to track when to use FindFirstFile and when FindNextFile (which you would still have with goto), but I'm sure you can sort it out.
Details are left as an exercise.
Unless necessary due to memory or processing constraints or infinite recursion tail conditions that would be complication to introduce there really isn't much need to not use recursion here, since it leads to a readable and elegant solution.
I also want to point out that in "modern" C, any solution using a GOTO is likely not a solution you want since they are so often confusing to use and leads to memory issues (we have loops now to make all of that so much simpler).
Instead of the GOTOs I would suggest implementing a stack of the directories. Wrap the printing logic a while or do-while, and as you are iterating over the files add any directories to the stack. At every new iteration pop and walk the directory at the head of the stack. The loop condition just needs to check if the directory stack is empty, before continuing its block.
I don´t know what I´m doing wrong, maybe I'm sitting here way too long on my project. However, I set up a settings menu in my menuScene and I want to create a simple on-off button with a texture with this code:
if ([settingsMenuNode.name isEqualToString:#"checkmark1"]) {
if (self.checkmarkBanner == NO) {
[self.menuCheckmark1 setTexture:[SKTexture textureWithImageNamed:#"menuCheckmark"]];
self.checkmarkBanner = YES;
NSLog(#"YES");
}
if (self.checkmarkBanner == YES) {
[self.menuCheckmark1 setTexture:[SKTexture textureWithImageNamed:#"menuCheckmarkEmpty"]];
self.checkmarkBanner = NO;
NSLog(#"NO");
}
}
every time I touch on the node, I get both logs for ON & OFF at the same time.
can anyone please help me out?
checkmarkBanner is my BOOL just to set whether a banner notification during the game appears or not.
ok, thank you for your quick answers, so i´ve updated my code to this (i added some NSUserDefaults):
//CheckMarkBanner
if ([settingsMenuNode.name isEqualToString:#"checkmarkBanner"]) {
if (self.checkmarkBanner == YES) {
[self.menuCheckmark1 setTexture:[SKTexture textureWithImageNamed:#"menuCheckmarkEmpty"]];
NSString *offString = #"NO";
[[NSUserDefaults standardUserDefaults]setObject:offString forKey:#"checkmark1Banner"];
self.checkmarkBanner = [[[NSUserDefaults standardUserDefaults]stringForKey:#"checkmark1Banner"]boolValue];
NSLog(#"Banner NO");
}
else {
[self.menuCheckmark1 setTexture:[SKTexture textureWithImageNamed:#"menuCheckmark"]];
NSString *onString = #"YES";
[[NSUserDefaults standardUserDefaults]setObject:onString forKey:#"checkmark1Banner"];
self.checkmarkBanner = [[[NSUserDefaults standardUserDefaults]stringForKey:#"checkmark1Banner"]boolValue];
NSLog(#"Banner YES");
}
}
I am trying to create a custom reduce function for a dataset attribute group that would sum a number of unique values for another attribute.
For example, my dataset looks like a list of actions on projects by team members:
{ project:"Website Hosting", teamMember:"Sam", action:"email" },
{ project:"Website Hosting", teamMember:"Sam", action:"phoneCall" },
{ project:"Budjet", teamMember:"Joe", action:"email" },
{ project:"Website Design", teamMember:"Joe", action:"design" },
{ project:"Budget", teamMember:"Sam", action:"email" }
So, team members work on a variable number of projects by performing one action per line. I have a dimension by team member, and would like to reduce it by the number of projects (uniques).
I tried the below (storing project in a uniques array) without success (sorry, this might hurt your eyes):
var teamMemberDimension = dataset.dimension(function(d) {
return d.teamMember;
});
var teamMemberDimensionGroup = teamMemberDimension.group().reduce(
// add
function(p,v) {
if( p.projects.indexOf(v.project) == -1 ) {
p.projects.push(v.project);
p.projectsCount += 1;
}
return p;
},
// remove
function(p,v) {
if( p.projects.indexOf(v.projects) != -1 ) {
p.projects.splice(p.projects.indexOf(v.projects), 1);
p.projectsCount -= 1;
}
return p;
},
// init
function(p,v) {
return { projects:[], projectsCount:0 }
}
);
Thanks a lot!
Edit after DJ Martin's answer ::
So, to be clearer, I would like to get the numbers I am after here would be:
-----------
Sam : 2 (projects he is workin on, no matter the number of actions)
Joe : 2 (projects he is workin on, no matter the number of actions)
-----------
The answer provided by DJ Martin gets me there. But rather than hard coding a table, I would like to find a way to use these numbers for my DC.JS bar chart. When I was only using the number of actions (so just a reduceCount() ), I did it like below:
teamMemberChart.width(270)
.height(220)
.margins({top: 5, left: 10, right: 10, bottom: 20})
.dimension(teamMemberDimension)
.group(teamMemberDimensionGroup)
.colors(d3.scale.category20())
.elasticX(true)
.xAxis().ticks(4);
I guess there might be something to change in the group().
UPDATED ANSWER
Sorry I misunderstood the question... you are actually on the right track. You'll just need to maintain a count of each project so that your subtract function can know when to remove the value.
teamMemberGroup = teamMemberDimension.group().reduce(
function (p, d) {
if( d.project in p.projects)
p.projects[d.project]++;
else p.projects[d.project] = 1;
return p;
},
function (p, d) {
p.projects[d.project]--;
if(p.projects[d.project] === 0)
delete p.projects[d.project];
return p;
},
function () {
return {projects: {}};
});
Here is an updated fiddle: http://jsfiddle.net/djmartin_umich/3LyhL/
I am porting over some Java code into Google's Go language and I converting all code except I am stuck on just one part after an amazingly smooth port. My Go code looks like this and the section I am talking about is commented out:
func main() {
var puzzleHistory * vector.Vector;
puzzleHistory = vector.New(0);
var puzzle PegPuzzle;
puzzle.InitPegPuzzle(3,2);
puzzleHistory.Push(puzzle);
var copyPuzzle PegPuzzle;
var currentPuzzle PegPuzzle;
currentPuzzle = puzzleHistory.At(0).(PegPuzzle);
isDone := false;
for !isDone {
currentPuzzle = puzzleHistory.At(0).(PegPuzzle);
currentPuzzle.findAllValidMoves();
for i := 0; i < currentPuzzle.validMoves.Len(); i++ {
copyPuzzle.NewPegPuzzle(currentPuzzle.holes, currentPuzzle.movesAlreadyDone);
copyPuzzle.doMove(currentPuzzle.validMoves.At(i).(Move));
// There is no function in Go's Vector that will remove an element like Java's Vector
//puzzleHistory.removeElement(currentPuzzle);
copyPuzzle.findAllValidMoves();
if copyPuzzle.validMoves.Len() != 0 {
puzzleHistory.Push(copyPuzzle);
}
if copyPuzzle.isSolutionPuzzle() {
fmt.Printf("Puzzle Solved");
copyPuzzle.show();
isDone = true;
}
}
}
}
If there is no version available, which I believe there isn't ... does anyone know how I would go about implementing such a thing on my own?
How about Vector.Delete( i ) ?
Right now Go doesn't support generic equality operators. So you'll have to write something that iterates over the vector and removes the correct one.