Messages

1

Graphics / Problem with using webcam - slow copying to image

« on: March 20, 2011, 05:48:43 pm »

It's a Samsung N140 netbook, so it's actually Intel 945GSE chipset. I know it's weak, but it's my requirement for the application to run on such a graphic card.

2

Graphics / Problem with using webcam - slow copying to image

« on: March 20, 2011, 11:52:10 am »

Just tried it - it's doesn't affect performance at all :-/

3

Graphics / Problem with using webcam - slow copying to image

« on: March 20, 2011, 11:48:44 am »

Copying from buffer to image is the only thing I'm doing here - the same program on Allegro, with changed just a few lines - works faster. Nothing else in the program doesn't slow down the capture, only altering the width and height parameters of LoadFromPixels changes the loading speed.

4

Graphics / Problem with using webcam - slow copying to image

« on: March 20, 2011, 10:54:08 am »

Hi,

I'm trying to use SFML with a webcam library (videoInput), but copying data (pixels) from camera buffer to image seems to be very slow - the video is no more than 5fps :-/ The same code written in Allegro runs few times faster. Is it some way to fasten it up? I'm using SFML v.1.6.

Code:

Code: [Select]


int WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
{
    // Create the main rendering window
App.Create(sf::VideoMode(800, 550, 32), "SFML Graphics");
cam1.Init(640,480);

    // Start game loop
    while (App.IsOpened())
    {
        // Process events
        sf::Event Event;
        while (App.GetEvent(Event))
        {
            // Close window : exit
            if (Event.Type == sf::Event::Closed)
                App.Close();
        }

        // Clear the screen (fill it with black color)
        App.Clear();
cam1.Draw(&App);
        // Display window contents on screen
        App.Display();
App.SetFramerateLimit(60);
    }

    return EXIT_SUCCESS;
}


And webcam functions:

Code: [Select]


int CCamera::Init(int width, int height)
{
if (!VI.setupDevice(device, width, height)) return 1;
VI.setIdealFramerate(device, 25);
w = VI.getWidth(device);
h = VI.getHeight(device);
size = VI.getSize(device);
buffer = new unsigned char[size];
buffer2= new unsigned char[w*h*4];
  image.Create(w, h, sf::Color(230, 230, 230));
image.SetSmooth(false);
sprite.SetImage(image);
return 0;
}


void CCamera::Draw(sf::RenderWindow * app)
{

if(VI.isFrameNew(device))
{
//Here I take the buffer of RGB values
VI.getPixels(device, buffer, true, true);
int z=0;
//Transform it into ARGB
for (int u=0; u<w*h*3; u+=3)
{
buffer2[z]=buffer[u];
buffer2[z+1]=buffer[u+1];
buffer2[z+2]=buffer[u+2];
buffer2[z+3]=255;
z+=4;
}
// And this is the problem - loading seems to be so slow
image.LoadFromPixels(w,h,buffer2);
}

app->Draw(sprite);
}