[libcamera-devel] [PATCH v2 5/5] qcam: Update window title with FPS

[Kieran Bingham]

Hi Laurent,

On 04/07/2019 14:52, Laurent Pinchart wrote:
> Hi Kieran,
> 
> Thank you for the patch.
> 
> On Thu, Jul 04, 2019 at 02:03:47PM +0100, Kieran Bingham wrote:
>> Provide an average FPS in the QCam title bar to show the current rate of
>> frame processing.
>>
>> The QCam compilation is updated to process the QT MoC headers to support
>> signals and slots accordingly.
>>
>> Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
>> ---
>>  src/qcam/main_window.cpp | 22 ++++++++++++++++++++++
>>  src/qcam/main_window.h   | 11 +++++++++++
>>  src/qcam/meson.build     | 11 ++++++++++-
>>  3 files changed, 43 insertions(+), 1 deletion(-)
>>
>> diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp
>> index d61369109d66..9f05ec05549f 100644
>> --- a/src/qcam/main_window.cpp
>> +++ b/src/qcam/main_window.cpp
>> @@ -29,6 +29,10 @@ MainWindow::MainWindow(const OptionsParser::Options &options)
>>  	title_ = "QCam " + QString::fromStdString(libcamera::version);
>>  	setWindowTitle(title_);
>>  
>> +	QTimer *timer = new QTimer(this);
>> +	connect(timer, SIGNAL(timeout()), this, SLOT(updateTitle()));
>> +	timer->start(2000);
>> +
> 
> Should you start the timer only when starting capture ? And stop it when
> stopping capture (and reset the title there to remove the fps) ?

Done.

> 
>>  	viewfinder_ = new ViewFinder(this);
>>  	setCentralWidget(viewfinder_);
>>  	viewfinder_->setFixedSize(500, 500);
>> @@ -54,6 +58,19 @@ MainWindow::~MainWindow()
>>  	CameraManager::instance()->stop();
>>  }
>>  
>> +void MainWindow::updateTitle()
>> +{
>> +	unsigned int duration = frameRateInterval_.elapsed();
>> +	unsigned int frames = framesCaptured_ - previousFrames_;
>> +	double fps = frames * 1000.0 / duration;
>> +
>> +	/* Restart counters */
>> +	frameRateInterval_.start();
>> +	previousFrames_ = framesCaptured_;
>> +
>> +	setWindowTitle(title_ + " : " + QString::number(fps, 'f', 2) + " fps");
>> +}
>> +
>>  int MainWindow::openCamera()
>>  {
>>  	CameraManager *cm = CameraManager::instance();
>> @@ -148,6 +165,9 @@ int MainWindow::startCapture()
>>  		requests.push_back(request);
>>  	}
>>  
>> +	frameRateInterval_.start();
>> +	previousFrames_ = 0;
>> +	framesCaptured_ = 0;
>>  	lastBufferTime_ = 0;
>>  
>>  	ret = camera_->start();
>> @@ -196,6 +216,8 @@ void MainWindow::requestComplete(Request *request,
>>  	if (request->status() == Request::RequestCancelled)
>>  		return;
>>  
>> +	framesCaptured_++;
>> +
>>  	Buffer *buffer = buffers.begin()->second;
>>  
>>  	double fps = buffer->timestamp() - lastBufferTime_;
>> diff --git a/src/qcam/main_window.h b/src/qcam/main_window.h
>> index 46a494a9d783..6b3dcab6d490 100644
>> --- a/src/qcam/main_window.h
>> +++ b/src/qcam/main_window.h
>> @@ -10,7 +10,9 @@
>>  #include <map>
>>  #include <memory>
>>  
>> +#include <QElapsedTimer>
>>  #include <QMainWindow>
>> +#include <QObject>
>>  
>>  #include <libcamera/camera.h>
>>  #include <libcamera/stream.h>
>> @@ -28,10 +30,15 @@ enum {
>>  
>>  class MainWindow : public QMainWindow
>>  {
>> +	Q_OBJECT
>> +
>>  public:
>>  	MainWindow(const OptionsParser::Options &options);
>>  	~MainWindow();
>>  
>> +public Q_SLOTS:
>> +	void updateTitle();
>> +
>>  private:
>>  	int openCamera();
>>  
>> @@ -51,6 +58,10 @@ private:
>>  
>>  	uint64_t lastBufferTime_;
>>  
>> +	QElapsedTimer frameRateInterval_;
>> +	uint32_t previousFrames_;
>> +	uint32_t framesCaptured_;
>> +
>>  	ViewFinder *viewfinder_;
>>  };
>>  
>> diff --git a/src/qcam/meson.build b/src/qcam/meson.build
>> index 9f1fa75f9813..c2c4d7cc9787 100644
>> --- a/src/qcam/meson.build
>> +++ b/src/qcam/meson.build
>> @@ -7,13 +7,22 @@ qcam_sources = files([
>>      'viewfinder.cpp',
>>  ])
>>  
>> -import('qt5')
>> +qcam_headers = files([
>> +    'main_window.h',
> 
> Should you list all the headers here ? Otherwise I would name this
> variable qcam_moc_headers.

Renamed to qcam_moc_headers

> 
>> +])
>> +
>> +qt5 = import('qt5')
>>  qt5_dep = dependency('qt5',
>>                       method : 'pkg-config',
>>                       modules : ['Core', 'Gui', 'Widgets'],
>>                       required : false)
>>  
>>  if qt5_dep.found()
>> +    moc_files = qt5.preprocess(moc_headers: qcam_headers,
>> +                               dependencies: qt5_dep)
>> +
>> +    qcam_sources += moc_files
>> +
>>      qcam  = executable('qcam', qcam_sources,
> 
> You don't need to update qcam_sources, you can list the moc files here:

Updated.

> 
>     qcam  = executable('qcam', qcam_sources, moc_files,
> 
>>                         install : true,
>>                         dependencies : [libcamera_dep, qt5_dep],
> 

-- 
Regards
--
Kieran