# OpenCV 4.5.0 on Pi 4 w/high-quality camera fails to stream

**URL:** <https://forum.opencv.org/t/opencv-4-5-0-on-pi-4-w-high-quality-camera-fails-to-stream/2113>\
**Category:** C++\
**Created:** [March 11, 2021, 3:53pm UTC](https://forum.opencv.org/t/opencv-4-5-0-on-pi-4-w-high-quality-camera-fails-to-stream/2113 "2021-03-11T15:53:41Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![scott14468](https://avatars.discourse-cdn.com/v4/letter/s/d6d6ee/32.png) [@scott14468](https://forum.opencv.org/u/scott14468)\
**Post date:** [March 11, 2021, 3:53pm UTC](https://forum.opencv.org/t/opencv-4-5-0-on-pi-4-w-high-quality-camera-fails-to-stream/2113/1 "2021-03-11T15:53:41Z")

</div>

Hi All,

I’ve just installed OpenCV 4.5.0 on a Raspberry Pi 4B with a high-quality camera. When I attempt to write a simple app to view the camera’s output, I get these errors:

```
[WARN:0] global /home/pi/opencv/modules/videoio/src/cap_gstreamer.cpp (1761) handleMessage OpenCV | GStreamer warning: Embedded video playback halted; module source reported: Could not read from resource.
[WARN:0] global /home/pi/opencv/modules/videoio/src/cap_gstreamer.cpp (888) open OpenCV | GStreamer warning: unable to start pipeline
[WARN:0] global /home/pi/opencv/modules/videoio/src/cap_gstreamer.cpp (480) isPipelinePlaying OpenCV | GStreamer warning: GStreamer: pipeline have not been created

```

The program is:

```auto
int main( int argc, char *argv[] )
{
	cv::Mat m( 768, 1360, CV_8UC3, cv::Scalar( 0, 0, 0 ) ), b, cam;
	cv::VideoCapture	cap = cv::VideoCapture( "/dev/video0" ); //	camera stream

	int i;
	char buf[50];

	if ( !cap.isOpened( ) )
	{
		printf( "Can't open camera\n" );
		return( 1 );
	}

	printf( "Camera opened\n" );

//	cap.set( cv::CAP_PROP_FRAME_WIDTH, 480 );
//	cap.set( cv::CAP_PROP_FRAME_HEIGHT, 480 );

	printf( "Properties set\n" );

//	cv::line( b, cv::Point( 0, 0 ), cv::Point( 1359, 767 ), cv::Scalar( 0, 0, 255 ), 1, 8, 0 );
//	cv::namedWindow( "MRS", cv::WINDOW_NORMAL | cv::WINDOW_FULLSCREEN );
	cv::namedWindow( "CAM", cv::WINDOW_NORMAL );

	printf( "windows named\n" );

	for ( i = 1; cv::waitKey( 1 ) != 0x1B; i ++ )
	{
// m.copyTo( b );
// sprintf( buf, "%d", i );
// cv::putText( b, buf, cv::Point( 500, 500 ), cv::FONT_HERSHEY_SIMPLEX, 10, cv::Scalar( 0, 255, 0 ) );
// cv::imshow( "MRS", b );
// cv::waitKey( 1 );
		cap.read( cam );
		printf( "camera read\n" );
		cv::imshow( "CAM", cam );
	}

	return( 0 );
}

```

If I change to the default video source `cv::VideoCapture	cap = cv::VideoCapture( 0 )` the Pi actually hangs and must be reset to recover.

Any thoughts most appreciated.

Thanks,  
Scott