cv::Rect in a struct pack - unpack

[MyraBaba]

Hi,

I have below struct and msg_pack:

struct  AlpBox 
{

cv::Rect  bbox;
double    confidence;
int       class_id;
MSGPACK_DEFINE(bbox,confidence,class_id);

} ;

struct Alpdetections
{
  std::vector<AlpBox>  detections;
  MSGPACK_DEFINE(detections)
}

it gives :

                                                                     │··········

../libs/postprocesses/alpullu/messaging.h:32:1: required from here │··········
/usr/local/include/msgpack/v1/object.hpp:647:7: error: ‘class cv::Rect_’ has no member named ‘msgpack_unpa│··········
ck’ │··········
647 | v.msgpack_unpack(o.convert());

what is the best practices for above vector of struct pack and unpack in C++

Best

[redboltz]

You need to prepare the adaptor for cv::Rect. The error message means cv::Rect doesn't have an adaptor.
You can define the adaptor for cv::Rect as
https://github.com/msgpack/msgpack-c/wiki/v2_0_cpp_adaptor#non-intrusive-approach

[MyraBaba]

@redboltz

Hi Again,

Is below approach is correct? I want to send AlpDetectionsthrough zmq

`struct  AlpBox 
{
int p1 ,p2 ,p3 ,p4 ;
float    confidence;
int       class_id;
MSGPACK_DEFINE(p1 ,p2 ,p3 ,p4,confidence,class_id);

}  ;

struct AlpDetections
{
  std::vector<AlpBox>  detections;
  MSGPACK_DEFINE(detections);
};`

[redboltz]

See https://github.com/msgpack/msgpack-c/wiki/v2_0_cpp_tutorial and othre documents.
and https://github.com/msgpack/msgpack-c/tree/cpp_master/example

[MyraBaba]

@redboltz for above struct:

`
std::vector<AlpulluBox>  alpdetections;
  AlpulluBox alpbbox;
            float confidence   = detection->get_confidence();
            int class_id     = detection->get_class_id();
            alpbbox ={xmin,ymin,xmax,ymax , detection->get_confidence() , detection->get_class_id()};
            alpdetections.push_back(alpbbox);

         }
    }

   msgpack::sbuffer seriailezAlpDetections;
   msgpack::pack(&seriailezAlpDetections, alpdetections );`

deserializing ::

zmq::message_t contents;
//zmq::recv_result_t result = subscriber.recv(contents);

            zmq::message_t response_data;
            subscriber.recv(response_data, zmq::recv_flags::none);
            msgpack::unpacked unpacked_response_data;
            msgpack::unpack(unpacked_response_data,
                            static_cast<const char*>(response_data.data()),
                            response_data.size());

            auto unpacked_response = unpacked_response_data.get().as<AlpulluBox>();

gives erro r:

: terminating with uncaught exception of type msgpack::v1::type_error: std::bad_cast

[redboltz]

I don't know about zmq.

[redboltz]

See https://stackoverflow.com/help/minimal-reproducible-example

[redboltz]

See also https://github.com/msgpack/msgpack/blob/master/spec.md
Check msgpack format using something like hex dump.
Then fix your code.

[MyraBaba]

@can we directly cast to the coming object for AlpDetection ?

struct  AlpBox 
{
int p1 ,p2 ,p3 ,p4 ;
float    confidence;
int       class_id;
MSGPACK_DEFINE(p1 ,p2 ,p3 ,p4,confidence,class_id);

}  ;

struct AlpDetections
{
  std::vector<AlpBox>  detections;
  MSGPACK_DEFINE(detections);
};`