I can succesfully save video which I captured from c++ opencv there is no problem.
Bu similar code not capturing the video. Just opening out.avi . and only 6 kb.
I put the code in showframe func. there is no resizing fyi.
Anybody has experience with the opencv videowriter on the Qt?
void Widget::show_frame(Mat &image)
{
Mat resized_image = image.clone();
video.write(image);
int width_of_label = ui->label_camera->width();
int height_of_label = ui->label_camera->height();
Size size(width_of_label, height_of_label);
// cv::resize(image, resized_image, size);
cvtColor(image,image,CV_BGR2RGB);
cvtColor(resized_image, resized_image, CV_BGR2RGB);
ps : Platform MacOSX
I encountered the same problem with you, and I have tried many solutions, I think you can make the fifth parameter of videowriter（) be false. That is, VideoWriter out = VideoWriter(video_name, CV_FOURCC('D', 'I', 'V', 'X'),frame_fps,Size(frame_width,frame_height),false). This works for me！
make sure that your application has access to the opencv_ffmpeg*.dll. For example place it in the working directory or the PATH variable.
Try different codecs, too. Afaik, MJPG did work on all tested machines/systems so far.
Related
Below a screenshot of my application. I want to get rid of the white spaces after the last tables lines marked by red rectangles :
The horizontal size policy is expanding and the vertical one is minimum and for other tables it is both set to expanding.
I'm using this method I found in another SO question but as you can see the result is not flawless.
void verticalResizeTableViewToContents(QTableView* tableView)
{
tableView->resizeRowsToContents();
// does it work ?
tableView->setSizeAdjustPolicy(QAbstractScrollArea::AdjustToContents);
int rowTotalHeight = 0;
// Rows height
int count = tableView->verticalHeader()->count();
for (int i = 0; i < count; ++i) {
// 2018-03 edit: only account for row if it is visible
if (!tableView->verticalHeader()->isSectionHidden(i)) {
rowTotalHeight += tableView->verticalHeader()->sectionSize(i);
}
}
// Check for scrollbar visibility
if (!tableView->horizontalScrollBar()->isHidden())
{
rowTotalHeight += tableView->horizontalScrollBar()->height();
}
// Check for header visibility
if (!tableView->horizontalHeader()->isHidden())
{
rowTotalHeight += tableView->horizontalHeader()->height();
}
tableView->setMaximumHeight(rowTotalHeight);
}
Somewhere, I'm using this code to setup one of the tables :
m_Internals->Ui.Measures->setModel(mm->getPh66MeasuresModel());
m_Internals->Ui.Measures->horizontalHeader()->setSectionsMovable(true);
m_Internals->Ui.Measures->horizontalHeader()->setHighlightSections(false);
m_Internals->Ui.Measures->horizontalHeader()->setSectionResizeMode(QHeaderView::Interactive);
m_Internals->Ui.Measures->horizontalHeader()->setStretchLastSection(true);
m_Internals->Ui.Measures->verticalHeader()->hide();
m_Internals->Ui.Measures->setSelectionBehavior(QAbstractItemView::SelectRows);
verticalResizeTableViewToContents(m_Internals->Ui.Measures);
I'm using Qt ModelView pattern to populate/update the tables.
Update : I made a small example to reproduce this issue with QTableView : https://github.com/embeddedmz/QTableViewAdjustPolicyNotWorkingProperly
Using the latest Qt version (from Qt official installer), there's no issue. However, using the Qt library provided by vcpkg (outdated for sure) the issue is there.
With Qt provided by vcpkg :
With the latest Qt provided by the Qt Company (update not the latest, it's 5.12.11) :
If you have something fully buildable on Ubuntu 20.04 LTS, post a link to the complete project (strip it down to just this part) and I will take an actual stab at it.
