VPI DCF tracker

Accelerated Computing Intelligent Video Analytics General
1

Hi, I’m attempting to utilize the VPI DCF tracker C API and encountering issues retrieving the CorrelationResponses and MaxCorrelationResponses outputs from vpiSubmitDCFTrackerLocalizeBatch.

The tracker is functional, and I can consistently track objects even in frames without detector inferences, so I don’t think this issue is connected to other sections of the program.

However, without CorrelationResponses and MaxCorrelationResponses data, I can only depend on the bounding box IOU score for detector/tracker data association.

The following is the code snippet.
Any help would be greatly appreciated. Thank you.

    VPIDCFTrackerCreationParams m_createParams;
    VPI_CHECK(vpiInitDCFTrackerCreationParams(&m_createParams));
    ...
    
    VPIImage m_outCorrelationResponses;
    int32_t outCorrelationResponsesWidth  = m_createParams.featurePatchSize;
    int32_t outCorrelationResponsesHeight = outCorrelationResponsesWidth * 128;
    VPI_CHECK(vpiImageCreate(outCorrelationResponsesWidth, outCorrelationResponsesHeight, VPI_IMAGE_FORMAT_F32, 0, &m_outCorrelationResponses));
    
    VPIArray m_outMaxCorrelationResponses;
    VPI_CHECK(vpiArrayCreate(128, VPI_ARRAY_TYPE_F32, 0, &m_outMaxCorrelationResponses));
    ...
    
    vpiSubmitDCFTrackerLocalizeBatch(m_vpiStream, VPI_BACKEND_CUDA, m_dcfPayload, m_enabledSequences, MAX_SEQUENCES,
                                        NULL, m_objPatches, m_inObjects, m_outObjects,
                                        m_outCorrelationResponses, m_outMaxCorrelationResponses,
                                        &m_params);
6

Hi,

Could you share more info with us?

Do you encounter errors when reading CorrelationResponses and MaxCorrelationResponses?
Or the value is all zero?

Thanks.

7

Hi, AastaLLL
Thank you for your response.
Yes, the value is all zero. The following is how I read the value. Any suggestion would be greatly appreciated.

vpiSubmitDCFTrackerLocalizeBatch(m_vpiStream, VPI_BACKEND_CUDA, m_dcfPayload, m_enabledSequences, MAX_SEQUENCES,
                                NULL, m_objPatches, m_inObjects, m_outObjects,
                                m_outCorrelationResponses, m_outMaxCorrelationResponses,
                                &m_params);

VPI_CHECK(vpiStreamSync(m_vpiStream));

VPIArrayData maxCorrelationResponsesData;
VPI_CHECK(vpiArrayLockData(m_outMaxCorrelationResponses, VPI_LOCK_READ, VPI_ARRAY_BUFFER_HOST_AOS, &maxCorrelationResponsesData));
float *maxCorrelationResponses = (float *)maxCorrelationResponsesData.buffer.aos.data;
for (int32_t i = 0; i < m_config.maxTargets; i++) {
    printf("%f ", maxCorrelationResponses[i]);
}
printf("\n");
VPI_CHECK(vpiArrayUnlock(m_outMaxCorrelationResponses));
9

There is no update from you for a period, assuming this is not an issue anymore. Hence we are closing this topic. If need further support, please open a new one. Thanks
Hi,

Sorry for the late response.

Based on the code snapshot shared above, it looks like the creation for CorrelationResponses and MaxCorrelationResponses is good.
We will need more info to further check this issue.

Would you mind sharing a simple reproducible source that can be compiled with us.
Thanks.

10

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