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#include "precomp.hpp"

using namespace cv;
using namespace cv::cuda;

#if !defined (HAVE_CUDA) || defined (CUDA_DISABLER)

void cv::cuda::gemm(InputArray, InputArray, double, InputArray, double, OutputArray, int, Stream&) { throw_no_cuda(); }

void cv::cuda::mulSpectrums(InputArray, InputArray, OutputArray, int, bool, Stream&) { throw_no_cuda(); }
void cv::cuda::mulAndScaleSpectrums(InputArray, InputArray, OutputArray, int, float, bool, Stream&) { throw_no_cuda(); }

void cv::cuda::dft(InputArray, OutputArray, Size, int, Stream&) { throw_no_cuda(); }

Ptr<Convolution> cv::cuda::createConvolution(Size) { throw_no_cuda(); return Ptr<Convolution>(); }

#else /* !defined (HAVE_CUDA) */

namespace
{
    #define error_entry(entry)  { entry, #entry }

    struct ErrorEntry
    {
        int code;
        const char* str;
    };

    struct ErrorEntryComparer
    {
        int code;
        ErrorEntryComparer(int code_) : code(code_) {}
        bool operator()(const ErrorEntry& e) const { return e.code == code; }
    };

    String getErrorString(int code, const ErrorEntry* errors, size_t n)
    {
        size_t idx = std::find_if(errors, errors + n, ErrorEntryComparer(code)) - errors;

        const char* msg = (idx != n) ? errors[idx].str : "Unknown error code";
        String str = cv::format("%s [Code = %d]", msg, code);

        return str;
    }
}

#ifdef HAVE_CUBLAS
    namespace
    {
        const ErrorEntry cublas_errors[] =
        {
            error_entry( CUBLAS_STATUS_SUCCESS ),
            error_entry( CUBLAS_STATUS_NOT_INITIALIZED ),
            error_entry( CUBLAS_STATUS_ALLOC_FAILED ),
            error_entry( CUBLAS_STATUS_INVALID_VALUE ),
            error_entry( CUBLAS_STATUS_ARCH_MISMATCH ),
            error_entry( CUBLAS_STATUS_MAPPING_ERROR ),
            error_entry( CUBLAS_STATUS_EXECUTION_FAILED ),
            error_entry( CUBLAS_STATUS_INTERNAL_ERROR )
        };

        const size_t cublas_error_num = sizeof(cublas_errors) / sizeof(cublas_errors[0]);

        static inline void ___cublasSafeCall(cublasStatus_t err, const char* file, const int line, const char* func)
        {
            if (CUBLAS_STATUS_SUCCESS != err)
            {
                String msg = getErrorString(err, cublas_errors, cublas_error_num);
                cv::error(cv::Error::GpuApiCallError, msg, func, file, line);
            }
        }
    }

    #define cublasSafeCall(expr)  ___cublasSafeCall(expr, __FILE__, __LINE__, CV_Func)
#endif // HAVE_CUBLAS

#ifdef HAVE_CUFFT
    namespace
    {
        //////////////////////////////////////////////////////////////////////////
        // CUFFT errors

        const ErrorEntry cufft_errors[] =
        {
            error_entry( CUFFT_INVALID_PLAN ),
            error_entry( CUFFT_ALLOC_FAILED ),
            error_entry( CUFFT_INVALID_TYPE ),
            error_entry( CUFFT_INVALID_VALUE ),
            error_entry( CUFFT_INTERNAL_ERROR ),
            error_entry( CUFFT_EXEC_FAILED ),
            error_entry( CUFFT_SETUP_FAILED ),
            error_entry( CUFFT_INVALID_SIZE ),
            error_entry( CUFFT_UNALIGNED_DATA )
        };

        const int cufft_error_num = sizeof(cufft_errors) / sizeof(cufft_errors[0]);

        void ___cufftSafeCall(int err, const char* file, const int line, const char* func)
        {
            if (CUFFT_SUCCESS != err)
            {
                String msg = getErrorString(err, cufft_errors, cufft_error_num);
                cv::error(cv::Error::GpuApiCallError, msg, func, file, line);
            }
        }
    }