My gut, having worked with Qt for years, is telling me you are being burned by Margins.
https://doc.qt.io/qt-5/qwidget.html#contentsMargins
You probably need to set a bottom margin of Zero.
https://doc.qt.io/qt-5/qmargins.html#setBottom
If you retrieve the margins for those widgets you will probably find they are non-zero.
you can also fix your problem with one trick, this problem happens for you because your data is lower than the table size. I clone your project and change sizepolicy
Under Qt 5.12.11, the bug does not exist. So I took a look at the QAbstractScrollArea::sizeHint code of this version and compared it with the implementation used in recent versions of Qt and found that setting verticalScrollBarPolicy to "ScrollBarAlwaysOff" the "AdjustToContents" adjustment policy works. The default value was "ScrollBarAsNeeded", in fact we can see that this value is not handled but since in Qt 5.12.11 we only compare the vertical|horizontal]scrollBarPolicy to Qt::ScrollBarAlwaysOn it prevents this bug from appearing.
I want to record a video using JavaCV in JOGL (Java Binding for OpenGL).
This is the code to open the video file:
VideoWriter wv;
wv.open("video.avi", CV_FOURCC_DEFAULT, 30 , new Size(width, height), true);
The problem is that wv.isOpened() always returns false and no video file is created.
Things I've tried:
Change "video.avi" to "video.mp4"
Change CV_FOURCC_DEFAULT to -1
Change width, height, fps values
Anyone have achieved this?
My machine is running an Ubuntu 14.04 LTS with JavaCV v1.3.2 and JOGL v2.3.2.
When using OpenCV with C++ I had to define this constant:
const int VIDEO_CODEC_FOURCC = CV_FOURCC('M','J','P','G');
Try doing using the CV_FOURCC function and the use the .avi file extension as you had originally. Also try to make sure that the camera's frame dimensions are the same as the Size that you passed in your width and height.
I use Dev-C++ , and I have a program in C where the output is not fully shown (only the last part is visible).
So, I tried with a simple program and I noticed the same problem , for example here :
#include <stdio.h>
#include <stdlib.h>
main(){
int i;
for(i=0;i<5000;i++){
printf("\n The number is : %d\n",i);
}
}
Well, when the program is finished, I only see in the Console numbers from (4852 to 4999), but I want to see all the output.
In most terminals you can scroll backwards to see what was printed earlier. In Windows, you can modify the visible history length by right-clicking on the titlebar at the top, choosing preferences and setting the Scrollback to as long as you like. In Linux, it is a property of the terminal emulator (try Shift-Page Up to scroll backwards).
You will need a 5000-line monitor. Try getting an array of the most powerful graphics cards you can buy and a high-res display array. Set the font to the smallest possible.
Alternatively, redirect the output to a printer and paste the output sheets to your wall.
Having the same problem I usually redirect the output to a text file.
I've got a really simple application for adding watermarks to pictures. So you can drop your pictures in a QListWidget which shows you a thumbnail and the path, adjust some things like the text, the transparency, the output format and so on.. and after pressing start it saves the copyrighted picture in a destination of your choice. This works with a QPainter which paints the logo and text on the picture.
Everything is able to work fine. But here's the misterious bug:
The application kills random letters. It's really strange, because I can't reproduce it. With every execution and combination of options it's different. For example:
Sometimes I can't write some letters in the QLineEdit of my interface (like E, 4 and 0 doesnt exist, or he changes the letters so some special signs).
The text of the items in the QListWidget aren't completly displayed, sometimes completley missing. But I can extract the text normally and use the path.
While execution I have a QTextBrowser as a log to display some interesting things like the font size. Although, the font is shown normaly on the resulting picture, it says " 4" or "6" instead of much higher and correct sizes. Betimes strange white blocks appear between some letters
When drawing text on the picture with a QPainter, there also letters missing. Sometimes, all the letters are printed over each other. It seems like this bug appears more often when using small pixelsizes (like 12):
//Text//
int fontSize = (watermarkHeight-(4*frame));
int fontX = 2*frame;
int fontY = (result.height()-(watermarkHeight-2*frame));
int fontWidth = watermarkWidth;
QRect place(fontX,fontY,fontWidth,fontSize);
QFont font("Helvetica Neue", QFont::Light);
font.setPixelSize(fontSize);
emit log(QString::number(fontSize));
pixPaint.setFont(font);
pixPaint.setPen(QColor(255,255,255,textOpacity));
pixPaint.drawText(place,text);
Not all of these bugs appear at once! Sometimes I haven't got any bugs...
