/* Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *  * Neither the name of NVIDIA CORPORATION nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


// Implements NV12 to BGR batch conversion

#include <cuda.h>
#include <cuda_runtime.h>

#include "resize_convert.h"

#define CONV_THREADS_X 64
#define CONV_THREADS_Y 10

__forceinline__ __device__ static float clampF(float x, float lower, float upper)
{
    return x < lower ? lower : (x > upper ? upper : x);
}

__global__ static void nv12ToBGRplanarBatchKernel(const uint8_t *pNv12,
                                                  int            nNv12Pitch,
                                                  float         *pBgr,
                                                  int            nRgbPitch,
                                                  int            nWidth,
                                                  int            nHeight,
                                                  int            nBatchSize)
{
    int x = threadIdx.x + blockIdx.x * blockDim.x;
    int y = threadIdx.y + blockIdx.y * blockDim.y;

    if ((x << 2) + 1 > nWidth || (y << 1) + 1 > nHeight)
        return;

    const uint8_t *__restrict__ pSrc = pNv12;

    for (int i = blockIdx.z; i < nBatchSize; i += gridDim.z) {
        pSrc = pNv12 + i * ((nHeight * nNv12Pitch * 3) >> 1) + (x << 2) + (y << 1) * nNv12Pitch;
        uchar4 luma2x01, luma2x23, uv2;
        *(uint32_t *)&luma2x01 = *(uint32_t *)pSrc;
        *(uint32_t *)&luma2x23 = *(uint32_t *)(pSrc + nNv12Pitch);
        *(uint32_t *)&uv2      = *(uint32_t *)(pSrc + (nHeight - y) * nNv12Pitch);

        float *pDstBlock = (pBgr + i * ((nHeight * nRgbPitch * 3) >> 2) + ((blockIdx.x * blockDim.x) << 2)
                            + ((blockIdx.y * blockDim.y) << 1) * (nRgbPitch >> 2));

        float2 add1;
        float2 add2;
        float2 add3;
        float2 add00, add01, add02, add03;
        float2 d, e;

        add00.x = 1.1644f * luma2x01.x;
        add01.x = 1.1644f * luma2x01.y;
        add00.y = 1.1644f * luma2x01.z;
        add01.y = 1.1644f * luma2x01.w;

        add02.x = 1.1644f * luma2x23.x;
        add03.x = 1.1644f * luma2x23.y;
        add02.y = 1.1644f * luma2x23.z;
        add03.y = 1.1644f * luma2x23.w;

        d.x = uv2.x - 128.0f;
        e.x = uv2.y - 128.0f;
        d.y = uv2.z - 128.0f;
        e.y = uv2.w - 128.0f;

        add1.x = 2.0172f * d.x;
        add1.y = 2.0172f * d.y;

        add2.x = (-0.3918f) * d.x + (-0.8130f) * e.x;
        add2.y = (-0.3918f) * d.y + (-0.8130f) * e.y;

        add3.x = 1.5960f * e.x;
        add3.y = 1.5960f * e.y;

        int rowStride     = (threadIdx.y << 1) * (nRgbPitch >> 2);
        int nextRowStride = ((threadIdx.y << 1) + 1) * (nRgbPitch >> 2);
        // B
        *((float4 *)&pDstBlock[rowStride + (threadIdx.x << 2)]) = make_float4(clampF(add00.x + add1.x, 0.0f, 255.0f),
                                                                              clampF(add01.x + add1.x, 0.0f, 255.0f),
                                                                              clampF(add00.y + add1.y, 0.0f, 255.0f),
                                                                              clampF(add01.y + add1.y, 0.0f, 255.0f));
        *((float4 *)&pDstBlock[nextRowStride + (threadIdx.x << 2)]) =
            make_float4(clampF(add02.x + add1.x, 0.0f, 255.0f),
                        clampF(add03.x + add1.x, 0.0f, 255.0f),
                        clampF(add02.y + add1.y, 0.0f, 255.0f),
                        clampF(add03.y + add1.y, 0.0f, 255.0f));

        int planeStride = nHeight * nRgbPitch >> 2;
        // G
        *((float4 *)&pDstBlock[planeStride + rowStride + (threadIdx.x << 2)]) =
            make_float4(clampF(add00.x + add2.x, 0.0f, 255.0f),
                        clampF(add01.x + add2.x, 0.0f, 255.0f),
                        clampF(add00.y + add2.y, 0.0f, 255.0f),
                        clampF(add01.y + add2.y, 0.0f, 255.0f));
        *((float4 *)&pDstBlock[planeStride + nextRowStride + (threadIdx.x << 2)]) =
            make_float4(clampF(add02.x + add2.x, 0.0f, 255.0f),
                        clampF(add03.x + add2.x, 0.0f, 255.0f),
                        clampF(add02.y + add2.y, 0.0f, 255.0f),
                        clampF(add03.y + add2.y, 0.0f, 255.0f));

        // R
        *((float4 *)&pDstBlock[(planeStride << 1) + rowStride + (threadIdx.x << 2)]) =
            make_float4(clampF(add00.x + add3.x, 0.0f, 255.0f),
                        clampF(add01.x + add3.x, 0.0f, 255.0f),
                        clampF(add00.y + add3.y, 0.0f, 255.0f),
                        clampF(add01.y + add3.y, 0.0f, 255.0f));
        *((float4 *)&pDstBlock[(planeStride << 1) + nextRowStride + (threadIdx.x << 2)]) =
            make_float4(clampF(add02.x + add3.x, 0.0f, 255.0f),
                        clampF(add03.x + add3.x, 0.0f, 255.0f),
                        clampF(add02.y + add3.y, 0.0f, 255.0f),
                        clampF(add03.y + add3.y, 0.0f, 255.0f));
    }
}

void nv12ToBGRplanarBatch(uint8_t     *pNv12,
                          int          nNv12Pitch,
                          float       *pBgr,
                          int          nRgbPitch,
                          int          nWidth,
                          int          nHeight,
                          int          nBatchSize,
                          cudaStream_t stream)
{
    dim3 threads(CONV_THREADS_X, CONV_THREADS_Y);

    size_t blockDimZ = nBatchSize;

    // Restricting blocks in Z-dim till 32 to not launch too many blocks
    blockDimZ = (blockDimZ > 32) ? 32 : blockDimZ;

    dim3 blocks((nWidth / 4 - 1) / threads.x + 1, (nHeight / 2 - 1) / threads.y + 1, blockDimZ);
    nv12ToBGRplanarBatchKernel<<<blocks, threads, 0, stream>>>(
        pNv12, nNv12Pitch, pBgr, nRgbPitch, nWidth, nHeight, nBatchSize);
}