    #define cufftSafeCall(expr)  ___cufftSafeCall(expr, __FILE__, __LINE__, CV_Func)

#endif

////////////////////////////////////////////////////////////////////////
// gemm

void cv::cuda::gemm(InputArray _src1, InputArray _src2, double alpha, InputArray _src3, double beta, OutputArray _dst, int flags, Stream& stream)
{
#ifndef HAVE_CUBLAS
    (void) _src1;
    (void) _src2;
    (void) alpha;
    (void) _src3;
    (void) beta;
    (void) _dst;
    (void) flags;
    (void) stream;
    CV_Error(Error::StsNotImplemented, "The library was build without CUBLAS");
#else
    // CUBLAS works with column-major matrices

    GpuMat src1 = _src1.getGpuMat();
    GpuMat src2 = _src2.getGpuMat();
    GpuMat src3 = _src3.getGpuMat();

    CV_Assert( src1.type() == CV_32FC1 || src1.type() == CV_32FC2 || src1.type() == CV_64FC1 || src1.type() == CV_64FC2 );
    CV_Assert( src2.type() == src1.type() && (src3.empty() || src3.type() == src1.type()) );

    if (src1.depth() == CV_64F)
    {
        if (!deviceSupports(NATIVE_DOUBLE))
            CV_Error(cv::Error::StsUnsupportedFormat, "The device doesn't support double");
    }

    bool tr1 = (flags & GEMM_1_T) != 0;
    bool tr2 = (flags & GEMM_2_T) != 0;
    bool tr3 = (flags & GEMM_3_T) != 0;

    if (src1.type() == CV_64FC2)
    {
        if (tr1 || tr2 || tr3)
            CV_Error(cv::Error::StsNotImplemented, "transpose operation doesn't implemented for CV_64FC2 type");
    }

    Size src1Size = tr1 ? Size(src1.rows, src1.cols) : src1.size();
    Size src2Size = tr2 ? Size(src2.rows, src2.cols) : src2.size();
    Size src3Size = tr3 ? Size(src3.rows, src3.cols) : src3.size();
    Size dstSize(src2Size.width, src1Size.height);

    CV_Assert( src1Size.width == src2Size.height );
    CV_Assert( src3.empty() || src3Size == dstSize );

    _dst.create(dstSize, src1.type());
    GpuMat dst = _dst.getGpuMat();

    if (beta != 0)
    {
        if (src3.empty())
        {
            dst.setTo(Scalar::all(0), stream);
        }
        else
        {
            if (tr3)
            {
                cuda::transpose(src3, dst, stream);
            }
            else
            {
                src3.copyTo(dst, stream);
            }
        }
    }

    cublasHandle_t handle;
    cublasSafeCall( cublasCreate_v2(&handle) );

    cublasSafeCall( cublasSetStream_v2(handle, StreamAccessor::getStream(stream)) );

    cublasSafeCall( cublasSetPointerMode_v2(handle, CUBLAS_POINTER_MODE_HOST) );

    const float alphaf = static_cast<float>(alpha);
    const float betaf = static_cast<float>(beta);

    const cuComplex alphacf = make_cuComplex(alphaf, 0);
    const cuComplex betacf = make_cuComplex(betaf, 0);

    const cuDoubleComplex alphac = make_cuDoubleComplex(alpha, 0);
    const cuDoubleComplex betac = make_cuDoubleComplex(beta, 0);

    cublasOperation_t transa = tr2 ? CUBLAS_OP_T : CUBLAS_OP_N;
    cublasOperation_t transb = tr1 ? CUBLAS_OP_T : CUBLAS_OP_N;

    switch (src1.type())
    {
    case CV_32FC1:
        cublasSafeCall( cublasSgemm_v2(handle, transa, transb, tr2 ? src2.rows : src2.cols, tr1 ? src1.cols : src1.rows, tr2 ? src2.cols : src2.rows,
            &alphaf,
            src2.ptr<float>(), static_cast<int>(src2.step / sizeof(float)),
            src1.ptr<float>(), static_cast<int>(src1.step / sizeof(float)),
            &betaf,
            dst.ptr<float>(), static_cast<int>(dst.step / sizeof(float))) );
        break;

