# BufferPool.getBuffer report "Unknown C++ exception from OpenCV code" in python

**URL:** <https://forum.opencv.org/t/bufferpool-getbuffer-report-unknown-c-exception-from-opencv-code-in-python/8528>\
**Category:** Python\
**Tags:** cuda\
**Created:** [April 24, 2022, 11:41am UTC](https://forum.opencv.org/t/bufferpool-getbuffer-report-unknown-c-exception-from-opencv-code-in-python/8528 "2022-04-24T11:41:32Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![hakaboom](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/hakaboom/32/5195_2.png) [@hakaboom](https://forum.opencv.org/u/hakaboom)\
**Post date:** [April 24, 2022, 11:41am UTC](https://forum.opencv.org/t/bufferpool-getbuffer-report-unknown-c-exception-from-opencv-code-in-python/8528/1 "2022-04-24T11:41:32Z")

</div>

I cant use getBuffer in python

In python report `cv2.error: Unknown C++ exception from OpenCV code`

```python
import cv2

cv2.cuda.setBufferPoolUsage(True)
cv2.cuda.setBufferPoolConfig(cv2.cuda.getDevice(), 1024 * 1024 * 64, 2)

stream_a = cv2.cuda.Stream()
stream_b = cv2.cuda.Stream()
pool_a = cv2.cuda.BufferPool(stream_a)
pool_b = cv2.cuda.BufferPool(stream_a)
pool_a.getBuffer(1024, 1024, cv2.CV_8UC3)

```

In c++, it works

```nohighlight
#include "opencv2/core/mat.hpp"
#include "opencv2/core/cuda.hpp"

using namespace std;

int main()
{

    cv::cuda::setBufferPoolUsage(true);
    cv::cuda::setBufferPoolConfig(cv::cuda::getDevice(), 1024 * 1024 * 64, 2);

    cv::cuda::Stream streamA, streamB;
    cv::cuda::BufferPool poolA(streamA), poolB(streamB);
    
    cv::cuda::GpuMat im_source_bgr = poolA.getBuffer(1024, 1024, CV_8UC3);
    cv::cuda::GpuMat im_search_bgr = poolB.getBuffer(1024, 1024, CV_8UC3);

    cv::cuda::GpuMat im_source = poolA.getBuffer(1024, 1024, CV_8UC3);
    cv::cuda::GpuMat im_search = poolB.getBuffer(1024, 1024, CV_8UC3);

    return 0;
}

```