RGBToYUV422

Converts an RGB image to a YUV422 color model using 4:2:2 sampling. A YUV422 image uses 4:2:2 sampling, that is, Y is sampled twice, and U and V are sampled once for every two pixel blocks.

The function interface declaration is as follows:

Operation on pixel-order data:
HmppResult HMPPI_RGBToYUV422_8u_C3C2R(const uint8_t *src, int32_t srcStep, uint8_t *dst, int32_t dstStep, HmppiSize roiSize);
Operation on planar data:
HmppResult HMPPI_RGBToYUV422_8u_P3R(const uint8_t *src[3], int32_t srcStep, uint8_t *dst[3], int32_t dstStep[3], HmppiSize roiSize);

HmppResult HMPPI_RGBToYUV422_8u_C3P3R(const uint8_t *src, int32_t srcStep, uint8_t *dst[3], int32_t dstStep[3], HmppiSize roiSize);
Operation on planar data (without ROI):
HmppResult HMPPI_RGBToYUV422_8u_P3(const uint8_t *src[3], uint8_t *dst[3], HmppiSize imgSize);

Conversion from pixel-order to planar data (without ROI):
HmppResult HMPPI_RGBToYUV422_8u_C3P3(const uint8_t *src, uint8_t *dst[3], HmppiSize imgSize);

Parameters

Parameter	Description	Value Range	Input/Output
src	Pointer to the source buffer of pixel-order data. If the input is planar data, this parameter indicates an array of pointers to separate source color planes.	The value cannot be NULL.	Input
srcStep	Distance between starts of consecutive lines in the source image, in bytes	The value must be zero or a positive integer.	Input
dst	Pointer to the destination buffer of pixel-order data. If the input is planar data, this parameter indicates an array of pointers to separate destination color planes.	The value cannot be NULL.	Output
dstStep	Distance between starts of consecutive lines in the destination image, in bytes	The value must be zero or a positive integer.	Input
roiSize	Size of the ROI of the source and destination images, in pixels	roiSize.width ∈ (0, INT_MAX], roiSize.height ∈ (0, INT_MAX]	Input
imgSize	Size of the source and destination images, in pixels	The value must be zero or a positive integer.	Input

Return Value

Success: HMPP_STS_NO_ERR
Failure: An error code is returned.

Error Codes

Error Code	Description
HMPP_STS_NULL_PTR_ERR	The value of src or dst is NULL.
HMPP_STS_SIZE_ERR	The value of roiSize or imgSize is 0 or a negative value.
HMPP_STS_STEP_ERR	The value of srcStep or dstStep is zero or negative.
HMPP_STS_ROI_ERR	The product of the width of roiSize and the number of channels is greater than the step.
HMPP_STS_NO_ERR	No error occurs.

Example

#define SRC_BUFFER_SIZE_T 180
#define DST_BUFFER_SIZE_T 120
void TestExample()
{
    HmppiSize roi = { 4, 4 };
    const uint8_t src[SRC_BUFFER_SIZE_T] = {
        11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
        11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
        11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
        11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
        11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
        11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
        11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
        11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
        11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
        11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
        11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
        11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33
    };
    uint8_t a[DST_BUFFER_SIZE_T] = { 0 };
    uint8_t b[DST_BUFFER_SIZE_T] = { 0 };
    uint8_t c[DST_BUFFER_SIZE_T] = { 0 };
    uint8_t *dst[3] = {a, b, c};

    int32_t srcStep = 12 * sizeof(uint8_t);
    int32_t dstStep[3] = {20 * sizeof(uint8_t), 20 * sizeof(uint8_t), 20 * sizeof(uint8_t)};
    HmppResult result = HMPPI_RGBToYUV422_8u_C3P3R(src, srcStep, dst, dstStep, roi);

    printf("result = %d \ndst = ", result);
    if (result != HMPP_STS_NO_ERR) {
        printf("result error: %d\n", result);
    }
    for(int32_t i = 0; i < 3; i++){
        int32_t dstWidth = dstStep[i] / sizeof(uint8_t);
        for (int32_t j = 0; j < DST_BUFFER_SIZE_T; j++) {
            if( j % dstWidth == 0 ){
                printf("\n");
            }
            printf("%3d ",dst[i][j]);
        }
    }
    printf("\n");
}

int main()
{
   TestExample();
   return 0;
}

Output:

result = 0
dst =
 19  52  77  79   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
 46  19  52  77   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
 79  46  19  52   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
 77  79  46  19   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
  0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
  0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
134 111   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
128 117   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
121 134   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
111 128   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
  0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
  0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
120 131   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
128 124   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
135 120   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
131 128   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
  0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
  0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0

Parent topic: Image Conversion