    case CV_64FC1:
        cublasSafeCall( cublasDgemm_v2(handle, transa, transb, tr2 ? src2.rows : src2.cols, tr1 ? src1.cols : src1.rows, tr2 ? src2.cols : src2.rows,
            &alpha,
            src2.ptr<double>(), static_cast<int>(src2.step / sizeof(double)),
            src1.ptr<double>(), static_cast<int>(src1.step / sizeof(double)),
            &beta,
            dst.ptr<double>(), static_cast<int>(dst.step / sizeof(double))) );
        break;

    case CV_32FC2:
        cublasSafeCall( cublasCgemm_v2(handle, transa, transb, tr2 ? src2.rows : src2.cols, tr1 ? src1.cols : src1.rows, tr2 ? src2.cols : src2.rows,
            &alphacf,
            src2.ptr<cuComplex>(), static_cast<int>(src2.step / sizeof(cuComplex)),
            src1.ptr<cuComplex>(), static_cast<int>(src1.step / sizeof(cuComplex)),
            &betacf,
            dst.ptr<cuComplex>(), static_cast<int>(dst.step / sizeof(cuComplex))) );
        break;

    case CV_64FC2:
        cublasSafeCall( cublasZgemm_v2(handle, transa, transb, tr2 ? src2.rows : src2.cols, tr1 ? src1.cols : src1.rows, tr2 ? src2.cols : src2.rows,
            &alphac,
            src2.ptr<cuDoubleComplex>(), static_cast<int>(src2.step / sizeof(cuDoubleComplex)),
            src1.ptr<cuDoubleComplex>(), static_cast<int>(src1.step / sizeof(cuDoubleComplex)),
            &betac,
            dst.ptr<cuDoubleComplex>(), static_cast<int>(dst.step / sizeof(cuDoubleComplex))) );
        break;
    }

    cublasSafeCall( cublasDestroy_v2(handle) );
#endif
}

//////////////////////////////////////////////////////////////////////////////
// dft

void cv::cuda::dft(InputArray _src, OutputArray _dst, Size dft_size, int flags, Stream& stream)
{
#ifndef HAVE_CUFFT
    (void) _src;
    (void) _dst;
    (void) dft_size;
    (void) flags;
    (void) stream;
    throw_no_cuda();
#else
    GpuMat src = _src.getGpuMat();

    CV_Assert( src.type() == CV_32FC1 || src.type() == CV_32FC2 );

    // We don't support unpacked output (in the case of real input)
    CV_Assert( !(flags & DFT_COMPLEX_OUTPUT) );

    const bool is_1d_input       = (dft_size.height == 1) || (dft_size.width == 1);
    const bool is_row_dft        = (flags & DFT_ROWS) != 0;
    const bool is_scaled_dft     = (flags & DFT_SCALE) != 0;
    const bool is_inverse        = (flags & DFT_INVERSE) != 0;
    const bool is_complex_input  = src.channels() == 2;
    const bool is_complex_output = !(flags & DFT_REAL_OUTPUT);

    // We don't support real-to-real transform
    CV_Assert( is_complex_input || is_complex_output );

    GpuMat src_cont = src;

    // Make sure here we work with the continuous input,
    // as CUFFT can't handle gaps
    createContinuous(src.rows, src.cols, src.type(), src_cont);
    if (src_cont.data != src.data)
        src.copyTo(src_cont, stream);

    Size dft_size_opt = dft_size;
    if (is_1d_input && !is_row_dft)
    {
        // If the source matrix is single column handle it as single row
        dft_size_opt.width = std::max(dft_size.width, dft_size.height);
        dft_size_opt.height = std::min(dft_size.width, dft_size.height);
    }