Perhaps someone had a similar bug before. Unfortunately I didn't found something like this in the internet. I didn't post a lot of code snippets because I think (and hope) that this is a gerneral problem. If you need something specific to help me, please let me know =)
I've added a example picture:
In the lineEdit I simply wrote ABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890 (look what he has done with the 7 and 9)
This small square in the lower corner of the picture should be the "ABC..." thing
The "62" looks very strange in the textBrowser
I'm using Qt 5.0.1 on a Windows 7 64Bit computer.
EDIT: Everytime after adding the first picture to the list, he's finding these warnings:
QFontEngine::loadEngine: GetTextMetrics failed ()
QWindowsFontEngine: GetTextMetrics failed ()
But when I change the height (and with it the pointSize of the font) its not emitted anymore, even with the start-parameters.
EDIT 2: Thank you for your help! I corrected my code so that he only uses correct fonts and correct sizes, but it still doesn't work. When I remove the QPainter::drawText() function it works fine (without the text). But as soon as I am adding text everything is bugged. I have something like this now:
//Text//
QList<int> smoothSizes = fontDatabase->smoothSizes("Verdana","Standard");
int fontSize = (watermarkHeight-(4*frame))*0.75;
emit log("Requested: "+QString::number(fontSize));
if(!smoothSizes.contains(fontSize)){
for(int i = 0; i<smoothSizes.length(); i++){
if(smoothSizes.at(i) > fontSize && i>0){
fontSize = smoothSizes.at(i-1);
break;
}
}
}
int fontX = 2*frame;
int fontY = (result.height()-(watermarkHeight/2)+frame);
QFont font = fontDatabase->font("Verdana","Standard",fontSize);
QFontInfo info(font);
emit log("Corrected: "+QString::number(fontSize));
emit log("Okay?: "+QString::number(info.exactMatch()));
pixPaint.setFont(font);
const QFontMetrics fontMetrics = pixPaint.fontMetrics();
if(info.exactMatch()){
pixPaint.setPen(QColor(255,255,255,textOpacity));
pixPaint.drawText(fontX,fontY+(fontMetrics.height()-fontMetrics.ascent()),text);
}
It almost sounds like you are corrupting random memory in your process, or you have a badly broken Windows install. Possibly your font request is matched by a very poorly chosen system font.
Whatever is set on a QFont is merely a request. To obtain the parameters of the actual font that was selected, you must create a QFontInfo, and get your information from there.
Imagine that you request a QFont that doesn't exist on a system, or that can't be scaled to a particular size. At some point the font object would need to morph to reflect what really happened - this would be very confusing. Thus, the QFontInfo provides the information about the font that was actually used. Think of QFontInfo as a response, and QFont as a request.
I finally found a solution: I simply updated Qt from 5.0.1 to 5.2.1, now it works. Perhaps someone has a similar bug and this post helps him. Thank you for your help!
I'm trying to create a VolumeSlider widget that changes the volume of my audio output.
log.debug("Starting audio player (%s)..." % url)
mediaSource = Phonon.MediaSource(url)
mediaSource.setAutoDelete(True)
self.player = Phonon.createPlayer(Phonon.VideoCategory, mediaSource)
self.player.setTickInterval(100)
self.player.tick.connect(self.updatePlayerLength)
self.mediaSlider.setMediaObject(self.player)
audioOutput = Phonon.AudioOutput(Phonon.MusicCategory)
Phonon.createPath(self.player, audioOutput)
self.mediaVolumeSlider.setAudioOutput(audioOutput)
self.player.play()
However even though I can move the volume slider, the actual volume doesn't change. What did I miss?
I have never used Phonon.createPlayer, because the API seems totally baffling. Apparently, it is supposed to be a "convenience" function that creates a path between an media object and an audio output. But it only gives a reference to the media object. There appears to be no access to the audio output object, which would seem to make it completely useless (but I may well be missing something).
Anyway, I think it is much more convenient to create the paths explicitly, so that it is clear how all the parts are connected together.
The following code works for me on Linux and WinXP:
self.media = Phonon.MediaObject(self)
self.video = Phonon.VideoWidget(self)
self.audio = Phonon.AudioOutput(Phonon.VideoCategory, self)
Phonon.createPath(self.media, self.audio)
Phonon.createPath(self.media, self.video)
self.slider = Phonon.VolumeSlider(self)
self.slider.setAudioOutput(self.audio)