Patch cv::cudacodec::createVideoReader() memory leak until cudacodec can be…

Patch cv::cudacodec::createVideoReader() memory leak until cudacodec can be updated to miirror NVidia example code.

modules/cudacodec/src/cuvid_video_source.cpp

@@ -62,7 +62,7 @@ cv::cudacodec::detail::CuvidVideoSource::CuvidVideoSource(const String& fname)
     // now create the actual source
     CUresult cuRes = cuvidCreateVideoSource(&videoSource_, fname.c_str(), &params);
     if (cuRes == CUDA_ERROR_INVALID_SOURCE)
-        throw std::runtime_error("");
+        CV_Error(Error::StsUnsupportedFormat, "Unsupported video source");
     cuSafeCall( cuRes );
 
     CUVIDEOFORMAT vidfmt;

modules/cudacodec/src/video_parser.cpp

@@ -118,6 +118,7 @@ int CUDAAPI cv::cudacodec::detail::VideoParser::HandleVideoSequence(void* userDa
 
         try
         {
+            thiz->videoDecoder_->release();
             thiz->videoDecoder_->create(newFormat);
         }
         catch (const cv::Exception&)