    CV_Assert( dft_size_opt.width > 1 );

    cufftType dft_type = CUFFT_R2C;
    if (is_complex_input)
        dft_type = is_complex_output ? CUFFT_C2C : CUFFT_C2R;

    cufftHandle plan;
    if (is_1d_input || is_row_dft)
        cufftSafeCall( cufftPlan1d(&plan, dft_size_opt.width, dft_type, dft_size_opt.height) );
    else
        cufftSafeCall( cufftPlan2d(&plan, dft_size_opt.height, dft_size_opt.width, dft_type) );

    cufftSafeCall( cufftSetStream(plan, StreamAccessor::getStream(stream)) );

    if (is_complex_input)
    {
        if (is_complex_output)
        {
            createContinuous(dft_size, CV_32FC2, _dst);
            GpuMat dst = _dst.getGpuMat();

            cufftSafeCall(cufftExecC2C(
                    plan, src_cont.ptr<cufftComplex>(), dst.ptr<cufftComplex>(),
                    is_inverse ? CUFFT_INVERSE : CUFFT_FORWARD));
        }
        else
        {
            createContinuous(dft_size, CV_32F, _dst);
            GpuMat dst = _dst.getGpuMat();

            cufftSafeCall(cufftExecC2R(
                    plan, src_cont.ptr<cufftComplex>(), dst.ptr<cufftReal>()));
        }
    }
    else
    {
        // We could swap dft_size for efficiency. Here we must reflect it
        if (dft_size == dft_size_opt)
            createContinuous(Size(dft_size.width / 2 + 1, dft_size.height), CV_32FC2, _dst);
        else
            createContinuous(Size(dft_size.width, dft_size.height / 2 + 1), CV_32FC2, _dst);

        GpuMat dst = _dst.getGpuMat();

        cufftSafeCall(cufftExecR2C(
                plan, src_cont.ptr<cufftReal>(), dst.ptr<cufftComplex>()));
    }

    cufftSafeCall( cufftDestroy(plan) );

    if (is_scaled_dft)
        cuda::multiply(_dst, Scalar::all(1. / dft_size.area()), _dst, 1, -1, stream);

#endif
}

//////////////////////////////////////////////////////////////////////////////
// Convolution

#ifdef HAVE_CUFFT

namespace
{
    class ConvolutionImpl : public Convolution
    {
    public:
        explicit ConvolutionImpl(Size user_block_size_) : user_block_size(user_block_size_) {}

        void convolve(InputArray image, InputArray templ, OutputArray result, bool ccorr = false, Stream& stream = Stream::Null());

    private:
        void create(Size image_size, Size templ_size);
        static Size estimateBlockSize(Size result_size);

        Size result_size;
        Size block_size;
        Size user_block_size;
        Size dft_size;
        int spect_len;

        GpuMat image_spect, templ_spect, result_spect;
        GpuMat image_block, templ_block, result_data;
    };

    void ConvolutionImpl::create(Size image_size, Size templ_size)
    {
        result_size = Size(image_size.width - templ_size.width + 1,
                           image_size.height - templ_size.height + 1);

        block_size = user_block_size;
        if (user_block_size.width == 0 || user_block_size.height == 0)
            block_size = estimateBlockSize(result_size);

        dft_size.width = 1 << int(ceil(std::log(block_size.width + templ_size.width - 1.) / std::log(2.)));
        dft_size.height = 1 << int(ceil(std::log(block_size.height + templ_size.height - 1.) / std::log(2.)));

        // CUFFT has hard-coded kernels for power-of-2 sizes (up to 8192),
        // see CUDA Toolkit 4.1 CUFFT Library Programming Guide
        if (dft_size.width > 8192)
            dft_size.width = getOptimalDFTSize(block_size.width + templ_size.width - 1);
        if (dft_size.height > 8192)
            dft_size.height = getOptimalDFTSize(block_size.height + templ_size.height - 1);

        // To avoid wasting time doing small DFTs
        dft_size.width = std::max(dft_size.width, 512);
        dft_size.height = std::max(dft_size.height, 512);

        createContinuous(dft_size, CV_32F, image_block);
        createContinuous(dft_size, CV_32F, templ_block);
        createContinuous(dft_size, CV_32F, result_data);

        spect_len = dft_size.height * (dft_size.width / 2 + 1);
        createContinuous(1, spect_len, CV_32FC2, image_spect);
        createContinuous(1, spect_len, CV_32FC2, templ_spect);
        createContinuous(1, spect_len, CV_32FC2, result_spect);

