Custom low level library for tracker

Accelerated Computing Intelligent Video Analytics DeepStream SDK
1

From my previous question https://devtalk.nvidia.com/default/topic/1070933/deepstream-sdk/iterate-bbox-in-nvmot/post/5426995/#5426995 For testing purpose I added hardcoded boxes in custom low level tracker. Below is my low_level_library code which I will compile it as .so file and use it as low level tracker in tracker config

#include <math.h>
#include <stdio.h>
#include "nvdstracker.h"
#include <iostream>
#include <glib.h>
#include "opencv2/opencv.hpp"
#include "nvbufsurface.h"
#include "nvbufsurftransform.h"
#include "gstnvdsmeta.h"
#include "gstnvdsinfer.h"
#include <cstddef>

NvMOTStatus NvMOT_Query(uint16_t customConfigFilePathSize, char* pCustomConfigFilePath, NvMOTQuery *pQuery)
{

pQuery->memType = NVBUF_MEM_CUDA_UNIFIED;
pQuery->colorFormats[0] = NVBUF_COLOR_FORMAT_RGBA;
pQuery->colorFormats[1] = NVBUF_COLOR_FORMAT_RGBA;
pQuery->colorFormats[2] = NVBUF_COLOR_FORMAT_RGBA;
pQuery->colorFormats[3] = NVBUF_COLOR_FORMAT_RGBA;

return NvMOTStatus_OK;
}

NvMOTStatus NvMOT_Init(NvMOTConfig *pConfigIn,NvMOTContextHandle *pContextHandle,NvMOTConfigResponse *pConfigResponse)
{

std::cout<<"trackerinit...!!!!!\n";
pConfigResponse->summaryStatus = NvMOTConfigStatus_OK;
pConfigResponse->computeStatus = NvMOTConfigStatus_OK;
pConfigResponse->transformBatchStatus = NvMOTConfigStatus_OK;
pConfigResponse->miscConfigStatus = NvMOTConfigStatus_OK;
pConfigResponse->customConfigStatus = NvMOTConfigStatus_OK;

NvMOTContextHandle *ctx = (NvMOTContextHandle *) pConfigIn;

*pContextHandle =  *ctx;
return NvMOTStatus_OK;

NvMOTStatus NvMOT_Process(NvMOTContextHandle contextHandle,NvMOTProcessParams *pParams,NvMOTTrackedObjBatch *pTrackedObjectsBatch)

{
NvMOTFrame *fr = pParams->frameList;
NvMOTObjToTrackList det_obj = fr->objectsIn;
NvMOTObjToTrack *obj_to_trk = det_obj.list;

for (int i = 0;i<det_obj.numFilled;i++){

  NvMOTTrackedObj OutObject ;
 OutObject.bbox.x = 100+i;
 OutObject.bbox.y = 100+i;
 OutObject.bbox.width = 258+i;
 OutObject.bbox.height = 897+i;
 OutObject.trackingId = i+1;
 OutObject.confidence = 0.9;
 OutObject.classId =0;
 out_trk.push_back(OutObject);
}
for (int i = 0;i<pTrackedObjectsBatch->numFilled;i++){
  NvMOTTrackedObjList OutObject_list ;
 OutObject_list.streamID = fr-> streamID;
 OutObject_list.frameNum = numbuf;
 OutObject_list.list = out_trk.data();
 OutObject_list.numFilled = det_obj.numFilled;
 OutObject_list.valid = true;
 OutObject_list.numAllocated = det_obj.numAllocated;
 out_trk_list.push_back(OutObject_list);
}

pTrackedObjectsBatch->list = out_trk_list.data();

return NvMOTStatus_OK;

}
void NvMOT_DeInit(NvMOTContextHandle contextHandle){

  std::cout<<"deinit...!!!!!\n";

}

when I send this hardcoded bbox value I can able to get these value in deepstream-sample-app(deepstream-infer-tensor-meta-test) for first two frames then I get segmentation fault error.
Help me to fix this error.

2

Before testing your own custom low-level tracker, you would need to make sure the caller to use the APIs properly. Have you tested your caller to be able to call and run KLT tracker?

3

Hi,

Yes I tested with KLT tracker, it is working fine, but when I change .so to point my tracker lib the above mentioned error appears. I think the issue is with my low level library.

4

any update?
I am also getting the below error,

gstnvtracker: Got output for unknown stream 7f804000b630
5

The following code snippets are suspicious. You assign the pre-allocated memory to OutObject_list.list, but you specify OutObject_list.numAllocated with different data. I am not sure if you are doing it correctly or not.

OutObject_list.list = out_trk.data();
OutObject_list.numFilled = det_obj.numFilled;
OutObject_list.numAllocated = det_obj.numAllocated;

Also SegFault happens typically when you make illegal memory access. Make sure if OutObject_list.numFilled <= OutObject_list.numAllocated always holds.

I can’t give you much advise/suggestion unless you provide full working code. You can create a partner ticket if you want us to review internally.

6

How to create partner ticket?

7

Hi sathiez,

Sorry for the late reply, have you got the update to move your project forward?

8

After some research. I find the problems.
The key point is we should use memcpy to set pTrackedObjectsBatch->list.

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