VideoStream::setVideoMode() function doesn't work - c++

Question

I want to change VideoStream setting in my program, but it doesn't work
#include <OpenNI.h>
int main()
{
OpenNI::initialize();
Device device;
device.open(ANY_DEVICE);
VideoStream depthStream;
depthStream.create(device, SENSOR_DEPTH);
depthStream.start();
VideoMode depthMode;
depthMode.setFps(20);
depthMode.setResolution(640, 480);
depthMode.setPixelFormat(PIXEL_FORMAT_DEPTH_100_UM);
depthStream.setVideoMode(depthMode);
...
}
Even I change depthStream.start() line after setVideoMode() function, but still doesn't work.
I changed Fps to 24, 20, 5, 1 but it doesn't change anything.
p.s. : This is my simple code, without error handling.
Edit:
Answer:
with the help of dear "api55" i found that my device (Kinect Xbox) support only one mode of videoMode. so I can't change it.
My only supported video is :
FPS:30
Width:640
Height:480

Answer 1

I change the VideoMode succesfully in a code a did before. After creating the VideoStream you should do something like:
rc = depth.create(device, openni::SENSOR_DEPTH);
if (rc != openni::STATUS_OK)
error_manager(3);
// set the new resolution and fps
openni::VideoMode depth_videoMode = depth.getVideoMode();
depth_videoMode.setResolution(frame_width,frame_height);
depth_videoMode.setFps(30);
depth.setVideoMode(depth_videoMode);
rc = depth.start();
if (rc != openni::STATUS_OK)
error_manager(4);
First I get the VideoMode that is inside the stream to conserve the other values and only change what I wanted. I think your code should work, but not all settings work in all cameras. To check the possible settings you can use the function openni::VideoStream::getSensorInfo. The code to check this should be something like:
#include <OpenNI.h>
int main()
{
OpenNI::initialize();
Device device;
device.open(ANY_DEVICE);
VideoStream depthStream;
depthStream.create(device, SENSOR_DEPTH);
depthStream.start();
SensorInfo& info = depthStream.getSensorInfo();
Array& videoModes = info.getSupportedVideoModes();
for (int i = 0; i < videoModes.getSize(); i++){
std::cout << "VideoMode " << i << std::endl;
std::cout << "FPS:" << videoModes[i].getFps() << std::endl;
std::cout << "Width:" << videoModes[i].getResolutionX() << std::endl;
std::cout << "Height:" << videoModes[i].getResolutionY() << std::endl;
}
...
}
I haven't test this last piece of code, so it may have errors, but you get the idea of it. The supported settings change with each camera, but I think the supported FPS in my camera were 15 and 30.
I hope this helps you