        // Use maximum result matrix block size for the estimated DFT block size
        block_size.width = std::min(dft_size.width - templ_size.width + 1, result_size.width);
        block_size.height = std::min(dft_size.height - templ_size.height + 1, result_size.height);
    }

    Size ConvolutionImpl::estimateBlockSize(Size result_size)
    {
        int width = (result_size.width + 2) / 3;
        int height = (result_size.height + 2) / 3;
        width = std::min(width, result_size.width);
        height = std::min(height, result_size.height);
        return Size(width, height);
    }

    void ConvolutionImpl::convolve(InputArray _image, InputArray _templ, OutputArray _result, bool ccorr, Stream& _stream)
    {
        GpuMat image = _image.getGpuMat();
        GpuMat templ = _templ.getGpuMat();

        CV_Assert( image.type() == CV_32FC1 );
        CV_Assert( templ.type() == CV_32FC1 );

        create(image.size(), templ.size());

        _result.create(result_size, CV_32FC1);
        GpuMat result = _result.getGpuMat();

        cudaStream_t stream = StreamAccessor::getStream(_stream);

        cufftHandle planR2C, planC2R;
        cufftSafeCall( cufftPlan2d(&planC2R, dft_size.height, dft_size.width, CUFFT_C2R) );
        cufftSafeCall( cufftPlan2d(&planR2C, dft_size.height, dft_size.width, CUFFT_R2C) );

        cufftSafeCall( cufftSetStream(planR2C, stream) );
        cufftSafeCall( cufftSetStream(planC2R, stream) );

        GpuMat templ_roi(templ.size(), CV_32FC1, templ.data, templ.step);
        cuda::copyMakeBorder(templ_roi, templ_block, 0, templ_block.rows - templ_roi.rows, 0,
                            templ_block.cols - templ_roi.cols, 0, Scalar(), _stream);

        cufftSafeCall( cufftExecR2C(planR2C, templ_block.ptr<cufftReal>(), templ_spect.ptr<cufftComplex>()) );

        // Process all blocks of the result matrix
        for (int y = 0; y < result.rows; y += block_size.height)
        {
            for (int x = 0; x < result.cols; x += block_size.width)
            {
                Size image_roi_size(std::min(x + dft_size.width, image.cols) - x,
                                    std::min(y + dft_size.height, image.rows) - y);
                GpuMat image_roi(image_roi_size, CV_32F, (void*)(image.ptr<float>(y) + x),
                                 image.step);
                cuda::copyMakeBorder(image_roi, image_block, 0, image_block.rows - image_roi.rows,
                                    0, image_block.cols - image_roi.cols, 0, Scalar(), _stream);

                cufftSafeCall(cufftExecR2C(planR2C, image_block.ptr<cufftReal>(),
                                           image_spect.ptr<cufftComplex>()));
                cuda::mulAndScaleSpectrums(image_spect, templ_spect, result_spect, 0,
                                          1.f / dft_size.area(), ccorr, _stream);
                cufftSafeCall(cufftExecC2R(planC2R, result_spect.ptr<cufftComplex>(),
                                           result_data.ptr<cufftReal>()));

                Size result_roi_size(std::min(x + block_size.width, result.cols) - x,
                                     std::min(y + block_size.height, result.rows) - y);
                GpuMat result_roi(result_roi_size, result.type(),
                                  (void*)(result.ptr<float>(y) + x), result.step);
                GpuMat result_block(result_roi_size, result_data.type(),
                                    result_data.ptr(), result_data.step);

                result_block.copyTo(result_roi, _stream);
            }
        }

        cufftSafeCall( cufftDestroy(planR2C) );
        cufftSafeCall( cufftDestroy(planC2R) );
    }
}

#endif

Ptr<Convolution> cv::cuda::createConvolution(Size user_block_size)
{
#ifndef HAVE_CUFFT
    (void) user_block_size;
    CV_Error(Error::StsNotImplemented, "The library was build without CUFFT");
    return Ptr<Convolution>();
#else
    return makePtr<ConvolutionImpl>(user_block_size);
#endif
}

#endif /* !defined (HAVE_CUDA) */
